India 2×600MW Mahan Coal Fired Thermal Power Plant Operation and Maintenance Manual Volume I: Operation Manual Part 1: Operation Manual of Steam Turbine
Harbin Power Engineering Company Limited Harbin Huitong Electric Power Engineering Co.,Ltd April, 10th, 2011 P
P
Content 1 Technical specifications and characteristics of main and auxiliary equipments of turbine-generator unit .................................................................................................................... 3 1.1 1.2 1.3 1.4 1.5 1.6 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 3 3.1 3.2 3.3 3.4 3.5 3.6 4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.20 4.21 4.22 4.23 4.24 4.25 4.26
Technical specifications of turbine proper ....................................................................... 3 Turbine characteristic ......................................................................................................... 5 Boiler and generator specification .................................................................................... 5 Auxiliary specification ........................................................................................................ 7 Regulation and protecting system .................................................................................. 26 Turbine unit protection ..................................................................................................... 30 Turbine unit start ................................................................................................................... 31 Unit start general rules ..................................................................................................... 31 Preparation before unit start ............................................................................................ 32 Test before start ................................................................................................................. 33 Turbine unit cold state start ............................................................................................. 34 Unit warm, hot, very hot start........................................................................................... 43 DEH operation mode explanation.................................................................................... 44 Unit stop ............................................................................................................................. 45 Maintaining after turbine stops ........................................................................................ 49 Unit operation and maintenance ......................................................................................... 49 Operation and maintenance ............................................................................................. 49 Motor normal operation and maintaining ....................................................................... 50 Unit operation mode ......................................................................................................... 52 Parameter supervision in normal operation................................................................... 53 Periodic work ..................................................................................................................... 60 Unit interlock protection and test .................................................................................... 62 Unit trouble shooting ............................................................................................................ 76 Principles of trouble shooting ......................................................................................... 76 Conditions and treatment of emergency stop and treatment ...................................... 77 Steam parameters are abnormal...................................................................................... 80 Unit load vibration ............................................................................................................. 81 Unit load rejection ............................................................................................................. 81 Condenser vacuum drop .................................................................................................. 82 Unit high vibration ............................................................................................................. 83 Turbine water impact......................................................................................................... 84 Turbine blades break......................................................................................................... 85 Turbine abnormal axial displacement ............................................................................. 85 Turbine lubricate oil system fault .................................................................................... 86 Turbine bearing temperature high ................................................................................... 88 EH oil system fault ............................................................................................................ 89 Sealing oil pressure low ................................................................................................... 90 Closed circulating water system fault............................................................................. 90 Auxiliary equipment fault ................................................................................................. 91 Motor fault .......................................................................................................................... 92 Auxiliary power lost .......................................................................................................... 94 Hydrogen system fault ...................................................................................................... 95 Stator cooling water interrupt .......................................................................................... 96 Fire ...................................................................................................................................... 96 DCS fault............................................................................................................................. 97 Measures avoiding water entering into turbine and bearing bend .............................. 98 Measures avoiding turbine oil leakage ......................................................................... 100 Main steam valve or governor valve blocks after turbine trips .................................. 100 Measures avoiding turbine over speed ........................................................................ 101 1
5 Start curve ............................................................................................................................. 102 5.1 Cold state curve ............................................................................................................... 102 5.2 Warm state start curve .................................................................................................... 103 5.3 Hot state start curve ........................................................................................................ 105 5.4 Extremely hot state curve ............................................................................................... 106 5.5 Recommended values of keeping turbine running speed .......................................... 107 5.6 Cold state rotor heating curve ....................................................................................... 108 5.7 Hot state start recommended value .............................................................................. 109 5.8 Main steam parameters during start ..............................................................................110 5.9 Changing load recommeded value——fixed pressure mode...................................... 111 5.10 Recommeded value of changing load............................................................................ 111 5.11 Circulating indexes under different load increase rate and decrease rate ................112 5.12 Gland sealing steam temperature recommended valves ............................................113 5.13 Typical HP cylinder cooling curve ..................................................................................114 6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.14 6.15 6.16 6.17 6.18
Auxiliary operation regulations ..........................................................................................115 General ..............................................................................................................................115 Start & stop of circulating water system .......................................................................117 Open cooling water system start and stop....................................................................118 Closed circulating cooling water system start and stop .............................................119 Start & stop of auxiliary steam system ......................................................................... 121 Condensing water system start and stop ..................................................................... 122 Deaerator start and stop ................................................................................................. 124 Motorized feeding water pump start and stop ............................................................. 127 Steam driven feed water pump group start & stop ...................................................... 129 Heaters start and stop..................................................................................................... 134 Turbine gland sealing start and stop ............................................................................ 137 Vacuum system stop....................................................................................................... 138 Turbine lubricate oil system start and stop .................................................................. 140 Turbine oil cooler start and stop.................................................................................... 142 EH oil system start and stop .......................................................................................... 143 Generator sealing oil system start and stop ................................................................ 145 Generator hydrogen cooling system start and stop ................................................... 148 Start and stop of generator stator cooling water system ........................................... 152
2
1 Technical specifications and characteristics of main and auxiliary equipments of turbine-generator unit 1.1 Technical specifications of turbine proper 1.1.1 Turbine specifications: Name
Specification
Unit Model
N600-16.7/538/538
Type
Sub-critical, once-middle reheat, single-shaft, three cylinder and four stages steam extraction, double back pressure condenser type turbine
Rated power
600 MW（TMCR working condition)
Maximum power
648.6 MW（VWO working condition）
Rated running speed
3000 r/min
Running direction
(from turbine to generator) clockwise
Working frequency
50 Hz
Steam exhaust pressure
10.13Kpa Total 40 stages
Flow stages
HP cylinder: one (1) single-row governing stage ＋ nine (9) pressure stages IP cylinder: six (6) pressure stages LP cylinder: 2×2×6 pressure stages (two double flow low pressure cylinders)
Turbine outline dimension
27.8×11.4×7.24 m
（L×W×H） Final stage blade highness
680 mm
Elevation from center line to operation layer
1070 mm
Steam distribution mode
Nozzle governing
Starting mode
HP-IP combined start-up mode
Feed water heat returning stage number
Three HP heaters＋one deaerator＋four LP heaters
Feed water temperature
276℃
Critical rotating speed of shaft
Rotor
Ⅰ stage
Ⅱ stage
HP &IP rotor
1704
4181
3
Heat rate Main steam pressure Reheat steam pressure Exhausting pressure of HP cylinder Main steam temperature Reheat steam temperature Main steam flow Reheat steam flow Average back-pressure Exhausting flow of LP cylinder Make-up water rate Final feed water temperature
1648
3859
LP rotor B
1610
3584
Generator rotor
780
2073
Turning gear running speed
3.35 r/min
Noise level
≤90 dB(A)
Manufacturer
Harbin Turbine Co., Ltd.
1.1.2
Unit output
LP rotor A
Main parameters of turbine designed working condition
Unit
TMCR condition
TMCR condition + 3% make up water 600
TMCR condition (maximum back -pressure) 600
VWO condition
VWO condition +3% make up water 644.4229
All HP heater cut off conditi on 600
75% TMCR (Sliding pressure)
60% TMCR (Sliding pressure)
40% TMCR (Sliding pressure)
MW kJ/kW .h MPa (a) MPa (a)
600
450.004
360
240.145
8149.5
8204.1
8269.1
8127.7
8182.7
8409.5
8275.7
8500.3
9089.5
16.7
16.7
16.7
16.7
16.7
16.7
13.64
11.07
7.64
3.438
3.442
3.473
3.752
3.728
3.567
2.556
2.076
1.459
MPa (a)
3.820
3.824
3.859
4.169
4.142
3.963
2.84
2.307
1.621
℃
538
538
538
538
538
538
538
538
524.9
℃
538
538
538
538
538
538
538
531.6
498.1
t/h
1875.12
1890.20
1908.71
2060
2060
1631.7
1359.21
1091.37
769
t/h
1579.60
1583.12
1597.75
1725.78
1716.49
1606.8
1168.13
949.10
678
KPa
10.13
10.13
11.87
10.13
10.13
10.13
10.13
10.13
10.13
t/h
1128.58
1116.52
1131.1
1228.07
1207.16
1210.3
866.36
722.53
521.32
%
0
3
3
0
3
0
0
0
0
℃
275.6
275.8
276.5
281.7
281.4
181.1
256.7
244.5
225.4
1.1.3
648.614
All stages extraction parameters when turbine in TMCR working condition Extraction Series
1st extraction (to no.1 HP heater) 2nd extraction (to no.2 HP heater) 3rd extraction (to no.3 HP heater) 4th extraction (to deaerator) 4th extraction (to BFP turbine) 4th extraction (to aux. steam header) 5th extraction (to no.5 LP heater) 6th extraction (to no.6 LP heater) 7th extraction (to no.7 LP heater) 8th extraction (to no.8 LP heater)
Flow kg/h 128990 122580 79790 86580 92960 ≤65000 46950 46130 56240 58400 4
Pressure MPa(a) 6.00 3.804 1.84 0.878 0.873 0.873 0.336 0.189 0.099 0.0391
Temperature ℃ 386.7 325.0 444.7 339.5 339.4 339.4 226.8 166.6 105.1 75.4
1.2 Turbine characteristic 1.2.1
This turbine is sub-critical, once-middle reheat, single-shaft, three cylinders and four stages steam extraction, condenser type turbine; it adopts reversal type impeller blade, whole forged rotor, multi-layer cylinder and digital electric hydraulic regulation. Its structure is compact and economic with high operation efficiency and safe reliability. This turbine is used for offer basic load for middle sized power grid and is also suitable for load regulation and supplying basic load for large scale power grid. Life of this unit is more than thirty (30) years. This kind of unit is fit to drought area, use air cooling system. Operation hours per year of this unit is more than 8000 hours.
1.2.2
#7 bearing in bearing system of turbine generator unit adopt Jingshiboli bearing, #1～6 bearing are four tile tilting-pad bearing. Bearing vibration measuring devices are installed on X and Y up tile of bearings and measuring devices are installed on down bearing. Thrust bearing is in bearing box and it is a equally loaded bearing with automatic and even load distribution between tiles, pile is supported on fixing inner balancing block composed of two halves. There‟re 3 absolute anchor point of the unit: first is at #2 bearing box, the other two is at center of #1 and #2 LP cylinder, two horizontal anchor keys and two axial anchor keys pre-buried in foundation limit the moving center of them, which forms absolute anchor point of the unit. HP & IP cylinder are supported by four „cylinder claws‟, which is built on bearing box. „Cylinder claw‟ can slide freely on keys through cooperation between „cylinder claw‟ and bearing box. Flange form steel joint connect rotators, thrust bearing at #1 bearing box which forms relative anchor point of the unit.
1.2.3
Two steam-driven feed water pumps with BMCR capacity of 50% and one motorized speed changing feed water pump with BMCR capacity of 50% for start/standby. Normal working steam source is from fourth stage extraction steam, steam source for low load operation and commission is from auxiliary steam system. Exhaust steam of BFPT is extracted to condenser of the turbine.
1.2.4
Three vertical condenser pumps with capacity of 50% are installed in condensing water system. Extractive treatment of condensing water adopts IP system. Condenser is single flow, double back pressure surface type; it has double shells and arranged horizontally.
1.2.5
Open circulating cooling water system and closed circulating cooling water system are adopted as cooling water system. Open circulating cooling water system is from circulating water, closed circulating cooling water system supply cooling water to auxiliary equipments in main hall.
1.2.6
Control oil system of turbine adopts HV fire resistant oil and is completely separated from lubricate oil system, which improves the speediness of speed regulation system, reliability and agility.
1.2.7
Unit is designed as HP cylinder starting mode. Bypass system adopts HP, LP bypass of two stages in series with capacity of 60% BMCR, which can protect unit operation safely.
1.3 Boiler and generator specification 1.3.1
Boiler designed specification ITEMS
UNIT
BMCR
Steam flow rate of superheater outlet
t/h
2060
1866.68
Steam pressure of superheater outlet
MPa(g)
17.5
Steam temperature of superheater outlet
℃
Steam flow rate of reheater outlet
t/h
541 1725.9
17.34 541
5
TMCR
1572.73
℃
Steam temperature of reheater outlet Steam pressure of reheater outlet
MPa. (g)
541 3.817
541 3.472
℃
335.0
335.0
MPa(g)
4.007
3.646
Temperature of feed water
℃
281.0
275
Flue gas temperature at air preheater outlet (unrevised)
℃
138
137
Flue gas temperature at air preheater outlet (revised)
℃
131
131
Boiler efficiency (based on HHV)
%
Steam temperature of reheater inlet Steam pressure of reheater inlet
1.3.2
87.1
Generator designed specification Item
Unit
Generator type
Data QFSN-660-2YHG
Rated capacity SN B
Rated power PN B
B
B
Rated power factor cosφN B
Stator rated voltage UN
MVA
705.88
MW
600 0.85(lagging)
B
kV
20
A
20377
Empty load excitation voltage
V
144.2
Empty load excitation current
A
1480
Rated excitation voltage UfN
V
465.6
A
4557
Full load frequency η
％
98.85
Rated frequency
Hz
50
Rated running speed
r／min
3000
B
Stator rated current IN B
B
B
B
Rated excitation current IfN B
B
B
phase
3
Stator winding connection mode
YY
Excitation mode
Static self and shunt excitation
6
1.4 Auxiliary specification 1.4.1
Bypass system
1.4.1.1 HP & LP bypass system Technical parameter name
Unit
Cold state start
Warm state start
Hot state start
Extreme hot state start
working condition
Inlet steam pressure
MPa
5.9
5.9
7
8
17.6
7.87
Inlet steam temperature
℃
340
420
450
485
541
520
Inlet steam flow
t/h
102.3
251.3
259.6
288.5
1236
769
Outlet steam pressure
MPa
1.1
1.1
1.1
1.1
4.17
1.5
Outlet steam temperature
℃
~200
~250
~270
~300
335.6
320
Outlet steam flow
t/h
111
283
293
326
1423
885
Pressure
MPa
~12
~12
~15
~15
23.33
~15
Temperature
℃
150
150
150
150
180.2
150
Flow
t/h
18
32
34
38
187
116
Inlet steam pressure
MPa
1.0
1.0
1.0
1.0
3.753
1.4
High pressure steam change-over valve
HP spraying governing valve
7
VWO
Auxiliary power working condition
Unit
Cold state start
Warm state start
Hot state start
Extreme hot state start
working condition
Inlet steam temperature
℃
300
400
435
470
538
501
Inlet steam flow (total flow of LP bypass)
t/h
111
283
293
326
1423
885
Outlet steam pressure
MPa
0.04
0.1
0.11
0.12
0.5884
0.34
Outlet steam temperature
℃
82
99
102
105
160
138
Outlet steam flow
t/h
2x65
2x177
2x188
2x214
2x968
2x592
Pressure
MPa
3.16
3.16
3.16
3.16
3.16
3.16
Temperature
℃
46.5
46.5
46.5
46.5
46.5
46.5
Flow
t/h
2x9
2x35
2x41
2x51
2x257
2x149
Technical parameter name LP change-over valve
LP spraying water governing valve
8
VWO
Auxiliary power working condition
1.4.1.2 Hydraulic actuator Sort Item
HP bypass HP bypass valve
Bypass constitution Type
HBSE280-350
Spraying governing valve 100DSV
LP bypass Spraying isolation valve 840
LP bypass valve NBSE60-700
Spraying governing valve 840H
Model
Angle
Angle
Through
Angle
Through
Drive mode
Hydraulic
Hydraulic
Hydraulic
Hydraulic
Hydraulic
State after losing electricity
Lock-up
Lock-up
Lock-up
Lock-up
Lock-up
17.6
22.81
23.33
3.75
2.42
C
541
180.2
180.2
538
46.5
Mpa
4.17
4.69
22.81
0.5884
1.11
C
335.6
180.2
180.2
160
46.5
Mpa
17.6
22.81
23.33
3.75
2.42
Rated value
t/h
1236
187
187
2x711.5
2x257
Maximum value
t/h
-
-
-
-
-
linear
=%
On/off
linear
=%
mm
199.7
38.1
76.2
402.9
76.2
kN
87
<36
36
88
<36
mm
145
63.5
40
300
50
F91
WCB
WCB
WC9
WCB
Valve front
Pressure
Mpa o
Temperature Pressure
P
Valve rear
P
Temperature Maximum differential pressure
o P
P
Flow Flow characteristic Valve Valve seat diameter related parameter Required thrust Valve stem Stroke Valve material
9
Leakage rate(or grade)
V
V
V
V
V
Connection mode
BWE
BWE
BWE
BWE
BWE
Material
F91/F22
G20Mo5
G20Mo5
WC9/F22
WCB
Joint Inlet
mm
ID368x38
-
-
ID616x35
-
Outlet
mm
OD914x23.83
-
-
OD1120x9
-
kg
About 2050
About 250
About 250
About 6000
About 250
Weight
1.4.1.3 Oil cylinder of bypass valve and spraying valve Name
High pressure bypass oil cylinder
Unit
Manufacturer Type Oil pressure
MPa
Diameter
mm
Section area
mm2
Force
N
Journey
mm
P
P
Low pressure bypass oil cylinder
High pressure bypass valve
Spraying governing valve
Spraying isolation valve
Low pressure bypass valve
Spraying governing valve
Spraying isolation valve
CCI
CCI
CCI
CCI
CCI
CCI
GHZ100
GHZ80
GHZ50
GHZ80
GHZ50
16
16
16
16
16
16
100
80
50
80
50
50
7150
4320
1650
4320
1650
1650
115752
69000
26380
69000
26380
26380
175
65
65
300
65
65
10
GHZ50
The whole journey action time
Quick open Quick close
4
4
4
4
-
4
4
4
4
4
15-20
-
-
15-20
-
-
s
Adjust
Weight
4
3
kg
Valve included
1.4.1.4 Working oil station equipment NO.
1
2
Name
Oil pump
Oil tank
Item
Unit
Number
NO.
Name
Item
Unit
Number
Type
QX
Type
Model
Internal gear pump
Quantity
Set
2
Power
kw
4
Voltage
V
415
Quantity
Set
2
Rated oil pressure
MPa
24
Rated flow
l/min
7.2
Frequency
Hz
50
Rotating speed
r/min
1420
Rotating speed
r/min
1420
Manufacturer
Truninger
Manufacturer
ABB
Type
AX
Type
Olaer
Quantity
Set
1
Capability
l(liter)
21
Working pressure
MPa
24
Quantity
Set
1
Working pressure
MPa
0.1
Volume
l（liter）
190
5
6
11
Oil pump motor
Accumulator
Maximum oil storage
3
Filter
l（liter）
310
Safety valve action pressure
MPa
26
Outer dimension
mm
1100*600*600
Buffering medium/pressure
/MPa
12
Weight
kg
505
Maintain time after power cut
min
Outer dimension
mm
1800
Group quantity
Group
1
Power
kw
2
Type
Hydac
Strainer material
Fabric
4
pump
Electric heater
Strainer aperture
μm
10
Voltage/power
V/Hz
380/50
Permit differential pressure
MPa
0.2
Quantity
set
2
Outer dimension
mm
100*200
power
kw
0.37
Weight
kg
0.3 Voltage
V
415
Frequency
Hz
50
Rotating speed
r/min
1420
Internal gear pump
Type
Filter
7
Quantity
set
2
Rated oil pressure
MPa
24
Rated flow
l/min
speed
r/min
Manufacturer
8
Filter pump motor
1420 Truninger
Manufacturer
12
ABB
1.4.2
Turbine lube oil system Mail oil tank
Type Oil type
Horizontal cylinder 32L-TSA/GB11120-89 turbine oil
Volume
45.7 m3
Outer dimension
φ3032×7000
P
P
Mail oil pump Type
Double suction centrifugal pump
Outlet pressure
2.352MPa(g)
Flow
7600L/min
Suction pressure
0.1764 MPa
Running speed
3000 r/min
Manufacturer
Harbin Turbine Co., Ltd
Oil tank gas exhausting air fan Air amount
824m3/h
Head
3530pa
Motor type
YB90L-2
Power
2.2kw
Turning speed
2840r/min
Voltage
415V
P
P
Hydrogen seal oil pump Type
SNH660-51T4
Flow
753 L/min
Outlet pressure Manufacture
1.0 Mpa
Rotating speed
1450 r/min
Zigong dongfang
Motor type
YB180M-4
Power
18.5 kW
Voltage
AC 415V
Running speed
1450 r/min
Insulation grade
F AC lube oil pump
Type
Vertical centrifugal oil pump
Type
LDX294-44
Flow
4900 L/min
Outlet pressure
0.37 MPa
Rotating speed Motor type
1450 r/min YB250M-4
Power
55 kW
Voltage
380v
Running speed
1450 r/min
Insulation grade
F DC lube oil pump
Type
Vertical centrifugal oil pump
Type
LDX294-44
Flow
4900 L/min
Outlet pressure
0.37 MPa（g）
13
Running speed Motor type
1500 r/min Z2-91
Power
55kW
Voltage
220v
Insulation grade
F
Running speed
1500 r/min #I Oil injector
Outlet flow
5660L/min
Outlet pressure
0.23MPa
Power oil pressure
2.27MPa
#II Oil injector Outlet flow
4950L/min
Outlet pressure
0.37MPa
Power oil pressure
2.27MPa
Turbine oil cooler Type
Plate type
Type
MX25-MFMS
Oil flow
322m3 /h
cooling area
2 X348.1m2
Cooling water flow
581.5 m3 /h
Manufacturer
APV
Inlet /outlet oil temp.
65 ℃/45℃
P
P
P
P
P
Jacking oil pump Type
AH37-FR01KK-10-X33
Quantity
2 sets
Capacity
3.7 m3/h
Outlet maximum pressure
32 MPa
Manufacturer
Nichiyu Giken Kogyo Co., Ltd
Motor type
YB2-200L-4
Power
30 kW
Voltage
415V
Rotating speed
1470r/min
Manufacturer
Nanyang explosion-proof group
P
P
Lube oil transfer pump Oil pump
Motor
Type
KCB-1000
Type
YB200L-4
Head（MPa）
0.6
Voltage (V)
415
Capacit（m3/h）
60
Power (KW)
30
Manufacturer
Zigong dongfang
Rotating speed （r/min）
1450
P
P
14
P
Oil purification device Type Working Oil temp. Heating power
LYJ-8
Flow
7800L/h
50～65℃
Filter fineness
≤5μm
48kW
Manufacture
Zigong chuanlv
Turbine turning gear motor Type
YB280S-6
Power
45 kW
Voltage
415 V
Current
85.4 A
Rotating speed
980 r/min
Insulation grade
F
Turning gear speed
3.35 r/min
1.4.3
EH oil system EH oil pump Model
Piston variation pump
Type
HQ31.01Z
Flow（maximum）
6.6 m3/h
Outlet pressure
31.5MPa
Rotating speed
1450 r/min
Working pressure
14MPa
P
P
EH oil pump motor Motor type
M2JA-225
Power
45 kW
Voltage
415 V
Current
84.7 A
Rotating speed
1450 r/min EH oil tank
Model
Container type
Capacity
1.3 m3
Oil type
Fyrquel EHC-plus
Manufacturer
Harbin Turbine Co., Ltd
P
P
EH oil cooler Model
Plate type
Cooling area
2×4.2m2
Working temperature
≤38 ℃(water temperature )
Working pressure
0.2～0.5 MPa(water pressure)
Manufacturer
Shanghai
15
P
P
1.4.4
Steam driven feed water pump group BFPT
Model
Single shaft, single cylinder, auxiliary steam out change, condensing type
Running speed coordination control range
3000～5900 r/min
Type
NGZ83.6/83.5/06
Turning gear speed
40.8 r/min
Control system
MEH
Max. rotating speed
5900r/min
Flow stages
6 stage
Maximum continuous power
9MW
Exhaust pressure
11.1kPa
Running direction
Clockwise(see from turbine head to pump)
Mechanical over speed
6160 r/min
Electric over speed
6050r/min
Critical rotating speed
1 stage
2246r/min
2 stage
6532 r/min
fourth extraction, steam two lines Steam source
Manufacturer
Harbin Turbine Co., Ltd.
auxiliary
Low pressure steam: 0.834Mpa/338.5℃ Auxiliary steam: 0.8MPa/300℃
Steam driven feed water pump Model
Horizontal centrifugal pump
Type
CHTC6/5
Seal type
Mechanical sealing
Running direction
Clockwise from driven end to pump
Flow（m3/h）
1179
Head（m）
2368
Shaft power（KW）
9012.5
Inlet temperature （℃）
171.4
Tap Pressure(MPa)
10.5
Tap flow(t/h)
49
Rotating speed（r/min）
5074
Efficiency （%）
82.3
Manufacturer
Shanghai Kaishibi Pump
P
P
BFPT oil system BFPT AC lube oil-pump motor
BFPT DC emergency oil-pump motor
Type
YB160L-2
Type
Z2-51
Power
18.5kw
Power
10kw
Voltage
415 V
Voltage
220 V
Rotating speed
2950 r/min
Rotating speed
3000r/min
Manufacturer
Shenyang pump company
16
BFPT AC lube oil pump
BFPT DC lube oil pump
Type
2LYD-100
Type
2LYD-50
Characteristic
centrifugal
Characteristic
centrifugal
Flow
500L/min
Flow
400L/min
Outlet Oil pressure
0.75Mpa
Outlet oil pressure
0.34Mpa
Rotating speed
2950r/min
Rotating speed
3000r/min
BFPT lube oil transfer pump Type
KCB-200
Capacity
12m3/h
Head
0.6MPa
Manufacture
Zigong chuanlv equipment Co.,Ltd.
Motor type
YN132S-4
Voltage
415V
Power
5.5kW
Rotating speed
1450r/min
Power factor
0.7
P
P
Turning gear motor Type
YB132S2-2
Rotating speed
2900r/min
Power
7.5KW
Voltage
415V
Steam pump booster pump Type
SQC300-670
Flow（t/h）
1179
Inlet temperature（℃）
171.4
NPSH_R（m）
4.2
Head（m）
134
Running speed （r/min）
1490
Efficiency（%）
82.5
Manufacturer
Shanghai Kaishibi Pump Co., Ltd.
Steam pump booster pump motor Type
YKS450-4
Power
710 kW
Voltage
3.3kV
Current
150A
Rotating speed
1490 r/min
Insulation grade
F
Power factor
0.87
Connection method
Y
Manufacturer 1.4.5
Jiamusi Motor Co., Ltd.
Motor-driven feed water pump group Main pump Model
Sleeve type multi-stage centrifugal pump
Type
CHTC6/5
Seal type
Mechanical seal
Inlet flow（t/h）
1179
Inlet temperature （℃） Outlet pressure （MPa）
171.4
Inlet pressure （MPa）
2.267
23.088
Head（m）
2368
17
Tap pressure （MPa）
10.5
Tap flow（t/h）
49
Efficiency（%）
82.3
Rotating speed （r/min）
5074
Running direction
clockwise（from driven end）
Manufacturer
Shanghai Kaishibi Pump Co., Ltd. Feed water pump motor
Type
YKS1000-4TH
Power
13000 kW
Voltage
11kV
Current
762A
Rotating speed
1496 r/min
Power factor
0.916
Efficiency（%）
97.7
Manufacturer
Shanghai Motor Co., Ltd
Booster pump Model
Single stage double-suction shell pump
Type
SQN300-670
Flow（t/h）
1179
Head（m）
134
NPSH_R (m)
4.2
Rotating speed （r/min）
1490
Seal type
Mechanical seal
Manufacturer
Shanghai Kaishibi Pump Co., Ltd.
Efficiency（%）
82.5 Hydraulic coupling
Type
R18K-500M
Rated Input running speed
1490 r/min
Maximum output running speed
5032 r/min
Speed adjustment range
25％～100％
Gear ratio
111/32
Driver power
8685kW
1.4.6
Deaerator Type
GC-2180
Model
Horizontal type deaerator
Designed pressure
1.07 MPa
Maximum working pressure
0.8564MPa(a)
Designed temperature
345 oC
Maximum working temperature
340.3 oC
Total capacity
345 m3
Efficient capacity
235 m3
Rated output
2180 t/h
Maximum output
2400 t/h
0.014MPa
Safety valve open pressure
1.0 MPa
Nozzle pressure drop Manufacturer
P
P
P
P
P
P
P
Shanghai Electrical Power Station Equipment Co., Ltd.
18
P
1.4.7
Condensing equipment
1.4.7.1 Condenser Condenser Type
N-38000-13
Cooling area
38000 m2 P
P
Model
Double shell and single flow, double back pressure
Cooling water amount
70980m3/h
Back pressure
0.01013KPa
Water chamber design pressure
0.46MPa(g)
Condensate over cooling degree
≤0.5℃
Condenser end difference
(LP / HP) 4.7/4.5 ℃
Condenser copper pipe total quantity
41248 Pieces
Cooling medium
River water
Cooling water temperature
33℃
Manufacturer
Harbin Turbine Co., Ltd.
P
P
1.4.7.2 Condenser water pump Condenser water pump Model
Vertical sleeve type pump
Type
B640Ⅲ-6
Head（m）
339.6
Seal type
Mechanical seal
Flow （m3/h） P
P
Manufacturer
Required steam corrosion surplus Changsha Water Pump Pump running amount speed Co., Ltd （r/min） Condensate water pump motor 823
2.69m 1480
Type
YKKL500-4TH
Power
1120 kW
Voltage
3.3kV
Current
233A
Running speed
1500 r/min
Power factor
0.89
Manufacturer
Xiangtan Motor Co., Ltd
Insulation grade
F/B
1.4.7.3 Circulating water sump drainage pump Circulating water pump Type
LCX100-20
Model
Vertical
Flow
40m3/h
Head
20m H2O
Manufacturer
Shanghai kaiquan Pump Co., Ltd
Motor type
Y2132S2-2
Rotating speed
1450 r/min
Voltage
415V
Power
7.5 KW
P
B
B
P
B
B
19
B
B
1.4.7.4 Sponge ball cleaning device Sponge ball pump Type
IZJ125-18BⅢ
Model
Horizontal type
Flow
110 m3/h
Head
18 mH2O
Motor type
Y60L-4
Rated power
15KW
Rated voltage
415 V
Rotating speed
1460 r/min
Protected stage
IP55
P
P
Ball collector Type
DZQS-1012
Diameter
Ф 480
Model
Vertical cylinder
Model
Horizontal
Ball screen Type
WBS-2200
Diameter
Ф 2228
1.4.7.5 Water-ring vacuum pump Water-ring Vacuum pump Type
TC11E
Extraction amount
≥78kg/h
Min. suction pressure
3.4KPa(a)
Running speed
590 r/min
Stage
2 stages
Manufacturer
Jidina mechanical Co., Ltd.
Vacuum pump motor Type
Y2 355M-10TH
Voltage
415V
Rated Power
132KW
Protected stage
IP54
Insulation grade
F
Running speed
590 r/min
Manufacturer 1.4.8
Beijing Huajie Motor Co., Ltd.
Sealing oil system Seal oil pump Item
AC/DC seal oil pump at air side
AC/DC seal oil pump at sealing oil side
Type
3GR85×2
3GR42×4A
Model
Cubage T
cubage
T
T
T
Flow
2×40 m3/h
2×10.5 m3/h
Outlet pressure
1MPa
1Mpa
Shaft power
18 KW
4.9 KW
P
P
P
20
P
Manufacturer
Tianjin Dingjia Indusrial Pump Co., Ltd.
Tianjin Dingjia Indusrial Pump Co., Ltd.
Item
Alternate current oil pump motor at air side
AC oil pump motor at hydrogen side
Type
180L-4
Y132S1-2
Power
22KW
5.5KW
Voltage
415V
415V
Current
44.5
11.1
Running speed
1470
2900
Manufacturer
Harbin Motor Co., Ltd.
Harbin Motor Co., Ltd.
DC oil pump motor at air side
DC oil pump motor at hydrogen side
Type
Z2-62
Z2-41
Power (kW)
22KW
5.5KW
Voltage
220V/110V
220V/110V
Current (A)
113.7
30.3
Running speed (r/min)
3000
3000
Manufacturer
Harbin Motor Co., Ltd.
Harbin Motor Co., Ltd.
1.4.9
Stator cooling water system Stator cooling water pump
Type
centrifugal
Flow
115t/h
Head
75m
Rotating speed
2970 r/min
Manufacturer
Jiangsu changzhou Stator cooling water pump motor
Type
Y225M-2
Power
45 kW
Voltage
415V
Current
84A
Running speed
2970 r/min
Manufacturer
Changzhou power station auxiliary equipments factory
1.4.10 Heater and pressure container 1.4.10.1
HP heater
Item Type
Unit
#1 HP heater
#2 HP heater
#3 HP heater
JG-2250-3-3
JG-2680-3-2
JG-2070-3-1
Model
Horizontal type
Manufacturer
Shanghai power station equipment Co.,Ltd.
21
Heater total area
m2
Steam cooling section heat exchange area
m2
Condensing section heat exchange area
m2
Drainage water cooling section heat exchange area
m2
Designed pressure at shell side
2550
2680
2070
316
245
232.5
1899.5
1996.5
1401.8
334.5
438.5
435.7
MPa
6.96
4.35
2.05
Designed temperature at shell side
℃
414.2/286.4
349.1/256.7
459.5/216.1
Designed pressure at pipe side
MPa
30
30
30
℃
286.4
256.7
216.1
MPa
11.3
6.87
3.65
Test pressure at pipe side Feed water end difference (TTD)
MPa
45.53
45.53
45.53
℃
-1.7
0
0
Drain end difference (DCA)
℃
5.6
5.6
5.6
Flow
t/h
1875.12
1875.12
1875.12
Inlet temperature
℃
245.8
206.9
177.0
Outlet temperature
℃
275.6
245.8
206.9
Heating steam flow
t/h
129.81
123.41
80.30
Heating steam pressure
MPa
5.852
3.706
1.793
℃
387.4
325.8
444.7
℃
251.4
212.5
182.6
Designed temperature at pipe side Test pressure at shell side
Heating steam temperature Drainage water temperature
P
P
P
P
P
P
P
P
22
1.4.10.2
LP heater
Item
Unit
Type
#5 LP heater
#6 LP heater
#7 LP heater
#8 LP heater
JD-1418-15
JD-1106-24
JD-640-21
JD-764-21
Model Manufacturer Heat transfer area Designed temperature at shell side Designed pressure at shell side Design temperature at pipe side
Single row horizontal type Harbin steam turbine Co., Ltd. m2
1418
1106
640
764
℃
300
200
120
95
MPa
0.6
0.6
0.6
0.6
℃
150
150
110
90
Designed pressure at pipe side
MPa
4.0
4.0
4.0
4.0
Condensing flow
t/h
1554.83
1554.83
777.35
777.35
Heating steam flow
t/h
52.55
51.48
31.38
33.475
0.351
0.198
0.104
0.041
227.4
167.3
100.6
76.4
3.35
3.35
3.35
3.35
136.2
117.1
97.9
73.5
P
P
Working pressure at MPa shell side Working temperature at
℃
shell side Working pressure at MPa pipe side Working temperature at pipe side 1.4.10.3
MPa
Gland sealing steam heater Model
Horizontal surface cooling
Type
LQ-150-7
Designed pressure(pipe side)
4.6 MPa
Designed pressure vacuum(shell side)
0.3 MPa
Designed temperature(pipe side)
90℃
Designed temperature(shell side)
300℃
Maximum working pressure(pipe side)
3.2 MPa
Maximum working pressure(shell side)
0.095 MPa
Cooling area
150 m2
Steam side flow
1.46 t/h
Cooling water amount
1662.23 t/h
Cooling water pipe dimension
25×1.0 mm
Material
stainless steel TP304
Manufacturer
Harbin Turbine Co., Ltd.
P
P
23
1.4.10.4
Gland sealing heater air fan Gland steam heater air fan
Type
17Y30-1000-11L
Original motor power
11KW
Full pressure
3 kPa
Flow
1800 m3/h
Manufacturer
Yuhang Special Air fan Co., Ltd.
Running speed
2930 r/min
P
P
Gland sealing heater air fan motor Voltage
415V
Power
11 kW
Running speed
2930 r/min
Insulation grade
F
1.4.10.5
Auxiliary steam header Capacity
m3
3.2
Working pressure
Mpa
1.0
Working temperature
℃
250～335
Designed pressure
Mpa
1.6
Designed temperature
℃
350
P
P
Manufacturer
Changshu HP container Co.,Ltd.
1.4.10.6 Continuous flash tank Capacity
m3
6
Designed pressure
Mpa
1.6
Designed temperature
℃
220
P
Manufacturer
P
Changshu HP container Co.,Ltd.
1.4.11 Open/closed cooling water 1.4.11.1
Open cooling water Open cooling water pump
Type
KPS20-600
Head
0.1MPa
Flow
2330 m3/h
Shaft power
72 kW
Running speed
590 r/min
Efficiency
89.3％
Water inlet pressure
~0.2 MPa
Water inlet temperature
33℃
NPSH_R
4.5m
Manufacturer
Guangdong foshan water pump factory
P
P
Open cooling water pump motor Type
Y3 315L2-10
Power
90 kW
Voltage
415V
Insulation grade
F
24
Running speed
590 r/min
Manufacturer
Jiamusi Motor Co., Ltd.
Open circulating water filter Type
LDS-800
Type
LDS-350
Designed flow
2330 t/h
Designed flow
660t/h
Working flow
2110t/h
Working flow
581.5t/h
Driven Power
1.1 KW
Driven Power
0.55kW
Strainer aperture
Ф2 mm
Strainer aperture
Ф2 mm
Designed pressure
0.6 MPa(g)
Designed pressure
0.6 MPa(g)
Working pressure
～0.2MPa(g)
Working pressure
～0.2MPa(g)
Manufacture
Zigong dongfang filter Co.,Ltd
Manufacture
Zigong dongfang filter Co.,Ltd
1.4.11.2
P
Closed cooling water Closed cooling water pump
Type
KPS50-350
Head
0.5 MPa
Flow
1780 m3/h
Running speed
1480 r/min
Shaft power
282 kW
Efficiency
87.8 ％
Water inlet pressure
~0.2 MPa
Water inlet temperature
45℃
NPSH_R
5.6 m
Manufacturer
Guangdong foshan water pump Co., Ltd.
P
P
Closed cooling water pump motor Type
YKK4003-4
Power
315kW
Power factor
0.86
Current
175 A
Voltage
3.3KV
Rotating speed
1483 r/min
Efficiency
93.3 ％
Manufacturer
Jiamusi Motor Co., Ltd.
Closed cooling water heat exchanger Model
Plate type
Type
CZ450A
Design pressure
1.0/1.0MPa(pipe/shell side)
Cooling water Flow
1989t/h
Heat transfer area
618.19m2
Manufacturer
APV Co., Ltd. (China)
P
P
1.4.12 Other equipments Boiler water circulating pump cooling water Emergency shutdown cooling water pump Type
AZ50-315
Head 25
100m H2O B
B
Running speed
Shanghai kaiquan pump Co., Ltd. Emergency shutdown cooling water pump motor 2960 r/min
Manufacturer
Voltage
415V
Power
30kW
Running speed
2940 r/min
Insulation grade
F
1.5 Regulation and protecting system Turbine regulation and protecting system can be divided into: mechanical emergency governor, HP & LP interface device (diaphragm valve), HP fire resistant fuel oil system and safety supervision protection system. 1.5.1 Reset Two reset methods: manual and remote control 1.5.1.1 Remote control: the lights indicated DEH reset and RSV actuator open shall be lighted by pushing the reset button in control room. If unit fails to be reset, it shall be checked whether 0.7MPa protection oil pressure has been established in diaphragm valve upper chamber and whether 20/ASR solenoid valve has been energized by using iron wire or saw blade. If there is no excitation, the solenoid valve has not been energized by DEH. 1.5.1.2 Local control: the reset handle shall be wheeled counterclockwise by hand and then loosened slowly which make handle back to normal position. If 0.7MPa protection oil pressure has been established in diaphragm valve upper chamber, unit successfully resets. 1.5.2 Breaking Three redundant breaking methods of electric, mechanical & manual are installed in speed governing protecting system. 1.5.2.1 Electric stop The function is completed by HP breaking module. Once electric stop signal is received, HP breaking module lose power until HP protecting oil is discharged, all the main steam and regulation valves are closed, which stops steam feeding to the turbine. 1.5.2.2 Mechanical over-speed protection Mechanical over speed and manual trip device Mechanical over speed and manual trip device consists of emergency governor, pilot valve of emergency governor and safety operation device. Emergency governor, pilot valve of emergency governor Emergency governor shall be equipped with one set of centrifugal stop bolt, which controls pilot valve of emergency governor. When steam turbine operation speed reaches to 110%-112% of rated speed, centrifugal force of centrifugal stop bolt overcomes the restriction force of spring and throws the centrifugal stop bolt outward striking pilot valve trigger which make pilot valve move towards right and then protection oil is connected with drain to open diaphragm valve rapidly. Pilot valve of emergency governor that is installed inside front bearing housing is the control and test device in emergency trip system, and it includes one trip pilot valve, one test isolation pilot valve, one manual trip lever and one test lever. Test isolation pilot valve could be used to isolate pilot valve of emergency governor from LP protection oil header. During oil injection test, test stop valve could be opened by manual to allow pressure oil coming into the chamber beneath centrifugal stop bolt through nozzle, and centrifugal stop bolt overcomes the restriction force of spring flying off. 1.5.2.3 Manual stop A manual shutoff valve id installed for emergency stop in front of turbine head. Press the shutoff button manually to discharge the lube oil above diaphragm valve, open diaphragm 26
valve to discharge HP protecting oil and close all main steam valves, regulation valves quickly to stop feeding steam. 1.5.3
EH (electro-hydraulic) system As per the function, EH control system could be constituted of three parts, which are EH fluid supply system, actuators and emergency trip part. 1.5.3.1 EH fluid supply system EH fluid supply system can be divided into EH fluid supply device, self-circulation cooling system, fluid regeneration system as well as EH fluid piping & accessory. The main function of EH fluid supply system shall be to supply necessary hydraulic power to actuators, and maintain the normal physical chemistry characteristics of hydraulic fluid. 1.5.3.2 Actuators Actuator part shall be constituted of two MSV (main stop valve) actuators, two RSV actuators, four GV (governor valve) actuators and four ICV (reheat interceptor valve) actuators. 1）RSV actuator Two RSV actuators equipped with valve activity testing solenoid valve shall be installed on RSV at unit side. RSV actuator shall be of “ON-OFF Control” type. RSV actuator will receive the control signal from DEH system, and a plug-in type dump valve is installed on the actuator. Should emergency condition occur during steam turbine operation, auto stop emergency trip (AST) fluid is discharged so that dump valve will open immediately to discharge the pressure fluid at working chamber of actuator cylinder and RSV will close quickly by spring force. There is an activity testing solenoid valve (2 position, 2 way) on actuator, which is connected with cylinder working chamber and return fluid. When valve activity test is performed, DEH control device will send out a signal to make the solenoid valve open for discharging part of pressure fluid in cylinder working chamber, then RSV is closed by spring force to perform valve activity test. 2）MSV actuator MSV actuator is “Proportional Control” type actuator, which can control MSV at any position and control steam admission to meet steam turbine operation requirement according to control requirement. DEH control signal drives servo valve to move main valve core and control servo valve pass to make HP fire resistant fluid go into actuator working chamber to move actuator piston, and finally to open MSV or to discharge pressure fluid from working chamber to close MSV through piston converse movement by spring force. When actuator piston moves, it will drive two linear displacement transducers (LVDT) to transform actuator piston displacement into electrical signal (as feedback signal) plus the aforesaid signal after computer treatment; however, it‟s actually minus each other because of the opposite polarity. Only in the condition of original input signal plus feedback signal to make input servoamplifier signal zero and main pilot valve of servo valve be back to center position without high-pressure fluid coming into working chamber, MSV will stop moving and remain at a new working position. A plug-in type dump valve is installed on MSV actuator. Should emergency stop condition occur during steam turbine operation, emergency trip system will act to discharge AST header fluid so that dump valve will open immediately to discharge the pressure fluid at working chamber of actuator cylinder and MSV will all close quickly by spring force. 3）GV, ICV actuator GV ,ICV actuators are “Proportional Control” type actuators, which can control GV,ICV at any position and control steam admission to meet steam turbine operation requirement according to control requirement. The control principle of servo valve shall be the same as that of MSV actuator. The GV actuator is equipped with one plug-in type dump valve. When steam turbine running speed exceeds 103% of rated speed or emergency stop caused by failure happens, after emergency trip system acts over speed protection control (OPC) header fluid will be discharged, dump valve will open immediately to discharge pressure fluid inside actuator working chamber and each GV will be closed quickly by 27
spring force. The control principle of ICV actuator shall be the same as that of GV actuator. 1.5.3.3 Emergency trip protection system For avoiding serious damage accident of unit caused by failure of some equipment during steam turbine operation, emergency trip protection system shall be prepared for the unit. 1）Emergency trip testing device Emergency trip testing device shall be constituted of one EH oil pressure test block, one bearing oil pressure test block, two condenser vacuum test block and two BOP & EOP start test block, which could be on-line tested and maintained. 2）OPC/AST solenoid valve unit OPC/AST solenoid valve unit consists of two OPC solenoid valves (20/OPC-1、2), two check valves, four AST solenoid valves (20/AST-1、2、3、4) and one control block. Two OPC solenoid valves are in the parallel arrangement, and four AST solenoid valves are in the series-parallel arrangement. When turbine speed exceeds 103% of rated speed, OPC acting signal will be sent out. OPC solenoid valves open when they are energized so that OPC header fluid drains to EH fluid reservoir through no pressure return (DV) fluid line. In that case, discharge valve of the corresponding control valve actuator will open fast so that each HP control valve will be closed immediately. When emergency happens to unit, AST signal will be sent out. Four AST solenoid valves will open for losing power so that AST header fluid drains to EH fluid reservoir through DV fluid line. In that case, dump valves of main steam valve actuator and control valve actuator will open fast to close each steam valve immediately. 3）Diaphragm valve Diaphragm valve provides an interface between the HP fire-resistant hydraulic fluid and LP turbine oil, thus the LP over speed tripping can be accomplished by the diaphragm valve to shutdown the steam turbine. 4）Mechanical over speed and manual trip device Mechanical over speed and manual trip device consists of emergency governor, pilot valve of emergency governor and safety operation device. Emergency governor shall be equipped with one set of centrifugal stop bolt, which controls pilot valve of emergency governor. When steam turbine operation speed reaches to 110%-112% of rated speed, centrifugal force of centrifugal stop bolt overcomes the restriction force of spring and throws the centrifugal stop bolt outward striking pilot valve trigger which make pilot valve move towards right and then protection oil is connected with drain to open diaphragm valve rapidly. Pilot valve of emergency governor that is installed inside front bearing housing is the control and test device in emergency trip system, and it includes one trip pilot valve, one test isolation pilot valve, one manual trip lever and one test lever. Safety operation device provides remote reset solenoid valve and reset air cylinder for unit. When it receives DEH reset signal and air cylinder moves upwards pushing connecting rod of emergency governor pilot valve, pilot valve of emergency governor resets. 1.5.4 Turbine supervisory instrument system TSI is an reliable multi-way supervision system for supervising generator-turbine unit rotor and mechanical working parameters continuously. 1.5.4.1 Casing expansion measurement When the unit turns into temperature rise and on-load conditions from cold condition, changes of temperature will certainly cause casing expansion. Casing expansion measurement is performed to measure casing‟s axial expansion value in the direction from the dead point to front bearing box, and the front bearing box can move freely along the longitudinal key for filling lubricants. When casing expansion occurs, if the movement of unit‟s free end on the guide key is blocked, the unit will be severely damaged. Actually, casing expansion measurement is performed to measure the movement value of bearing box relative to the dead point (foundation) and record casing‟s expansion & contraction values under start-up, shut-down and load & temperature change conditions of the unit. If the indicated values are abnormal under these transient conditions, then 28
operation personnels shall analyse them. Under similar load, steam parameters and vacuum conditions, the relative positions of front bearing box indicated by this instrument shall be identical basically. 1.5.4.2 Axial displacement measurement This device indicates and records the axial displacement of rotor thrust disc relative to the axial position of bearing seat, to monitor the abrasion conditions along the thrust direction and of thrust bearing pad. For the existence of steam, thrust disc applies axial pressure to the thrust pads on its two sides, which will cause bearing pad abrasion, and the axial displacement due to this bearing pad abrasion will be displayed on TSI measurement device. Each measurement block is equipped with alarm and trip switching value outputs, which will alarm automatically once the rotor‟s axial displacement exceeds the first preset position. If the rotor‟s axial displacement value exceeds the second preset position, then tripping relay will operate to trip out the turbine. 1.5.4.3 Differential expansion measurement When steam enters into turbine, the rotating & static parts will expand along with steam. For the rotor can be heated, it will also expand faster. Although the axial clearances between rotating and static parts allow certain differential expansion inside the turbine, it will cause abrasion and even crash of rotating and static parts if the differential expansion exceeds allowable limits. Differential expansion measurement is performed to show the relative displacement of rotating and static parts, and continuously indicate the axial clearances of turbine during operation. The measurement blocks are equipped with alarm and trip outputs, and the relay will operate when axial clearances reach the limits due to differential expansion. After a transient process, temperatures of rotating and static parts will gradually tend to be the same, and differential expansion reduces accordingly. Then, it is permitted to change the steam flow and temperature for another time. 1.5.4.4 Rotor eccentricity measurement This device is used to indicate and record the rotor eccentricity with a rotating speed less than 600rpm. When turbine‟s rotating speed is more than 600rpm, this device can be switched off automatically by rotating speed signal controls.If it is possible to measure at bearing oil retainer with portable rotor eccentricity meter, the double amplitude eccentricity value measured before turbine rotation impulsing should not exceed 0.025mm.. The rotor eccentricity measurement is equipped with alarm signal outputs, which will alarm when eccentricity value reaches the limits. 1.5.4.5 Vibration measurement Vibration measurement instrument is used to measure and record vibration of rotors with rotating speed higher than 600r／min. A couple of eddy current sensors vertical to each other and a bearing pad vibration probe fixed vertically are installed at each bearing seat of this turbo-generator unit, and signals from sensors are connected to turbine supervisory instruments, which will measure the rotor‟s vibration value directly. Excessive vibration indicates that accidents of turbine may occur or that turbine is operating abnormally. Each vibration measurement is equipped with alarm and trip switching value outputs, and relay will operate accordingly when excessive vibration value is measured on any bearing. TSI can supply the vibration signals to vibration analysis and failure diagnosis system TDM via buffer outputs for performing analysis, diagnosis, dynamic balance, etc. of unit vibration. 1.5.4.6 Key phase measurement Key phase signals show the angular relation between the protruding position of certain bearing and one reference point on the rotor. TDM system can accurately calculate the phase of rotor vibration via key phase signals. 1.5.4.7 Speed & zero speed measurement Speed indicator is provided with the function of monitoring the shaft rotating speed continuously. There is rotating speed sensor arranged in front bearing box, and speed indicator receives signals from eddy current probe, after that, it calculates the speed in RPM. When the speed drops to zero, it will send an interlock signal to automatic barring 29
gear to start the barring gear. When the rotating speed exceeds certain preset value, relevant relay will operate to control water spray device and jacking device of steam exhaust casing.
1.6
Turbine unit protection
1.6.1
Over speed protection
1.6.1.1 OPC overspeed limitation（DEH） When the unit running speed exceeds 103% of rated running speed or is under load of more than 30% rated load and the oil switch trips, OPC solenoid acts and discharges protecting oil pressure of oil-servo motor under HP & IP speed regulation valves and close HP & IP speed regulation valves quickly. 1.6.1.3 Electric overspeed protection When running speed reaches to 110% of rated running speed, over speed protecting signal from the electric is sent to ETS, which makes 20－1/AST—20－4/AST shutoff solenoid valve lose power and open to discharge HP protecting oil, the HP & IP automatic main steam valve and speed regulation valve close to stop the unit. 1.6.1.2 Mechanical overspeed protection A mechanical shutoff protecting system consists of emergency governor, emergency breaking oil valve, constant close & constant open solenoid valve, orifice plate and diaphragm valves installed at turbine head inside of front bearing box of turbine unit. Emergency breaker runs with the same speed of main bearing. When turbine running speed reaches to rated running speed (110～112％), the flying hammer of emergency governor flies out under effect of centrifugal force of the flying hammer of emergency breaker, which strikes on emergency breaking oil valve damper and makes the pothook drop; meanwhile, under the force of bottom spring, sliding valve of emergency breaking oil valve upspring quickly, which opens LP protecting oil discharging orifice and closes main steam valve and steam regulation valve quickly to stop the unit. 1.6.2
ETS (Turbine emergency trip system) ETS receives alarm or stop signals from TSI system or other system of turbine-genrator unit for logical treatment and outputs signal indicating or turbine shutoff signal. ETS sends stop instructions under following situations:
1.6.2.1 When turbine is over speeding to 3300rpm. 1.6.2.2 When condenser pressure is more than 65Kpa. 1.6.2.3 When axial displacement is more than +1.0mm or less than -1.0mm. 1.6.2.4 When lube oil pressure is as low as 0.049Mpa. 1.6.2.5 HP /LP casing expansion difference reachs to +11.1mm or -5.1mm. 1.6.2.6 LP casing expansion difference reachs to +27.8mm or -4.3mm. 1.6.2.7 When generator trips. 1.6.2.8 When boiler MFT. 1.6.2.9 When EH oil pressure is as low as 8.5MPa. 1.6.2.10 DEH is in fault (power off). 1.6.2.11 ETS is in fault (power off). 1.6.2.12 X or Y bearing vibration of any bearing of #1～8 is ≥250μm. 1.6.2.13 Stop unit manually by button on standby manual operation panel. 1.6.2.14 Stop turbine remotely. 1.6.2.15 Local STOP button in turbine hall. 30
2 Turbine unit start 2.1 Unit start general rules 2.1.1
Unit start states can be divided into Unit start adopts HP, IP cylinder combined mode, turbine should adopt single valve control mode during first six (6)-month operation. Five (5) start state are decided by first stage temperature of HP cylinder: Cold state start: first stage metal temperature ＜120℃ and after long term stop; Warm state-1 start: 120℃≤ first stage metal temperature ＜260℃ and turbine stops for more than 72 hours; Warm state-2 start: 260℃≤ first stage metal temperature ＜415℃ and turbine stops from 10 to 72 hours; Hot state start: 415℃≤ first stage metal temperature ＜450℃ and turbine stops from 1 to10 hours; Extreme hot state start: 450℃ ≤first stage metal temperature and turbine stops for less than one hour.
2.1.2
Measures should be taken if any condition occurs, otherwise turbine is prohibited to start
2.1.2.1
Any trip protection of turbine is in failure.
2.1.2.2
Main meters can not be put in operation or are in failure and there are no other supervision measures: such as unit load, running speed, axial displacement, differential expansion, rotor eccentricity, vibration, absolute expansion, cylinder main metal temperature, vacuum degree of condenser, levels in deaerator, condenser, main oil tank and EH oil tank and lubricate oil pressure, EH oil pressure and oil temperature etc.
2.1.2.3
HP & IP main steam valve, speed regulation steam valve, HP steam discharging check valve, steam extraction check valve is blocked or is not in agility.
2.1.2.4
Rotor eccentricity exceeds 0.075mm.
2.1.2.5
Any differential expansion or axial displacement of turbine HP, IP or LP cylinder exceeds limitation.
2.1.2.6
During running turning gear, there is obvious metal friction sound at dynamic and static part of turbine or current of turning gear obviously increases or swings greatly.
2.1.2.7
HP or LP bypass system fault, and can‟t satisfy system start .
2.1.2.8
Instrument-air supply system fault, and can‟t supply the normal air to the unit.
2.1.2.9
Differential temperature of up and down cylinder of turbine HP outer cylinder is higher than 50℃; differential temperature of up and down cylinder of turbine HP inner cylinder is higher than 35℃.
2.1.2.10
Main oil pump, AC, DC lubricate oil pump, generator sealing oil pump, EH oil pump, jacking oil pump works abnormally or emergency pump automatic starting device is in failure.
2.1.2.11
DEH and DCS and main control system works abnormally, which affects unit operation and supervision.
2.1.2.12
Controlling air source or regulation protection power is lost.
2.1.2.13
Reason of turbine trip has not been found out.
2.1.2.14
There are defects that seriously threaten safe start or safe operation.
2.1.2.15
Steam, water or oil (turbine oil, fire resistant oil) is not qualified or oil temperature, oil 31
level is abnormal. 2.1.2.16
Generator sealing oil system is abnormal.
2.1.2.17
Main automatic regulation control system (such as HP & LP bypass control system, gland sealing pressure regulation system) is in failure.
2.1.2.18
Speed regulation system acts abnormally.
2.1.2.19
Insulation for main pipelines and turbine proper is not complete or there is serious leakage in main pipeline system.
2.1.2.20
Main and reheat steam temperature lower than HP-IP rotor‟s average temperature exceed 50℃, degree of superheat under 30℃.
2.1.2.21
Regulation system can not keep empty load operation, or running speed can not be controlled after load rejection, and the speed is lower than emergency shutoff acting speed.
2.1.2.22
Automatic main steam valve, steam speed regulation valve tightness tests are not qualified.
2.1.2.23
Over speed test disqualification
2.1.2.24
Cooling water system or hydrogen system in generator can not be put into operation.
2.1.3
Unit start principles
2.1.3.1
Turbine adopts HP-IP cylinders unite start-up
2.1.3.2
Turbine stop and start should be done according to shift manager‟s instruction.
2.1.3.3
Following works should be done under guidance of general engineer or personnel designated by general engineer: 1) Turbine start after major or minor maintenance. 2) Unit actual over speed test. 3) Unit load rejection test. 4) First start of main equipments or systems after important modification or first trial operation of relevant new technology. 5) Special test items.
2.1.3.4
When turbine is in cold state start, steam temperature at inlet of main steam valve at least should be with overheating temperature of 56℃ but no higher than 430℃. Main steam valve inlet steam temperature and pressure should be within curve of „Main steam parameters during start‟. Heating up time and speed rise should be confirmed according to cold state start curve.
2.1.3.5
When start the unit in hot state, turbine main steam, reheating steam temperature should with overheating temperature of no less than 56℃, starting parameters and time is decided according to cylinder metal temperature and hot state start steam parameter curve and steam inlet temperature of HP & IP cylinder in start working condition.
2.2 Preparation before unit start 2.2.1
After receiving the order for starting unit from the shift manager, monitor should inform all chief shifters and relevant positions and inform the measures for dangerous points and sign.
2.2.2
Necessary tools, instrumental meters should be prepared, all positions should be ready and notebooks and operation tickets should be prepared.
2.2.3
Check and make sure that all maintenance works are completed and all work permit tickets are concluded. All safety precautions are dismantled and site is cleaned up, equipment pipelines insulation are complete, roads are smooth and lighting is good. 32
2.2.4
After maintenance, operators should acknowledge and grasp equipment conditions of maintenance, improvement and modification.
2.2.5
According to the operate card of unit start, check and make sure that valves positions in system are right and equipments are complete and in fine condition.
2.2.6
Contact with I&C personnel to send power to all instrumental meters and protectors. Check and make sure that DCS, DEH work normally and all parameters are right. I&C personnel should calibrate the instrumental meters and protectors and static tests are successful for starting the unit after major and minor maintenance.
2.2.7
Contact with I&C and electric personnel to send power to regulation valves and motorized valves; switch tests are successful. Up and down stroke tests should be done for the repaired motorized valves. Check and make sure that openness on DCS are consistent with local indications. Check and make sure that signals on local control box and control panel are right and all indications are normal.
2.2.8
Contact with boiler to start air compressor. Check and make sure that all instrumental meters and air source of pneumatic control valves are normal. All the switch tests of pneumatic control valves are successful. The openness on DCS are consistent with local indications.
2.2.9
Check and make sure that all switches of running machines are at „OPEN‟ position and interlock switches are at „RELEASED‟ position; contact with the electric to measure insulation and send power after qualification. Make sure that all mechanical parts of auxiliary equipments are not blocked and bearing lubricate oil is in good quality and oil level is normal. Cooling water and sealing water are normal.
2.2.10
Make up water for cooling water tower, condenser, deaerator, cooling water tank and vacuum pump air-water separator is normal. Oil levels in main oil tank, fire resistant oil tank, HP & LP bypass oil station tank, oil tank of hydraulic check butterfly valve of circulating water pump, hydraulic coupler oil tank of feeding water pump and generator sealing oil tank are normal. Oil supplement for bearing of auxiliary equipments are normal. Inform the chemical analyzers to analyze water and oil.
2.2.11
Put industrial water system into operation. Check and make sure that industrial water pressure is normal. Put industrial cooling water system into operation according to actual requirements.
2.2.12
All interlock protection tests are completed according to operation tickets before starting unit and all the tests are qualified.
2.2.13
Check and make sure that primary valves of pressure meters in all systems are open.
2.2.14
Safety valves in all systems should be regulated on test-bed after maintenance.
2.2.15
Audible and visual alarm are work normal.
2.3 Test before start 2.3.1
Test regulations
2.3.1.1
Equipment tests and trial operation can only be executed after maintenance application and shift manager‟s approval and instruction.
2.3.1.2
Tests are coordinated by maintenance principal and cooperated by operator; relevant personnel should be at site.
2.3.1.3
All oil pumps can satisfy remote control requirement conditions; test can only be done after all conditions are satisfied by forcing before protection and interlock tests.
2.3.1.4
Dynamic test must be done after static test is qualified.
2.3.1.5
Test should not be done for the systems in operation or motorized valve, regulation valve bearing pressure.
2.3.1.6
Remote and local test should be done for servo actuators with remote control and local control; special personnel should record open & close time and test information. 33
2.3.2
Test method
2.3.2.1
According to test card, full open and full close tests with remote & local control should be done for all the motorized valves. Openness indications should be consistent with local indications. Motorized valves needs to be stopped intermediately should be tested normally.
2.3.2.2
Pneumatic regulation devices should act in agility with no air leakage or abnormity.
2.3.2.3
All interlock and protection tests should be done according to regulated items one by one.
2.3.3
Test item
2.3.3.1
Unit complete interlock test.
2.3.3.2
Turbine regulating system static characteristic test.
2.3.3.3
Turbine AC lubricate oil pump, generator sealing oil standby pump, turbine DC lubricate oil interlock test.
2.3.3.4
Interlock test for main oil pump and lubricate oil pump of feeding water pump turbine.
2.3.3.5
EH oil pump interlock test.
2.3.3.6
Jacking oil pump interlock test.
2.3.3.7
Generator water-break protection test.
2.3.3.8
Sealing oil air discharging air fan and turbine lubricate oil air discharging air fan interlock test.
2.3.3.9
Vacuum pump interlock test.
2.3.3.10
Circulating water pump test.
2.3.3.11
Closed circulating cooling water pump interlock test.
2.3.3.12
Closed circulating cooling water pump interlock test.
2.3.3.13
Condensing water pump interlock test.
2.3.3.14
Interlock test for cooling water pump in generator stator.
2.3.3.15
Motorized water pump and steam driven water pump interlock test.
2.3.3.16
Condenser, HP & LP heaters and deaerator water level protection test.
2.3.3.17
ETS channel test.
2.3.3.18
OPC solenoid valve test.
2.3.3.19
Turbine protection interlock test.
2.3.3.20
On-off test for all motorized valves, pneumatic valves and regulation valves. Above tests are executed after major or minor maintenance. Some tests can be done separately after maintenance according to actual requirement.
2.4 Turbine unit cold state start 2.4.1
Check before start
2.4.1.1
Maintenance of the unit is completed and all work permit tickets are concluded.
2.4.1.2
Ladders, fences and platforms are complete and there is no foreign materials in channels and around equipment disturbing work or passing.
2.4.1.3
Insulations of turbine proper should complete, all the connections in system should be complete and pipeline supporters and suspending devices are fixed.
2.4.1.4
Lighting in turbine hall is good and emergency lighting system works normally.
2.4.1.5
Communication system in turbine hall is normal. 34
2.4.1.6
Fire fighting water system is normal and fire fighting facilities are complete.
2.4.1.7
HP & IP main steam valve, governor valve and control actuator are normal.
2.4.1.8
Turbine sliding pin system is normal and cylinder proper can expand freely.
2.4.1.9
LP cylinder safety valve is complete and in fine condition.
2.4.1.10
Emergency oil discharging valve of main oil tank is closed and sealed with lead. Before start, all original parameters of turbine and main auxiliary equipments should be recorded.
2.4.2
Put auxiliary equipments and systems into operation before start Put the following systems into operation according to check cards and relevant regulations in Unit Auxiliary Equipment Start and Stop and make sure that they are running normally. Balance of load distribution in all sections should be comprehensively considered.
2.4.2.1
Before boiler ignition, put the following systems into operation one by one and make sure that they are running normally.
1） Put fire fighting system into operation. 2） Put circulating water system into operation, condenser works normally. 3） Put opened circulating water system into operation. 4） Put closed circulating water system into operation, all coolers are filled with water and air is discharged. All valves state is right. 5） Put unit air compressor system into operation, air pressure is normal. 6） Put EH oil system into operation. 7） Put lubricate oil system into operation, one AC lubricate oil pump is running and the other one is in standby. DC lubricate oil pump in standby and all returning oil for bearings are normal. Oil temperature can regulate itself. Water passes water side of oil cooler that is running; oil cooler in standby is isolated after filled with water. 8） Put the generator oil sealing system into operation, AC sealing oil pumps at air, hydrogen side of generator sealing oil are running, DC sealing oil pump is in standby, Water side of air and hydrogen side oil cooler is put into operation, all the oil pressure, oil temperature and oil levels in oil tanks are normal. 9） Generator changes hydrogen. Put hydrogen system into operation. 10）When the hydrogen pressure in generator is 0.2MPa, make sure that water in make up water tank is qualified and air in stator is completely discharged; put cooling water system in generator into operation. Adjust the differential pressure keep normal. 11）Start jacking oil pump, check and make sure that jacking oil supplying head pipe pressure, bearing jacking oil pressure are normal. Confirm the relevant interlocks of turning gear device are in fine condition and protection test is successfully completed; lubricate oil temperature should be higher than 21℃. Put turning gear into operation and check the turning gear current is normal. There is no abrasion sound at running parts and rotor eccentricity should be no bigger than 110% of original value. Record relevant parameters. Continuous turning gear time should be no less than 4 hours before starting the turbine. 12）Put condensing water system into operation. a. Start make up water pump and fill water into condenser. b. Make sure that protection tests of relevant interlocks of condensing water are successful, when the water level is normal, run the condensate pump, each LP-heater transit water .Air discharging and water filling at water side of LP heater are completed and water level protection has been put into operation. 35
c. Make sure that condenser and system flushing water are qualified and feed water to deaerator. Make sure that flushing water in deaerator is qualified. 13）Auxiliary steam system drain and warming pipes, put it into operation, check the head pipe pressure and temperature are normal. 14）Put deaerator water tank for heating a. Fill deaerator water tank to normal water level and contact chemical to dose to deaerator. b Make sure that turning gear runs normally, open regulation valve from auxiliary steam to deaerator and put deaerator for heating. Regulate the pressure regulation valve from auxiliary steam to deaerator and make the water temperature rise according to boiler need. （temperature-rise ratio not exceed 1.5℃/min） 15）Oil system of two (2) steam driven feeding water pumps are put into operation and, water passes through water side of running oil cooler; water side of standby oil cooler is isolated after air discharging and oil temperature regulation automation is in operation. Before boiler ignition, turning gear of feeding water pump should be running for more than three (3) hours. 16）Feeding water temperature reaches to the requirement of deeding water to boiler; run the electric feed pump transmit the feed water to boiler when water quality in deaerator is qualified. HP-heater connect water. 17）After water side of gland sealing heater putting into operation, put the turbine gland sealing system into operation. a. Start one gland sealing heating air fan, open general valve from auxiliary steam to gland sealing steam head pipe and isolation valve heating pipes before and after gland sealing steam regulation valve. b. After discharging all the drainage water, open gland sealing steam regulation valve and keep gland sealing steam pressure at 0.007～0.021MPa and LP gland sealing steam temperature at 120～180℃ and, LP gland sealing steam desuperheater water temperature control automation is in operation. c. During unit start or stop, differential temperature between HP & IP rotor gland sealing steam temperature and rotor surface metal should <110℃. Note: Steam supplying is prohibited when rotor is in stationary state. Turning gear operation should be strictly supervised during supplying gland sealing steam. Vacuum pump can only be started after gland sealing supplied to rotor to establish condenser vacuum. 18）Put gland sealing system of feed water pump turbine into operation. 19）Close the vacuum break-valve, open the sealing water valve, open the drain butterfly valve of feed pump turbine, start the vacuum pump,(according to the need decided how many pump run) 20）After establishing condenser vacuum, open drainage valves of turbine, feed pump turbine cylinder proper, main and reheat steam pipelines, extraction pipeline. 21）Make sure the all the works before starting are completed, equipments and systems in operation run normally and equipments and systems in standby can be put into operation at any moment. 2.4.2.2
Work after boiler ignition
1） After boiler ignition, inform the boiler about required parameters according to cylinder temperature. 2） Put bypass system into operation according to requirements. Put LP bypass system into operation first and then HP bypass system. Pressure before main steam valve should keep above 0.1MPa. Put HP & LP bypass attemperating water into operation according to temperature after bypass. Pay attention to vacuum and steam discharging temperature, contact with chemical to analyze condensing water quality. 36
3） Following parameters should be recorded before starting turbine: temperature and pressure of main and reheat steam, rotor eccentricity, absolute expansion, differential expanse, axial displacement, temperature of cylinder metal, vacuum, drain steam temperature, turning gear current, oil level of lube oil tank, lube oil pressure and temperature, jacking oil pressure ,hydrogen side sealing oil tank oil level, hydrogen pressure, hydrogen-oil differential pressure, stator cooling water flow and pressure, oil level of EH oil tank, EH oil pressure and temperature. 2.4.3 2.4.3.1
Turbine start Check and preparation before starting turbine
1） Interlock protection test of turbine is qualified and in operation 2） Auxiliary equipments and systems run normally and there is no condition prohibiting unit start. 3） When turbine is in cold state start, steam temperature at inlet of main steam valve at least should be with overheating temperature of 56℃ but no higher than 430℃. Main steam valve inlet steam temperature and pressure should be within curve of „Main steam parameters during start. 4） Turning gear device runs normally, rotor eccentricity ＜0.075mm, and turning gear runs for more than 4 hours, cylinder inside and shaft seal part without clash sound or other abnormal sound .(regulation of minimum continuous running time before starting turbine must be executed). 5） Check and make sure that gland sealing steam head pipe pressure is 0.007-0.021Mpa, gland sealing steam temperature and rotor surface metal temperature match with each other with differential temperature less than 110℃, LP gland sealing temperature control automation is in operation. 6） Affirm that turbine lubricate oil pressure is 0.1～0.18MPa, lubricate oil temperature is 38℃～ 42℃. 7） Generator sealing oil system, stator cooling water system and hydrogen cooling system work normally. 8） Turbine TSI indication is normal. 2.4.3.2
Conditions for turbine latch
1） There is no condition prohibiting unit start. 2） Make sure that HP & LP differential expansion, axial displacement, HP & IP & LP up and down differential temperature, eccentricity, differential temperature of inner & outer wall of steam chamber are in limited range. Changing trend should not exceed limitation after turbine starts. 3） Cold state start parameter： Main steam pressure: 5.9MPa
Reheat steam temperature: 300℃
Main steam temperature: 340℃
Reheat steam pressure: 1Mpa.
Main and reheat steam have >56℃ superheat degree. 4） Condenser vacuum at HP & LP side >80KPa。 5） Lubricate oil temperature is higher than 35℃, returning oil of all bearings are normal. 6） Lubricate oil pressure: 0.1～0.18MPa。 7） Turbine turning gear works normally and sound is normal. 8） LP cylinder water spraying valve is in „automation‟. 9） Close HP & LP bypass valves. 37
10）Remote and manual latch handle is recovered. 11）DEH screen check: Stick chart or explanation
State
Literal explanation
HP main steam valve position indication
0％ valve position
TV1，2
hp regulating valve position indication
0％ valve position
GV1，2，3，4
Reheating regulating valve position indication
0％ valve position
IV1，2，3，4
Reheating main steam valve position indication
CLOSED
Closed (green light shine)
Main breaker state
Breaker Open
Breaker Open
Turbine state
Turbine stop
Trip
Valve control mode
SINGLE
Single valve
Generator power control loop
OFF
Cut-off
Main steam pressure control loop
OFF
Cut-off
Turbine control mode
MANUAL
Manual
2.4.3.3
Turbine latch
1） Select „Latch turbine‟ button on screen and click „ETS recover‟, click „Latch turbine‟ after ETS recovered and select „YES‟ for turbine latch. After successful latch, check that IP main steam valve is open, green light of „Enable Roll‟ is on. 2） Select „automation‟ in „control mode‟ on DEH screen. 3） Select „Valve position high limitation‟ from „Limitation value‟ on DEH screen, enter „120‟ and click „GO‟, check that IP regulation valves and HP regulation valves are open. 4） Operate over speed trip actuator with remote trip button or manual trip pole installed at front box, close all steam inlet valves. Test and check whether trip system is normal or not. 5） Repeat above operations, turbine latch again. 2.4.3.4
Operation and check before starting turbine
1） Test the OPC function on DEH screen, click „OPC Test‟ button and click „IN‟, check OPC solenoid valve action. HP & IP governor valves, HP steam discharging check valve and check valves of all steam extraction are closed. Click „OPC Protection‟ button, OPC protection „IN‟, above valves open. 2） Select „Single valve‟ mode from „Valve Mode‟ on DEH screen. 3） Make sure that main steam pressure, temperature meet the requirements of cold state start. 4） Make sure that turbine first stage metal temperature is less than 120℃, according to IP cylinder steam inlet blades metal temperature, turbine should be heated up for 150min when running speed is 2000r／min. 5） Make sure that turning gear is running and turbine is latched. 6） Make sure that all the auxiliary system and equipments are running normally with no abnormal alarm signals. 7） Make sure that drainage valves of turbine proper, HP & IP system and LP cylinder water 38
spraying control switch are at „Automation‟. 8） Lubricate oil cooler, coolers at air & hydrogen side of sealing oil, hydrogen cooler and generator stator water cooler are ready for operation. 9） LP heater start with the turbine and start the LP heater steam supplying motorized valve, drainage water flows automatically stage by stage. 2.4.3.5
Start turbine with target speed of 600r/min, check the turbine clash
1） Click „Control set value‟ button on DEH screen and set speed rise rate of 150r/min with target speed of 600r/min. Click „GO‟ button, turbine starts to rise speed. 2） When running speed >3r/min, make sure that turning gear on CRT really exit from running and turning gear motor stops. 3） When running speed reaches to 200r/min, check and make sure that turning gear oil spraying solenoid valves are closed automatically. 4） When the turbine rotate speed reach 600r/min, keep 600r/min, press the “emergency shut down” button，check that HP-LP main throttle valve closed, rotate speed downgrade. Check turbine clash, listen sound of the cylinder inside, check that if the running part and static part have abnormal sound, check that if the rotor eccentricity normal, when eccentricity >0.075mm must forbid unit start. 5） After checking the friction, turbine latch again, the turbine rotate speed reach 600r/min, keep 600r/min,check the unit completely: a. Up and down gas side start with the turbine. b. Check bearing vibration, axial displacement ,differential expanse, cylinder absolute expansion, bearing metal temperature, return oil temperature, up and down cylinder differential temperature and so on in normal range. check eccentric recorder automatically disengage, vibration recorder begin to record the final rotor eccentric degree at rotate speed is 400～600r/min. c. Check condenser hot well level, deaerator water level, up and down feeding water level all adjusting put into automatic control and operating normally. d. Check turbine lube oil pressure and temperature, EH oil pressure and temperature, oil level of EH oil tank, bearing current are normal. e. Check the generator hydrogen pressure, hydrogen temperature, sealing oil pressure and hydrogen-oil differential pressure are normal. f.
Confirm the LP watering door open automatically, LP exhaust temperature is less than70℃,vacuum is normal.
g. If the gauge above parameters or close to the parameters and may rise, should report 2.4.3.6
immediately, identify the reason and prohibit to increase the speed. Continue to rise speed with target of 2000r/min
1） Click „Control set value‟ button on DEH screen and set speed rise rate of 150rpm/min with target speed of 2000r/min. Click „GO‟ button, turbine continues to rise speed. 2） Unit continues to rise speed to 2000r/min and keep running speed of 2000r/min for heating up turbine. During heating up, heat up pipes with auxiliary steam. 3） During speed rise, if running speed needs to stay, click the „HOLD‟ button in „Control set value‟ on screen. It is prohibited to stay in resonance running speed range to avoid turbine resonance. (1)700～900rpm (2)1300～1700rpm (3)2100～2300rpm 39
(4)2650～2850rpm 4） Heating up time should be decided according to first stage metal temperature, when this temperature is ≤120℃, heating up time should be 150min. Heat time should not be shortened under any condition. During medium speed heating up time, main steam temperature slowly slide to 380℃,reheated steam temperature slowly slide to 335℃(during this process, inlet steam can increase to 430℃,but the temperature rise rate can not more than 55℃/hour.) 5） During heating up, main steam temperature should not exceed 430℃ and reheating steam temperature should be higher than 300℃. Temperature rise should be controlled at 0.92℃/min. 6） During heating up, auxiliary equipments and systems should be checked completely, sounds in running parts are normal with no abnormal alarm. 7） After pipe heating, check and make sure that parameters for starting turbine are qualified and start the first steam driven pump with auxiliary steam according to actual conditions to avoid water impact. 8） The finishing condition of medium speed heating up : a. Make sure that time is up and heating up is completed. b. Check and make sure that steam cylinder is evenly expanded. c. HP & LP differential expansion decreases stably and gradually. d. Indications do not exceed limitation and are stable. 2.4.3.7
Turbine running speed rise from 2000r/min to 2900r/min, transfer the valves
1） Click „Control set value‟ button on DEH screen and set speed rise rate of 150rpm/min with target speed of 2900r/min. Click „GO‟ button, turbine continues to rise speed. 2） When turbine rotate speed is 2850r/min,check that jacking oil pump stop automatically, or stop manual, put into standby. 3） Running speed continues to rise to 2900 r/min and running speed keeps at 2900 r/min; it is ready for valve transfer. Make sure that inner wall temperature in steam chamber at least equals to saturation temperature under main steam pressure. See as annex of turbine inlet steam state which shows the relationship between inlet temperature and pressure of main steam valve in cold state start. If you want to make the temperature of steam chamber meet the required value, this parameter relationship should be obeyed. 4） „TV-GV‟ transfer operation “（TV/GV CHANGE）”button, GV will close slowly, TV/GV CHANGE IN PROGRESS in the information bar will bright, when GV close to certain valve, TV will open slowly when TV completely open, switch is finished, unit increase speed to 3000rpm automatically, “TV/GV CHANGE IN PROGRESS” become dark. During the recorder valve switching process, speed fluctuation value does not exceed 30r/min. 5）Check EH oil system, regulate that hydraulic mechanism of system is not leakage and abnormal, it can continue to increase the speed. 2.4.3.8
Unit running speed increase to 3000 r/min
1） Click „Control set value‟ button on DEH screen and set speed rise rate of 150r/min with target speed of 3000r/min. Click „GO‟ button. 2） Running speed continues to rise to 3000 r/min and running speed keeps at 3000 r/min. 3） After turbine operating in normal speed, completely check unit and each system is normal. a. Check and make sure that main oil pump outlet pressure is 2.0～2.5MPa and inlet oil pressure is 0.12～0.14MPa，main oil pump work normal. 40
b. Stop AC lubricate oil pump, sealing oil standby oil pump and put them in standby. c. Regulate lubricate oil temperature to be 38～42℃ and bearing returning oil temperature <77℃. 4） The following experiments as needed a. ETS channel online experiment b. Critical protection device injection test(running 2000 hours) c. Main steam valve, regulating steam valve strict test(after each overhaul, before speed (test) 2.4.4 2.4.4.1
Unit synchronization and loading Following conditions should be prepared for turbine during unit synchronization:
1） Make sure that turbine runs with speed of 3000r/min and is stable; DEH device is normal. 2） All control indications are normal when turbine runs with empty load; auxiliary equipments are normal. 3） Tests under 3000r/min for unit are completed. 4） Main steam temperature and steam pressure are stable. 2.4.4.2
After completely checking that unit is operating normally, report to dispatcher, shift chief supervisor orders that the generator is synchronization
2.4.4.3
With 5% rated load
2.4.4.4
Check after synchronization Heating up 30min at 5% rated load, during this period, maintain steam temperature, pressure stability, temperature rising rate is maximum not more than 83℃/h,regulating metal temperature rising rate is maximum not more than 110℃/h.
1） Check and make sure that vibration, differential expansion, absolute expansion, axial displacement and metal temperatures of all bearings are normal, lubricate oil pressure, bearing returning oil temperature and EH oil pressure are normal. Temperature difference of up & down wall of cylinder is within permit range. 2） Make sure that following control devices are in automation: a. Motorized feeding water pumps re-circulating control. b. Steam driven feeding water pump re-circulating control. c. Deaerator pressure and water level control. d. Turbine lubricate oil temperature control. e. Hydrogen temperature control. 3） After heating up with primary load, check and make sure that turbine differential expansion is within permit range and absolute expansion of cylinder is normal. 2.4.4.5 Increase load to 60MW(10%rated load) 1） Check BFPT lubricate oil system, MEH system is normal, meet the BFPT operating condition to make the first BFPT standby. 2） Check turbine main steam pipe all the drain valve close automatically. 2.4.4.6 When load increase to 90MW,check LP cylinder injecting valve open automatically. 2.4.4.7 Increase load to 100MW 1） Station-service power supplying to start-up/stand by transformer changes to be supplied by high plant transformer, common part power supplying to start-up/stand by transformer changes to be supplied by high common transformer. 2） Steam supplying to gland sealing changes to be supplied cold reheater. 2.4.4.8 Increase load to120MW (20%rated load) 41
1） Check turbine proper, reheat steam pipe, bypass system pipe and each part extraction pipe and so on all the drain valve close. 2） The first start after new installation or overhaul, the unit should operate at least seven hours at the condition that 120MW load, reheat steam temperature is not more than 400℃ then to heat up, according to the normal stop process, unit load reduce to zero, after cutting off do the turbine exceed test after exceed test, recover the rotate speed 3000r/min,contact to dispatcher, generator synchronizes again and with load. 3） When load is 120MW,after the drum water level stability, according to the operating condition of pneumatic feeding water pump, parallel the first pneumatic feeding water pump and power pump and put into automatically control. 4） When the fourth steam extraction pressure is more than0.165MPa,Deaerator steam source returns to be supplied by fourth section steam extraction. 2.4.4.9 Increase the load to 240MW, start and heat up the secondary pneumatic feeding water pump. 2.4.4.10 Increase load to 300MW,open the proper reheat cooling part to high pressure auxiliary steam header automatic isolation valve, steam supplying to proper auxiliary steam connecting box by fourth steam extraction, completely check to close drain/dewatering outlet valve, secondary pneumatic pump put into system, stop power pump standby, maintain the combustion stability when switching. 2.4.4.11 Increase load to 600MW 1） When load is 420MW, proper auxiliary steam connecting steam source supplying to high auxiliary slowly changed to be supplied by fourth section steam extraction. 2） Check turbine bearing sealing steam source supplying to cooling reheat automatically changed to supplied by sealing, bearing sealing supply steam header pipe pressure is 0.028～0.031MPa,open each standby steam source valve to maintain the heating standby condition. 3） When the parameters of the turbine pump auxiliary steam source and fourth section steam extraction are matching, and the temperature differential of two part is not great, avoid water rushing. 4） Maintain single valve operating one day, when load is 540MW,single valve and sequence valve control methods changed with each other, to reduce solid particle corrosion(during the first six month operating period, the turbine valve control method must be single valve control, to make regulating blade uniform heating, improve the stress distribution of regulating blade, reduce the rush for the blade, to make sure the safety of the unit operation). 5） When load is 600MW,completely check and regulate each equipment, system in normal operating condition, confirm each parameter is normal, make recorder, report to shift chief supervisor, start-up stop. 2.4.5 Notice during start 2.4.5.1
During the start, condenser, deaerator, heaters, closed water tank, stator cooling water tank level is normal, oil levels in all oil tanks are normal and oil temperature complies with requirements.
2.4.5.2
After starting the turbine, lubricate oil temperature should be regulated and maintained at 40±2℃; parameters should be stable when turbine running speed is rising.
2.4.5.3
When running speed is <600r/min, turbine eccentricity should be supervised strictly; when running speed is >600 r/min, unit vibration should be supervised strictly. When unit running speed is increased to resonance area, vibration should be strictly supervised and stop the unit as emergency stop immediately if any bearing vibration reaches to 0.25mm at any running speed. When decreasing running speed due to high vibration and running speed is decreased to be less than 600r/min, rotor eccentricity should be supervised; when eccentricity is higher than 0.075mm, stop the unit and start turning gear; the unit can only be started again until eccentricity is lower than 0.075mm.
2.4.5.4
During turbine speed rising, unit abrasion sound should be listened carefully at local; if 42
any abnormity is found, unit should be stopped for finding out the reason. During speed rising, DEH should keep running speed if any of the following conditions occurs; if the running speed is within critical sunning speed range, then it should keep the running speed after running speed rises and exceeds critical running speed: 1） Bearing vibration is higher than 0.125mm. 2） Expansion difference of HP and IP is high. 3） Bearing returning oil temperature is 75℃ higher. 4） Thrust bearing metal temperature is 85℃ higher. 5） LP cylinder steam exhausting temperature is 80℃ higher. 2.4.5.5
AC lubricate oil pump should be put into standby in time after stops.
2.4.5.6
LP cylinder steam exhausting temperature should not exceed 80℃ before generator synchronization.
2.4.5.7
During load increasing, nitrogen should be charged to generator in time.
2.4.5.8
Coordination control should be put into operation as soon as possible when unit load is higher than 30%.
2.5 Unit warm, hot, very hot start 2.5.1 Unit warm, hot, very hot start general rules Before unit warm, hot, very hot start, completely check it. The auxiliary equipment start operating step is the same as cooling condition start, other operation and regulation according to the cooling condition start requirement to operate for there is no special representation. When warm, hot, very hot start, should load immediately to avoid the rotor metal temperature reducing to have over hot stress. Unit increase speed rate, load rate and heating up time should reference the relevant start curve to confirm. 2.5.2 Unit warm, hot, very hot start regulation 2.5.2.1 Before exhaust air vacuum, first put into sealing supplying air, then vacuum, vacuum break valve should close before vacuum. Sealing supplying air temperature should match cylinder metal temperature. 2.5.2.2 After boiler burning, exhaust air equipment vacuum qualified, put into bypass system. Strictly according to increase temperature and increase pressure rate to control main reheat steam temperature, to make sure the unit life. 2.5.2.3 The rotor eccentricity is normal. 2.5.2.4 Before starting, should make sure that the turbine is at the condition of turning gear or still at idling step, but rotate speed is not at the critical period, starting and increase the speed of turbine when it is idling at critical period is prohibited. 2.5.2.5 Before turbine starting, should make sure turbine proper and each steam pipe drain valve opening and can drain water 15 min continuously. When turbine staring, pay attention to supervise up and down temperature differential of the HP and IP cylinder is less than 42℃,if the temperature differential is exceed and axial displacement alarm at the same time, should trip to stop immediately and drain steam pipe fully. 2.5.2.6 When turbine starting, make sure main steam superheat temperature is above 56℃,and the first grade steam temperature and metal temperature is matching at any condition, first steam temperature can‟t above first metal temperature110℃or below 56℃. 2.5.2.7 When main, reheat steam near to starting parameters, turbine have to install again, then should pay attention to the changing of turbine rotate speed. 2.5.2.8 Turbine doesn‟t need 2000r/min heating up during starting(except warm-1) 2.5.2.9 Very hot, hot and warm start should make expansion differential, absolute expansion of the cylinder, vibration, axial displacement, each bearing temperature and oil temperature at the regulating range, after starting, turbine should increase speed, parallel and load as soon as possible, not let metal cool and appear temperature differential. 2.5.2.10 In very hot start, after synchronization should increase the load to 300MW by the speed 43
18MW/min,to avoid making HP cylinder exhaust air temperature high, and turbine trip, influence the unit start. 2.5.2.11 When unit increase speed, pay attention to LP cylinder exhaust air temperature is not more than 80℃. 2.5.2.12 When unit start, condenser water system and feeding water system rushing should operate normally. 2.5.2.13 During hot start, for the load increasing rate is great, pay attention to the change of the condenser water level. 2.5.2.14 When warm start should maintain single valve control one day to reduce solid corrosion. 2.5.3 Unit warm, hot, very hot start reference parameter Start parameter Start condition
Regulating metal temperature
Main steam pressure
Main steam temperature
Reheat steam pressure
Reheat steam temperature
T＜120℃
5.9MPa
340℃
1MPa
300℃
warm-1
260℃＞T≥120℃
5.9MPa
340℃
1MPa
300℃
warm-2
415℃＞T≥260℃
5.9MPa
420℃
1MPa
400℃
hot
450℃＞T≥415℃
7MPa
450℃
1MPa
435℃
T≥450℃
8MPa
485℃
1MPa
470℃
cold
very hot
2.6 DEH operation mode explanation There are four basic control modes: Automatic control; CCS remote control; Manual control; Synchronize Control. 2.6.1
Automatic control
2.6.1.1 During rising speed, speed rising rate and target running speed can be confirmed or corrected. 2.6.1.2 Transfer from main steam valve to HP regulation valve control can be done. 2.6.1.3 When unit reaches rated running speed, automatic synchronization can be done. 2.6.1.4 After unit synchronization, speed rising rate and target running speed can be confirmed or corrected. 2.6.1.5 Remote control can be put into operation. 2.6.1.6 It has valve management function——single valve and sequence valve control. 2.6.2
CCS remote control
2.6.2.1 Conditions for putting into operation 1）
DEH device is at automatic mode.
2）
Outlet breaker of generator is closed.
3）
DEH did not put main steam pressure circuit into operation.
4）
DEH did not put power control circuit into operation.
5）
Contact point allowable for remote control is closed. 44
2.6.2.2 Method for putting into operation After pressing „remote control‟, control device is put into coordination control operation mode; „remote control selection‟ is sent form contact point to CCS, it indicates that DEH has accepted parameter increasing or decreasing pulse from CCS. 2.6.2.3 Cutting off method When any of the above five conditions is not satisfied or press „remote control‟ button again, it exits from remote control mode and enters into DEH „automation‟ mode. 2.6.3
Manual control
2.6.3.1 Conditions for DEH changing from automation to manual control mode Unit has not been synchronized, speed measuring system is in fault; the system switches automation to manual control mode directly. 2.6.3.2 In manual control mode, operator controls HP main steam valve, HP regulation valve openness directly; slow velocity is 10% valve position/min and quick velocity is 30% valve position/min. Valves will be closed or opened according to set velocity of corresponding button that is long time pressed. 2.6.3.3 Notices 1）
During unit speed rise, manual control mode is prohibited.
2）
During speed rise, if automation is transferred to manual control, unit speed rising should be stopped. When unit is in manual control, latch should be opened and then closed, then automatic control can be put into operation.
2.6.4
Synchronization control
2.6.4.1 Conditions for synchronization putting into operation 1）
DEH device is at automatic mode.
2）
HP regulation valve is at control mode.
3）
Outlet breaker of generator is opened.
4）
Turbine running speed is within synchronization range （2985～3015r/min）.
2.6.4.2 Method for putting synchronization into operation Click „Control Mode‟ button on DEH screen in main control room and select „synchronization‟ and confirm; dialog box displays „IN‟. 2.6.4.3 Conditions for cutting off synchronization 1）
Outlet breaker of generator is closed.
2）
System is in manual control or actual running speed exceeds synchronous running speed.
2.7 Unit stop 2.7.1
Preparation before Stopping Unit
2.7.1.1 Start and put AC, DC oil pump, jacking oil pump into trial operation, check that their running are normal and trial operation of turning gear motor is normal. 2.7.1.2 Preparation of steam source transfer should be done for auxiliary steam, gland sealing and deaerator. 2.7.1.3 Inform all personnel check the equipment system completely, collect the defects and prepare for stop unit.
45
2.7.2
Unit stopping with sliding parameter
2.7.2.1 Unit load from 600MW to 540MW 1）Accept the command of the shift chief supervisor to stop. report to dispatcher to stop AGC, Accept the sliding stop command of the shift chief supervisor to make the load changing rate ≯15MW/min,reduce unit load, boiler combustion rate is reducing, according to unit sliding parameter stop curve to reduce load. 2）When load reduce to 540MW,turbine sequence valve and single valve control method switch with each other. 2.7.2.2 Unit load from 540MW to240MW 1）Continue to reduce the load with the load changing rate≯15MW/min,reduce main steam with main steam pressure reducing speed≯0.15MPa/min.slowly reduce boiler combustion rate, unit begin to sliding stop step, unit load reduce with the drop of the main steam pressure. 2）When load reduce to 480MW, according the condition to do the vacuum sealing test. 3）When load reduce to 420MW,proper auxiliary connecting box steam source transfer from fourth steam extraction to high pressure auxiliary header pipe can be done, check that proper auxiliary steam connecting box‟ pressure and temperature is normal. 4）Check turbine bearing sealing steam source transfer from sealing automatically to cold reheater can be done, sealing supplying temperature is normal. 5）When load is 300MW,according to the condition, one feeding water pump changed to manual control, slowly reduce its output and check another feeding water automatically add output, maintain drum water level normal. 6）When load is 240MW,after starting electric pump and parallel pump, stop one steam pump. 2.7.2.3 Unit load from 240MW to 30MW 1）Continue to reduce the load with load changing rate≯15MW/min, reduce main steam pressure with main steam pressure changing rate≯0.1MPa/min. 2）When cold reheater pressure is below 1.27Mpa(load is 190MW),high pressure auxiliary steam header pipe steam source transfer from cold reheat to starting boiler or adjacent equipment can be done, check that high pressure auxiliary steam header pipe pressure and temperature are normal. 3） Load is 180MW and unit operating stability, station service power supplying to high station transformer changed to be supplied by start/standby transformer, common section power supplying to high common transformer changed to be supplied by start/standby transformer. after transferring, unit continuously reduce the load. 4） When load reduce to 120 MW(20%rated load),check turbine proper, reheat steam pipe, bypass system, each section steam extraction pipe and so on all drain water valve open automatically. 5） Check turbine sealing steam source transfer from cold reheater automatically to auxiliary steam can be done ,bearing sealing supplying temperature is normal. 6） When fourth steam extraction pressure is less than 0.147MPa, deaetator heating steam source transfer from fourth steam extraction to auxiliary steam can be done. 7） When load reduce to 90MW or LP cylinder exhaust air temperature is more than 70℃, check LP cylinder injecting valve open automatically. 8） When load reduce to 60MW (10%rated load),check turbine main steam pipe all drain water valve open automatically. 9） HP,LP heater adopt random sliding way, when #3 high heater steam side and deaerator pressure differential is not enough, should check #3 high heater failure drain water regulating valve open automatically, regulate that high heater water level is normal. 10）Unit should not stay at low load condition for long time, and pay attention to the change of HP,LP cylinder exhaust air temperature. 11）When load reduce to 30MW,start turbine AC lube oil pump, hydrogen sealing oil standby pump and AC jacking oil pump, check it operating normal, check jacking oil header pipe and each bearing jacking oil pressure is normal and make record. 46
12）Contact to shift chief supervisor, turbine is ready for trip. 2.7.3
Operation after turbine parallel off
2.7.3.1 When the load decreases to minimum value after generator parallel off, open the latch first, then start reverse power protection and open the breaker of generator-transformer unit to stop the unit. 2.7.3.2 Press „Turbine Trip‟ on control panel or latch manually at local, check and make sure that all the HP & IP main steam valves, HP & IP governor valves, steam extraction check valves of all stages and check valves of HP steam discharging are strictly closed. 2.7.3.3 After turbine trips, make sure that turbine HP & IP main steam valves, governor valves are closed to ensure that protection of water entering into turbine is normal. 2.7.3.4 When running speed decreases, pay attention to critical vibration and listen to sound in cylinder. 2.7.3.5 Make sure that running speed of turbine decreases and vacuum breaking valve is prohibited to open when running speed is high then 2000r/min if there is no special situation. 2.7.3.6 After turbine trips and running speed is 2850rpm (or lubricate oil is abnormal and decreases to 0.076MPa), AC lubricate oil pump and standby oil sealing pump starts automatically, otherwise start them manually; if oil pressure decreases, DC lubricate oil pump should start in interlock, otherwise start it manually. 2.7.3.7 During inertia, the lubricate oil pressure and temperature changing should be normal. Sealing oil/hydrogen differential pressure regulation should be normal, air/hydrogen side sealing oil differential pressure balancing valve regulation should be normal. 2.7.3.8 When running speed decreases to 2800r/min, check jacking oil pump start automatically normal. Check all bearing jacking oil pressures are normal. 2.7.3.9 When turbine running speed is 600r/min, check and make sure that LP cylinder water spraying valve closes automatically. 2.7.3.10
When running speed decreases to be lower than 400rpm, vacuum is allowed to be broken.
2.7.3.11
When running speed is 0, rotate speed fall to 200rpm,check turning gear injection solenoid valve open automatically, put turning gear into operation manually. Records the inertia time of rotor, check turning gear current, rotor eccentric degree, pay attention to hear the inside sounds. After turning gear putting into operation, record rotor eccentricity, HP & IP cylinder expansion, differential expansion, first stage temperature and axial displacement periodically.
2.7.3.12
Start condensate water transfer pump.
2.7.3.13
After boiler flameout, make sure that bypass system and 5% bypass is isolated, close the drainage valves before HP & IP main steam valve and check valve after HP steam discharging, make sure that there is no steam or drainage water with pressure enters into condenser (especially there should no auxiliary steam or drainage water enters into cylinder or condenser), otherwise check and make sure that all the drainage valves to condenser are closed and vacuum pump is closed and all vacuum breaking valves of HP & LP condenser are stopped.
2.7.3.14
When condenser vacuum is zero, stop steam supplying for gland sealing, close all lines of steam source of gland sealing and stop gland steam air fan. Steam discharging cylinder should be ＜50℃.
2.7.3.15
Stop EH oil pump and maintain EH oil system operation according to actual requirements.
2.7.3.16
Contact with chemical, cut off the condenser water fine treatment device.
2.7.3.17
When boiler do not need feeding water completely, stop deaeretor heating and feeding 47
water pump. 2.7.3.18
Stop open cooling water pump according closed cooling water temperature.
2.7.3.19
When drum pressure is close to 0, LP cylinder steam discharging temperature should be lower than 50℃ and there is no high temperature steam or water enters into condenser; when closed cooling water temperature is quite low, stop the other circulating water pump.
2.7.3.20
Condenser pump can be stopped if there is no condenser water user or LP cylinder steam discharging temperature decrease to 50℃.
2.7.3.21
Stop the turning gear device when all requirements for stopping turning gear are satisfied.
2.7.3.22
Gas in generator is generally changed after turning gear stops, sealing oil levels in oil tanks should be strictly supervised during gas changing to avoid oil entering into generator.
2.7.3.23
Sealing oil system can only be stopped after gas changing and turning gear stopping.
2.7.3.24
Stop generator stator water system, to do the stator water backwash as needed.
2.7.3.25
Stop the lubricate oil system of the turbine.
2.7.3.26
Decide whether to stop closed cooling water pump or not according to closed cooling water users.
2.7.3.27
Stop condensing water transportation pump.
2.7.3.28
After sealing oil system stop operating, according to the bearing temperature can stop main unit lubricating oil system and oil purifier.
2.7.3.29
Equipment maintaining and isolation for maintenance after stop should be done well.
2.7.4
Notice for stopping the unit
2.7.4.1 During stopping the unit with sliding parameter, turbine and boiler should cooperate well. There should be return during decreasing temperature or pressure. When stopping mill, main steam pressure, temperature, furnace pressure and drum water level should be supervised strictly. Pay attention the decreasing speed of steam temperature and cylinder wall temperature, steam temperature decreasing speed should comply with requirement of sliding stop curve strictly. If steam temperature decreases acutely 50℃ within 10min, turbine should be stopped. 2.7.4.2 During decreasing load, all water levels should be normal. HP & LP heaters should exit from running in time. Feeding water minimum flow valve can be opened manually in advance according to load conditions. 2.7.4.3 Bearing vibration, measuring should be strictly supervised during sliding stop, stop the turbine immediately if any abnormal vibration is found. 2.7.4.4 Unit should avoid running with 60MW for a long time, active power of generator should be decreased o rapidly and reactive power is close to 0 before parallel off; Disconnect turbine manually, check and make sure that HP & IP main steam valves, HP & IP regulation valves, all stages steam extraction check valves and HP steam discharging valves are closed. 2.7.4.5 Make sure that running speed decreases after open latch. Vacuum breaking valve is prohibited to be opened when running speed is higher than 400r/min if there is no special situation. 2.7.4.6 When speed decrease to 2800r/min, check jacking oil pump start normal. check the sealing oil ball cock and oil level in sealing oil tank to avoid oil entering into generator. 2.7.4.7 Before condenser vacuum decreases to zero, all the drainage valves to condenser should be closed. When vacuum is at zero, stop the gland sealing system and close the general manual valve at 6.9m. Close pipe expansion attemperating water. 48
2.7.4.8 Records the inertia time of rotor. Put turning gear into operation manually after rotor stops. After turning gear putting into operation, record rotor eccentricity, HP & IP cylinder expansion, differential expansion, first stage temperature and axial displacement periodically. During turning gear running, lubricate oil temperature should be within 38～ 42℃, keep sealing oil system of generator running normally. Listen to HP & LP gland sealing sounds carefully. Supervise cylinder metal temperature changing strictly to avoid cold steam or cold water entering into turbine. 2.7.4.9 Turning gear should keep in running until HP cylinder first stage metal inner wall temperature is less than 150℃. During turning gear running after turbine stops, all maintenance for systems relevant to turbine proper is prohibited to avoid cold air entering into cylinder. If any special situation occurs, it should be reported to general engineer and following regulations should be executed: 2.7.4.10
When boiler absolutely does not need to be filled with water, stop deaerator heating, stop motorized feeding water pump, keep one circulating water pump running and stop condenser water pump according to actual situation.
2.7.4.11
When LP cylinder steam discharging temperature decreases to be lower than 50℃, one circulating water pump should be kept running after open circulating water system stops.
2.7.4.12
Anti-freezing should be done well after stop in winter.
2.7.4.13
When load ≤300MW, record the cylinder temperature once per hour until the highest temperature point decreases to 100℃.
2.8 Maintaining after turbine stops 2.8.1
Maintaining principles for stopping time less than one week
2.8.1.1 Discharge remaining water in hot well of deaerator and condenser. 2.8.1.2 Discharge the remaining water at steam side of HP & LP heaters. 2.8.1.3 All the steam water valves through which steam or water may enter into turbine should be isolated. 2.8.1.4 Open all the steam extraction pipelines, main steam, reheating steam pipelines and drainage valves of turbine proper. 2.8.2
Maintaining principles for stopping time more than one week
2.8.2.1 Above 1~4 measures should be executed. 2.8.2.2 Nitrogen should be charged to steam & water side of HP & LP heaters and deaerator for maintaining. 2.8.2.3 Accumulated water should be discharged for equipments that will stop for a long time. 2.8.2.4 Hot air should be used or drying for the long-term stop turbine.
3 Unit operation and maintenance 3.1 Operation and maintenance 3.1.1
Operators should periodically and rightly record the indications on meters according to requirements of operation log and record and abnormity and operations occurs during shift.
3.1.2
When unit is in operation or standby, circuit check for equipments should be done periodically and routinely. Oil system should be checked to avoid fire accident. If any problem is found, it should be reported and cleaned by relevant department. Defects should be entered into computers and accident precautions should be done for defects. When making isolation measures, make sure that it will not affect sampling by I&C; I&C will confirm it and dismantle protection that may act by mistake if it necessary.
3.1.3
Check operation conditions and supervise meter indications frequently. If any difference is 49
found between meter indications and normal values, reason should be found out. When there is defect, it should be reported to and necessary measures should be taken. The current, sound, temperature, vibration and bearing oil level of running equipments are normal. 3.1.4
Standby equipments should be in good state and interlocks are in operation; bearing oil quality is good and oil level is normal.
3.1.5
Unit operation should be especially paid attention under following conditions:
3.1.5.1 Load changes acutely; 3.1.5.2 Steam parameters or vacuum changes acutely; 3.1.5.3 There is abnormal sound in turbine; 3.1.5.4 System is in failure; 3.1.5.5 Automation can not be put into operation. 3.1.6
Regulate operation mode reasonably and timely, analyze and treat the abnormity to ensure safe and economic operation of the unit.
3.1.7
According to load variation, supervise and regulate turbine gland sealing steam pressure to ensure no air enters into turbine and no steam leaks from turbine.
3.1.8
The operators should do the periodic tests and transfer for equipments according to regulations and supervise the relevant personnel doing maintaining works such as periodic oil filling, medium analysis, periodic bolts tightening and flushing meters and pipes etc.
3.1.9
Supervise the parameters and operation state of the running equipments strictly; except for accident treatment, equipment is not allowed to run with over output.
3.1.10 Equipments newly put into operation or with defects should be inspected periodically and intensively supervised. 3.1.11 During unit operation, control equipment should be put into automation for supervising the reliability of automatic equipment; when automatic equipments is in failure, automation should be cutoff and operate it manually to keep the parameters within permit range. 3.1.12 When abnormal working condition occurs or unit working condition changes greatly, the operators on duty should cut off the relevant automatic regulation according to actual condition and regulate it manually to ensure stable parameters. Cutting automation or operating manually should be carefully done. Excessive regulation should be avoided when regulating mill load, air fan output, main steam attemperating water and reheating attemperating water. All aspects should be in contact and cooperation and coordination to avoid abnormity or accident. 3.2 Motor normal operation and maintaining 3.2.1
After maintenance of the motor, working personnel should conclude work permit tickets and disclose the status and insulation resistant value to the operators.
3.2.2
Check items before motor start
3.2.2.1 Check and make sure that work permit ticket has been concluded, working personnel at local withdraw and there is no foreign material around the motor. 3.2.2.2 Check and make sure that power off protection and interlock devices are rightly put into operation. 3.2.2.3 Check and make sure that motor and its driven equipment are with starting conditions and do not run in reverse. 3.2.2.4 Bearing oil level is normal, oil is transparent with no foreign material and cover has no defect. Oil system should be put into operation if oil circulating lubrication is adopted by forcing. 50
3.2.2.5 For DC motors, rectifier bush should be in good contact, its surface should be smooth and spring pressure is proper. 3.2.2.6 Motor anchor bolts, earth wires, coupler, protection cover and connection box are fixed. 3.2.2.7 There is no block when turning gear manually and there is no block between stator and rotor. 3.2.2.8 Electric meters and instrumental maters of motor and its driven equipment are complete and in operation. 3.2.3
Notice for motor start
3.2.3.1 Permit start times of rat cage type motor should be executed according to regulations from the manufacturer. If there is no regulation from the manufacturer, it can be decided according to mechanical characteristics and start conditions of the motor. Under normal condition, motor can be started for twice (2) with time interval of no less than 5min and can be started once. Only motors that is in accident treatment and start time not exceeding 2～ 3s can be started for once more. Motor produced by Shanghai Motor Co., Ltd only can be started again after four (4) hours of two (2) continuous starts in cold state and after 4 hours of one (1) start in cold state. Motor should stop naturally during twice start operation. 3.2.3.2 Motor cold and hot state regulation: 1) Cold state: Motor temperature is under 60℃; 2) Hot state: Motor temperature is above 60℃. 3.2.3.3 Current variation should be strictly supervised during motor start, if current does not return after start or current does change after closing switch or motor does not run, motor should be stopped immediately. Start it again after finding out the reason. 3.2.4
Check during motor running
3.2.4.1 Current indication is stable and not exceeding rated value, otherwise, it should be reported to the shift manager and measures should be taken according to indication. If current indication reaches to maximum value suddenly, motor should be stopped immediately. 3.2.4.2 Motor sound is normal, vibration and axial moving do not exceed regulated value, indicator light is normal. 3.2.4.3 Temperatures of parts of motor do not exceed regulated values and there is no smoke, burning smell or over temperature. 3.2.4.4 Earth wires of motor shell and start device are in fine condition, anchor bolts are not loosened. Bearing oil level is normal with no oil spraying and oil leakage. Oil is transparent with no foreign material and oil ring turns freely. Covers are well sealed. 3.2.4.5 There is no block in motor aeration, positions of cooling water valves and air channel dampers are right and there is no foreign material around motor. 3.2.5
Motor normal maintaining
3.2.5.1 Running motors that using oil ring to lubricate bearing should be added oil according to oil level indications and rolling bearing should also be added with oil. Lubricant with same oil quality can be added with oil gun if it is necessary. 3.2.5.2 The changing of bearing lube oil is not less than one time in one year, bearing should be cleaned completely when changing. 3.2.5.3 In normal condition,motor will hot as operating,although some area feel hot,motor heat still in the limit range ,RIT or TC coil temperature is right. Measuring coil temperature(not temperature rising) is the basis of the motor safety operating.if using temperature measurer in the coil to measure the temperature,it does not pass 155℃.if pass,the motor operating condition will be checked. Stator temperature measurement,bearing temperature measurement and so on temperature measurers are platinum resistance Pt100 as no special instruction. 51
3.2.5.4 Stator temperature,bearing temperature‟alarm and stop value should confirm according to actual operating condition,at the condition of highest circumstance temperature and biggest load, the temperature of stator and bearing each add 5℃ will be the alarm value,add 10℃ will be the stop value. Stator temperature,bearing temperature‟s alarm value and stop value （℃） Stator Bearing temperature temperature Roll Sliding bearing （ force Sliding bearing （ auto bearing lubrication） lubrication） Alarm 150 90 75 90 value Stop 155 95 80 95 value
3.3 Unit operation mode 3.3.1
Unit control
3.3.1.1 Coordination control mode can be adopted for running when unit load is within 30%～ 100%. Coordination control should be put into operation if there is no fault in system. During unit start and after three mills have been put into automation, coordination mode should be put into operation gradually and CBF should be chosen in priority. During normal operation, unit control mode is chosen according to equipment conditions and abnormity should be taken as following target. Coordination control should be rapidly released and manual regulation should be adopted to avoid accident, if any of following conditions occurs: 1) RB working condition occurs but RB function is not realized. 2) Regulation characteristic is getting worse and main parameters of the unit departures from normal control range with no reply for a long time. 3) Unit is running with high load, main steam pressure continues to increase but main steam temperature decreases acutely. After generator-transformer unit trips, hot standby of should be out and 500kV system should be put into closed-loop operation. 3.3.2
Unit control mode
3.3.2.1 Unit following mode 1) Turbine following boiler (TFB): Boiler controls power and turbine controls pressure. 2) Boiler following turbine (BFT): boiler controls pressure, turbine controls power and pressure. This mode is common used mode that is transferred by changing buttons on CRT. 3.3.2.2 Base mode（BASE） When boiler and turbine are in manual mode, control mode is base mode. 3.3.2.3 Boiler following turbine (BFT) 1）In boiler following turbine mode, boiler automation should be put into operation to control pressure and turbine controls power manually. 2） When boiler MFT, it transfers to turbine following boiler mode automatically. 3）When power measuring difference is big, it changes to turbine following boiler mode automatically. 3.3.2.4 Turbine following boiler (TFB) In turbine following boiler mode, turbine automation should be put into operation to control pressure and boiler controls power manually. 3.3.2.5 Boiler following turbine coordination control system (CCS) 1）In boiler following turbine mode, turbine automation should be put into operation and unit 52
enters into boiler following coordination control system mode (CBF). This mode is common used coordination mode. 2）When RB occurs at boiler side, it changes to turbine following boiler mode automatically. 3）When boiler is in manual mode, it changes to turbine following boiler mode automatically. 3.3.2.6 Turbine following turbine coordination control system (CCS) 1）In turbine following boiler mode, boiler automation should be put into operation and unit enters into turbine following coordination control mode (CTF). 2） When RB occurs at turbine side, it changes to turbine following boiler mode automatically. 3 ） When turbine is in manual mode, it changes to turbine following boiler mode automatically. 3.3.2.7 Remote automatic dispatch system （ADS） 1）Unit can enter into ADS form CBF and CTF mode. In this control mode, middle power dispatch authority is allowed to control the load of the unit. 2） ADS mode may appear under CBF and CTF, and operation mode can be transferred between these modes. ADS mode will be transferred to original control mode under following conditions: load increase is blocked, load decrease is blocked, remote dispatch is invalid or unit is in load rejection. Unit maximum load and minimum load are still valid in ADS mode. 3.3.3
Unit protection interlock operation mode
3.3.3.1 All protections and interlocks for running and standby equipments should be put into operation. If there is any problem, protection or interlock needs to exit, it must be approved according to relevant regulations. If any abnormal parameter is found during operation which is confirmed to be measuring loop fault or measuring element fault, I&C personnel must be contacted for releasing the protection that may act by mistake. After power equipment trips, electric protection must be checked firstly and then check the I&C protection; if the reason is unclear, this equipment can not be put into operation again (except for accident treatment).If standby equipment acts by interlock, the reason should be completely found out and it is due to running equipment fault, it should be stopped for maintenance. 3.3.3.2 For generator-transformer unit, part protections can be stopped in emergency, but two kind protections can not be stopped at the same time. 3.3.3.3 When any fault occurs to running electric equipments, protection and automatic device acts should be checked timely, report to the shift manager and take records. Signal can only be recovered after a second person check and makes sure that this no mistake. 3.3.3.4 After unit trips, protections of „generator trips after turbine trips‟ and „turbine trips after generator trips‟ should be released. After synchronization, protections of „generator trips after turbine trips‟ and „turbine trips after generator trips‟ should be put into operation immediately.
3.4 Parameter supervision in normal operation 3.4.1
Parameter limit of turbine
NO.
Parameter
Unit
Normal
1
Running speed
r/min
3000
2
Load
MW
600
647
3
Main steam temperature
℃
538
546
53
High limit
Low
Trip 3300
530
566（manual）
NO.
Parameter
Unit
Normal
High limit
4
HP steam exhaust temperature
℃
326.6
404
427
5
Back pressure
KPa
60
65
6
Exhaust steam temperature
℃
80
120（manual）
7
HP & IP cylinder differential expansion
mm
10.3
-4.5
+11.1/-5.1
8
LP differential expansion
mm
27
-3.5
+27.8/-4.3
9
Axial displacement
mm
0.9
-0.9
+1.0/-1.0
10
Turbine bearing vibration
mm
0.125
11
EH oil pressure
MPa
14±0.5
16.2
11.2
12
EH oil temperature
℃
37～60
60
37
13
Lube oil pressure
MPa
0.1~0.18
14
Lube oil temperature
℃
45～55
15
Jacking oil pressure
MPa
16
Bearing returning oil temperature
℃
77
17
Support bearing temperature
℃
107
113
18
Thrust pad temperature
℃
99
107
19
Main oil tank level
mm
50
20
EH oil tank level
mm
500～730
21
Turbine gland steam sealing pressure
KPa
27
30.99
10
Gland steam heater negative pressure
KPa
23
Condenser A hot well level
mm
1580
1810
1350
24
Condenser B hot well level
mm
480
1120(I)
250(I)
1600(II)
100(II)
LP gland sealing steam temperature
℃
150
177
121
22
25
<70
54
Low
0.25
0.083
300
Trip
9.8
0.049
-200
-300
370
230(select)
3.4.2 NO.
Feed water pump group parameter limit Parameter
Unit
Normal
High limit Low limit
Trip
Feed water pump turbine 1
Running speed
r/min
Electrical:6050 Mechanical:6160
2
Exhaust steam pressure
KPa
3
Exhaust steam temperature
℃
4
Bearing vibration
5
Lube oil pressure
6
3100--5900
25
30
40～50
90
120
mm
0.036
0.08
0.13
MPa
0.137
Differential pressure KPa between front and rear lube strainer
90
7
Lube oil temperature
℃
8
Axial displacement
mm
+0.18
9
Support bearing temperature
℃
95
115
10
Thrust bearing temperature
℃
100
115
11
Gland steam sealing pressure
KPa
12
Gland steam sealing temperature
℃
40～45
150～177
-0.18
0.25
190
Booster pump, main pump 1
Booster pump radial bearing temperature
℃
2
Booster pump outlet flow
t/h
3
Booster pump inlet strainer differential pressure
KPa
60
4
Booster pump motor radial bearing temperature
℃
80
90
5
Main pump thrust bearing temperature
℃
90
100
6
Main pump support bearing temperature
℃
90
100
7
Main pump mechanical sealing water temperature
℃
80
90
90
100
1179
Motorized pump 1
Booster pump support bearing temperature
℃
90
100
2
Motor support bearing temperature
℃
80
90
3
Booster pump thrust bearing temperature
℃
90
55
100
NO.
Parameter
Unit
Normal
High limit Low limit
Trip
4
Motor coil temperature
℃
135
140
5
Main pump support bearing temperature
℃
90
100
6
Main pump thrust bearing temperature
℃
90
100
7
Main pump mechanical sealing water temperature
℃
80
90
8
Coupler support bearing temperature
℃
90
95
9
Coupler thrust bearing temperature
℃
90
95
10
Main pump support bearing vibration
mm
0.036
11
Lube oil pressure
KPa
250～350
12
Lube oil strainer differential pressure
KPa
80
13
Working oil cooler inlet temperature
℃
14
Working oil cooler outlet temperature
15
150
80
110
60
130
℃
75
35
85
Lube oil cooler inlet temperature
℃
65
45
70
16
Lube oil cooler outlet temperature
℃
55
35
60
17
Main pump water inlet & outlet water ends sleeve differential temperature
℃
25
18
Main pump inlet flow
t/h
3.4.3
1179
HP & LP heater, deaerator parameter limit
No.
Parameter
Unit
Normal
High limit
Low limit
Override
1
#1 HP heater water level
mm
-802
-764(I)、-714(II)
-840
-664
2
#2 HP heater water level
mm
-736
-698(I)、-648(II)
-774
-598
3
#3 HP heater water level
mm
-690.5
-652.5 (I)、-602.5(II)
-728.4
-552.5
4
#5 LP heater water level
mm
Not available
Not available
Not available
540
5
#6 LP heater water level
mm
Not available
Not available
Not available
555
6
#7 LP heater water level
mm
Not available
Not available
Not available
787
7
#8 LP heater
mm
Not
Not available
Not available
787
56
No.
Parameter
Unit
water level 8 3.4.4
Hydrogen
Hydrogen cooler
Stator coil
Deaerator water level
Normal
High limit
Low limit
Override
900(I) -1140(II)
Not available
available mm
1100
1300(I)、1400(II) 1600（Ⅲ）
Generator hydrogen, oil and water system parameter limit Parameter Hydrogen pressure in generator Hydrogen pressure Cold hydrogen temperature in generator Hydrogen purity in turbine Input water pressure Input water flow
Unit MPa
Rated 0.4
Normal 0.38~0.42
High limit 0.43
MPa
Low limit 0.385
0.35
℃
45
44~46
48
42
%
98
95~98
100
95
MPa
0.25~0.35
0.25~0.35
0.36
0.2
m3/h
240
230~250
Total input water temperature Total output water temperature Stator bar temperature between stage Output water temperature difference between stator bar in same stage Total input water pressure Total input flow Stator cooling water filter pressure difference Stator cooling water tank level Stator cooling water tank pressure Stator coil water pressure difference
℃
45~50
45~50
60
75%of Normal 40
℃
69~75
69~75
85
℃
＜90
90
℃
＜8
8
12
MPa
0.25~0.35
0.25~0.35
0.36
0.20
m3/h MPa
90
87~93 0.02~0.04
Ion exchanger conductivity Stator coil input water
P
P
P
P
Trip value
66%
500~550
650
MPa
0~0.01
0.04
μS/cm
0.1~0.2
Higher than normal 0.035 0.5
μS/cm
1.0~1.5
MPa
57
High：5 Super
30%of Normal
90
Higher than actual 0.021
mm
90
450
52%
Stator core
3.4.5
conductivity Pressure difference of hydrogen and water Stator core temperature Stator core top temperature Pressure difference of oil and hydrogen
high：9.5 ＜0.05
MPa
＜0.035
℃
＜80
70~100
120
130
℃
＜80
70~100
120
130
MPa
0.084
0.035
Other parameter limit of turbine
3.4.5.1 Water and steam quality standard Name
Make up water
Feed water
Boiler water
Item
Control index (under different drum pressure)（MPa）） 3.8-5.8
5.9-12.6
12.7-15.6
15.7-18.3
Rigidity（umol/L）
0
0
0
0
Silicon dioxide（ug/L）
≤100
≤20
≤20
≤20
Conductivity (uS/cm)
≤5
≤0.2
≤0.2
≤0.2
Rigidity（umol/L）
≤1.0
≤0.3
≈0
≈0
Dissolved oxygen （ug/L）
≤15
7
≤7
≤7
Iron（ug/L）
≤50
≤30
≤20
≤15
Copper（ug/L）
≤10
≤5
≤5
≤5 ≤20
Silicon dioxide（ug/L） Hydrazine（ug/L）
<30
<30
<30
<30
pH
9.0～9.6
9.0～9.6
9.0～9.6
9.0～9.6
DDH
≤0.3
≤0.3
≤0.3
pH
9～9.8
9～9.7
9～9.7
Phosphor acid radical （mg/L）
1.5～3
0.5～3
0.3～2
Conductivity (uS/cm)
≤60
≤40
≤30
Silicon dioxide（mg/L)
2.0
0.45
≤0.25
≤2
≤0.5
Chlorine ion（mg/L）
Steam
Natrium（ug/kg）
≤15
≤10
≤10
≤10
Silicon dioxide（ug/kg）
≤20
≤20
≤20
≤20
Iron (ug/kg)
≤20
≤20
Copper（ug/kg）
≤5
≤5
≤0.3
≤0.3
≤0.3
≤2.0
≤2.0
0
Conductivity (uS/cm) Rigidity (umol/L)
≤3.0 58
Name
Control index (under different drum pressure)（MPa））
Item
Condensing water
3.8-5.8
5.9-12.6
12.7-15.6
15.7-18.3
≤50
≤50
≤40
≤30
Conductivity (uS/cm)
≤0.3
≤0.3
Sodium（ug/L）
≤10
≤10
Dissolved oxygen (ug/L)
≤15
Silicon dioxide（ug/L）
Outlet of condensing mixture
Rigidity (umol/L)
≈0
≈0
Conductivity (uS/cm)
≤0.15
≤0.15
Sodium（ug/L）
≤10
≤10
Silicon dioxide（ug/L）
≤20
≤20
Iron（ug/L）
≤8
≤8
Copper（ug/L）
≤3
≤3
3.4.5.2 Inner-cooled water Name
Index
Item
Inner-cooled water
Standard
Control standard
Conductivity（μs/cm） （25℃）
≤2.0
≤2.0
PH（25℃）
＞6.8
8.5＞PH＞7.0
Rigidity（μmol/L）
0
0
Copper（μg/L）
≤40
≤28
3.4.5.3 Turbine new oil quality standard No.
Item
Quality standard #20
#32
Transparent
Transparent
1
Appearance
2
Mechanical impurity
None
None
3
2
Moving viscidity (mm /s)
18-22
28-32
4
Flash point (℃)
≮180
≮180
5
Solidifying point(℃)
≯-15
≯-15
6
Acid number (mg KOH/g)
≯0.03
≯0.03
7
Oxidation acid number
≯0.2
≯0.2
P
P
(mg KOH/g) 8
Sediment after oxidation（%）
≯0.1
≯0.1
9
Emulsification break (min)
≯8
≯8
10
Water-solubility acid or alkali
None
None
11
Sodium hydroxide test (grade)
2
2
59
Remark
30℃
3.4.5.4 Turbine oil quality standard No.
Item
Quality standard
Supervision method or usage standard
1
Appearance
Transparent
Eyeballing
2
Water content
None
Eyeballing or YS-12-1-78
3
Moving viscidity (mm2/s)
Less than or equals to 1.2 new oil standard
GB265-75 YS-9-1-84
Flash point (℃)
No less 8℃ lower than former measured value
GB267-77
5
Mechanical impurity
None
GB511-77 or Eyeballing
6
Acid number (mg KOH/g)
0.2
GB264-83
7
Hydraulic rust
No rust
YS-21-1-84
8
Emulsification break (min)
60
YS-C-1-1-84
P
4
P
3.5 Periodic work 3.5.1 Periodic work during normal running No.
Work content
Date
1
I&C signal test
Once per shift
When Vice duty changing operator shift
--
Light and sound are normal
2
Clean trash remover outlet of circulating water pump strainer
Once per shift
Inspector
--
Clean it timely if it is dirty
3
Calibration of local & remote water level indicators of deaerator and condenser
Once per shift
Duty operator, inspector
--
Indications on meters are in consistent
Duty operator
Unit chief
EOP should run for more than 30min
8th,every month
Afternoon Duty shift operator
Unit chief
8th,every month
Latter Duty night shift operator
Unit chief
DC oil pump should continuously run for more than 10min
4
5
6
Shift
Turbine AC & DC oil pump interlock, manual start test, HV 8th,every month standby pump start test Condenser water pump transfer Feed water pump turbine transfer DC oil pump start test
Morning shift
Operator Supervisor
Requirement
7
Mechanical vacuum pump
9th,every month
Latter Inspector night shift
Duty operator
Measuring insulation before start
8
Closed circulating water transfer
9th,every month
Afternoon Inspector shift
Duty operator
Measuring insulation before start
Open circulating water transfer 9th,every month
Up night Inspector shift
Duty operator
Measuring insulation before start
--
Running should be more than 30min
9 10
Boiler feed water pump start Latter 10th,every month Inspector test night shift
11
Oil pump transfer
10th,every month
Afternoon Inspector Unit chief shift
12
Gland steam air fan transfer
10th,every month
Up night Inspector shift
60
Duty operator
No.
Work content
Date
Shift
Operator Supervisor
13
Boiler water pump emergency Latter stop 11th,every month Inspector night shift Cooling water pump start
14
Boiler water pump cooling Afternoon 11th,every month Inspector water booster pump transfer shift
15
DC sealing oil pump start test 11th,every month
16
Turbine oil tank, A&B feed water pump turbine oil tank water discharging
12th,every month
17
Stator cooling water pump transfer
12th,every month
Up night shift
Duty operator
Latter Inspector night shift Morning shift
Requirement
Duty Running should be more operator than 30min Duty operator Unit chief
DC oil pump should continuously run for more than 10min
--
Duty operator
Unit chief
18
Motorized pump auxiliary oil pump low pressure test, Afternoon 12th,every month Inspector motorized pump start & stop shift test
Duty operator
19
Turbine oil tank air discharging Up night air fan and generator air side 12th,every month Inspector shift air discharging air fan transfer
Duty operator
20
Turbine vacuum tightness test 13th,every month
Morning shift
Duty operator
Unit chief
550MW≥load≥480MW
21
Feed water pump HP & LP Up night 13th,every month main steam valve moving test shift
Duty operator
Unit chief
There is no block after low load
Oil pump should continuously run for more than 10min
Stator water tank, main oil tank Afternoon 13th,every month Inspector and air discharging point shift hydrogen measurement Main steam valve, governor 23 Once per year Unit chief valve tightness test
Shift manager
Execute after shutdown every year
Generator hydrogen leakage Morning 15th,every month Inspector detection test shift
Duty operator
Start from 11:00 and complete it at 11:00 in the next day
Duty operator
300MW—400MW
22
24
25
26
Turbine steam extraction check valve moving test
Latter Inspector night shift
13th,every month
Turbine HP main steam valve 8th, 14th, 20th, 26th Up night & governor valve moving test every month shift P
P
P
P
P
P
--
Duty operator
Load is less than 420MW, supervise it normally and Unit chief contact with I&C to complete it
27
Emergency protector action test
Four times every year
Duty operator
Unit chief
Execute during start every season
28
Sealing oil strainer dirty discharging
15th,every month
Afternoon Inspector shift
Duty operator
Pay attention to sealing oil pressure
29
Miscellaneous water pump transfer test
22nd,every month
Morning Vice duty shift operator
Duty operator
30
Oil filter transfer
Morning Vice duty shift operator
Duty operator
61
Oil filter front and rear differential pressure ≥0.05MPa
3.5.2
Work before and after maintenance
No.
Item
Requirement
1
Turbine over speed
Two tests after major maintenance, action running speed is 3300～3330r/min, running speed difference between two actions <18r/min
2
Oil filling for emergency protector and filling oil speed rise test
After maintenance or 6～12 months after maintenance
3
Turbine, boiler, generator main protection tests
After unit major & minor maintenance
4
Auxiliary equipments interlock and protection tests
After unit major & minor maintenance
5
Motorized valve and pneumatic valve test
After unit major & minor maintenance
6
Turbine speed regulation system captive test
After major maintenance or regulating speed regulation system
7
Main steam valve, governor valve tightness test
Before and after major maintenance
8
Safety valve calibration of HP&LP heaters, deaerator, After major maintenance or safety valve regulation auxiliary steam system and boiler steam water system
9
Deaerator hydraulic tests
Once every six years
10
Over speed test of feed water pump turbine
After major maintenance or regulating speed regulation system
11
Unit thermal test
Once before and after major maintenance respectively
3.6 Unit interlock protection and test 3.6.1
Turbine interlock protection
3.6.1.1 Turbine main protection 1）Over speed mechanical trip When turbine running speed reaches to 110％～111％ of rated running speed, mechanical emergency governor actuates; LP protection oil is discharged through sliding valve of mechanical emergency governor, diaphragm valve opens to make AST oil head pipe discharge oil, to close HP & IP main steam valves and governor valves and to close all stages steam extraction check valves and HP steam discharging check valves, and then the turbine stops. 2） Local manual mechanical trip This trip device lies in front of turbine front box. During operation, turn it for 90°and then pull it out; LP protection oil is discharged through sliding valve of mechanical emergency governor, diaphragm valve opens to make AST oil head pipe discharge oil, to close HP & IP main steam valves and governor valves and to close all stages steam extraction check valves and HP steam discharging check valves, and then the turbine stops. P
P
3） Remote manual trip Two buttons are installed on DEH panel in main control room. During operation, press the two buttons at the same time, then four automatic stop emergency governor protecting solenoid valves （AST-1.2.3.4）actuate to make AST oil head pipe discharge oil, to close HP & IP main steam valves and governor valves and to close all stages steam extraction check valves and HP steam discharging check valves, and then the turbine stops. 4) Any of the following abnormities occurs, automatic stop emergency governor protecting solenoid valves （AST-1.2.3.4）actuate, and then turbine trips: a. Unit bearing vibration reaches to 0.25mm; b. Turbine lubricate oil pressure is low as 0.049MPa; 62
c. Thrust bearing abrasion is high and axial displacement reaches to ±1.0 mm; d. EH oil pressure is low ≤8.5MPa; e. Condenser vacuum is ≥65KPa(absolute value); f. HP IP differential expansion reaches to 11.1mm (Rotor extends) or —5.1mm (rotor shortens); g. LP differential expansion reaches to 27.8mm (Rotor extends) or —4.3 mm (rotor shortens); h. Turbine generator unit supporting bearing metal temperature reaches to 113℃; i. Turbine thrust bearing metal temperature reaches to 107℃; j. DEH TSI over speed ≥3300r/min; k. Generator main protection actuates (turbine trips after generator trips); l. Boiler MFT (turbine trips after boiler MFT); m. DEH loses power. 5） Stop the turbine manually if any of the following happens: a. Reach over speed protection value, but turbine over speed protection device does not actuate; b. Protection device does not actuate when unit vibrates heavily; c. Turbine impeller blade breaks or there is obvious metal friction sound in cylinder; d. There is water impact in turbine; e. There is friction sound or spark at turbine gland sealing; f. Any bearing of turbine is in short of oil or in smoke; g. Oil system is on fire or there is fire around turbine generator unit, which can not be extinguished and threatens safety operation; h. Smoke comes out from generator or hydrogen explodes; i. LP cylinder steam exhausting temperature is within 80～120℃ and running exceeds 15min or the temperature is higher than 120℃; j. HP & IP up and down cylinder metal temperature difference reaches to 56℃; k. Main steam temperature exceeds 565℃; l. Reheating temperature exceeds 565℃; m. Main steam, reheating steam temperature decreases to 454℃; n. Bearing returning oil temperature is higher than 82℃; o. Turbine lubricate oil tank level is lower than normal level 300mm; p. Control value reaches to protection device actuation value, but protection refuses to actuate. 3.6.1.2 OPC interlock protection 1) When load is ≥30% rated load, generator overrides, over speed limit solenoid valve actuates to discharge over speed limit oil (OPC), all steam regulating valves close quickly under forces of valve operation seat spring and steam pressure. When running speed decreases to 3090r/min, over speed limit solenoid valve recovers and opens all the steam regulating valves again to keep turbine running speed of 3000r/min. 2) When running speed reaches to 103% rated running speed, over speed limit solenoid valve actuates to discharge over speed limit oil (OPC), all steam regulating valves close quickly under forces of valve operation seat spring and steam pressure. When running speed decreases to 3090r/min, over speed limit solenoid valve recovers and opens all the steam regulating valves again to keep turbine running speed of 3000r/min. 3.6.1.3 Turbine oil system interlock protection 63
1) When bearing lubricate oil is lower than 0.083MPa, #1 AC lubricate oil pump starts automatically and alarm; 2) When bearing lubricate oil is lower than 0.076MPa, #2 AC lubricate oil pump starts automatically and alarm; 3) When bearing lubricate oil is lower to 0.06MPa, start DC lube oil pump and stop unit put turning gear into operation; 4) When bearing lubricate oil is lower to 0.03MPa, switch to auto turning gear and interrupt turning gearing manually. 5) When jacking oil pump inlet oil pressure is lower than 0.0823MPa, AC lubricate oil pump starts automatically; 6) When turbine running speed increase more than 200 r/min, jacking oil pump stops automatically; running speed decrease to 200 r/min , jacking oil pump starts automatically; 7) When turbine oil tank oil temperature is lower than 25℃, electric heaters put into operation automatically; when the temperature is higher than 30℃, electric heaters stop automatically; 8) When EH oil pressure is lower than 11.2MPa, standby EH oil pump starts automatically; 9) When EH oil temperature is lower than 15℃, electric heaters put into operation; when it is higher than 25℃, heaters stop; 10) When EH oil temperature is higher than 55℃, put cooling water solenoid valve into operation and circulating water pump starts automatically; when the temperature is lower than 40℃, close cooling water solenoid valve and circulating water pump stops automatically; 11) EH oil tank level is lower than 370mm, it alarms; 3.6.1.4 LP steam exhausting cylinder water spraying protection interlock 1) LP steam exhausting cylinder water spraying is under automatic control, when running speed reaches to 600r/min, it starts to spray water until unit is running with 15% load. 2) When LP cylinder steam exhausting temperature reaches to 70℃, LP steam exhausting cylinder water spraying system puts into operation automatically; When LP cylinder steam exhausting temperature reaches to 80℃, alarm, and if reach to 120℃, stop unit at once. 3.6.1.5 Bypass system protection 1) Conditions for automatic open of HP bypass control valve a. Main steam pressure exceed regulating value when pressure recover to rated value and lower than it, HP bypass close automatically; b. When turbine trip, auto main steam valve close; c. When outlet switch of generator trip; d. When generator reject 60% load or more than 60%. 2) Conditions for automatic close of LP bypass control valve: a. HP & LP condenser vacuum is low to 60KPa. b. HP & LP condenser steam exhausting temperature ≥120℃. c. Condenser hot well water level is high to 1300mm. d. LP bypass outlet temperature is high to 160℃. e. LP bypass attemperating water pressure is low to 1.5MPa.
64
3.6.1.6 Turbine turning gear device interlock protection 1) Automatic start conditions for turning gear motor: a. Turning gear motor interlock switch is at „Automatic‟; b. Bearing lubricate oil pressure ＞0.028MPa; c. All jacking oil pressures are not low; d. Turning gear motor has no electric fault; e. Turning gear device is at „Automatic‟; f. Turbine tripped; g. Turbine running speed is zero (0). 2) Turning gear motor trips when any of the following conditions occurs: a. Any jacking oil pressure ＜ 6MPa; b. Bearing lubricate oil pressure ＜ 0.028MPa; c. Turning gear motor has electric fault; d. Shaft protection is in fault. 3.6.1.7 Turbine water entering proof protection 1) When turbine load is lower than 20％, following drainage valves start automatically: a. Drainage valves after first extraction motorized valve and before check valve; b. Drainage valves after second extraction motorized valve and before check valve; c. Drainage valves after third extraction motorized valve and before check valve; d. Drainage valves before and after fourth extraction motorized valve, before first check valve and after second check valve; e. Drainage valve of fifth extraction motorized valve; f. Drainage valves before and after fifth extraction check valve; g. Drainage valves before and after sixth extraction check valve; h. Main steam head pipe drainage valve; i. Drainage valve after main steam governor valve; j. Drainage valve at hot section head pipe; k. Drainage valves before and after HP steam exhausting check valve. 2) After boiler ignition, check and make sure that condensing water system, circulating water system, vacuum system run normally; all drainage valves at turbine side should be opened according to actual situation. When load is higher than 20％, close all the drainage valves (following drainage valve are closed automatically); during stopping the unit, when load is lower than 20%, unit drainage water valves should be opened manually: a. HP & IP cylinder inner cylinder drainage water; b. HP & IP cylinder outer cylinder drainage water; c. HP governor valve guiding pipe drainage water; d. IP governor valve guiding pipe drainage water. 3.6.1.8 HP heater water level protection 1) HP heater water level high Ⅰvalue, alarm; 2) HP heater water level highⅡ value, HP heater emergency drainage water opens by interlock; 65
3) HP heater water level high Ⅲ value, any two of switch value, high Ⅲ value simulation value and high Ⅱ value switch value reach to actuation value, HP heater overrides and HP heater water side bypass works, HP heater steam extraction motorized isolation valve and check valve close and steam extraction pipeline drainage water open at the same time. 4) HP heater water level low Ⅰvalue, alarm; 3.6.1.9 LP heater water level protection 1) LP heater water level high Ⅰvalue, alarm; 2) LP heater water level highⅡ value, LP heater emergency drainage water opens by interlock; 3) LP heater water level high Ⅲ value, any two of switch value, high Ⅲ value simulation value and high Ⅱ value switch value reach to actuation value, LP heater overrides and LP heater water side bypass works, LP heater steam extraction motorized isolation valve and check valve close and steam extraction pipeline drainage water open at the same time. 4) LP heater water level low Ⅰvalue, alarm. 3.6.1.10
Deaerator water level and pressure protection 1) When deaerator pressure is lower than 0.15MPa, motorized isolation valve from fourth section steam extraction to deaerator closes by interlock, motorized valve of standby steam source opens by interlock, standby steam source puts into operation (transferred to be fourth section steam extraction before putting HP heater into operation); 2) When deaerator pressure is higher than 0.15MPa, standby air source motorized valve close by interlock; motorized isolation valve from fourth section steam extraction to deaerator opens by interlock. 3) Deaerator water level high Ⅰvalue, open deaerator overflow valve by interlock. 4) Deaerator water level highⅡ value, deaerator emergency water discharging valve opens by interlock. 5) Deaerator water level high Ⅲ value, close water level main governor front and back motorized valve of deaerator and motorized valve of bypass by interlock. 6) Deaerator water level low Ⅰvalue, alarm. 7) When deaerator water level low value and deaerator low Ⅰ value hydraulic level acts (or soft act produced by deaerator water level transmitter), booster pump of steam driven pump and motorized pump trip by interlock. 8) When feeding water flow is higher than 30%, deaerator water level is allowed to be transferred from single impulse to three pulses.
3.6.1.11
Steam extraction check valve interlock: 1) When all steam extraction check valves, HP cylinder steam discharging check valves are at „Automation‟ position and turbine main steam valve trip device closes, all above valves close by interlock. 2) When all steam extraction check valves, HP cylinder steam discharging check valves are at „Manual‟ position, all above valves can be opened or closed individually.
3.6.1.12
Pump equipment interlock 1) Condensing water pump trips or outlet head pipe pressure is lower than 2.5MPa, standby pump puts into operation by interlock. 2) Circulating water pump trips, standby pump puts into operation by interlock. 66
3) Vacuum pump trips, standby pump puts into operation by interlock. 4) When open cooling circulating water pump trips or outlet head pipe pressure is lower than 0.20MPa, standby pump puts into operation by interlock. 5) When closed cooling circulating water pump trips or outlet head pipe pressure is lower than 0.35MPa, standby pump puts into operation by interlock. 6) When stator cooling water pump trips or outlet head pipe pressure is lower than 0.40MPa, standby pump puts into operation by interlock. 7) When turbine oil tank discharging air fan trips, standby discharging air fan puts into operation by interlock. 3.6.1.13
Steam driven feed water pump main protection 1) Local stop button a. Press „Emergency stop‟ button on front bearing box of feed water pump turbine, stop solenoid valve actuates to discharge control oil and close HP & LP main steam valve and governor valve, the turbine stops. b. Press „Emergency stop‟ button on operation panel in earth room, stop solenoid valve actuates to discharge control oil and close HP & LP main steam valve and governor valve, the turbine stops. c. Press „Emergency stop‟ button DSC-CRT, stop solenoid valve actuates to discharge control oil and close HP & LP main steam valve and governor valve, the turbine stops. 2) Remote stop button 3) Protection actuates to stop the turbine if any of following abnormities occurs in steam driven feed water group: a. Feed water pump turbine bearing vibration is high to 0.125mm; b. Rotor axial displacement is high to ±0.25mm; c. Lubricate oil pressure is low to 0.07MPa; d. Steam exhausting pressure reach to 30KPa; e. Feed water pump turbine is in over speed to 6050r/min; f. Feed water pump turbine steam discharging temperature is 120℃; g. Booster pump stops; h. MEH loses power; i. LP safety oil pressure is low to 0.25MPa; j. Oil tank level low to 400mm; k. Bearing metal temperature at water inlet & outlet side of steam driven pump ≥100℃; l. Steam driven feed water pump thrust bearing temperature ≥100℃; m. Mechanical sealing water temperature at water inlet & outlet side of steam driven pump ≥90℃; n. Steam driven feed water pump inlet flow low, overtime 90s and recirculating valve is not open. o. Steam driven feed water pump inlet pressure is low, overtime 3s; p. Deaerator level low II, overtime 3s; q. Turbine trip. r. Local emergency button is pressed down. 67
3.6.1.14
Steam driven pump booster pump trip protection 1) Deaerator level low II, overtime 3s; 2) Booster pump drive end, non-drive end bearing temperature ≥100℃; 3) Booster pump inlet valve is closed; 4) Steam driven feed water pump inlet flow low, overtime 90s and recirculating valve is not open. 5) Steam-drive feed water pump trip, overtime 3s. 6) Booster pump inlet pressure low, overtime 30s. 7) Local emergency button is pressed down.
3.6.1.15
Motorized feed water pump trip protection 1) Motorized pump inlet flow is low, and minimum flow valve position<30%. 2) Deaerator low, overtime 3s; 3) Motorized pump inlet pressure is low, overtime 3s. 4) Oil pressure after lubricate oil filter of motorized pump ≤0.08 MPa, the pump trips. 5) Motorized pump operated 30s and outlet valve closed. 6) Motorized pump inlet, outlet end radial bearing temperature ≥90℃, alarms; ≥110℃, the pump trips. 7) Motorized thrust bearing temperature ≥90℃, alarms; ≥110℃, the pump trips. 8) Motorized pump motor coupler end bearing temperature ≥80℃, alarms; ≥90℃, the pump trips. 9) Motorized pump booster pump drive end and non-drive end radial bearing temperature ≥90℃, alarms; ≥100℃, the pump trips. 10) Motorized pump motor non-drive end thrust bearing temperature ≥90℃, alarms; ≥100℃, the pump trips. 11) Motorized pump inlet & outlet end sealing water temperature ≥80℃, alarms; ≥90℃, the pump trips. 12) Motorized pump motor drive end and non-drive end radial bearing temperature ≥80℃, alarms; ≥90℃, the pump trips. 13) Motorized pump hydraulic coupler radial bearing & thrust bearing temperature ≥90℃, alarms; ≥95℃, the pump trips. 14) Motorized pump lubricate oil cooler inlet oil temperature ≥65℃, alarms; ≥70℃, the pump trips. 15) Motorized pump lubricate oil cooler outlet oil temperature ≥55℃, alarms; ≥60℃, the pump trips. 16) Motorized coupler working oil cooler inlet oil temperature ≥110℃, alarms; ≥130℃, the pump trips. 17) Motorized pump coupler working oil cooler outlet oil temperature ≥75℃, alarms; ≥85℃, the pump trips. 18) Local emergency stop button is pressed down.
3.6.1.16
Motorized feed water pump system interlock protection 1) During motorized pump running, lubricate oil pressure after lubricate oil filter ≥0.22 MPa, the auxiliary oil pump stops in interlock. 2) During motorized pump running, lubricate oil pressure after lubricate oil filter≤0.15 MPa, the auxiliary oil pump stops in interlock. 68
3) Oil pressure after motorized pump working oil 0.3 MPa＜p＜0.4 MPa. 4) Motorized pump working oil pressure is normally ≥0.17 MPa. 5) Working oil pressure before motorized working oil control valve ＞0.1 MPa. 6) Working oil pressure after motorized pump spoon pipe ＞0.15 MPa. 3.6.1.17
Condensing water pump 1) Condensing water pump up & down bearing temperature ≥95℃. 2) Condensing water pump motor thrust bearing ≥80℃. 3) Inlet valve of condenser water pump is confirmed to be closed. 4) Condensing water flow ≤380t/h and condensing water re-circulating valve does not open with a timely of 15s. 5) Hot well water level low II value ≤100mm and water level low I value ≤250mm. 6) Press emergency stop button locally.
3.6.1.18
Generator hydrogen, oil and water system interlock protection 1) Front and rear differential pressure of AC sealing oil pump at air side is less than 0.035MPa, DC sealing oil pump starts by interlock. 2) Main oil pump is working and AC oil pump at air side is in operation; when hydrogen-oil differential pressure decreases to 0.056MPa, standby differential pressure valve actuates and first standby oil source puts into operation controlled by standby differential pressure valve automatically. 3) Main pump does not work normally and AC oil pump at air side is in operation; when hydrogen-oil differential pressure decreases to 0.056MPa, HP sealing oil standby pump starts automatically, standby differential pressure valve actuates and second standby oil source puts into operation automatically. 4) AC oil pump at air side is in operation; when hydrogen-oil differential pressure decreases to 0.035MPa, third standby oil source of DC standby oil pump at air side starts automatically. 5) Stator water pump out and inlet differential pressure ＜0.14MPa, standby pump starts with a time delay of 3－5s. 6) When stator water tank level is low than 450mm, make up water solenoid valve opens. 7) When generator stator winding inlet water conductivity is >9.5μs/cm, reject load or stop the unit. 8) When stator water flow is <52% rated flow, generator trips with a time delay of 30s.
3.6.1.19
Other interlock protections of the turbine 1) When condensing water pump outlet head pipe pressure is lower than 2.5MPa, standby condensing water pump starts by interlock. 2) 300m3 water tank level ≤1.2m, condensing water transportation pump trips. P
P
3) When open circulating water pump outlet head pipe pressure is lower than 0.20MPa, standby open circulating water pump starts by interlock. 4) When closed circulating water pump outlet head pipe pressure is lower than 0.35MPa, standby closed circulating water pump starts by interlock. 5) When closed circulating water tank level is lower than 700mm, closed circulating water pump trips. 6) When condenser vacuum is lower than 75KPa, standby vacuum pump starts by 69
interlock. 7) When condenser hot well water level is high to 710mm, it alarms. 8) When condenser hot well water level is low to 250mm, it alarms. 9) When condensing water pump motor winding temperature is high to 105℃, it alarms. 10) When boiler circulating water pump cooling water booster pump returning pipe pressure is lower than 0.45MPa, the pumps run together. 11) When boiler circulating water pump cooling returning pipe pressure is lower than 0.45MPa, emergency cooling water pump starts. 3.6.2
Unit test
3.6.2.1 Unit interlock protection test Equipments and systems interlock protection test should be simulated by I&C personnel after all the test conditions are satisfied (unsatisfied conditions should be forced by I&C personnel) to check whether actions and alarms are normal or not. 3.6.2.2 Motorized valve (damper) and pneumatic valve (damper) test Before test, make sure that motorized valves (damper) turning directions are right, pneumatic valve (damper) switches are right and light signal status indications are right. Record the time and act information of all the valves (dampers) and switches. 3.6.2.3 Main steam valve and governor valve test 1) Test regulations and notices a. DEH chooses „Automation‟ mode and CRT shows relevant screens. b. DEH must be under „Single valve‟ control mode and test should be done with 5%～ 69% rated load and 25%～100% rated main steam pressure. Tests out of the above range are strictly prohibited. c. Test should be done from left side to right side; tests can not be done on both left and right side at the same time. An other side test only can be done after one side valve test and five (5) minutes stable operation d. Parameters (such as load, main reheating steam pressure and temperature, bearing metal temperature, vibration and axial displacement) should be supervised during test. e. Contact with I&C personnel for cooperation at site, test should be stopped immediately if abnormal change occurs during test or control device is changed to be manual. Test can only be restarted after valves are recovered manually and reason for abnormity is found out. f. During test, make sure that whether valves act normally or not, there is block or not. Test time for each side should be recorded. g. When DEH manual, full stroke test is not allowed be done and only flexibility test can be done. h. It is regulated that this test should be done once a week and operation log should be recorded. Test period can be extended to once per two weeks if special condition occurs and it is approved by the managers. 2) Test method a. Make sure that DEH is at „Automatic‟ and „Single Valve‟ button light is on. b. Unit load and pressure complies with regulated range. c. Click “TV1” on DEH screen and then click “TEST” (take #1 HP main steam valve as an example) button, button changes color. The test starts. 70
d. The governor valves GV1/GV4 at the same side of selected main steam valve close by speed of 1.5%/s at first, after governor valves closed, TV1 close by speed of 1.5%/s, it should be confirmed from CRT and local that valves are closed and act freely. e. After TV1 fully closed, open it by speed of 1.5%/s, when TV1 fully opened, governor valves GV1/GV4 open by speed of 1%/s. It should be confirmed from CRT and local that valves are open. When GV opened again and reach to the position same as the position before test, test is over. f. During close or start, press „Intermit Test‟ button if any abnormity occurs and valves recover to status before test. g. Test other main steam valves according to above process. 3.6.2.4 Steam extraction check valve test 1) Turn test switch of steam extraction check valve to „Test‟ position. 2) Check and make sure that all check valves close freely with no block. 3) Turn test switch to normal position as soon as possible to confirm open of check valve. 4) During test, it should not be closed for too long a time. Pay attention to unit load and axial displacement variation. 5) Test all the steam extraction check valves one by one with the same process. 3.6.2.5 Low oil pressure interlock test for auxiliary lubricate oil pump, hydrogen sealing oil standby pump and DC lubricate oil pump 1) Check and make sure that all the switches of the above pumps are at „Interlock‟ position. Test personnel should be in contact with main control room and open test oil discharging valve slowly. 2) Watch test oil pressure meter indication and record the oil pressure when oil pump is interlocking; check and make sure that oil pump runs normally. 3) Stop the interlocked oil pump. 4) Turn the switches of test oil pump to „Automation‟. 3.6.2.6 Jacking oil pump and turning gear low oil pressure test 1) Turbine oil system and sealing oil system are running normally. 2) Jacking oil and turning gear system are running normally. 3) Contact with I&C personnel to prepare conditions of oil pressure low. 4) Record oil pressures when jacking oil and turning gear trip. 3.6.2.7 Turbine protection device test 1) Test regulations and notices a. According to periodic test regulations, test should be done once per month, rest records should be taken and analyzed and compared with former test record. b. Reason should be found out and it should be cleaned if any error is found. c. This test must be done before starting the turbine and after protection devices are calibrated and set in unit major maintenance and minor maintenance. Oil control over speed trip valve test should be done when turbine speed is 3000r/min. d. When turbine speed increases to 3000r/min, protection test should be qualified before synchronization and load increase. e. The production chief and engineers of the test must be at site and strictly execute operation and supervision mechanism, and special person will be responsible for operation and supervision. 71
f. It should be confirmed that unit runs normally and all test meters indications are right before test. 2) Emergency trip device test Low EH oil pressure test method: a. Choose „online test‟ on CRT of emergency trip system. b. Press button of „Side A low EH oil pressure test‟, lights in test channel of side A are on. c. Check and make sure that EH low pressure #1, #3 and trip channel #1 are bright. d. Press „Trip recover‟ button, trip channel #1 light gets off. e. Test EH oil low pressure at B side with the same method. Test the „Low lubricate oil pressure‟ and „Low vacuum‟ with above method; press corresponding test button only during test. 3) Oil control over speed trip valve test a. Put test handle at test position and keep the position. b. Open test valve slowly; when oil pressure reaches to a certain value, trip hammer extends and impact trip contactor and emergency trip oil drains. Read the oil pressure through meter pressure. c. Close test valve and confirm that test oil pressure changes to be zero. d. Recover handle manually and put test handle at normal position. 3.6.2.8 Vacuum tightness test 1) Confirm that standby vacuum pump can be started at any moment. 2) Record load, vacuum, steam exhausting temperature and atmosphere pressure before test. 3) Stop the running vacuum pump manually and watch the vacuum vibration. 4) Thirty seconds later, record the vacuum values of LP & HP condenser every minute. 5) Eight (8) minutes after stopping vacuum pump, recover the vacuum pump. 6) Take the vacuum decrease value within latter five (5) minutes and calculate the average value of vacuum decrease per minute. 7) Decrease of no more than 0.399KPa per minute of vacuum tightness is deemed as to be qualified. Vacuum tightness evaluation standard is as following: Excellent: 0.133KPa/min（1mmHg/min）; Fine: 0.27KPa/min（2mmHg/min）; Qualified: 0.4KPa/min（3mmHg/min）. 8) During test, vacuum of any condenser should be no less than 75KPa; if vacuum decreases, test should be stopped immediately and recover it to status before test. 3.6.2.9 Generator sealing oil system interlock test 1) Air side sealing oil standby pump automatically open test a. Check air side AC sealing oil pump operating normal, oil hydrogen differential pressure is normal, air side DC sealing oil pump switch put into “interlock”. b. Contact I &C personnel to short connect oil hydrogen differential pressure 0.035Mpa, check air side DC sealing oil pump should open automatically. c. Stop operating air side DC sealing oil pump. d. Check oil hydrogen differential pressure is 0.084MPa, immediately close differential 72
pressure switch oil pressure isolation valve, slowly open drain oil valve, when pressure meter reduce to0.035MPa,air side DC sealing oil pump should open automatically. e. Close drain oil valve after confirming it‟s normal, open differential pressure switch isolation valve, stop air side DC sealing oil pump until differential pressure recover normal. 2) Sealing oil standby differential pressure valve operating test a. Check air side AC sealing oil pump operating normally, oil hydrogen differential pressure is 0.084MPa, standby oil pressure is normal, record air side oil pressure. b. Slowly close air side oil pump outlet valve, when oil hydrogen reduce to 0.056MPa, standby differential pressure valve should open automatically. c. Continue to close air side oil pump outlet valve, oil hydrogen differential pressure should keep at the level of 0.056MPa and not reduce. if oil hydrogen differential pressure continuously reduce, contact to maintenance personnel to regulate again. Confirm standby differential pressure valve can maintain oil hydrogen differential pressure is 0.056MPa,slowly open air side oil pump outlet valve, recover system. 3.6.2.10
EH oil pump interlock test 1) Check and make sure that EH oil system runs normally and standby oil pump switch is at „Standby‟ position. 2) Press „EH oil pump test magnet‟ on CRT and then press „Open‟ button, make sure that magnet valve is open. 3) Watch EH oil pressure drop. When EH oil pressure drops to 11.0～11.4MPa, start standby oil pump, record self-start oil pressure and confirm that oil pump runs normally and EH oil pressure recovers. 4) Press „EH oil pump test magnet‟ on CRT and then press „Close‟ button, make sure that magnet valve is closed. 5) Stop the former running EH oil pump and test the other standby EH oil pump.
3.6.2.11
Turbine over speed test 1) Test regulations and notices a. Over speed test must be done after unit major maintenance or half-year or one year continuous running and individual maintenance of emergency protector. b. Over speed test during cold start of the unit only can be done after seven (7) hours of unit runs with 20% rated load and reheating steam temperature above 400℃. c. This test must be agreed by shift manager and should be charged by chief engineer. Test must be done under supervision of assigned person, and turbine engineer must direct at site. d. This test can only be done after HP & IP main steam valve, governor steam valve tightness test, oil filling test and manual trip test. e. During test, special person should be in charged of the manual trip handle and he can open it timely avoid trip equipment does not work when running speed reach to 3300r/min. f. Twice (2) mechanical over speed trip test should be done when unit is with empty load, the running speed difference of the two over speed test should be no higher than 18r/min. Unit running speed, vibration, axial displacement and LP steam exhausting temperature should be strictly supervised during test. g. Sufficient test personnel, instrumental meters and tools should be prepared before test. 73
2) OPC over speed test a. After 3000RPM stable speed, open(over speed test)screen. b. Click “OPC test” button, open RCM operation panel; choose “YES. Click “OK”. c. “OPC test” button change to blue, mean that OPC over speed test have been put into. d. Automatically set objective running speed is 3100RPM and rising speed rate is 200RPM/min. e. Click “continue/hold”, set continue, start test. f. When running speed is more than 3090 RPM, OPC solenoid valve close, test stop. 3) Electric over speed test a. After 3000RPM stable speed, open(over speed test)screen. b. Click “electric over speed test” button, open RCM operation panel; click “OK”. c. “electric over speed test” button change to blue, mean that electric over speed test have been put into. d. Automatically set objective running speed is 3100 RPM ,click “rising speed rate” button, rising speed rate is 200RPM/min. e. Click “continue/hold”, set continue, start test. f. When running speed is more than 3300 RPM, AST solenoid valve operate, turbine trip, test stop. 4) Mechanical over speed test a. After 3000RPM stable speed, open(over speed test)screen. b. Click “mechanical over speed test” button, open RCM operation panel; click “OK”. c. “mechanical over speed test” button change to blue, mean that mechanical over speed test have been put into. d. Automatically set objective running speed is 3360RPM ,click “Acc Rate” button, rising speed rate is 200RPM/min. e. Click “continue/hold”, set continue, start test. f. Turbine running speed rising to mechanical centrifugal stop bolt, security system operate, turbine trip, test stop. 3.6.2.12 BFPT MEH captive test and trip test 1) Test regulation and notes a. This test must be done before BFPT cold starting or regulating system maintenance, test have to be done before boiler burning. b. One main oil pump operating normally, fire-resistant fluid system operating normal. c. Contact I&C personnel to match, BFPT latch normal. d. Check that quick closing valve open, open speed regulation valve and pipe regulating valve, confirm each valves switch flexible on local. e. On MEH screen, push “tripper” button, check BFPT quick closing valve, speed regulating valve and pipe regulating should close quickly, tripper light. f. Test finish, recover former operating mode. 2) BFPT trip protection test Other trip protection test should operate according to I&C requirement.
74
3.6.2.13 BFPT LP main steam valve operating test (1/4 route test) 1) Test regulation and notes a. When test, should confirm whether LP main steam valve have fasten phenomenon on local. b. During test, should supervise BFPT‟s speed, vibration, axial displacement and so on parameters. 2) Test methods a. Come into “BFPT control” screen from MEH. b. Confirm “running speed automatically” light, “boiler remote control” light. c. Confirm quick closing oil pressure is normal, quick closing valve completely open. d. Push the button “LP main stop valve test” to close the main stop valve for 1/4 travel. e. When the LP main stop valve closed to required travel, the test button light will be on. f. During LP main stop valve test, confirm no clip phenomenon on local. g. After the test, the main stop valve will open automatically. The indication light of button will be off. 3.6.2.14 BFPT over speed protection test BFPT should be disconnected from feed water pump coupler before test, and test the BFPT separately. BFPT manual trip test should be done before the test. Check and make sure that main steam valve and governor valve close rapidly; otherwise over speed test is prohibited. 1) Electric over speed test a. Increase running speed of feed water pump turbine to normal working running speed according to normal speed rise process. Press „over speed test‟, press „electrical‟, make it bright. b. Press „increase speed‟. Set target running speed is 6100r/min. c. When feed water pump turbine speed increases to 6050r/min, electric over speed protection acts and the feed water pump turbine trips. d. HP main steam valve, LP main steam valve and LP governor valve close automatically; running speed should decrease. e. After test, „electrical‟ test button extinguished. 2) Mechanical over speed test a. Increases the running speed of feed water pump turbine to normal running speed according to normal speed rise process. Press „over speed test‟, press „mechanical‟, make it bright. b. During mechanical over speed test, electrical trip does not work, and relative indicate lamp bright in operator station. c. Press „increase speed‟, keep rising running speed to the value of emergency protector tuning value. d. When running speed increase to 6160r/min, mechanical over speed protection operate, BFPT trip. e. After mechanical test, „mechanical‟ over speed lamp extinguished. 3.6.2.15 BFPT emergency protector filling oil test 1) Raise the running speed of BFPT to 3500-3550r/min according to normal start 75
process. 2) Keep the rated steam parameter of 0.72MPa/346℃, check and make sure that parameters of bearing vibration, oil temperature, oil pressure and vacuum are normal. 3) Press „Spraying oil test‟ button on MEH screen of BFPT, „Spraying oil test‟ dialog box springs out; press „In‟ button. 4) Excitation of isolation solenoid valve closes and excitation of oil spraying solenoid valve opens. When „Latch‟ becomes grey, signal of „Oil pressure for latch not formed‟ and „Primary oil pressure low‟ appear, oil spraying test „Successful‟ light on CRT shines. 5) After spraying oil test succeeds, latch locally. When „Latch‟ signal appears, „Oil pressure for latch not formed‟ and „Primary oil pressure low‟ disappears at the same time. 6) Press „Cut off‟ button. Test is completed. 7) I&C personnel should be contacted for treatment If isolation solenoid valve or oil spraying solenoid valve do not actuate normally, oil spraying test is not successful or feed water pump turbine trips.
4 Unit trouble shooting 4.1 Principles of trouble shooting 4.1.1
When accident occurs, duty operator should guide all the unit personnel to treat the accident rapidly according to regulations in manual book under the direct guidance of the shift manager. Shift manager‟s instructions (except for that direct endanger personal or equipment safety) should be executed immediately, otherwise reason should be declared. If the shift manager insists on his instruction, it should be reported to superior manager.
4.1.2
When accident occurs, operators should find out the main reason of accident rapidly, eliminate the threats to personal and equipment safety and try their best to ensure safe operation of non-fault equipments. The influence of all operations to relevant systems should be fully considered during accident treatment to avoid accident expansion. Auxiliary power should be ensured not to be lost during emergency stop.
4.1.3
When accident occurs, operators should treat the accident according the following processes:
4.1.3.1 According to parameters change, CRT display, equipment interlock, screen alarm, fault print and exterior phenomenon of the unit, it is confirmed that fault occurs in the unit, thus: 1) Rapidly eliminate the threats to personal and equipment safety, disconnect the equipments in fault immediately if it necessary. 2) Rapidly find out the character, location and range of the accident and then treat and report. 3) To keep the non-faults equipment running. 4) During every step of accident treatment, it should be reported to the shift manager for reporting to superior manager to take right measures to avoid accident expanding. 4.1.3.2 When it is confirmed that fault happens in other equipment of the system, measures should be taken to keep the unit running, which will benefit for recovering whole unit start normal operation as soon as possible. 4.1.3.3 During accident treatment, all positions should inform each other and cooperate with each other, treat the accident rapidly according to regulations of manual book to avoid accident expanding. 4.1.3.4 Accident treatment should be rapid and right. Repeat the instruction after receiving it and report the execution result rapidly. 4.1.4
When accident or fault out of this manual occur, duty operators should make right 76
judgment according to their own experience, take measures positively and treat it rapidly. If time is allowed, ask for instruction from the shift manager and treat it under the guidance of the shift manager. 4.1.5
During accident treatment, when conditions of emergency stop of boiler and turbine are satisfied but the protectors have not actuated, MFT or latch open should be done manually immediately. When conditions of emergency stop of auxiliary equipment are satisfied but the protectors have not actuated, the auxiliary equipment should be stopped immediately.
4.1.6
If the unit trips suddenly, after accident treatment and reason found out, unit should be recovered to run as soon as possible.
4.1.7
During fault and accident treatment, operators should not make bold to leave away from his position. If the accident treatment happens during shifts changing time, shift changing should be delayed. Before issuing handing over procedures, the operators should be continue to work until to accident treatment completion or part completion. The successive operators should assist initiatively to treat the accident.
4.1.8
During accident treatment, unrelated personnel are prohibited to gather in main control room or stay in fault location.
4.1.9
After accident treatment, the duty operators should be immediately report the accident and treatment information according to the facts and, record in details about the accident time, phenomenon, development, treatment course and analysis. All the personnel in the shift should be organized on meeting after shift to analyze the accident and prepare accident report.
4.2 Conditions and treatment of emergency stop and treatment 4.2.1
Any of the following conditions occurs, stop the unit in emergency by vacuum:
4.2.1.1 Unit running speed rises to 3300rpm and emergency governor vibrating. 4.2.1.2 Unit vibrates suddenly and acutely or turbine impeller blades break and are with obvious metal friction sound and clash (any bearings of T-G vibration reach to 0.25mm). 4.2.1.3 There is water impact in turbine, main steam and reheat steam temperature decreased 50% suddenly, or HP and LP cylinder temperature difference between up and down more than 56℃. 4.2.1.4 Any bearing of turbine-generator is in shortage of oil or in smoke, or temperature of thrust bearing and bearing returning oil more than limit value. 4.2.1.5 Turbine oil system, generator sealing oil system is on fire that can not be extinguished and threats personal and equipment safety. 4.2.1.6 Oil-hydrogen differential pressure of sealing oil system loses or there is hydrogen leakage at sealing pad of the generator. 4.2.1.7 Oil system leaks oil seriously, main oil tank level decreases to extreme low value and it alarms and it can not be remedied. 4.2.1.8 Turbine axial displacement reaches to trip value. 4.2.1.9 Any differential expansion of HP, IP or LP cylinder exceeds limit value. 4.2.1.10
Lubricate oil pressure drops to 0.049 MPa (trip value), start AC and DC lube oil pump still can‟t recover.
4.2.1.11
Generator is in smoke or on fire or hydrogen explodes.
4.2.1.12
Turbine gland sealing abrades abnormally with spark.
4.2.2
Any of the following conditions occurs, it should be reported to the shift manager immediately and approved to stop the unit without breaking the vacuum:
4.2.2.1 Unit runs for more than 15min when main steam temperature, reheating temperature rise to 552～566℃ or the steam temperatures exceed 566℃. 77
4.2.2.2 Pressure before HP main steam valve of turbine exceeds 21.71MPa. 4.2.2.3 Condenser vacuum drops and can not recover. 4.2.2.4 Generator stator cooling water flow is lower than 45T/H and can not be recovered and, the protector does not actuate. 4.2.2.5 When DEH, TSI, DCS, O/I system fault caused some important parameters can‟t be controlled, can‟t keep unit operation normally. 4.2.2.6 DEH works abnormally and turbine running speed and load can not be controlled. 4.2.2.7 Fault of EH oil pump or EH oil system threats unit safety. 4.2.2.8 LP cylinder exhausting steam temperature is high to 120℃. 4.2.2.9 Sealing oil system of the generator is in fault and can not maintain necessary oil pressure and oil level. 4.2.2.10
Main, reheating steam pipes, HP feed water pipes or pressure bearing parts break, and unit can not keep running.
4.2.2.11
All auxiliary power loses.
4.2.2.12
When operation station in DSC system is in fault (CRT „blank screen‟ or „Crush‟) and there is no reliable supervision measure.
4.2.2.13
During full load operation, temperature differences between main steam and reheat steam more than 42℃, or during 0 load operation, temperature differences between main steam and reheat steam more than 83℃(only when reheat steam temperature lower than main steam temperature.)
4.2.2.14
Unit runs for more than 1min with no steam.
4.2.2.15
Control steam source pressure is low or disappeared which can not maintain the original operation mode.
4.2.2.16
Refer to turbine and boiler protection controller is in fault and can not be recovered.
4.2.2.17
Any protector should actuate but not actuate (except for stop due to vacuum break).
4.2.3
Operation process for stopping the unit by breaking vacuum:
4.2.3.1 Press „Emergency stop‟ button in main control room or open turbine trip handle manually at local. 4.2.3.2 Check load decrease to 0, turbine running speed is dropping. Check and make sure that HP & IP main steam valve, governor valve, HP steam exhausting check valve and all check valves of all stages steam extraction are closed, HP cylinder extraction valve open. make sure that generator is disconnected, G-T outlet switch and exciter switch trip, auxiliary power has been transferred successfully. Make sure boiler MFT operated, all coal mill, coal feeder, primary fan, sealing fan trip, all burning gun oil feeding valve and closing valve closed. 4.2.3.3 Check AC lubricate oil pump, hydrogen sealing oil standby pump start automatically, or start them manually at once. check and make sure that lubricate oil pressure and temperature are normal. 4.2.3.4 Check jacking oil pump start automatically when turbine running speed drops to 2800r/min, or start it manually at once. 4.2.3.5 Release vacuum interlock, open air exhaust equipment break valve, stop vacuum pump. 4.2.3.6 Check HP, LP bypass operate or not, if it opened should close manually at once. 4.2.3.7 Check turbine proper drainage valve open automatically, close drainage valve of main steam and reheat steam and extracting pipe, prohibit to drain hot water and exhaust steam to air exhaust equipments. 4.2.3.8 Check motorized pump operation normally, adjust drum, deaerator, air exhaust 78
equipments to keep water level at normal range, make sure that reheater, superheater attemperating water control governor valve and isolating valve closed. 4.2.3.9 Check switch auxiliary steam to neighbor unit or start boiler feeding HP,IP auxiliary steam connecter pressure and temperature is normal. 4.2.3.10
Check switch turbine gland sealing to auxiliary steam main pipe pressure and temperature is normal. When vacuum decrease to 0, stop gland sealing steam feeding system.
4.2.3.11
Check LP cylinder water sprinkler open automatically and adjust LP cylinder exhausted steam temperature is at normal range.
4.2.3.12
During running speed decreasing, check carefully, notice sound in unit, check vibration, differential expansion, shaft displacement, bearing metal temperature, lube oil temperature, pressure difference between oil and hydrogen and so on of the unit. If there‟s clashing inside the unit or rotor coasting time decrease obviously, prohibit to start unit again.
4.2.3.13
Waiting for running speed decrease to 0, put turning gearing into operation, record rotor coasting time and turning gear current & rotor eccentricity.
4.2.3.14
Stop turbine and boiler by normal operation.
4.2.4
Operation process for stopping the unit without breaking vacuum:
4.2.4.1 Press „Emergency stop‟ button in main control room or open turbine trip handle manually at local. 4.2.4.2 Check load decrease to 0, turbine running speed is dropping. Check and make sure that HP & IP main steam valve, governor valve, HP steam exhausting check valve and all check valves of all stages steam extraction are closed, HP cylinder extraction valve open. make sure that generator is disconnected, G-T outlet switch and exciter switch trip, auxiliary power has been transferred successfully. Make sure boiler MFT operated, all coal mill, coal feeder, primary fan, sealing fan trip, all burning gun oil feeding valve and closing valve closed. 4.2.4.3 Check AC lubricate oil pump, hydrogen sealing oil standby pump start automatically, or start them manually at once. check and make sure that lubricate oil pressure and temperature are normal. 4.2.4.4 Check jacking oil pump start automatically when turbine running speed drops to 2800r/min, or start it manually at once. 4.2.4.5 Check and make sure that all the drainage valves of turbine proper, reheating steam pipes, steam extraction pipes open automatically. 4.2.4.6 If HP, LP bypass open automatically, check HP, LP bypass attemprating water operation normally, air exhaust equipment vacuum should be normal. 4.2.4.7 Check motorized pump operation normally, adjust drum, deaerator, air exhaust equipments to keep water level at normal range, make sure that reheater, superheater attemperating water control governor valve and isolating valve closed. 4.2.4.8 Check switch auxiliary steam to neighbor unit or start boiler feeding HP,IP auxiliary steam connecter pressure and temperature is normal. 4.2.4.9 Check switch turbine gland sealing to auxiliary steam main pipe pressure and temperature is normal. 4.2.4.10
Check LP cylinder water sprinkler open automatically and adjust LP cylinder exhausted steam temperature is at normal range.
4.2.4.11
During running speed decreasing, check carefully, notice sound in unit, check vibration, differential expansion, shaft displacement, bearing metal temperature, lube oil temperature, pressure difference between oil and hydrogen and so on of the unit. If there‟s clashing inside the unit or rotor coasting time decrease obviously, prohibit to 79
start unit again. 4.2.4.12
Open vacuum break valve when turbine running speed drops to 400r/min.
4.2.4.13
Waiting for running speed decrease to 0, put turning gearing into operation, record rotor coasting time and turning gear current & rotor eccentricity.
4.2.4.14
Complete other operations for stopping the unit.
4.3 Steam parameters are abnormal 4.3.1
Phenomenon
4.3.1.1 All main, reheating steam pressures and temperatures are over high or over low. 4.3.1.2 Parameters exceed limitation and alarm. 4.3.1.3 Unit load changes. 4.3.1.4 Turbine axial displacement, differential expansion change. 4.3.2
Reason
4.3.2.1 Pressure or temperature control system is in failure or attemperating water is improperly regulated. 4.3.2.2 Unit rejects load suddenly. 4.3.2.3 HP heaters step out system suddenly. 4.3.2.4 Steam system safety valves open suddenly. 4.3.2.5 Coal quality changes suddenly or system runs abnormally. 4.3.3
Treatment
4.3.3.1 Control system is in fault, treat it according to faults, regulate pressure and temperature to be normal manually if it is necessary and regulate it through regulating combustion and load. 4.3.3.2 If it happens due to too fast or too slow load variation, load variation should be regulated. If load changes due to working conditions such as protector action, it should be treated according to relevant regulations. 4.3.3.3 If HP protector steps out of system, unit load should be regulated in time. 4.3.3.4 If pulverizing system runs abnormally and coal powder is not well-proportioned that makes boiler hot load unstable, pulverizing system should be regulated and stop the unit if it is necessary. 4.3.3.5 When main, reheating steam temperature is abnormal, treat it according to following regulations: 1) When main, reheating steam temperature changes within range of 5388℃, unit is allowed to run continuously in a long time. 2) When steam temperature rises to 552℃, annual accumulated time should not exceed 400 hours. If accumulated time exceeds 400h, unit should be stopped as fault stop when temperature exceeds 545～551℃. 3) Main, reheating steam temperature is allowed to increase from rated temperature to 566℃ at most within 15min. Unit runs within temperature of 552～566℃ with annual accumulated time of no more than 80 hours; if the time exceeds 80 hours, unit should be stopped immediately as fault stop. If steam temperature exceeds 566℃, unit should be stopped as fault stop immediately. 4) If main steam temperature and reheating steam temperature is abnormal, measures should be taken rapidly to recover steam temperature to be normal. During treatment, if main steam and reheating steam temperature continues to decrease to be 83℃ lower than rated value or steam temperature decrease rapidly more than 50℃, unit should be 80
stopped immediately as fault stop. 5) When steam pressure or temperature changes abnormally, watch turbine differential expansion, axial displacement, bearing vibration, pressure and all control indexes; if they exceed limitation, unit should be stopped as fault stop.
4.4 Unit load vibration 4.4.1
Reason
4.4.1.1 System is impacted, vibrates or boiler runs abnormally. 4.4.1.2 Generator is in asynchronous. 4.4.1.3 Turbine control system is abnormal or speed regulating steam valve acts abnormally. 4.4.1.4 HP, LP bypass act wrongly or returning extraction steam stops suddenly. 4.4.2
Treatment
4.4.2.1 Release CCS coordination control and find out the reason according to CRT display and relevant meters indications. 4.4.2.2 If the system vibrates, relevant operations should be executed according to shift manager‟s instructions. 4.4.2.3 If generator is asynchronous, generator active power should be decreased and increase excitation manually. 4.4.2.4 If unit load changes suddenly due to grid frequency, unit output should be controlled strictly, no over output is allowed. 4.4.2.5 If it happens due to abnormal control system, it should be changed to be manual control; unit should be stopped if it can not be treated during running. 4.4.2.6 If load changes suddenly due to boiler abnormal operation, steam inlet amount to turbine should be regulated to stabilize steam parameters. 4.4.2.7 When speed regulating steam valve drops, load should be done according to steam inlet amount; load should not be increased or decreased by force when the valve is blocked. 4.4.2.8 Check whether thrust bearing, bearing oil exhausting temperature, axial displacement, differential expansion and vibration are normal or not. 4.4.2.9 Check whether water level of deaerator, condenser, heaters and gland sealing heater are normal or not.
4.5 Unit load rejection 4.5.1
Phenomenon
4.5.1.1 Unit load drops suddenly, local sound changes suddenly and axial displacement changes. 4.5.1.2 Steam pressure rises, boiler safety valve (or PVC valve) may acts. 4.5.1.3 Extraction steam pressures at all sections drop. 4.5.1.4 When „RUN BACK‟ occurs, relevant interlocks at boiler at actuate. 4.5.2
Reason
4.5.2.1 Electric power system is in fault, power sending line trips. 4.5.2.2 Unit protector acts. 4.5.2.3 Speed regulating system is in fault, governor valve wrongly close or important auxiliary equipment trips. 4.5.3
Treatment
4.5.3.1 Supervise the changing of main, reheating steam parameters, try best to maintain normal parameters of the boiler. 81
4.5.3.2 Check the unit completely, find out the reason and treat it. If there is no obvious fault, report to the shift manager immediately and prepare to increase the load. 4.5.3.3 If speed regulation system is in fault that can not be treated during running, unit should be stopped for treatment. 4.5.3.4 Check steam driven pump and feed water automatic regulation; if feed water automatic regulation can not satisfy boiler requirement, release the automation of main feed water and BFPT. Pay attention to minimum flow valve action of feed water pump. 4.5.3.5 Pay attention to auxiliary power, condenser vacuum and LP cylinder steam exhausting temperature. Supervise and regulate water levels of condenser, deaeratoor and heaters. Maintain the auxiliary steam head pipe pressure to be normal. 4.5.3.6 Pay attention to deaerator pressure and gland sealing steam supplying. 4.5.3.7 If the unit protector acts wrongly, it should be reported to the shift manager immediately and execute the instructions from the shift manager rapidly.
4.6 Condenser vacuum drop 4.6.1
Phenomenon
4.6.1.1 CRT and local condenser vacuum indications drop. 4.6.1.2 Exhausting steam temperature rises and condensing water temperature rises. 4.6.1.3 Unit steam flow increases and regulation stage pressure increases under the same load. 4.6.1.4 Vacuum decreases to 75KPa or exhausting temperature rises to 80℃; alarm sends. 4.6.2
Reason
4.6.2.1 Circulating water pump works abnormally or trips, butterfly valve openness at circulating pump outlet decrease or fully closed, condenser circulating inlet or outlet valve is wrongly closed, which makes the circulating water decrease or intermit. 4.6.2.2 Condenser stainless pipes are dirty. 4.6.2.3 Vacuum pump works abnormally or trips; vacuum pump cooling device is in fault or heat exchanger is dirty. 4.6.2.4 Vacuum breaking valve open wrongly or not strictly closed; there is leakage or damage at pipes in vacuum system or other equipment system; water sealing in valves of vacuum system is unavailable. 4.6.2.5 Gland sealing supplying steam pressure drops obviously and gland sealing heater water level and negative pressure are abnormal. 4.6.2.6 Condenser hot well water level is too high. 4.6.2.7 BFPT vacuum system leaks. 4.6.2.8 Turbine LP cylinder explosion proof valve breaks. 4.6.2.9 Heat load of condenser is too high. 4.6.3
Treatment
4.6.3.1 If condenser vacuum is found dropping, all vacuum meters indications should be checked rapidly, clarify the vacuum drop according to exhausting steam temperature increase. 4.6.3.2 Circulating water system should be checked as following: 1) Whether circulating water pressure is normal or not; if pressure is low, check whether there is any leakage or block in circulating water system. 2) Check whether suction water well level is normal or not; if water level is low, inlet strainer of circulating water pump should be leaned timely. Check whether cooling water tower level is normal or not, otherwise supplement water timely. 3) Check whether circulating water temperature rises or not. 82
4) If condenser inlet water pressure outlet water temperature increase which shows pipe system is dirty, the condenser should be cleaned. 5) Check whether circulating water pump runs normally or not, otherwise start the standby pump. 4.6.3.3 Check the vacuum system and prepare the isolations as following: 1) Vacuum pump, vacuum pump cooling device work normally or not. 2) Vacuum system has leaking points or not. 3) Check whether there is damage in pipeline of vacuum system or LP heater continuous air discharging pipes or not. 4) Check whether vacuum breaking valve is strictly closed or not, sealing water is normal or not. 5) Gland sealing supplying steam pressure is normal or not; check whether gland sealing steam inlet valve, overflow valve are normal or not; gland sealing heater U type water sealing is normal or not; if gland sealing heater air fan is in fault or negative pressure of gland heater is low, standby air fan can be started. 6) Check whether BFPT steam exhausting system is normal or not; start motorized pump, stop BFPT and close steam exhausting butterfly valve if it is necessary. 4.6.3.4 Check and make sure that condensing water pump sealing water is normal or not, gland packing leaks air or not; whether condenser water level is over high. If condensing water rigidity and conductivity rise which show stainless steel pipes leak, stop the unit or find out the leakage according to actual conditions. 4.6.3.5 Condenser vacuum drops to 75KPa, standby vacuum pump starts automatically, otherwise put it into operation manually. If vacuum continues to drop, load should be decreased. If vacuum drops to 69.3KPa, trip protector should actuate, otherwise stop the unit manually. 4.6.3.6 During vacuum decrease, watch out for LP cylinder steam exhausting temperature. When steam exhausting temperature rises to 70℃, LP cylinder spraying water valve should be opened and fully open the spraying water when the temperature rises to 80℃; if the temperature rises to 120℃, unit should be stopped as fault stop. 4.6.3.7 When vacuum drops to 47.46KPa, BFPT trips, otherwise stop the unit manually.
4.7 Unit high vibration 4.7.1
Phenomenon
4.7.1.1 TSI bearing vibration indications are high and they are high measured locally. 4.7.1.2 Vibration of location unit increasing obviously and unit sound is abnormal. 4.7.1.3 All bearing metal temperature and returning oil temperature will rise. 4.7.1.4 Unit “bearing vibration ” alarm. 4.7.2
Reason
4.7.2.1 Lubricate oil pressure and temperature are abnormal or oil film vibrates. 4.7.2.2 Unit has not been sufficiently heated, cylinder expansion is not smooth or drainage water is not good; temperature difference between HP & IP cylinder is high. 4.7.2.3 Bearing bends. 4.7.2.4 Operation parameters and working conditions changes acutely which makes axial thrust change abnormally. 4.7.2.5 Impeller blades break or mechanical parts inside turbine damages or drops. 4.7.2.6 Turbine bearing damages. 4.7.2.7 Cold steam or water enters into turbine or there is water impact inside the turbine. 83
4.7.2.8 Vacuum drops which causes turbine central line deviate or end stage blade vibrate. 4.7.2.9 During start and stop, unit running speed should be within critical running speed area. 4.7.2.10 4.7.3
Unit vibrates due to generator, such as unbalanced magnetic field.
Treatment
4.7.3.1 When unit vibrates abnormally to protector actuate value, turbine should trip, otherwise stop the unit manually in emergency. 4.7.3.2 Check and make sure that whether lubricate oil pressure and temperature are normal or not, whether bearing metal temperature and returning oil temperature are normal or not; otherwise they should be regulated. 4.7.3.3 During turbine running speed rising, it is prohibit to keep running speed or warm up at critical running speed. 4.7.3.4 If vibration caused by bearing oil film vibrating, it is hard to solve during operation, it should be started after oil film vibration solved. 4.7.3.5 If the unit vibrates due to water impact, cold steam, water source should be isolated and drainage water for turbine proper should be enhanced. 4.7.3.6 If unit vibrates due to generator, load should be decreased for watch and treatment.
4.8 Turbine water impact 4.8.1
Phenomenon
4.8.1.1 Main, reheating steam temperature drop acutely and alarm, reheat ratio decreased. 4.8.1.2 Turbine up and down cylinder temperature difference gets bigger and alarm. 4.8.1.3 There is water clash in turbine or steam pipes, unit or steam pipes vibrate more acutely. 4.8.1.4 Load fluctuation decreases, differential expansion decreases, axial displacement increases and thrust bearing temperature rises. There is steam leakage or water drop spraying at steam pipe flange, valve stem, cylinder combination surface and gland sealing. 4.8.1.5 Turning gear current increases when it is running. 4.8.2
Reason
4.8.2.1 Drum is full of water or steam flow increases suddenly which makes boiling og water and steam. 4.8.2.2 Boiler combustion regulation is improper or out of control. 4.8.2.3 Boiler main, reheating steam attemperating water is improperly regulated or in failure. 4.8.2.4 During start, drainage water in pipes is not smooth. 4.8.2.5 Heaters or deaerator is full of water, which enters into turbine. 4.8.2.6 Drainage water in gland sealing system is not smooth, accumulated water or drainage water enters into cylinder. 4.8.2.7 Main steam or reheating steam temperature indications are abnormal. 4.8.2.8 During unit start and stop, HP bypass attemprating water fault, feed water through reheat cooling section pipe. 4.8.3
Treatment
4.8.3.1 When main steam or reheating steam temperature is found dropping abnormally, relevant meters should be checked immediately to confirm the real drop. 4.8.3.2 If it is confirmed that there is water impact in unit, unit should be stopped in emergency by breaking vacuum. 4.8.3.3 During operation, if main steam or reheating steam temperature drops suddenly and exceeds regulated value, unit should be stopped in emergency by breaking vacuum. 84
4.8.3.4 When main steam or reheating steam temperature drops abnormally, temperatures and temperature difference between up and down cylinder should be intensively supervised. Temperature difference between up and down of HP, IP cylinder more than 56℃. 4.8.3.5 Check and make sure that all the drainage valves in turbine proper and relevant steam pipes for sufficient water drainage. 4.8.3.6 Find out and eliminate the reason of water impact and isolate the equipments in fault. 4.8.3.7 Rightly record and analyze the inertia time, put turning gear into operation in time, measure bearing bend and listen to the sound inside turbine. If inertia time, thrust bearing temperature, axial displacement, differential expansion and temperature difference between up and down cylinders are normal; there is no friction or abnormal sound between stator and rotor; eliminate the water impact reason and drain water in proper, main & reheating steam pipes and steam extraction pipes completely. Contact with the shift manager to restart the unit. 4.8.3.8 If there is water impact, axial displacement or thrust bearing temperature exceed limit, inertia time is obviously shortened or there is abnormal sound or friction between stator and rotor, cylinder should be opened for check. 4.8.3.9 If it is found that there is water in turning gear, it should keep running until the temperature difference between up and down cylinders. At the same time, supervision should be enhanced for sound inside turbine, rotor eccentricity and turning gear current.
4.9 Turbine blades break 4.9.1
Phenomenon
4.9.1.1 There is metal clash inside cylinder or there is friction sound when turning gear is running. 4.9.1.2 Unit vibrates acutely. 4.9.1.3 Axial displacement, differential expansion change abnormally; thrust pad temperature and returning oil temperature rises. 4.9.1.4 Pressures at supervision sections rise. 4.9.1.5 If LP cylinder blade breaks, broken blades enter into condenser and break stainless steel pipes, which may rise conductivity and rigidity of condensing water and makes water level in hot well extremely high. 4.9.2
Treatment
4.9.2.1 If it is confirmed that blades are broken and unit vibrates acutely, break vacuum and the unit should be stopped immediately. 4.9.2.2 If regulation stage or extraction pressure is found to be abnormal, it should be analyzed immediately and vibration, axial displacement and metal temperature changing should be taken as references. If it is confirmed that blades are broken, unit should be stopped immediately for treatment. 4.9.2.3 Condenser water level rises, water should be discharged from #5 LP heater outlet valve to keep a normal water level or discharge water to condensing water storage tank. 4.9.3
Prevention
4.9.3.1 Keep the unit run within permit range of frequency. 4.9.3.2 Keep the unit steam parameter normal. 4.9.3.3 Keep heaters and deaerator run normally and relevant drainage water smooth. 4.9.3.4 To keep unit output normal. Over limit running is prohibited. 4.9.3.5 Turbine over speed is strictly prohibited. 4.9.3.6 Supervise the water quality to avoid blade corrosion.
4.10
Turbine abnormal axial displacement 85
4.10.1 Phenomenon 4.10.1.1
CRT and recorder show that axial displacement exceeds limit.
4.10.1.2
“turbine shaft displacement big” alarm.
4.10.1.3
Thrust bearing and its returning oil temperature are abnormally high. Unit vibration may be high.
4.10.1.4
Turbine trips when it reaches to protector actuation value.
4.10.2 Reason 4.10.2.1
Unit is in overload or unit load, steam flow changes suddenly.
4.10.2.2
Under the same load, steam parameters are on the low side, or working condition of steam extraction changes suddenly.
4.10.2.3
There is water impact in turbine.
4.10.2.4
Thrust pad abrades.
4.10.2.5
Blades are seriously dirty.
4.10.2.6
Blades break.
4.10.2.7
Condenser vacuum is low.
4.10.2.8
Axial vibration is abnormal.
4.10.2.9
Generator rotor is in axial moving.
4.10.2.10
Frequency decreases.
4.10.2.11
Re-heater safety valve actuates.
4.10.3 Treatment 4.10.3.1
If axial displacement is abnormal during operation, immediately check and make sure that whether thrust pad temperature rises or not, whether there is abnormal sound inside turbine or not, whether lubricate oil pressure and temperature are normal or not, unit vibration is normal or not, steam parameters and condenser vacuum are normal or not.
4.10.3.2
If it is due to above parameters‟ abnormity, the parameters should be regulated to be normal.
4.10.3.3
Report to the shift manager and decrease unit load properly to recover axial displacement, returning oil temperature and thrust bearing temperature.
4.10.3.4
If it is caused by load or steam parameter changing, it should keep load stably, adjust steam parameter to normal value.
4.10.3.5
If it is due to blade break or water impact inside turbine, unit should be stopped immediately.
4.10.3.6
If shaft displacement increasing, and accompany with abnormal sound or big vibration of unit, break vacuum and stop unit at once.
4.10.3.7
When axial displacement rises to up limit value but protector does not actuate, unit should be stopped in emergency.
4.11
Turbine lubricate oil system fault
4.11.1 Familiar faults 4.11.1.1
Lubricate oil pressure drops.
4.11.1.2
Lubricate oil temperature rises abnormally.
4.11.1.3
Main oil tank level drops.
4.11.1.4
Lubricate oil quality is unqualified. 86
4.11.1.5
Oil pipes leak.
4.11.2 Lubricate oil pressure drops 4.11.2.1
Phenomenon 1) All local meters and CRT display lubricate oil pressure drops. 2) All bearing temperatures and returning oil temperature may rise or alarm. 3) Lubricate oil pressure is low to 0.083MPa, it alarms and #1 AC lubricate oil pump starts automatically. 4) Lubricate oil pressure is low to 0.076MPa, it alarms and #2 AC lubricate oil pump starts automatically.
4.11.2.2
Reason and treatment 1) Main oil pump or oil injector works abnormally, AC lubricate oil should be started; unit should be stopped as fault stop if main oil pump works extremely abnormally. 2) Lubricate oil pipes leak, leaks should be cleaned and contact with maintenance for treatment, watch main oil tank level and add oil if it is necessary.
4.11.2.3
Lubricate oil pressure drops to 0.06MPa, DC emergency oil pump starts automatically。 If lubricate oil pressure continues to drop to 0.049MPa, unit should be stopped in emergency. 1) AC, DC lubricate oil outlet check valves are not strict, report it to the shift manager and contact with maintenance for treatment. 2) When over pressure valve acts wrongly, it should be regulated to be normal. 3) When lubricate oil pressure drops, immediately check bearing, returning oil temperature and oil flow of returning oil. 4) When lubricate oil pressure drops, bearing temperature and returning oil temperature should be supervised strictly. If supporting bearing temperature rises abnormally and is close to limit, unit should be stopped immediately as fault stop and break the vacuum. 5) Unit should be stopped in emergency if bearing is in short of oil. 6) During speed rise in unit start, if auxiliary oil pump is fault that make lubricate oil pressure drop, it should be decided according to running speed and fault character: if running speed approaches to 2750rmin and the fault can be cleaned in a short time, running speed should be increased to rated running speed and treat with the auxiliary lubricate oil pump; if running speed is lower than 2750rmin and the fault can not be cleaned in a short time, unit should be stopped for treatment.
4.11.3 Lubricate oil temperature high 4.11.3.1
Phenomenon 1) Oil cooler outlet temperature high. 2) All bearing temperature or their returning oil temperature is high or alarms.
4.11.3.2
Reason and treatment 1) Cooling water in oil cooler is little or its temperature is high, cooling water should be added and its temperature should be decreased. 2) Oil cooler is dirty, transfer to standby oil cooler for operation and contact with maintenance for treatment. 3) Lubricate oil temperature automatic regulation is in failure, it should be changed to manual regulation. 4) Electric heater of main oil tank is put into operation by mistake, stop the electric heater immediately. 87
5) Unit vibration is high, bearing works abnormally and gland sealing leaks steam heavily, all of which may cause oil temperature rise. Confirm the reason and treat it correspondingly. 4.11.4 Reason and treatment of main oil tank level drop 4.11.4.1
Lubricate oil pipe breaks, measures should be taken for isolation, contact with maintenance for treatment and add oil timely. If oil pipeline is seriously broken, decrease load or stop the unit in emergency according to actual conditions. Make sure that oil is sufficient for inertia when stop the unit.
4.11.4.2
Sealing oil system is in fault and leaks oil, treat it according to regulations for fault treatment in sealing oil system.
4.11.4.3
Oil cooler leaks. Transfer it to standby oil cooler for operation and isolate it for treatment.
4.11.4.4
Oil purifying device is in fault and leaks oil, oil inlet valve of the device should be closed immediately and oil purifying device should be stopped.
4.11.4.5
If main oil tank level slowly decreases to 60%, oil should be added timely; if time is limited for adding oil and oil level in main oil tank drops acutely to 20%, unit should be stopped in emergency.
4.11.5 Reason and treatment of unqualified lubricate oil 4.11.5.1
For new unit or unit after maintenance, mechanical impurity or water is brought in due to incompletely cleaning of oil system. Oil purifying or changing should be enhanced.
4.11.5.2
Gland sealing supplying steam pressure is high, which makes moisture in oil increases. Under the condition of not affecting condenser vacuum, regulate bearing steam supplying pressure to be lower and gland sealing heater negative pressure to be higher properly.
4.11.5.3
There is over temperature point in oil system and oil is aging. Oil filtering and changing should be enhanced and over temperature points should be eliminated.
4.12
Turbine bearing temperature high
4.12.1 Phenomenon 4.12.1.1
CRT shows bearing temperature is high or alarms.
4.12.1.2
“turbine bearing temperature high” alarm.
4.12.1.3
Bearing returning oil temperature indication is high.
4.12.1.4
Unit vibration may be higher.
4.12.2 Reason 4.12.2.1
Cooling water system of oil cooler is in fault, lubricate oil temperature is high.
4.12.2.2
Lubricate oil pressure is low or oil is unqualified.
4.12.2.3
Bearing oil inlet and outlet are not smooth.
4.12.2.4
Unit vibrates acutely.
4.12.2.5
Bearing is damaged.
4.12.2.6
Gland sealing leaks steam seriously.
4.12.2.7
Unit is in overload, steam extraction system, vacuum system are running abnormally; thrust bearing temperature and returning oil temperature will rise.
4.12.3 Treatment 4.12.3.1
When bearing temperature and returning oil temperature are higher than normal values, following parameters should be checked immediately: 88
1) Whether the same bearing temperature on CRT and returning oil temperature at local rise or not. 2) All bearing temperatures rise, generally it is due to lubricate oil temperature high, lubricate oil pressure low, unit running speed rise or unit vibration high, all of which should be regulated to be normal. 3) Check bearing return oil flow and listen to the sound inside bearings. 4.12.3.2
Regulate lubricate oil temperature and pressure to normal values.
4.12.3.3
If oil is unqualified, oil filtering and changing should be enhanced. If oil is aging seriously, unit should be stopped according to requirements.
4.12.3.4
Thrust bearing temperature rises due to over load, unit load should be regulated.
4.12.3.5
If gland sealing leaks too much steam, gland sealing steam pressure should be properly decreased under the precondition of ensuring condenser vacuum.
4.12.3.6
Supporting bearing temperature reaches to 113℃ or thrust bearing temperature reaches to 107℃ and its returning oil temperature reaches to 77℃; if it is treated but with no effect, unit should be stopped as fault stop.
4.13
EH oil system fault
4.13.1 Familiar fault 4.13.1.1
Oil pressure swings.
4.13.1.2
Oil pressure drops.
4.13.1.3
Oil tank level decreases.
4.13.1.4
Oil pipe leaks.
4.13.1.5
Oil temperature is abnormal.
4.13.1.6
Oil is unqualified.
4.13.2 Fault treatment 4.13.2.1
When EH oil pressure swings, running oil pump should be checked: whether overflow valve acts or not, whether oil tank level is normal or not; check working condition of standby oil pump outlet check valve. If the oil pump does not work normally, oil pump should be transferred.
4.13.2.2
Oil pressure drops, it may due to oil pump not working normally, system leaking, strainer block or overflow valve action; it should be treated according to different conditions: 1) If oil pump does not work normally, standby oil pump should be transferred for operation. 2) If oil system leaks, try to isolate the leaking point under precondition of keep EH oil pressure is not too low and contact with maintenance for oil supplement; if oil leaks seriously and can not be isolated, unit should be stopped as fault stop. 3) If strainer differential pressure is high or overflow valve acts, it should be isolated for treatment. 4) When oil pressure decreases to value ”Low I”, standby pump starts automatically, otherwise start it manually; when oil pressure decreases to value ”Low II”, protector actuates to stop the unit, otherwise unit should be stopped manually.
4.13.2.3
When oil tank level decreases to 450mm, alarm sends, oil should be supplemented timely. Oil level drops generally because of oil pipes leak or oil cooler leak. If it is the reason, the leaking point should be isolated, if it can not be isolated and oil level continues to drop, unit should be stopped for treatment.
4.13.2.4
When oil temperature is abnormal, heating pump should be checked, cooling water 89
should be checked locally and oil cooler should be checked. 4.13.2.5
4.14
When oil is unqualified, check whether system regeneration pump is in normal operation or not, check diatomite strainer runs normal or not and change it if it is necessary.
Sealing oil pressure low
4.14.1 Reason 4.14.1.1
Sealing oil pump does not run normally.
4.14.1.2
Sealing oil strainer is seriously blocked.
4.14.1.3
Sealing pad leaks oil seriously.
4.14.1.4
Sealing oil pump re-circulating valve wrongly open or is in failure.
4.14.1.5
Differential pressure regulation valve does not work normally.
4.14.2 Treatment 4.14.2.1
Check and make sure that standby oil source is working; standby oil differential pressure regulator is working, which ensures that oil/hydrogen differential pressure is normal.
4.14.2.2
If it is due to sealing oil strainer block, the strainer should be changed and relevant person should be contacted for treatment.
4.14.2.3
If it is due to sealing oil pump re-circulating valve, the re-circulating valve should be regulated.
4.14.2.4
If sealing pad leaks oil seriously, it should be reported to the shift manager; if it can not keep running, ask for stopping the unit.
4.14.2.5
If differential pressure regulation valve is in failure, bypass valve can be regulated manually; keep supplying oil to sealing pad and contact with maintenance for treatment.
4.15
Closed circulating water system fault
4.15.1 Familiar faults 4.15.1.1
Closed cooling water intermits.
4.15.1.2
Closed cooling water head pipe pressure drops or fluctuates.
4.15.1.3
Closed cooling water tank level is low.
4.15.1.4
Closed cooling water pump vibration is high.
4.15.1.5
Closed cooling water pump motor current increases abnormally.
4.15.1.6
Closed cooling water quality gets worse.
4.15.2 Fault treatment 4.15.2.1
If closed cooling water head pipe pressure drops, check the working condition of closed water pump: whether closed cooling water tank is too low or not, whether system water discharging valve is strictly closed or not. If pump output is not sufficient or output pressure is lower than 0.35MPa, it should be confirmed that standby pump starts automatically, otherwise start it manually.
4.15.2.2
If closed cooling water head pipe pressure fluctuates greatly and motor current fluctuates, it is generally because closed cooling water tank level is low or air enters into pump. If it is because water tank level low, water should be supplemented to be normal. If it is because pump inlet strainer is blocked with differential pressure ≥0.02 MPa and standby pump starts automatically, the former running pump should be stopped and inlet strainer should be cleaned. If it because air enters into pump, all air discharging valves should be opened to discharge air, standby pump should be immediately transferred for running during gasification. 90
4.15.2.3
If closed cooling water pump vibrates highly, check whether gasification happens in pump or not, whether there abnormal sounds in pump and pump group bearings or not. When above abnormities happen, standby pump should be transferred immediately for running.
4.15.2.4
If motor current displays it is increasing, it should be measured. The reason may be two phases running or bearing damage. Standby pump should be transferred for running. Contact with maintenance for treatment.
4.15.2.5
If closed cooling water quality gets worse, it may due to that supplement water source is polluted. Water should be changed and contact with chemical for dosing.
4.16
Auxiliary equipment fault
4.16.1 Running equipment should be stopped in emergency if any of the following occurs: 4.16.1.1
Equipment vibrates heavily and, stator and rotor abrade.
4.16.1.2
Metal friction sound is clear inside equipment.
4.16.1.3
Motor is in smoke or on fire.
4.16.1.4
Bearing is in shortage of oil or in smoke.
4.16.1.5
Other faults threatening personal and equipment safety happen.
4.16.2 Standby auxiliary equipments should started firstly and stop the equipments in fault under following conditions: 4.16.2.1
Equipment sound is abnormal.
4.16.2.2
Motor current increases abnormally, insulation has burning smell or motor winding temperature exceeds limit.
4.16.2.3
Generator runs with two phases.
4.16.2.4
Gasification occurs in running pump.
4.16.2.5
Bearing temperature exceeds limit.
4.16.2.6
Air cooling system of big scale air fan is in fault.
4.16.2.7
Gland packing gets hot, smokes or leaks oil or water greatly.
4.16.2.8
Other conditions that threatening auxiliary equipment safety operation happen.
4.16.3 During starting motor, it should be stopped immediately if following abnormities occur: 4.16.3.1
Current does not return for a long time after starting.
4.16.3.2
After switch is closed, motor does not run but buzzes.
4.16.3.3
Motor has spark or smoke inside.
4.16.3.4 Equipment vibrates abnormally and there are serious leakages at connection pipes and flanges. 4.16.4 Auxiliary equipment vibration high 4.16.4.1
Phenomenon 1) Vibration values both measured locally and indicated remotely are high, corresponding vibration high alarm of auxiliary equipment occurs and, the auxiliary equipment trips when vibration value reaches to action value. 2) There is abnormal sound locally and bearing temperature may rise. 3) When water pump vibrates greatly due to gasification inside water pump, generally there is abnormal sound at local.
4.16.4.2
Reason 91
1) Coupler alignment does not comply with requirement or coupler is damaged. 2) Rotor center is not right. 3) Bearing installation clearance is too big or bearing is damaged. 4) Anchor bolts or mechanical parts are loosened. 5) Water pump‟s gasification. 4.16.4.3
Treatment 1) Rotor center is not right and it should be aligned again. 2) Check whether bearing is damaged or not, loosened anchor bolts or mechanical parts should be tightened. 3) When there is breathing vibration or gasification, it should be regulated effectively. 4) For equipment with no protections, it should be stopped when vibration value increases to limit value. 5) Auxiliary equipment vibration value exceeding following values should be deemed as vibration high:
Rated running speed (r/min) Vibration value (Double amplitude um)
4.17
7600
3000
1500
1000
750
40
50
85
100
120
Motor fault
4.17.1 Conditions for stopping motor Any of the following conditions occurs, motor should be stopped immediately: 4.17.1.1
It is threatening personal safety.
4.17.1.2
Motor and its affiliated electric equipments are in smoke and on fire.
4.17.1.3
The mechanical equipment is damaged and can not run.
4.17.1.4
Motor vibrates heavily or impacts inside, stator and rotor abrades.
4.17.1.5
Motor running speed drops acutely, current rises or drops to zero.
4.17.1.6
Motor temperature and bearing temperature rise acutely, which exceed permit values.
4.17.1.7
Flood or fire threatening motor safety occurs.
4.17.2 Conditions of motor fault stop For important auxiliary motor, firstly start the standby equipment, then stop the motor when the following happen: 4.17.2.1
Motor has abnormal sound or insulation has burning smell.
4.17.2.2
There is spark or smoke in generator or starting regulation device.
4.17.2.3
Stator current exceeds normal operation value (under same load);
4.17.2.4
Cable down-lead of motor is over heated.
4.17.2.5
Cooling system of large scale motor is in fault.
4.17.2.6
Motor three phases unbalancing current exceeds 10%.
4.17.3 If the tripped motor affecting unit output or safe operation, and there is no standby motor or standby motor can not be started rapidly; the tripped motor can be restarted except for following conditions: 4.17.3.1
There is an obvious sign of short circuit or damage on regulation device or power 92
cables before starting the unit. 4.17.3.2
Personal accident happens and unit has to be stopped immediately.
4.17.3.3
Motor affiliated machinery is damaged.
4.17.3.4
Motor that tripped due to protector action.
4.17.4 Important motor loses voltage or its voltage drops, manually cutting off auxiliary motor is prohibited within 1min. 4.17.5 Motor trips automatically during running 4.17.5.1
Reason 1) Stator winding is in short circuit in circles or phases. 2) Power cable is in failure. 3) Mechanical parts are blocked to death. 4) Voltage drops. 5) Relay protector actuates or is wrongly operated.
4.17.5.2
Treatment 1) Start standby equipment. 2) If there is no standby equipment, check the motor as soon as possible. Restart it after no problem is confirmed. It can be started immediately after wrong operation is confirmed. 3) If the motor trips during start, it can not be started before finding out the reason. 4) Check the following to the tripped motor: a. What kind of protector action it is. b. Whether motor winding and cable have short circuit, earth and broken line or not. c. Whether affiliated machinery is blocked to death or not, fuse is broken or not and interlock circuit is in fine condition or not. d. Whether switch actuator is in fine condition or not, power switch and brake are well closed or not. e. Measure motor insulation resistance (including cables).
4.17.6 Motor is in smoke and on fire with burning smell 4.17.6.1
Reason: 1) Bearing center is not right or bearing pad abrade, which makes stator and rotor clash. 2) Stator winding insulation is wet, dirty or aging and, short circuit between phases or earth fault occurs. 3) Motor rat cage bar break.
4.17.6.2
Treatment 1) Open the power supply switch of motor immediately. 2) Dry powder, 1211, oxidation carbon fire extinguisher or spraying water is used for putting out fire. Water flow, sand or foam is prohibited. 3) Check the motor in details.
4.17.7 Motor vibrates acutely 4.17.7.1
Reason 1) The centers of motor and affiliated equipment are not the same, bearing bends and mechanical part damages. 93
2) Unit bearing is damaged or balance weight displacement is unbalanced. 3) Stator and rotor abrade or fan drops. 4) Rotor rat cage bar breaks. 5) Mechanical part vibrates and anchor bolts are loosened. 4.17.7.2
Treatment 1) Start standby motor. 2) If there is no standby motor, motor load should be decreased, check whether vibration is lightened or eliminated or not; otherwise contact with maintenance for treatment.
4.17.8 When motor temperature rises abnormally, the following should be checked: 4.17.8.1
Whether voltage is lower than or current exceeds regulated value or not:
4.17.8.2
Check whether cooling air exceeds 35℃ or not, cooling system is blocked or not and fan runs normally or not.
4.17.8.3
Three phases current are in balance or not, whether exceed regulated values or not.
4.17.8.4
Whether affiliated mechanical parts are blocked which causes over load.
4.18
Auxiliary power lost
4.18.1 Phenomenon 4.18.1.1
Unit trips, boiler MFT, turbine trips and generator steps out of the system; alarm sounds and corresponding light-word plate shines.
4.18.1.2
Auxiliary bus line voltages at all sections drop to zero (0) and their power supply switches green lights are on.
4.18.1.3
All running AC auxiliary equipments stop and standby AC auxiliary equipments do not start by interlock; motorized valve can not be operated.
4.18.1.4
All DC equipments actuate by interlock.
4.18.1.5
AC head lamps are off, DC head lamps are on and control room gets dark.
4.18.2 Reason Generator steps out of the system, auxiliary power supply at all sections are lost, standby power supply can not be transferred successfully or standby transformer trips but emergency power supplies have not put into operation successfully. 4.18.3 Treatment 4.18.3.1
Make sure that turbine, BFPT DC oil pump, DC sealing oil pump at air side are started; otherwise they may be closed manually by force 2 times. Check and make sure that turbine lubricate oil pressure, oil-hydrogen differential pressure are normal. If DC sealing oil pump can not start, exhaust hydrogen from generator at once, avoid hydrogen leaking caused exploding.
4.18.3.2
Open condenser vacuum breaking valve manually and close all the drainage valves to condenser. Put air pre-heater pneumatic motor into operation. Close manual valve of fuel oil trip valve before boiler and retuning oil manual valve.
4.18.3.3
Inform relevant positions fro corresponding treatments. Recover all the tripped equipments and release standby equipment interlocks.
4.18.3.4
Check and operate the emergency power supply:
4.18.3.5
After emergency power recovered, following works should be done: 1) Start turbine AC lubricate oil pump, jacking oil pump, AC sealing oil pumps at air and hydrogen side, sealing oil standby pump, BFPT AC oil pump, air pre-heater motor and AC flame detection air fans. 94
2) Put lubricate oil systems of all auxiliary equipments into operation. 3) Start emergency stop cooling water pump of boiler and put boiler water pump LP cooling water system into operation. 4) Close outlets of steam driven feed water pump and motorized feed water pump; check and make sure that pump do not run in reversal. 5) Check and make sure that HP & IP main steam valve, governor valve, HP steam extraction check valve and check valves of all extraction steam are closed. Close relevant motorized valve and open relevant drainage valve at boiler side. 6) Check and regulate all the air valves, dampers of stopped pulverizing system are right. Motorized valves of super heaters and re-heaters are closed. 7) Put turning gear into operation when turbine running speed reaches to zero (0). If turning gear stops before rotor, rotor should be turned 180O and put turning gear into operation after a period of time. P
P
8) Check and make sure that DC system and UPS power transfers normally. 4.18.3.6
Open all the closed switches at all sections of HP, IP auxiliary power. Check the reason why auxiliary standby power supply can not be put into operation successfully. After defects are cleaned, recover power supplies at all sections of LV transformer.
4.18.3.7
Recover auxiliary power supplies gradually and recover all systems gradually according to unit actual conditions.
4.18.3.8
If circulating water interrupted and LP cylinder exhausting steam temperature is higher than 50℃, firstly start condensing water pump and start one vacuum pump and keep condenser vacuum of -20KPa. Circulating water system only can be put into operation after stainless steel pipes are cooled and exhausting steam temperature is lower than 50℃.
4.18.3.9
Feed water to boiler according to drum wall temperature difference and after chief engineer‟s approval. Keep drum water level and deaerator water temperature normal.
4.18.3.10
4.19
Do the other operations gradually to recover unit operation.
Hydrogen system fault
4.19.1 Generator is in smoke, on fire or explodes, unit should be stopped in emergency and discharge hydrogen. 4.19.2 During generator operation, hydrogen purity in generator is low to 96％, it should be supplemented. It should be confirmed that there are no fire near outlets of pollutant discharging when discharging pollutant. The operation should be slow to avoid explosion and fire due to static. 4.19.3 Hydrogen temperature is abnormal, check hydrogen cooler working condition; if hydrogen temperature automatic regulation is in failure, regulate the temperature manually through bypass valve and inform maintenance for treatment. 4.19.4 One hydrogen cooler is in fault and stops and unit load decreases to 80%, temperature of generator stator iron core and winding should be strictly supervised. 4.19.5 Hydrogen purity meter is in fault, inform maintenance immediately for treatment and contact with chemical to sample and analyze hydrogen purity once every four hours until hydrogen purity analysis meter recovers and works normally. 4.19.6 Hydrogen pressure inside generator drops or hydrogen leaks, the reason should be found out immediately and eliminated. Reason and treatment of much hydrogen leakage and hydrogen pressure dropping are as following: 1) Sealing oil intermits. Stop the unit and discharge hydrogen in emergency. 2) Sealing oil pressure is low, which can not keep a normal oil-hydrogen differential pressure. Try to regulate it to be normal or start an other standby pump. If sealing 95
oil pressure can not be improved, keep the unit running by decreasing hydrogen pressure. When hydrogen pressure decreases, unit load should be controlled according to corresponding curve between hydrogen pressure and load. 3) Hydrogen leaks due to pipe break, valve flange leakage or generator measuring down-lead leakage. Treat the leakages under precondition of not effecting unit normal operation; if it can not be treated, stop the unit. 4) Generator sealing pad or outgoing line bushing ia damaged, which should be rapidly reported to the shift manager and stop the unit for treatment. 5) Wrong operation or hydrogen discharging valve is not strictly closed, operation should be corrected immediately and the valve should be strictly closed; supplement hydrogen to normal pressure. 6) If it is due to generator stator winding or hydrogen cooler leakage, it should be reported the to shift manager immediately; stop the unit for treatment if it is necessary. 7) If hydrogen leaks to workshop, all the doors and windows in relevant area should be opened and air fan at roof should be started to enhance aeration. Any fire for working is prohibited.
4.20
Stator cooling water interrupt
4.20.1 Check standby stator cooling water pump start or not. If not start automatically, start standby pump manually by force at once, if not successful, start primary pump by force once more and adjust cooling water flux and pressure normal. 4.20.2 Check stator cooling water system, find the reason why stator cooling water pump trip. 4.20.3 If stator cooling water system can not recover, decrease generator load, take preparation for generator trip, switch auxiliary power to start standby transformer instead at once. 4.20.4 Supervise temperature of each section of generator, can not exceed allowed value. 4.20.5 Water interrupt protection operated after generator water interrupting for 30 seconds, disconnection at once. If protection not operation, make G-T trip manually. 4.20.6 Waiting for stator cooling water system recovery and make sure that unit is normal, generator synchronizing.
4.21
Fire
4.21.1 When fire occurs with his working area, operators should: 4.21.1.1
Not to leave away from his position by himself or run in a rush.
4.21.1.2
Enhance unit operation and maintenance according to accident treatment regulations.
4.21.1.3
Execute the instruction from superior positions rightly and immediately.
4.21.2 Treatment during fire 4.21.2.1
When fire alarm sends out, relevant person should go to fire spots to see the fire, to check the fire fighting system and to use relevant extinguisher for putting out the fire.
4.21.2.2
When electric equipments are on fire, power supply should be cut off first then use extinguisher for putting out the fire. When fire occurs around electric equipments that threatening equipments safety, the equipments also should be stopped and power supply should be cut off.
4.21.2.3
When fire is still not threatening unit operation, try to limit the fire and move away the tinder around fire and put out the fire as soon as possible.
4.21.2.4
Enhance supervision and get ready to stop the unit.
4.21.2.5
When fire seriously threatens unit safety, unit should be stopped in emergency.
4.21.2.6
When oil tank is on fire or fire seriously threatens oil tank safety, stop the unit with 96
breaking vacuum and open emergency oil discharging valve of oil tank at the same time; it should be paid attention that lubricate oil does not intermit before unit stops to avoid burning bearing. 4.21.2.7
When sealing oil system is on fire that can not be put out rapidly and threatens equipment safety, unit should be stopped in emergency; hydrogen should be discharged rapidly during unit inertia and sealing oil system should maintain until unit completely stops.
4.21.2.8
When generator or hydrogen cooling system is on fire, unit should be stopped in emergency; CO2 should be charged into generator to discharge H2 for extinguishing at the same time and cooling water system keeps running. B
B
B
B
4.21.3 Extinguishing methods, equipments and notices: 4.21.3.1
When impurities that not immersed with oil are on fire; water, foam fire extinguisher and sand can be used for putting out the fire.
4.21.3.2
When impurities that immersed with oil are on fire; foam fire extinguisher and sand should be used for putting out the fire.
4.21.3.3
When oil tank or oil in other vessels are on fire, foam extinguisher, CO2, CCL4, or 1211 extinguisher can be used for extinguishing. Wet cloth can be used for extinguishing or air isolation if it is necessary. Sand or hydrant with no nozzles is prohibited for putting out fire.
4.21.3.4
When equipments with power are on fire, CO2, CCL4, 1211 or dry powder extinguisher can be used for extinguishing after cutting off power supply. When motor is on fire, sand or water feeding into motor for extinguishing is not allowed.
4.21.3.5
When equipments with power are on fire, if power supply can not be cut off immediately, CO2 or CCL4 extinguisher can be used for extinguishing; other non-insulation fire extinguishers are prohibited.
B
B
B
B
B
B
B
B
B
B
B
B
4.21.3.6
When pipe or other high temperature parts are on fire, CO2 fire extinguisher is not allowed for extinguishing; water should be use carefully to avoid equipments damage by heat stress.
4.21.3.7
When running part or speed regulating system is on fire, sand is prohibited for extinguishing and above relevant regulations should be executed.
4.21.3.8
When hydrogen system is on fire, CO2 and 1211 extinguisher are mainly used for extinguishing.
4.22
B
B
B
B
DCS fault
4.22.1 All DCS operation station and engineer station are in fault 4.22.1.1
Phenomenon 1) All host computers are in „Blank screen‟ or crashes. 2) Mouse or keyboard can not operate screen successfully. 3) All parameters and alarms on DCS screen do not change.
4.22.1.2
Reason 1) DCS power supply is in fault. 2) DCS signal connection opens circuit. 3) Inner software of DCS control is wrong. 4) Hardware inside DCS is in fault.
4.22.1.3
Treatment 1) If DCS is in fault and boiler extinguishes, it should be treated as extinguishing. 2) If boiler has not extinguished and main standby manual operation and supervision 97
meters are available which can keep normal running of the unit temporarily, transfer to standby operation mode for operation, eliminate faults and recover running mode of operators‟ station. Otherwise, turbine and boiler should be stopped. If there is no reliable standby operation supervision measures, turbine and boiler also should be stopped. 3) Supervise drum level, furnace negative pressure, temperature, pressure and boiler combustion by local water level video, flame video, drum water level indicator, supervision meters for furnace negative pressure, main, reheating steam pressure and temperature. 4) Keep unit load stable, when steam pressure in unstable, regulate load manually and properly to maintain normal pressure. 5) Contact with IC immediately for treatment. 6) If boiler combustion working conditions is out of control, parameters are abnormal and fault in DCS can not be cleaned in time, boiler should be stopped. 7) After boiler stops, close all oil, air, gas valves or dampers and stop all the running equipments that have to be stopped for boiler emergency stop. 4.22.2 Part operator stations of DCS fault 4.22.2.1
When part operator stations are in fault, use the operator station that still available for supervising the running of the unit.
4.22.2.2
Stop important operations.
4.22.2.3
Contact with I&C for treatment.
4.22.2.4
If fault can not be eliminated, it should be treated according to running conditions.
4.22.3 Treatment when controller or corresponding power supply are in fault: 4.22.3.1
When auxiliary controller or corresponding power supply is in fault, it can be transferred to manual mode running and treat it rapidly; if the conditions are not allowed to transfer, the auxiliary equipment should exit from running.
4.22.3.2
When regulation circuit controller or corresponding power is in fault, it should be changed to manual mode foe keeping running; treat the fault in system rapidly and relevant measures should be taken according to treatment.
4.22.3.3
When controller of boiler protection is in fault, controller should be renewed or repaired; when power supply of boiler protection is in fault, measures for sending power by force should be taken. At this time, measures for avoiding controller initialization should be done well. If it can not be recovered, stop the boiler in emergency.
4.23
Measures avoiding water entering into turbine and bearing bend
4.23.1 Before starting turbine, check and make sure that condition of insulation for turbine is good; it is prohibited to be started if insulation is not completely to ensure that there will be no too high temperature difference during normal start and stop. When temperature difference between up and down cylinder is higher than 42℃, speed rise should be stopped or increase load to heat up the turbine until the temperature difference is lower than 30℃. 4.23.2 All metal temperature detection points of turbine should be complete and reliable, bearing eccentricity indication should be right. Bearing eccentricity should not exceed 0.075mm before starting the turbine. Otherwise it is not allowed to start. 4.23.3 Continuous running of turning gear should be no less than 4 hours before starting the turbine. After stop the unit, turning gear should be put into continuous running immediately. If turning gear can not be put into continuous running, turning gear should be turned 180° every 30min to eliminate rotor flexible distortion and hot distortion and, then out turning gear into continuous running. 4.23.4 During start or stop, unit should avoid running a long time with load of 60MW. During normal running, check the unit periodically, listen to the sound in cylinder and at gland 98
sealing, report and treat it immediately if any abnormity is found. 4.23.5 Check cards should be strictly executed before starting. Check and make sure that all the drainage valves are fully open before starting the turbine; touch locally to confirm that drainage water is smooth. 4.23.6 During hot state start, gland sealing steam should be supplied first and then extract the vacuum. After unit stopped, only when condenser vacuum decrease to 0, gland sealing steam feeding can stop. Before supplying steam to gland sealing, gland system should be completely heated and then drain water; cold steam or drainage water is prohibited to enter into gland sealing. Choose steam source according to cylinder temperature in order to make feeding steam temperature match with cylinder steam temperature; maximum steam temperature of gland sealing should not be higher than 375℃. Boiler ignition only can be done after vacuum is established. 4.23.7 Turbine starting should adopt „Automation‟ mode to the best. 600r/min low speed friction check should be strictly executed. During start, there should be special person to supervise turbine TSI system vibration, pad temperature, differential expansion and metal temperature and there should be special person at local to supervise bearing vibration and total cylinder expansion. Critical running speed area is prohibited to stay. Once vibration value exceeding standard value (especially before first critical running speed area) is found, the unit should be stopped immediately; it is prohibited to decrease speed and watch. 4.23.8 Under any working condition, drum level, turbine axial displacement, differential expansion, vibration, main and reheating steam temperature should be strictly supervised; especially during start & stop and changing working condition, main & reheating steam temperature changing rate should be strictly controlled. When main steam temperature drops to trip value but protector does not actuate, unit should be stopped immediately and manually. If steam temperature drops 50℃ acutely within 10min, unit should be stopped immediately. 4.23.9 When load is under 20%, HP heaters are not allowed to run. Under any working condition (especially during unit start & stop), water levels of HP & LP heaters and deaerator should be strictly supervised. When heaters all full of water, check and make sure that protectors act rightly; otherwise stop it manually, check whether steam extraction motorized valve, check valve are closed or not and feed water has been transferred to bypass line. Start drainage water of steam extraction pipes. 4.23.10 After HP & LP bypass system stop, attemperating water manual valves should be closed reliably. 4.23.11 After unit stops or in maintenance, before cylinder temperature reaches to environment temperature and steam water system is completely isolated, turbine should be deemed as running, condenser water level, cylinder metal temperatures should be supervised and parameters should be recorded periodically. Close the motorized valves and manual valves at proper coal section and from fourth extraction to auxiliary steam, close make up water valve from condensing water to hydrogen station, close condenser make up water valve, close inlet valve from make up water tank to condensing booster pump and close attemperating water valves for heating to avoid full water of condenser. When look for leakage of condenser, the water level of condenser should be no less than 8.5m, temporary measures for supervising water level should be prepared. After looking for leakage, all the drainage valves should be opened for water drainage. 4.23.12 After turbine trips; gland sealing steam supplying is not allowed to stop before vacuum reaches zero (0) to avoid cold air entering into turbine. During rotor inertia, breaking vacuum is prohibited; inertia time should be recorded and analyzed. Gland sealing steam is not allowed to supply without turning gear. Half an hour after rotor inertia, vacuum can be decreased to about 30KPa. All the drainage valves to condenser should be closed before condenser vacuum reaches to zero (0), and then vacuum breaking valve can be opened. 4.23.13 Execute all periodic works seriously and do the moving tests of main steam valve and steam extraction check valve well. Report and treat it is any problem is found. Exit from 99
heaters operation if it necessary. 4.23.14 Turbine cylinder temperature should not be lower than 400℃ when stopping the unit with sliding parameter. 4.23.15 During turning gear running time after turbine stops, maintenance for systems relevant to turbine proper is prohibited to avoid cold air entering into cylinder; under especial conditions, it should be approved and measures should be prepared.
4.24
Measures avoiding turbine oil leakage
4.24.1 During normal operation, main oil tank and BFPT oil tank level keeps at normal level (Local oil mark is visible). 4.24.2 Move the main oil tank level indicator once a day, check and make sure that there is no block at oil level indicator and oil level alarm is normal. Two oil level indications should be basically in consistent. 4.24.3 BFPT oil tank level alarm test is normal. 4.24.4 Oil purifying device fault alarm test is normal. It should be checked from time to time during its operation; if oil leakage is fount, it should be isolated and main oil tank level should be paid attention. Add it to normal level when oil level decreases. 4.24.5 Emergency oil discharging valve, water discharging valve of turbine and BFPT oil tank and „NO OPERATION‟ warning plate should be hung. 4.24.6 Outdoor oil storage tank should be with a certain qualified turbine oil, lubricate oil transportation pump should be ready for standby to ensure main oil tank and BFPT oil tank can be added with oil. 4.24.7 During normal operation, check it immediately if oil level in oil tank drops. If oil pipe leaks, isolation should be managed. Watch oil level changing in oil tank and supplement oil ifit is necessary. 4.24.8 Check and make sure that whether oil cooler leaks or not; if it leaks, it should be changed for isolation. 4.24.9 Check sealing oil system: sealing oil tank indicator at air side should be at normal level; if oil pipe leaks, measures should be taken for isolation. 4.24.10 If main oil tank level drops and can not be added oil, oil level continues to drop to 20%, stop the unit in emergency with breaking vacuum for ensuring oil for inertia of turbine. 4.24.11 Turbine oil system and relevant test and periodic works should be executed strictly according to regulations in this manual book. 4.24.12 During unit start, stop and running, thrust pad, bearing pad and returning oil temperature. When temperature exceeds limited value, it should be reported to shift manager and treated according to regulations 4.24.13 During operation, it is not allowed that standby pump work at the same time and lose its standby function. 4.24.14 Unit is not allowed to run when unit vibration is not qualified. 4.24.15 Analyze oil periodically and treat it if oil quality is getting worse. Under oil quality and condition of cleanness exceeds standard, unit is not allowed to start. 4.24.16 During operation, bearing pad may be damaged (such as water impact or instantaneous oil break), unit can only be started after it is confirmed that unit bearing pad is not damaged. 4.24.17 Low oil protection thrust bearing protection and low pressure interlock must be reliable and can not be released casually.
4.25
Main steam valve or governor valve blocks after turbine trips
4.25.1 Phenomenon 100
4.25.1.1
Turbine trips.
4.25.1.2
HP & IP main steam valve „Close‟ signal are not completely sent out.
4.25.1.3
IP governor valve on DEH screen is not completely closed to „0‟ position.
4.25.2 Treatment 4.25.2.1
Check and make sure that running speed decreases or not.
4.25.2.2
After turbine trips, if it is found out steam valve is blocked and not completely closed and running speed decrease quickly, unit should be stopped according to normal stop.
4.25.2.3
After turbine trips, if it is found that steam valve is blocked and not completely closed which makes running speed rise, unit should be stopped in emergency by breaking vacuum.
4.25.2.4
Stop vacuum pump and release pressure in boiler as soon as possible. Stop A, B small turbine and EH oil pump.
4.25.2.5
Contact maintenance to treat the block of steam valve and find out the reason. Unit only can be started after defects are cleaned.
4.26
Measures avoiding turbine over speed
4.26.1 Do the over speed test, oil spraying test and static test according to regulations. Make sure that speed change rate and stagnant rate comply with the regulation. 4.26.2 Unit oil filling test is normal and actions are right. 4.26.3 Over speed test should be done with rising speed method one month after major maintenance and emergency protector disassembly. 4.26.4 If over speed test needs to be done during cold state start, it should be synchronized firstly. The test is then done after low load heating up according to regulations. 4.26.5 During emergency protector over speed test, speed rise should be stable. 4.26.6 I&C protection signals should be tested after minor or major maintenance to ensure that I&C signals set values are right and all additional protections are reliable. 4.26.7 OPC test period should be the same with over speed test period. 4.26.8 When main steam valve or governor valve is found to be blocked, it should be reported and eliminated and steam valve moving test should be done according to regulations. 4.26.9 Check the tightness of main steam valve, speed regulating valve and steam extraction check valve before every start or stop. It any is found not strict, unit can only be started after defects are eliminated. 4.26.10 Steam and turbine oil should be analyzed periodically; corresponding measures should be taken if the qualities are not qualified. 4.26.11 Regulate gland sealing pressure of the unit properly to avoid water entering into oil. Water should be eliminated as soon as possible if water enters into oil. 4.26.12 During over speed test, governor valve should be opened gradually and running speed should be increased gradually to emergency protector action running speed. If governor valve suddenly open to maximum, unit should be stopped manually to avoid serious over speed. 4.26.13 Proper parameters should be chose during over speed test; pressure and temperature should be controlled within regulated range, over speed test can only be done after parameters are stable.
101
5
Start curve
5.1 Cold state curve
102
5.2 Warm state start curve
103
104
5.3 Hot state start curve
105
5.4 Very hot state curve
106
5.5 Recommended values of keeping turbine running speed
Note: Running speed should not stay in any resonance area. If running speed has to stay, the running speed should be decreased to be lower than resonance area. The shadow section in above figure stands for resonance running speed area and rotor critical running speed, which must be avoided.
107
5.6 Cold state rotor heating curve
HP & IP Rotor Initial Metal Temperature （℉）
108
5.7 Hot state start recommended value Starting turbine and operating with minimum load
Note: 1) If main steam temperature pressure (parameter) is lower than the metal temperature under exact match line in figure 3, unit should raise its speed to rated running speed within 10min 109
and synchronize and run with minimum load according to figure 4. Under this condition, it is not necessary to hold long with minimum load, because long time starting and long time running with minimum load will cool turbine metal. 2) In order to decrease heat stress and shorten starting time, figure 3 can be used for choosing main steam parameter in figure 1, which will make it closer to residual metal temperature.
5.8 Main steam parameters during start
Note: To avoid heat impact in steam chamber, this curve shows the relationship between inlet steam pressure of main steam valve, inlet steam temperature of main steam valve and inner wall metal temperature in steam chamber. These parameters are the ones during control switching from main steam valve to governor running speed. When metal temperature in steam chamber is lower than corresponding saturation temperature of main steam pressure, temperature equals to or higher than minimum inlet steam temperature in above will be obtained. Use pre-start valve of main steam valve to continue to run the unit until metal temperature in steam chamber reaches to saturation temperature. Then valves can be switched. During cold state start, before control switching from main steam valve to governor valve, inlet 110
steam parameter of main steam valve should be in „Cold state start‟. During hot state start, before control switching from main steam valve to governor valve, inlet steam parameter of main steam valve should be higher than „Main seam valve minimum inlet steam temperature‟.
5.9 Changing load recommeded value——fixed pressure mode
5.10
Recommeded value of changing load Sliding pressure and sequence valve mode
111
5.11
Circulating indexes under different load increase rate and decrease rate
112
5.12
Gland sealing steam temperature recommended valves
113
5.13
Typical HP cylinder cooling curve
中文 典型高压缸冷却时间曲线 如果机组在跳闸时的第一级，金属温度不同于图 中时间，所对应的温度（即 9000F，4820C，则 可移动时间比如R，使时间零点对应于发生跳闸 时的第一级金属温度 P
P
P
P
跳闸后的时间 小时 第一级金属温度
114
English Typical HP cylinder cooling time curve If the unit trips at first stage, metal temperature is different from the corresponding time in chart (i.e. 000F,4820C, ) removable time is R, which makes zero point of time correspond the first stage metal time when trip Time after trip hour First stage metal temperature P
P
P
P
6 Auxiliary operation regulations 6.1 General 6.1.1
Notices for start and stop
6.1.1.1 All interlocks, protection tests must be done for repaired equipments before trial operation, its control circuit, automatic devices, I&C interlock protections, mechanical devices and pneumatic devices should be tested to be qualified according to regulations before trial operation. 6.1.1.2 Repaired auxiliary equipments can only be put into operation or standby after its trial operations are qualified. Trial operation should be presided by maintenance principal. If motor is in maintenance, running direction should be right and then connect it to the auxiliary equipment. Static open & close test should be tested for 11kV & 3.3kV power equipment or maintenance has made it clear. 6.1.1.3 Before trial operation, auxiliary equipments must be checked locally and only can be sent power after all the conditions for starting are satisfied. 6.1.1.4 Insulation should be measured before sending power or starting for motors that stopped for more than one (1) week or may be wet. 6.1.1.5 Special person should be sent to local for supervision when starting 11kV & 3.3kV equipments and important 415V equipments. Person at local should be stand beside emergency button and stop the equipment if any problem is found. 6.1.1.6 Two (2) or more 11kV & 3.3kV sets that are on same bus line can not be started at the same time. 6.1.1.7 If the auxiliary equipment trips during starting, it can not be started before faults are cleaned. 6.1.1.8 Oil system of auxiliary equipments that equipped with forced circulating lubricate oil system or hydraulic control oil system should be started two (2) hours in advance after a long term stop in winter. 6.1.1.9 Relevant personnel should be contacted before starting the auxiliary equipments. 6.1.1.10
Start of auxiliary equipments should be done according to logic relationship and try best not to start with load.
6.1.1.11
Special personnel should be sent to supervise current and start time during auxiliary equipment start; if start time exceeds regulations and current does not recover, the equipment should be stopped at once.
6.1.1.12
Start and stop of auxiliary equipments are generally operated on relevant CRT screen; pay attention that control switch should be at „Remote‟ position. If it needs to be started or stopped locally, the control switch should be at „Local‟ position.
6.1.1.13
When starting auxiliary equipments or selecting standby equipment, pay attention that load at sections of unit power is evenly distributed to avoid load collecting at one section.
6.1.2
Checking content before start
6.1.2.1 Check and make sure that all work permit tickets relevant to starting equipment are concluded. All working personnel checking locally have withdrawal. Check and make sure that there is no foreign material in or round the equipment and lighting is sufficient. 6.1.2.2 Check and make sure that equipment appearances are complete and connections are fixed and reliable. Safety sleeve for running parts should be installed. Manholes are strictly closed and anchor screws and connecting bolts are not loosened. Relevant meters should be in operation. 6.1.2.3 Check and make sure that lubricate oil is filled for bearings; oil quality, oil level and oil temperature comply with requirements. Cooling water and sealing water of equipments are 115
in operation and normal. Temperature of auxiliary equipments and motors should comply with requirements. 6.1.2.4 Check and make sure that motor connections are fixed, earth wires are good and insulation is measured to be qualified. 6.1.2.5 Check and make sure that local emergency button connections are good and safety sleeve is complete. 6.1.2.6 Check the system completely according to check card; discharge air and fill oil or water for relevant oil, water system and pump proper. 6.1.2.7 Turn the rotors of auxiliary equipments that can be turned manually; make sure that running is agile with no block. 6.1.2.8 Complete the check before starting auxiliary equipments and send relevant dynamic power and control power to auxiliary equipment and relevant system devices after starting conditions are confirmed. 6.1.3
Check after start
6.1.3.1 Temperature rise for bearing (tile) of running equipments and speed reducing box should obey regulations from the manufacturer; if there is no regulation from manufacturer, generally sliding bearing should not exceed 80℃; rolling bearing temperature should not exceed 100℃ (environment temperature is calculated as 40℃). Sliding bearing temperature of motors produced by Shanghai Motor Co., Ltd should not exceed 90℃ and rolling bearing temperature should not exceed 95℃. 6.1.3.2 Vibration of equipments complies with regulations. Bearing vibration should be controlled as following table: Bearing vibration permit value Running speed（rpm）
3000
1500
1000
750 及以下
Vibration permit double amplitude (mm)
0.05
0.085
0.10
0.12
6.1.3.3 Temperature rise and current indications of motors comply with regulations. 6.1.3.4 Oil levels in lubricate oil tank is normal and there is no oil leakage in the system. 6.1.3.5 Sealing part of equipments should be well sealed. 6.1.3.6 There is no abnormal sound and friction in motor or equipments. 6.1.3.7 Mechanical connections of regulation devices should be complete with no drop. 6.1.3.8 Inlet, outlet pressure and flow are normal. 6.1.3.9 Make sure that all interlocks and automatic regulation devices are in operation and are normal. 6.1.3.10 6.1.4
There is no water leakage, steam leakage or oil leakage in system.
Auxiliary equipment stop
6.1.4.1 Auxiliary equipments should be stopped according to logic relation among the equipments. 6.1.4.2 Relations between protections and interlocks should be fully considered during stopping auxiliary equipments to avoid appearance of interlock act and trip etc. 6.1.4.3 Stopped auxiliary equipment also should be normally supervised, it should be isolated if any reversal running happens. 6.1.4.4 Necessary anti-freezing measures should be prepared for relevant stopped equipments in winter. 6.1.4.5 During isolation for maintenance, isolation only can be done after stopping auxiliary equipments. 116
6.1.5
Conditions for auxiliary equipments emergency stop
6.1.5.1 There is acute vibration or axial moving which may damage equipment. 6.1.5.2 Bearing temperature increases abnormally or exceeds regulated value. 6.1.5.3 Motor stator and rotor abrade heavily or are in smoke or on fire. 6.1.5.4 Auxiliary rotor and shell abrade heavily or impact with each. 6.1.5.5 Auxiliary equipment is on fire or immersed in water. 6.1.5.6 Equipment threatens personal safety.
6.2 Start & stop of circulating water system 6.2.1
Start of circulating water system
6.2.1.1 Feeding water into circulating water system 1) Start circulating pump trash remover. 2) Start circulating water pump rotating strainer. 3) Open outlet of circulating water pump manually, check and make sure that inlet &outlet water valve of condenser are fully open. 4) Start circulating water vacuum pump, extract air and fill water to circulating watersystem. 5) Make sure that interlock protection test of circulating water system is qualified and in operation, I&C power is working. 6.2.1.2 Check of circulating water system and circulating water pump 1) Circulating pump group alignment is completed and anchor bolts are complete and tight. 2) Circulating water pump outlet butterfly valve is closed, circulating water pump butterfly valve oil pump station works normally, butterfly valve interlock switch is at „Remote‟ position, outlet butterfly valve control mode on CRT is at „Pump valve interlock‟ position. 3) Circulating water pump inlet suction well water level is normal, circulating water pump inlet trash remover trial operation is good and is ready for operation at any moment. 4) Circulating water pump motor oil system is at normal standby. 5) Condenser circulating water inlet valve is open. 6) Condenser circulating water outlet valve is open. 7) Circulating vacuum pump runs normally and system is fulfilled with water. 8) Water discharging valves in circulating water system are closed. 6.2.1.3 Circulating water pump start 1) Check and make sure that oil levels in high position oil tank and low position oil tank are higher than 1/2. 2) Check and make sure that circulating water pump and bearing oil levels are normal and oil is qualified. All oil discharging valves are strictly closed. 3) Check and make sure that oil level in butterfly valve oil station is higher than 1/2 and oil pressure is normal. 4) Open the general stop valve from industrial water head pipe to circulating water pump motor. 5) Open manual isolation valves before and after cooling water strainer of circulating water pump motor. 6) Open the outlet hydraulic butterfly valve of circulating water pump to be started remotely to 150, start circulating water pump. 117
7) Fully open outlet hydraulic check valve of running circulating water pump manually. 8) Check and make sure that circulating water pump current, outlet pressure and vibration are normal. Outlet hydraulic butterfly of running pump is in interlock. 9) Stop circulating water vacuum pump, completely check and make sure that all parts of circulating water system are normal. 10) When start the second circulating water pump, start the circulating water pump remotely. Check and make sure that outlet butterfly valve opens normally by interlock. 11) Pay attention to the working condition of circulating water pump motor cooling water. 6.2.2
Circulating water stop
6.2.2.1 Check and make sure that pump valve local control mode is at „Remote‟ position; outlet butterfly control mode on CRT is at „Pump valve interlock‟ position. Special personnel should be at site for supervision before stopping pump. 6.2.2.2 Stop circulating water pump, check and make sure that outlet butterfly valve should close by interlock and pump does not run in reversal; otherwise relief pressure and close the valve manually. 6.2.2.3 Stop the last circulating water pump after all auxiliary equipment stop, LP cylinder (Ⅰ, Ⅱ) temperature is lower than 50℃ and there is no user of circulating water. 6.2.3
Circulating water system operation and maintenance
6.2.3.1 Circulating water pump outlet pressure is 0.18— 0.25 MPa and motor current is lower than 368A. 6.2.3.2 Circulating water pump motor oil chamber level is at 1/2 -- 3/4, temperatures of circulating water pump motor upper guide pad and circulating water pump thrust pad temperature are lower than 75℃. 6.2.3.3 Pump group coupler horizontal vibration is no higher than 0.05 mm, axial vibration is no higher than 0.03 mm, the sound is normal and generator stator winding temperature is no higher than 140℃. 6.2.3.4 Circulating water pump outlet butterfly oil pump station is working normal. Oil pump starts when oil pressure is lower than 6MPa and stops when oil pressure is higher than 11MPa. 6.2.3.5 Check trash remover and rotating strainer working condition to prevent strainer from blocking by impurities. 6.2.3.6 Trash remover starts automatically when front and rear water level difference reaches to 200mm and stops automatically when the water level difference reaches to 30mm.
6.3 Open cooling water system start and stop 6.3.1
Open circulating cooling water system
6.3.1.1 Check before starting open circulating cooling water pump 1) Make sure that system and pump interlock test id qualified. 2) Circulating water system is working normally. 3) Open inlet strainer front and rear check valves of open circulating water pump, close bypass valve, close blow down valve after blowing down and put inlet strainer into „Automation‟ control mode. 4) Close all water discharging valve in the system and open inlet valve of open cooling circulating water pump. 5) Open air discharging valves in open circulating water pump proper and the system; close the valves when water is seen. 6) Open cooling water inlet & outlet valves of closed cooling water heat exchanger (A, B or 118
C) to offer access of open circulating water. 6.3.1.2 Open circulating water system start 1) Start open circulating water pump A or B, check and make sure that outlet valve actuates normally. Motor current, vibration, sound, pressure and bearing temperature are normal. 2) Fully Open outlet valves of standby open circulating cooling water pump and put into standby. 6.3.2
Open circulating cooling water system stop
6.3.2.1 Make sure that open circulating cooling water users are with conditions for cutting off water supply. 6.3.2.2 Release „Standby‟ interlock of standby pump and close outlet valve of standby pump. 6.3.2.3 Stop the pump, outlet valve of the former running open circulating cooling water pump closes automatically. 6.3.3
Open circulating cooling water pump switching
6.3.3.1 Check and make sure that standby open circulating cooling water pump is in fine condition and with conditions for starting. 6.3.3.2 Check and make sure that standby open circulating cooling water pump inlet valve is open. 6.3.3.3 Release standby open circulating cooling water pump from „Standby‟. 6.3.3.4 Start standby open circulating cooling water pump, check and make sure that it current, vibration, sound and outlet pressure are normal. 6.3.3.5 Stop the former running open circulating cooling water pump, check and make sure that CRT indications are right and pump does not run in reversal locally. 6.3.3.6 Check the signal of open circulating cooling water head pipe pressure low; put the former running pump into „Standby‟ according to requirement. 6.3.4
Open circulating system operation and maintenance
6.3.4.1 Open circulating cooling water pump inlet strainer differential pressure is not higher than specified value. 6.3.4.2 Open circulating cooling water pump and motor bearing temperature are normal. 6.3.4.3 Open circulating cooling water pump motor winding temperature, the sound, vibration and friction between pump and motor are normal.
6.4 Closed circulating cooling water system start and stop 6.4.1
Closed circulating cooling water system start
6.4.1.1 Check before start 1) Open the head pipe inlet valve from closed water tank to closed water returning water. 2) Put closed cooling water tank water level indicator into operation. 3) Close all the water discharging valves in the system; open air discharging valve and close it as water is seen. 4) Open check valves before and after closed cooling water tank level automatic regulating valve. 5) Start condensing water transfer pump to supplement water to closed cooling water tank to normal level (Make-up water valve from condensing water pump outlet to closed water tank can be open). 6) Open closed cooling water pump inlet motorized valve.
119
7) Open closed cooling water cooler inlet and outlet valve, feed water and discharge air for the pump proper and the system, close air discharging valve after air discharged. 8) Offer closed cooling water access. 9) Check and make sure that closed water pump bearing oil is qualified. 6.4.1.2 Make sure water feeding and air discharging is completed, close pump outlet valve. 6.4.1.3 Start closed cooling water pump (A or B), pay attention that pump outlet valve opens by interlock until it is fully open and closed water tank level is normal; otherwise open bypass valve for water supplement. Check and make sure that motor current, pump group vibration, sound, outlet pressure, bearing temperature are normal; regulate the closed cooling water system users to ensure that closed pump is in over current. 6.4.1.4 After standby closed pump water feeding and air discharging is completed, open the outlet valve of standby pump and put the pump into „Standby‟. 6.4.1.5 Closed cooling water pump interlock protection. 6.4.1.6 Conditions of starting closed circulating cooling water pump 6.4.1.7 Open circulating cooling water system is working normal. 6.4.1.8 Closed circulating cooling water level is not low. 6.4.1.9 Closed circulating cooling water pump trip conditions 1) Closed circulating cooling water pump on for 60s and it‟s outlet valve closed. 2) Closed water pump suction header pressure low low. 3) Closed water pump motor drive end bearing temperature ≥95℃. 4) Closed water pump motor non-drive end bearing temperature ≥95℃. 5) Local emergency button is pressed down. 6.4.1.10
Closed water pump interlock start conditions
1) The closed water pump outlet main pipe pressure still low, while one of the pumps running more than 10s. 2) Running closed water pump trips. 6.4.2
Closed circulating cooling water system stop
6.4.2.1 Make sure that all the closed water users are with conditions for cutt off water supply. 6.4.2.2 Release standby pump from „Standby‟ and close it outlet valve. 6.4.2.3 Stop closed cooling water pump. 6.4.2.4 Check and make sure that running pump outlet valve closes automatically, otherwise close it manually. 6.4.2.5 Stop supplementing water to closed cooling water tank. 6.4.2.6 Close closed cooling water and cooling water inlet & outlet valve according to requirement and stop closed water cooler. 6.4.3
Closed cooling water pump switching
6.4.3.1 Check and make sure that standby pump is in fine condition and with start conditions. 6.4.3.2 Check and make sure that closed water tank level is normal. 6.4.3.3 Check and make sure that standby pump inlet valve is open. 6.4.3.4 Release standby pump from „Standby‟. 6.4.3.5 Start standby pump. Check and make sure that current, vibration, sound and outlet pressure are normal; CRT status indications are right. 120
6.4.3.6 After complete check, make sure that former running pump outlet valve and closed water head pipe pressure is normal. 6.4.3.7 Stop former running pump, check and make sure that CRT indications are right. 6.4.3.8 Start former running pump outlet. 6.4.3.9 Check that closed water head pipe has no low pressure signal, put former running pump into „Standby‟.
6.5 Start & stop of auxiliary steam system 6.5.1 Preparation for starting auxiliary steam 6.5.1.1 Preparation for machinery, see as in valve operation card. 6.5.1.2 Make sure that auxiliary safety is calibrated and normal. 6.5.2 Start HP auxiliary steam connection 6.5.2.1 Contact start-up boiler to start auxiliary steam. 6.5.2.2 Make sure that all drainage valves before HP auxiliary steam head pipe and user‟s valve are fully open, Slightly open HP auxiliary motorized valve from start-up boiler, keep the pressure of HP auxiliary steam connection is 0.05～0.1MPa, heat HP auxiliary steam connection pipes about 20 minutes. 6.5.2.3 When there is steam emitting from all drainage water pipe, Slightly open HP auxiliary motorized valve from start-up boiler, and rise the pressure of HP auxiliary steam connection to 1.27MPa. 6.5.2.4 Check start-up boiler HP auxiliary steam desuperheat valve adjust normally, HP auxiliary steam connection temperature is between 315～335℃. 6.5.2.5 Put all auxiliary users into operation according requirements, and make sure that auxiliary steam head pipes are sufficiently heated. 6.5.3 Start IP auxiliary steam connection 6.5.3.1 Contact start-up boiler to start auxiliary steam. 6.5.3.2 Open HP auxiliary steam to IP auxiliary steam connection motorized valve, front and back drainage valve, and IP auxiliary steam connection to drainage valves of head pipe, slightly open HP auxiliary steam to IP auxiliary steam valve, keep IP auxiliary steam connection is 0.05～0.1MPa, heat IP auxiliary steam connection pipes about 20 minutes. 6.5.3.3 Open HP auxiliary steam to IP auxiliary steam motorized valve, rise the pressure of IP auxiliary steam connection to 0.75～1MPa, put HP auxiliary steam to IP auxiliary steam valve into automatically control, check HP auxiliary steam to IP auxiliary steam valve adjust normally. 6.5.3.4 Check HP auxiliary steam to IP auxiliary steam valve adjust normally, IP auxiliary steam 6.5.4
connection temperature is between 250℃. Switching HP auxiliary steam to reheating cold section:
6.5.4.1 Switching HP auxiliary steam header to reheating cold section when pressure of reheating cold section higher than pressure of HP auxiliary steam header. 6.5.4.2 Confirm that isolation valve after auxiliary steam regulation valve from reheating cold section to auxiliary steam head pipes is open, drainage valve before check valve from cold section to auxiliary is open and drainage valve before isolation valve is open. 6.5.4.3 Check and make sure that auxiliary cold section inlet steam regulation valve set pressure value is lower than auxiliary head pipe pressure; regulation valve is at automatic close position. 121
6.5.4.4 Sufficiently open auxiliary cold section steam inlet motorized valve, then set auxiliary clod section inlet steam regulation valve pressure a little higher than auxiliary header pressure. Make sure that auxiliary steam cold section inlet steam regulation valve open slowly and regulates automatically to required set value. Start up boiler may run with decreased load. 6.5.4.5 Check and make sure that all drainage valves of auxiliary steam headers and users are at regulation position; auxiliary pipe and auxiliary steam safety valve have no leakage. 6.5.5
Switching from IP auxiliary steam to fourth section extraction
6.5.5.1 Switch IP auxiliary steam to fourth section extraction when pressure of fourth section extraction higher than pressure of IP auxiliary steam header. 6.5.5.2 Make sure that all drainage water regulations in pipes from fourth extraction are normal, slowly open steam incoming motorized valve from auxiliary steam. Make sure that there is no impact or vibration in pipes. 6.5.5.3 Regulate auxiliary steam cold section inlet steam regulation valve pressure to be lightly lower than auxiliary steam fourth extraction pressure. Check and make sure that auxiliary steam cold section inlet steam regulation valve closes gradually with the rising of auxiliary steam fourth extraction steam. 6.5.5.4 Stop start up boiler according to requirement. 6.5.6
Auxiliary steam system stop
6.5.6.1 If auxiliary steam system needs to be stopped, it can be stopped after confirming that there is no auxiliary steam user and shift manager‟s approval. 6.5.6.2 Close auxiliary steam cold section steam inlet isolation valve, motorized valve, auxiliary steam head pipe connection valve, fourth extraction motorized valve, auxiliary steam isolation valve and motorized from start up boiler. 6.5.6.3 Sufficiently open all the drainage water valves of auxiliary steam head pipe. 6.5.6.4 Auxiliary steam system start, stop and switching should be reported to shift manager timely.
6.6 Condensing water system start and stop 6.6.1
Preparation before starting condensing water system
6.6.1.1 Preparation part for machinery, please see as in check cards. 6.6.1.2 Make sure that closed cooling water system and air compress system is working normally. 6.6.1.3 Contact with chemical to supplement water to desalt water tank to about normal value, condensate water make-up water tank make-up control valve put into automatically control. 6.6.1.4 Start condensing water transfer pump. 1) Confirm that condensing water pump inlet valve, re-circulating valve is open and pump outlet valve is closed. 2) Open condensing water transfer pump air discharging valve, inlet strainer air discharging valve; close them when water is seen. 3) Slightly open outlet valve, start condensing water transfer pump, check and make sure that pump and motor sound, vibration, bearing temperature, motor current and outlet pressure are normal. 6.6.1.5 Water feeding to condensing water system and water supplement for condenser 1) Open condensing water transfer pump outlet valve gradually and regulate re-circulating valve openness properly. 2) Open condenser water supplement bypass valve to supplement water to condenser.
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3) When condenser water level is normal, close water supplement bypass valve and slightly open condensing water transfer pump re-circulating valve. 4) Open check valves before and after condenser water supplement regulation valve and put water level into automatic control. 5) Open feeding water valve from condensing water transfer pump to condensing water system, open air discharging valves in condensing water system to feed water and discharge air. Close all air discharging valves when continuously water is seen. 6.6.2
Conditions for starting condensing water pump:
6.6.2.1 Condenser water pump motor up and down bearing temperature <85℃. 6.6.2.2 Condenser water pump thrust bearing temperature <75℃. 6.6.2.3 Open condenser water pump inlet valve. 6.6.2.4 High and low back pressure condenser water level is not low. 6.6.2.5 Condenser water pump sealing water pressure is not low. 6.6.2.6 Condenser water pump re-circulating valve is open >95%. 6.6.2.7 No fault signals for condensing water pump. 6.6.3
Condensing water pump start:
6.6.3.1 Make sure that condenser water pump water level is normal; all interlock protection tests of condenser water pump are qualified. 6.6.3.2 Make sure that condensing water system is feeding water and air discharging is completed. 6.6.3.3 Make sure that condensing water transfer pump outlet pressure is normal. 6.6.3.4 Start sealing water valve from condensing water transfer pump outlet to condensing water pump, put condensing water pump sealing water into operation. 6.6.3.5 Open air discharging valves of condenser water pump inlet strainer, pump proper and air discharging valve before outlet valve. 6.6.3.6 Open condenser water pump inlet valve, feed water to condenser water pump. Make sure that condenser water pump re-circulating valve is open. 6.6.3.7 Send power to condenser water pump. 6.6.3.8 According to actual conditions, start condensing water pump with frequency conversion or working frequency. Make sure that current, vibration, sound and pressure indications are normal. Make sure that outlet valve opens automatically after pump starts; otherwise open it manually. 6.6.3.9 Check whether water level of condenser hot well and pressure of condensate water pipe is normal, check system has no leakage phenomenon. 6.6.3.10
Open sealing water valve form condenser water pump outlet to pump proper, close sealing water valve from condenser water transfer pump to condenser water pump.
6.6.3.11
Open inlet valve of the other condenser water pump, open extraction valve before pump proper and outlet valve, open outlet valve (notice: pump should not running reverse)and put into standby.
6.6.4
Condensing water stop:
6.6.4.1 After unit stop, make sure that LP cylinder steam exhausting temperature (HP, LP condenser) is lower than 50℃ and there is no other users suing water, then stop the condenser water pump. 6.6.4.2 Release standby condenser water from „Standby‟. 6.6.4.3 Stop condenser water pump. 123
6.6.4.4 Make sure that condenser water pump outlet valve should close automatically; otherwise close it manually. 6.6.5
When condenser water pump should be isolated for maintenance after stopping condenser water pump, close pump proper and outlet valve, close inlet valve, close sealing water pump from condenser water pump outlet to pump, close sealing water valve from condensing water transfer pump to condenser water pump.
6.6.6
Condensing water pump switching:
6.6.6.1 Make sure that condenser water pump is in standby and with starting conditions. 6.6.6.2 Make sure that sealing water of condenser water pump is working normally. 6.6.6.3 Make sure that standby condenser water pump inlet valve is open. 6.6.6.4 Make sure that standby condenser water pump outlet is open. 6.6.6.5 Make sure that condensing water system is working normally. 6.6.6.6 Make sure that pump proper and outlet valve are open. 6.6.6.7 Release standby condenser water pump from „Standby‟. 6.6.6.8 Start standby condenser water pump. 6.6.6.9 Check and make sure that motor current, vibration and sound are normal after condenser water pump starts, CRT indications are right. 6.6.6.10
Check and make sure that condensing water system pressure is normal.
6.6.6.11 Stop the former running pump, outlet valve closes automatically. Make sure that CRT indications are right. 6.6.6.12
Check and make sure that pump does not run in reversal after the running pump stops.
6.6.6.13 Check and make sure that there is no signal of pressure low at outlet head pipe of condenser water pump, open outlet valve of former running pump and put the former running pump into standby according to requirement. 6.6.7
Condensing water pump operation and maintenance
6.6.7.1 Condenser water pump outlet pressure is normal and current does not exceed set value. 6.6.7.2 Condenser water pump thrust bearing oil is qualified. Condenser water pump motor bearing does not exceed 85℃. 6.6.7.3 Condenser water pump gland packing has no leakage, sealing water and motor bearing cooling water are working normally. 6.6.7.4 There is abnormal sound in water pump or motor, motor up and down bearing vibration do not exceed set value. 6.6.7.5 Condenser water pump motor winding temperature does not exceed set value.
6.7 Deaerator start and stop 6.7.1
Preparation before starting deaerator
6.7.1.1 Make sure that compressed air system is working normal and air pressures of instrumental meters are normal. 6.7.1.2 Make sure that all instrumental meters of deaerator are complete and all water level indicators are working normally. 6.7.1.3 Make sure that auxiliary steam system is working normally; auxiliary steam pressure and temperature comply with requirements. 6.7.1.4 Make sure that condensing water system is working normally and water is qualified. 6.7.1.5 Deaerator water, pressure interlock protection tests are qualified. Put measuring and 124
protecting devices for deaerator water level and pressure etc into operation. 6.7.1.6 Make sure that following valves are closed: 1) Continuous air discharging primary and secondary valves from #1, 2, 3 HP heaters to deaerator. 2) Relevant isolation valves for nitrogen charging protection of deaerator. 3) Deaerator emergency water discharging valve and over flow valve. 4) Open normal discharged water control valve and front, back manually valve from deaerator to #3 HP heater before #3 HP heater is running. 5) Motorized isolation valve and check valve from fourth steam extraction to deaerator. 6) Pressure regulating valve and its isolation valve from auxiliary steam to deaerator. 7) Valve from boiler air heater drainage water to deaerator. 8) Valve from continuous blow down to deaerator. 6.7.1.7 Start deaerator and open air discharging valve. 6.7.1.8 All the pipes of deaerator should be flushed and cleaned after major or minor maintenance or for the first start. 6.7.2
Deaerator start
6.7.2.1 Supply water to deaerator can use condensate pump or condensate transformation pump. 6.7.2.2 Supply water from condensate water to deaerator after deaerator cleaning is over and quality of condensate water is ok, keep deaerator water level at about 1400mm, slightly open deaerator water level control valve, feed water into pipe, increase flux when air has been exhausted, avoid damage nozzle. 6.7.2.3 Open motorized pump booster pump inlet valve, open isolation valve before and after re-circulating regulation valve of motorized pump. Feed water and discharge water for the motorized pump. 6.7.2.4 Open inlet valve of A, B steam driven steam pump booster pump; open isolation valves before and after A, B steam driven pump re-circulating; feed water and discharge water for A, B steam driven pump booster pump. 6.7.2.5 Check whether motorized pump comply with start conditions or not, start motorized pump (or start steam driven feed water pump booster pump, put deaerator into operation for heating). 6.7.2.6 Check and make sure that drainage valve after motorized valve from HP auxiliary steam to deaerator, open motorized valve from HP auxiliary steam to deaerator slowly for heating pipe. Pay attention to control pipe temperature rise rate to avoid pipe vibration. 6.7.2.7 After heating pipes, close the drainage water valves. Open motorized valve from auxiliary steam to deaerator. Open regulation valve slowly to keep deaerator temperature rise rate be within 1.5℃/min and heat and deoxidize the water in deaerator water tank. 6.7.2.8 Heat the water in deaerator according to boiler feed water temperature requirement, control the temperature difference of drum inlet water and inner wall metal to be lower than 90℃ to make the drum inner & outer wall temperature difference and up & down wall temperature difference be within regulated values. 6.7.2.9 After putting condensing water system into operation, control deaerator water level with deaerator water level regulation valve. 6.7.2.10
When feed water pump starts and deaerator water level and flow are normal, put deaerator water level automatic regulation into operation according to requirement.
6.7.2.11
During unit start and feeding water to boiler, deaerator pressure should be controlled at 0.147MPa and deaerator is working with fixed pressure. 125
6.7.2.12
When unit is running normally, switch deaerator start steam exhaust to normal continuous steam exhaust. Regulate the openness of oxygen discharging valve according to oxygen content in feeding water.
6.7.2.13
With the load increase of the unit, fourth extraction pressure reaches to 0.147MPa and deaerator steam source changes from auxiliary steam to fourth steam extraction; deaerator changes from running with fixed pressure to running with sliding pressure.
6.7.2.14
During sliding pressure and when steam and water are qualified, open isolation valve from continuous blow down to deaerator.
6.7.3
Deaerator normal operation and maintenance
6.7.3.1 During normal operation, deaerator pressure ＜1.03MPa and temperature ≯340℃, which is corresponding to unit running working condition with sliding pressure range of 0.147～ 0.962MPa. 6.7.3.2 Indication of water level on CRT and local indicator should be compared frequently and in consistent. 6.7.3.3 Deaerator water level control automation should be in operation to ensure deaerator runs with a normal water level. 6.7.3.4 When auxiliary steam is used as standby steam source during deaerator normal operation, manual isolation valve of pressure regulation valve of deaerator should be fully open, drainage water should be slightly open and pressure regulation valve should be put into automation. 6.7.3.5 During deaerator normal operation, dissolved oxygen should be complies with requirement (≤7PPb mg/L). Regulate the openness of continuous air discharging valve according to oxygen content variation in feeding water. Open the valve from continuous air discharging valve to atmosphere to make oxygen content be within regulated range if it is necessary. 6.7.3.6 Deaerator outlet temperature ≤178.3℃. 6.7.3.7 Deaerator safety valve action value is 1.0MPa. 6.7.3.8 When boiler air heater returning water enters into deaerator, the water should be firstly analyzed to be qualified. 6.7.4
Deaerator stop
6.7.4.1 In normal load decrease or unit stop, deaerator should be stopped with sliding parameter mode with sliding pressure range of 0.147～0.962MPa. 6.7.4.2 With the decreasing of unit load, when fourth steam extraction pressure reaches to 0.147MPa, steam source of deaerator should be changed from fourth extraction steam to auxiliary steam. 6.7.4.3 Pay attention that the dropping water level automatic regulation should be normal when unit load is decreasing, otherwise it should be switched to be manual. 6.7.4.4 When unit stopped, stop feeding water to deaerator according to actual conditions. 6.7.4.5 Close the isolation valve from boiler continuous blow down vessel to deaerator when boiler continuous blow down stopped. 6.7.4.6 When unit stopped, close normal drainage valve and front & back manually valve from #3 HP heater to deaerator, close continuous exhaust first and second valve from #1 #2 #3 HP heater to deaerator. 6.7.4.7 When unit stopped and boiler don‟t need supply water, valve from auxiliary steam to deaerator main, bypass should switch to manual control and then close it, close front & back motorized valve
from auxiliary steam to deaerator main, bypass valve, stop
deaerator heating. 126
6.4.7.8 When feed water pump stopped, water level control valve of deaerator should switch to manual control and then close it, stop supply water to deaerator. 6.4.7.9 Take good care of deaerator after stop it. If deaerator stops for more than one week, it should be protected by charging nitrogen. Cut off all steam source and water source, close water discharging valve after water in water tank is completely discharged. After full isolation, open nitrogen charging valve and isolation valve to charge nitrogen into deaerator and keep a certain pressure.
6.8 Motorized feeding water pump start and stop 6.8.1
Check before start
6.8.2
All interlocks of motorized feeding water pump should be tested to be qualified, all interlocks and relevant meters are working:
6.8.2.1 Check and make sure that cooling water is working normally. 6.8.2.2 Check and make sure that motorized feeding water pump oil tank level is normal and oil system is ready for operation. 6.8.2.3 Start motorized feeding water pump, check and make sure that oil system is working normally. 6.8.2.4 Regulate oil cooler water outlet valve of motorized feeding water pump, keep oil temperature within 36～54℃. 6.8.2.5 Check and make sure that all water discharging valves of pump group and its pipelines are closed. 6.8.2.6 Check and make sure that deaerator water tank level is normal, water is qualified and water temperature meets the requirement of feeding water to boiler. Slightly open booster pump inlet valve and feed water to booster pump, feeding water pump and pipeline and discharge air in them. Air valve closes after seeing water. After water feeding and air discharging, fully open inlet valve. 6.8.2.7 Outlet motorized valve of motorized feeding water is closed. 6.8.3
Open check valves before and after minimum flow valve of motorized feeding water pump, open circulating valve after it is confirmed.
6.8.3.1 Open closed water inlet valve of mechanical sealing of motorized feeding water pump, open the outlet valve after feeding water and discharging air. 6.8.3.2 Open mechanical sealing water magnetism filter inlet & outlet valves of motorized feeding water pump, close bypass valve. 6.8.3.3 Put mechanical sealing water of motorized feeding water pump booster pump into operation. 6.8.3.4 Check and make sure that spoon actuator power supply of motorized feeding water is normal. 6.8.3.5 Send power to motorized feeding water pump. 6.8.4
Motorized feeding water pump start
6.8.4.1 Make sure that all the conditions for motorized feed water pump start are satisfied. 1) Motorized feeding water pump temperature is normal. 2) Motorized feeding water pump re-circulating regulation valve is open. 3) Lubricate oil pressure is not low. 4) Motorized feeding water pump outlet valve is closed. 5) Motorized feeding water pump booster pump inlet valve is open. 6) Deaerator water level is not low. 127
7) Motorized feeding water pump spoon pipe is at minimum position. 6.8.4.2 Make sure that motorized feeding water pump outlet motorized valve is closed. 6.8.4.3 Set motorized feeding water pump spoon pipe at 10%~15% position. 6.8.4.4 Start motorized feeding water pump; make sure that motor cooling water is working. If 10s after motorized feeding water pump start, current has not recovered to be normal, pump should be stopped immediately. 6.8.4.5 Completely check and make sure that all bearing inlet oil and returning oil temperatures, vibration, sound and strainer differential pressure are normal. 6.8.4.6 Open motorized feeding water pump outlet valve, regulate motorized feeding water pump spoon pipe to required position to feed water to feeding water pipes and discharge air; after air is completely discharged, regulate motorized feeding water pump spoon pipe to feed water to boiler. 6.8.4.7 When motorized feeding water pump lubricate oil pressure is higher than 0.22MPa, motorized feeding water pump auxiliary oil pump stops normally by interlock. 6.8.4.8 After pump runs normally, pay attention to the change of motorized feeding water pump sealing water temperature, regulate oil cooler cooling water timely to make lubricate oil of motorized feeding water pump be within 36～54℃ and working oil temperature be within 36～70℃. 6.8.4.9 Check and make sure that motorized feeding water pump lubricate oil pressure and working oil pressure are normal. 6.8.4.10 6.8.5
Open the tap valve in the middle according to requirement.
Motorized feeding water pump stop
6.8.5.1 Check and make sure that motorized feeding water pump minimum flow valve is at „Automation‟ position. 6.8.5.2 Close motorized feeding water pump spoon pipe gradually and make sure that minimum flow valve is normally open. 6.8.5.3 When motorized feeding water pump lubricate oil pressure is lower than 0.15MPa, motorized feeding water pump auxiliary pump can start normally by interlock. 6.8.5.4 Continue to close motorized feeding water pump spoon pipe until it is fully closed. 6.8.5.5 Close tap valve in the middle of motorized feeding water pump. 6.8.5.6 Stop motorized feeding water pump and close outlet motorized valve of the pump. 6.8.6
Conditions for motorized feeding water pump standby
6.8.6.1 All AC & DC power supply of motorized feeding water pump are sent (power supply of actuator of pump spoon pipe) . 6.8.6.2 Motorized feeding water pump oil tank level is normal and oil is qualified. 6.8.6.3 Motorized feeding water pump has been put into „Standby‟. 6.8.6.4 Motorized feeding water pump auxiliary lubricate oil pump runs continuously; oil pressure, oil temperature and all flows of all bearings are normal. 6.8.6.5 Motorized feeding water pump booster pump inlet valve are fully open. 6.8.6.6 Motorized feeding water pump spoon pipe is at „5%‟ position. 6.8.6.7 Motorized feeding water pump outlet motorized valves are fully open. 6.8.6.8 Isolation valves before and after motorized feeding water pump minimum flow are fully open. Minimum flow valve is fully open and in „Automation‟. 6.8.6.9 Manual isolation valves of motorized feeding water pump tap valve are fully open. 128
6.8.6.10 All interlock protectors of motorized feeding water pump are working and all measuring meters, transmitters are working. 6.8.7
Motorized feeding water pump operation and maintenance
6.8.7.1 Motorized feeding water pump inlet and outlet pressure are normal, current does not exceed rated value. 6.8.7.2 Motorized feeding water pump oil tank level is normal, oil is qualified. Motorized feeding water pump lubricate oil pressure is higher than 0.17MPa, filtered lubricate oil pressure of motorized feeding water pump is normal within 0.25～0.35 MPa. Motorized feeding water pump lubricate oil cooler inlet temperature is lower than 65℃, lubricate oil cooler outlet temperature is ＜55℃, working oil cooler inlet oil temperature is lower than 110℃, working oil cooler outlet oil temperature is lower than 75℃. All bearings returning oil temperature do not exceed 65℃. 6.8.7.3 Motorized feeding water pump radial bearing temperature is lower than 80℃, thrust bearing temperature is lower than 90℃, booster pump bearing temperature is lower than 90℃, all bearing metal temperatures of motorized feeding water pump coupler are less than 90℃, mechanical sealing water temperature is normal and sealing ring temperature is no higher than 80℃. 6.8.7.4 Motor cooling water is normal, cooling water temperature is lower than 38℃, water pressure is normal. 6.8.7.5 There is no abnormal sound in water pump and motor. Motorized feeding water pump drive end and non-drive end bearing vibration is lower than 7.1 mm/s and do not exceed 11.2 mm/s at most. 6.8.7.6 Motorized feeding water pump and booster pump axial displacement is normal. 6.8.7.7 Pump shell and oil system have no leakage. Motorized feeding water pump and booster pump strainer differential pressure is normal.
6.9 Steam driven feed water pump group start & stop 6.9.1
Conditions should be prepared for starting steam driven feed water pump group
6.9.1.1 Feed water pump turbine is in shutoff. 6.9.1.2 MEH control power supply and other power supplies in system are working. 6.9.1.3 All compressed air source valves are open. 6.9.1.4 Steam parameters comply with requirement. 6.9.1.5 Cooling water source could supply water for oil cooler and steam seal desuperheater at any time. 6.9.1.6 Preparation of mechanical part, see as in valve check cards. 6.9.2
Start lubricate oil system
6.9.2.1 Make sure that lubricate oil system are with conditions for starting, start oil-fume extractor and make sure that it runs normally. 6.9.2.2 Make sure that conditions for starting #1, #2 lubricate oil pumps and emergency oil pump are satisfied. 6.9.2.3 Send the power of emergency oil pump and put emergency oil pump interlock into operation. Check automatic start of emergency oil pump and make sure that it runs normally; stop the emergency oil pump. 6.9.2.4 Send #1 lubricate oil pump power and put #1 lubricate oil pump interlock into operation; #1 lubricate oil pump starts automatically. Make sure that #1 lubricate oil pump runs normally. 6.9.2.5 Send #2 lubricate oil pump power and put #2 lubricate oil pump interlock into operation; open #1 lubricate oil pump test magnet and check #1 lubricate oil pump outlet pressure 129
low alarm. #2 lubricate oil pump automatic start is normal. 6.9.2.6 Stop #1 lubricate oil pump and start interlock, test #2 lubricate oil pump with above method. 6.9.2.7 Put emergency oil pump interlock, check the interlock of emergency oil pump interlock with above method. 6.9.2.8 Decide whether supplement oil or not according to oil tank level and decide whether put oil cooler into operation or not according to oil temperature. 6.9.3
Put HP control oil system into operation
6.9.3.1 Turbine fire-resistant oil system is in operation and runs normally. 6.9.3.2 Check and make sure that fire-resistant oil HP accumulator is in normal operation. 6.9.3.3 Open the inlet for supplying fire-resistant oil to feed water pump turbine from turbine, open the oil returning valve and check whether is leakage or not. 6.9.4
BFPT could put into operation when oil pressure of lube oil is satisfied. BFPT can start only when turning gear running more than 45 minutes in order to avoid rotor bending and librating.
6.9.5
Put gland sealing system into operation and start exhaust valve of BFPT, vacuum of BFPT is established.
6.9.5.1 Check and make sure that #1, #2 BFPT gland sealing steam inlet isolation valve is open, gland sealing steam returning valve is open, isolation valves before and after LP attemperating regulation valve of BFPT gland sealing steam supplying are open and bypass valve of attemperating water is closed. 6.9.5.2 Slightly open gland sealing steam inlet isolation valve of BFPT, check and make sure that drainage water in gland sealing air supplying pipes are smooth and BFPT gland sealing sends steam for heating pipes. Regulate gland sealing supplying steam temperature to about 0.101MPa and steam temperature to 150℃—177℃. 6.9.5.3 After gland sealing starts to supply steam, open BFPT steam exhausting butterfly valve and try to maintain a high vacuum. 6.9.6
Start BFPT water drainage
6.9.6.1 Make sure that all drainage valve of BFPT and its steam pipe is open before small turbine start up until turbine load reaches to 40% of rated load. 6.9.6.2 During unit stop, when turbine load decreases to 25% of rated value, above drain valves should be opened again. 6.9.6.3 When BFPT trips, pneumatic drainage valve should be opened immediately. 6.9.7
Booster pump start Booster pump start conditions should be confirmed: Pump group re-circulating valve is open; booster pump temperature is normal, booster pump inlet valve is open, steam driven outlet motorized valve is closed, deaerator water tank level is normal and booster pump feeding water is completed.
6.9.8
BFPT start Following conditions should be satisfied before starting BFPT:
6.9.8.1 Make sure that instrumental meters for supervising rotor vibration, axial displacement and running speed are complete and working normally. 6.9.8.2 EH oil system is normal, oil pressure is normal. 6.9.8.3 LP main steam valve and governor valve are closed. 6.9.8.4 Gland sealing system is working, gland sealing steam temperature is normal (150℃) and pressure is controlled within 0.101MPa. 130
6.9.8.5 Small steam turbine vacuum＞85KPa. 6.9.8.6 All drainage valves and steam exhausting valves of BFPT are open. 6.9.8.7 Lubricate oil pressure and temperature is normal. 6.9.8.8 Deaerator water tank water level is normal. 6.9.8.9 Pump re-circulating valve is fully open and governor valve is in AUTOMATION. 6.9.8.10
Valves of sealing water and cooling of the pump are open and water flow is smooth.
6.9.8.11
Make sure that protections of booster pump, BFPT and steam driven feeding water pump are working.
6.9.8.12
BFPT heating pipe. Open water discharging valves before and after LP steam source motorized valve from auxiliary steam to BFPT, slightly open LP steam source motorized valve from auxiliary steam to BFPT; close the water discharging valve after steam is seen. Fully open LP steam source motorized valve from auxiliary steam to BFPT and pay attention to pipe vibration when heating pipes.
6.9.8.13
Parameters of starting BFPT Steam pressure: 0.6～1.3MPa。 Steam temperature: with over temperature surplus of more than 50℃.
6.9.9
Starting BFPT
6.9.9.1 Press „Latch open‟ button, unit latch opens. 6.9.9.2 Choose “open LP main steam valve” button at MEH operation station, open LP main steam valve. 6.9.9.3 „Target running speed‟ sets as 800r/min, speed rising rate: 100～200r/min/min. 6.9.9.4 Press „GO‟ button, LP regulation valve opens gradually, unit increases running speed according to set velocity. 6.9.9.5 Check at 800r/min, check. 6.9.9.6 Under this speed, heat up the turbine for 15min, check the unit completely: whether stator and rotor abrade or not, vibration is high or not and axial displacement etc. 6.9.9.7 Speed rise to 1800r/min, min-speed warm up. Press „GO‟ button, running speed rises to target value. Under this speed, heat up the turbine for 45min, check the unit completely. 6.9.9.8 „Target running speed‟ sets as 3000r/min Press „GO‟ button, running speed rises to target value. 6.9.9.9 Note: Unit first critical running speed is about 2236 r/min, when turbine runs stably with speed of 1800 r/min, check all parts are working normally or not, make sure that all supervision and control meters are working. When there is no abnormity, then it can overcome first critical running speed rapidly. 6.9.9.10
When turbine actual running speed rises to 3000 r/min and it satisfies boiler automatic control conditions, turbine control mode switches stably from running speed automation to boiler automation. Later, turbine running speed changes with required signals from of feeding water amount from CCS (Boiler feeding water coordination control system).
6.9.9.11
Start steam driven feed water pump outlet motorized valve and pumps run in parallel (when steam driven pump outlet pressure approaches to feeding water head pipe, outlet valve opens).
131
6.9.9.12
Open middle tap valve of steam driven pump according to requirement.
6.9.9.13
When unit load reaches to 40% of rated load, close BFPT main steam valve, governor valve and all drainage valve on steam pipelines and steam cylinder.
6.9.10 Regulations for feeding water pumps run in parallel 6.9.10.1
Motorized pump and single steam driven pump 1) Check and make sure that boiler is at automatic control state, steam driven pump outlet pressure and motorized pump outlet pressure are close and differential pressure before and after steam driven pump is lower than 0.06MPa. 2) Make sure that motorized pump runs normally; motorized pump is at automatic control and feed water control is at automation. 3) Unit load is about 180MW. 4) Open steam drive outlet valve, watch the motorized pump and steam driven pump inlet flow, outlet pressure and minimum re-circulating flow. 5) During paralleling the pumps, try best to keep feeding water flow stable and watch the variation of drum water level. 6) If unit load decreases suddenly, switch steam driven pump from „Automatic‟ to „Manual‟ to avoid sudden flow decrease in „Automatic‟ state and trip due to steam driven pump inlet flow low protection because minimum floe valve can not open timely.
6.9.10.2
Two steam driven pumps 1) Confirm that the second BFPT stars and running speed is at boiler control. 2) Regulate steam driven running speed and make its front and rear outlet differential pressure be lower than 0.06 MPa. 3) Start steam driven outlet motorized valve and open middle tap valve. 4) Confirm that motorized pump and steam driven pump run normally, running speed is at automation and feeding water is at boiler control automation. 5) Regulate steam driven pump running speed, when the third pump outlet pressure is close, decrease motorized pump running speed and stop motorized pump. Check and make sure that motorized auxiliary oil pump automatic start and oil pressure is normal. 6) When two steam driven pumps are running in parallel and at „Standby‟ and motorized pump is at standby, if one steam driven pump trips, motorized pump starts by interlock or manually, the running steam driven pump should be switched to be manual regulation mode to ensure stable running speed of BFPT.
6.9.11 BFPT stop 6.9.11.1
Preparation before normal stop 1) Test standby main oil pump, emergency oil pump, turning gear, all of which can work normally. 2) Make sure that main steam valve, governor valve should actuate freely with no block.
6.9.11.2
Normal stop 1) When turbine load decreases to 60% of rated load, start motorized pump. Check if feeding water system is normal, a steam driven pump may be stopped. 2) Release steam driven pump from automation, decrease steam driven pump running speed and increase motorized pump load; check and make sure that the load the steam driven pump to be stopped has already been transferred. 132
3) Close the motorized valve from middle tap of the steam driven pump to be stopped to re-heater attemperating water. 4) Close steam driven pump outlet motorized valve, check and make sure that minimum flow valve is open. 5) When turbine load decreases to be lower than 25% rated value, open all the drainage valves on BFPT cylinder and steam pipeline and, open pneumatic drainage valves before LP main steam valve at the same time. 6) CCS will decrease BFPT running speed automatically with the turbine load decreasing, when BFPT running speed decreases to minimum value 3000r/min of „Boiler Automation‟ control mode, press „Trip‟ button on „MEH operation panel‟. 7) Check and make sure that BFPT LP main steam valve, valve are closed shortly and corresponding lights are on. 8) When running speed decrease to 0 r/min, turning gear could be put into operation manually. Turning gear must be operating at least 4 hours until cylinder temperature decrease to very low, and then turning gear also has to discontinuous running. 9) If BFPT stops fro a long time, following work should be done: a. If turbine continues to run with load less than 50% rated load, boiler should be supplied with water through motorized valve; vacuum butterfly valve on BFPT steam exhaustion should be closed to avoid breaking vacuum of the condenser. b. Stop supply to steam seal after vacuum is released. 10) Keep lube oil circulating for more than 4 hours after unit stopped in order to avoid heat can be transmitted from cylinder to bearing along rotor. 6.9.11.3
Emergency stop 1) Unit vibrates acutely with vibration amplitude that is higher than stop value, but protection device does not act, or unit vibrates more acutely. 2) There is clear metal friction sound and clash inside turbine. 3) There is water impact in water. 4) Bearing temperature rises acutely to 113 or any bearing returning oil temperature increases to 75℃. 5) Gland sealing or oil ring abrade seriously and sparkles. 6) Bearing lubricate oil is low to 0.059MPa, start standby oil pump but it is invalid. 7) Oil tank level is low to unit stop value, supplement oil but it is invalid. 8) Oil system is on fire and can not be put out. 9) Axial displacement exceeds ±0.25mm, and axial displacement protection device does not act. 10) Turbine running speed rises to trip running value but unit is not in shut off.
6.9.12 BFPT normal operation and maintenance 6.9.12.1
There is no impurities and leakages such steam, oil or water.
6.9.12.2
Oil tank oil level normal, if oil level is lower than 550mm, oil should be supplemented in timed.
6.9.12.3
Bearing returning oil temperature normally ＜60℃ and alarms at and above 65℃.
6.9.12.4
Control oil pressure, lubricate oil pressure and oil temperature are normal.
6.9.12.5
Measure the vibration of bearing and proper every day, vibration value should not exceed 0.08mm. 133
6.9.12.6
Check oil tank smoke discharging air fan and make sure it runs normally, keep small turbine oil tank vacuum at 1KPa.
6.9.12.7
Check feeding water pump lubricate oil strainer differential pressure, differential pressure should lower than 0.09MPa.
6.9.12.8
Check and make sure feeding water pump turbine lubricate oil cooling water pressure is normal at 0.3MPa.
6.9.13 BFPT oil cooler switching 6.9.13.1
Confirm running or standby status of the two oil coolers.
6.9.13.2
Check and make sure standby oil cooler is in fine condition.
6.9.13.3
Slightly open standby oil cooler oil filling valve and standby oil cooler outlet high position air discharging valve to fill oil and discharge air. When oil continuously emit from air discharging point, close the air discharging valve.
6.9.13.4
Fully open oil filling valve of oil cooler and rise the pressure of oil cooler to check leakage.
6.9.13.5
Start standby oil cooler cooling water inlet & outlet water valve.
6.9.13.6
Turn oil cooler and switch handle slightly to watch working condition of standby oil cooler.
6.9.13.7
Continue to turn switching handle slowly. Stay for a moment to watch after slight turning and put standby oil cooler into operation gradually until switch it to the running position of former running oil cooler, pay attention to oil temperature changes.
6.9.13.8
Close oil filling valve of oil cooler and close inlet & outlet water valve of former running oil cooler. Switch it into standby.
6.9.14 BFPT oil strainer switching 6.9.14.1
Open standby strainer oil filling valve slowly.
6.9.14.2
Open air discharging valve at top of standby strainer slowly.
6.9.14.3
After oil filling and air discharging for standby strainer, close air discharging valve at top of standby strainer and standby strainer oil filling valve.
6.9.14.4
Turn strainer switching handle slowly and switch the strainer to former standby strainer for operation.
6.10 Heaters start and stop 6.10.1 Operation principles of heaters start and stop 6.10.1.1
When putting heaters into operation, water side should be put into operation firstly and then steam side; during stop, stop steam side and then stop water side. LP heater should be put into operation at water side when filling water to condensing water system or put into operation after condensing water system work normally.
6.10.1.2
Air-side of heater adopt stochastic sliding start and stop in principle, but when this condition is not allowed it should be start from LP to HP, and stop from HP to LP.
6.10.1.3
Heaters with serious leakage are not allowed to be put into operation.
6.10.1.4
Heaters are allowed to be put into operation when water level indicators are complete, alarm signal and protection device are working normally.
6.10.1.5
Temperature changing rate of heater outlet water should be controlled critically during start and stop heaters.
6.10.1.6
During heaters start and stop, when heater drainage water flows stage by stage and can not meet the requirement, heater level should be controlled through emergency drainage water. 134
6.10.2 Check before putting heaters into operation 6.10.2.1
Make sure that heaters and pipelines are flushed and relevant tests and calibrations are qualified and, all protections for heaters are working.
6.10.2.2
Make sure that all meters working well.
6.10.2.3
Make sure that control air sources of all pneumatic valves are working normally.
6.10.2.4
Make sure that all drainage valves actuate normally and their automatic control has been put into operation.
6.10.2.5
Open the quick-close valves of all instrumental meters.
6.10.2.6
Make sure that heaters are charged with nitrogen and moisture protection system are isolated.
6.10.2.7
Make sure that all water discharging valves are closed.
6.10.2.8
Slightly open primary and secondary valves from LP continuous air discharging to condenser.
6.10.2.9
Make sure that primary and secondary valves from HP heater continuous air discharging to deaerator are closed.
6.10.2.10 Make sure that HP heater start air discharging valve si open. 6.10.2.11
Make sure that check valve of normal drainage water valve of heater is open and isolation valves before and after emergency drainage valves are open.
6.10.2.12
Make sure that steam extraction check valve is closed and drainage valves before and after steam extraction check valve are open.
6.10.3 Put LP heaters into operation during operation 6.10.3.1
Put LP heater water side into operation and close air discharging valve when air discharging valve in water chamber see water. Make sure that LP heater inlet 7 outlet water valves are normally open and bypass valve at water side is closed. Check and make sure that LP heater steam side water level indicator has no water level and condensing water flow does not change.
6.10.3.2
Open valve from heater drainage water to condenser, open steam extraction check valve of LP heater in operation, slightly open steam extraction motorized valve of LP heater in operation. Make sure that LP heater outlet water temperature changing rate ≯1.5℃/min.
6.10.3.3
Fully open LP heater steam extraction motorized valve gradually, open continuous air discharging valve and close water discharging valve from heater to condenser gradually. Make sure that condenser vacuum change and drainage valve actions are normal.
6.10.3.4
Check and make sure that drainage valves before and after steam extraction motorized isolation valve are closed.
6.10.4 Put HP heaters into operation during operation 6.10.4.1
Open small bypass valve of heater inlet valve to fill water to HP heater. Close air discharging valve when air discharging valve at water side sees water. When HP heater pressure reaches to bypass pipeline pressure, open HP heater outlet valve, close HP heater outlet valve and open inlet motorized three-way valve. Put HP heater water side into operation.
6.10.4.2
Open valve from heater drainage water to condenser, open steam extraction check valve of HP heater in operation, slightly open steam extraction motorized valve of HP heater in operation. Heater heats pipes. HP heater outlet temperature changing is strictly controlled ≯1. 5℃/min.
6.10.4.3
Open HP starting air discharging valve. 135
6.10.4.4
Close water drainage valve from heater to condenser gradually, fully open steam extraction motorized valve of HPP heater in operation gradually. Make sure that drainage valve from drainage water to deaerator act normally.
6.10.4.5
Close starting air discharging valve and open continuous air discharging valve.
6.10.4.6
Check and make sure that drainage water valve in steam extraction pipe are closed and HP heater water level is within normal range.
6.10.5 HP heater operation and maintenance 6.10.5.1
Lighting for local water level indicator is normal; water level is clear and normal. Compare the indications on local meters and in control room; drainage valve act should be normal.
6.10.5.2
Heater insulation is good and there is no vibration, steam water impact and steam water pipe has no leakage.
6.10.5.3
Check and make sure that all the pressures and temperatures of heater are normal with the unit load changing.
6.10.5.4
Check and make sure that heater drainage water temperature difference is normal at about 5～6℃.
6.10.5.5
During normal operation, drainage water of heater should floe automatically stage by stage. During low load period, neighboring heater pressure changing should be checked to avoid reversal steam. At the same time, heater water level can be controlled by emergency drainage water valve, but condenser vacuum change should be paid attention.
6.10.6 Stop HP heater in unit operation 6.10.6.1 Contact shift manager to decrease unit load properly, make sure that pressure of each supervision section is less than limit. 6.10.6.2 Switch normal drainage valve of HP heater to manual control then close, check accident drainage valve of HP heater open gradually, water level in air-side of HP heater is normal. 6.10.6.3 Close continuous exhaust manual valve from HP heater to deaerator. 6.10.6.4 Slowly close air extracting motorized valve of #1、#2、#3 HP heater from HP to LP in sequence until fully closed, pay attention to control water temperature changing rate of HP heater outlet, HP heater has no vibration. 6.10.6.5 When air extracting motorized valve of HP heater is fully closed, check steam extracting check valve of HP heater close automatically. 6.10.6.6 Check front & back drainage steam-drive valve of extracting motorized valve of HP heater open automatically. 6.10.6.7 Open accident drainage valve of HP heater, make pressure of HP heater air-side to 0. 6.10.6.8 Check turbine shaft position, metal temperature and vibration and expending difference of thrust bearing is normal. 6.10.6.9 Close HP heater inlet motorized three-way valve until it is fully closed, close HP heater outlet motorized valve. HP heater water side goes through bypass. 6.10.6.10 Open steam extracting valve and drainage valve of HP heater water-side to decrease pressure and drain water according to requirement, it should be avoid steam ejecting hurt people or influence equipment operate normally. 6.10.7 HP emergency stop condition 6.10.7.1
Heater steam water pipe and valve break, which threatens personal and equipment safety.
6.10.7.2
HP heater water level rises and is full.
6.10.7.3
All water level indications are in failure and water level can not be supervised.
6.10.7.4
HP emergency drainage water acts frequently, which makes water supplement difficult.
6.10.8 HP heater emergency stop 136
6.10.8.1
Close HP steam inlet motorized valve and steam extraction check valve immediately, open steam extraction pipe drainage water pneumatic valves.
6.10.8.2
HP heater water side steps out of system, feeding water goes through bypass.
6.10.8.3
Close valve from drainage water to deaerator.
6.10.8.4
When HP heater water level is too high and protector acts, the reason should be found immediately. HP heater is strictly prohibited to put into operation when there is leakage.
6.10.8.5
When HP steam side and water step out of system at the same time, feeding water pressure and floe should be strictly supervised to avoid feeding water intermitting.
6.10.8.6
When unit runs without HP heater, pressure at all sections should be within limit. Load can be limited if it is necessary.
6.11 Turbine gland sealing start and stop 6.11.1 Check before starting gland sealing system 6.11.1.1
Make sure that unit is in turning gear running state; circulating water, condensing water and auxiliary steam system are working normally.
6.11.1.2
Feed water and discharge air for gland sealing heater and switch returning water to condenser.
6.11.1.3
Put gland sealing steam heater water side into operation.
6.11.2 Gland sealing system start 6.11.2.1
Check and make sure that drainage valves of auxiliary steam supplying steam pipes are open.
6.11.2.2
Check and make sure that auxiliary steam supplying pressure and temperature are normal.
6.11.2.3
Gland sealing steam pressure set values: 1) Auxiliary steam supplying pressure regulation valve set value is 0.024MPa. 2) Re-heater steam supplying pressure regulation valve set value is 0.028MPa. 3) Gland sealing overflow valve set value is 0.031MPa.
6.11.2.4
Gland sealing steam temperature set values: 1) LP gland sealing steam temperature set value is 150℃. 2) BFPT gland sealing steam temperature set value is 150℃.
6.11.2.5
Steam source using principles: 1) When starting in cold state, auxiliary steam is used. When starting in hot state, gland sealing air source is from re-heater; if auxiliary steam is used, its temperature should reach 310℃. 2) After unit runs with load and when steam supplying pressure and temperature of re-heater meet requirement, steam source should be switched to be supplied by re-heater. 3) When unit trips, rejects load and re-heater pressure is low, put auxiliary steam into operation.
6.11.2.6
Slightly open auxiliary supplying steam bypass motorized valve to heat pipes.
6.11.2.7
Open drainage water manual valves of turbine proper and BFPT gland sealing strainer; close the manual valves after water drainage is completed. Pipe heating is completed.
6.11.2.8
Set pressure value and temperature value; regulation valve puts into operation automatically. 137
6.11.2.9
Open manual valves before and after auxiliary steam source regulation valve, close bypass valve and check that regulation valve works normally.
6.11.2.10
After gland sealing pressure is stable, start gland sealing air fan. Check and make sure that air fan vibration, sound, gland sealing vacuum and inlet & outlet temperature rise are normal.
6.11.2.11
Check and make sure that there is no steam leakage at steam sealing of all parts of turbine; otherwise check the working condition of gland sealing pressure regulation station and regulate it to be normal. Close drainage water valve in gland sealing system.
6.11.3 Gland sealing system stop 6.11.3.1
Close drainage water to condenser.
6.11.3.2
Stop vacuum pump and open vacuum breaking valve.
6.11.3.3
When condenser vacuum reaches to zero (0), close motorized valve before regulation valve from re-heater to gland sealing. Isolation valves from auxiliary to gland sealing and from re-heater to gland sealing are fully closed. Make sure that isolation valve of gland sealing attemperating water is strictly closed.
6.11.3.4
Release standby gland sealing air fan from „Standby‟ on CRT, stop gland sealing air fan.
6.11.3.5
Open all drainage valve, water discharging valves in gland sealing system, system releases pressure.
6.11.4 Gland sealing system operation and maintenance 6.11.4.1
Supervision during normal operation 1) Gland sealing steam head pipe pressure 24～28KPa. 2) LP gland sealing steam supplying pressure and temperature. 3) Gland sealing steam supplying pressure and temperature of BFPT A, B. 4) Gland sealing heater drainage water level. 5) Gland sealing heater steam side negative pressure. 6) Gland sealing air fan operation condition.
6.11.4.2
Operation limits for gland sealing system 1) Gland sealing supplying steam should be with over temperature surplus of no less than 14℃. 2) Gland sealing should be put into operation before running turning gear to avoid rotor bending. 3) LP gland sealing supplying steam temperature is 121-177℃ with control set value of 150℃. 4) During start and stop, temperature difference between gland sealing steam and rotor surface should be decreased as much as possible to avoid heat stress at gland sealing that may damage rotor. 5) If start the unit in hot state, auxiliary steam supplying gland sealing should be adopted; steam temperature should be paid attention to, the temperature difference between gland sealing steam and rotor surface metal should nor exceed maximum permit value 85℃.
6.12 Vacuum system stop 6.12.1 Preparation before starting vacuum system 6.12.1.1
Completely check vacuum pump and vacuum system and confirm that all conditions 138
for starting are satisfied. 6.12.1.2
Send power to vacuum pump.
6.12.1.3
Check and make sure that all the air discharging valves, water discharging vales are closed and relevant meters are working.
6.12.1.4
Make sure that manual isolation valves from condenser too vacuum pumps inlets are open.
6.12.1.5
Check and make sure that vacuum pump inlet valve is closed.
6.12.1.6
Make sure that condensing water system and closed circulating cooling water system are working normally.
6.12.1.7
Open the manual isolation valves from condensing water to vacuum pump steam water separator to fill water to separator; make sure that automatic water supplement valve acts normally, supply water to steam water air discharging about 1/2～2/3 of location water level meter.
6.12.1.8
Put vacuum pump cooler cooling water into operation.
6.12.1.9
Close condenser vacuum breaking valve.
6.12.1.10
Open vacuum breaking valve sealing water general valve regulate all the branch valves and keep a certain sealing water level without overflowing.
6.12.1.11
Start the three vacuum pumps at the same time when initially establishing vacuum; when maintaining vacuum, two pump run and one is in standby.
6.12.2 Vacuum start 6.12.2.1
Start the first vacuum pump, when vacuum pump inlet front and rear differential pressure reaches to -4.5KPa, vacuum pump inlet pneumatic valve starts automatically.
6.12.2.2
Make sure that vacuum pump inlet vacuum indication and steam water air discharging is normal.
6.12.2.3
Start the other 2 vacuum pump by sequence.
6.12.3 Vacuum pump operation and maintenance 6.12.3.1
Check and make sure that pump vibration is normal, no friction, no noise and motor current is normal.
6.12.3.2
Check leakage of pump stuffing box.
6.12.3.3
Check and make sure that vacuum pump steam water separator water level, working water temperature is normal.
6.12.3.4
Check and make sure that condenser vacuum breaking valve sealing water level is normal.
6.12.3.5
Check and make sure that vacuum cooler works normally
6.12.4 Vacuum pump stop 6.12.4.1
Release standby vacuum pump from „Standby‟ and stop the running vacuum pump.
6.12.4.2
Make sure that vacuum pump inlet valve is closed.
6.12.4.3
If pump is in fault or maintenance, pump should be isolated for work.
6.12.5 Vacuum pump switching 6.12.5.1
Check the standby vacuum pump completely and make sure that it is with starting conditions.
6.12.5.2
Release standby vacuum pump from „Standby‟. 139
6.12.5.3
Start standby vacuum pump, check and make sure that its current, vibration and sound are normal. CRT status indications are right.
6.12.5.4
Check and make sure that after starting standby pump, when front and rear differential pressure reaches to -4.5KPa, inlet valve starts automatically by interlock; otherwise contact with I&C for treatment.
6.12.5.5
After complete check, stop one former running vacuum pump. Check and make sure that CRT indications are right and all valves are closed locally.
6.12.5.6
Check and make sure that condenser vacuum is normal, put the vacuum stopped into „Standby‟ according to requirement.
6.13 Turbine lubricate oil system start and stop 6.13.1 Conditions for system start 6.13.1.1
All equipments interlock protection tests are completed and qualified.
6.13.1.2
Main oil tank is filled with suitable amount qualified oil (oil level should ≥500mm).
6.13.1.3
All oil & water discharging valves are closed.
6.13.1.4
Relevant oil coolers are working.
6.13.2 Equipment trial run and system leakage check 6.13.2.1
Start smoke discharging air fan of main oil tank, check and make sure that vibration and sound are normal.
6.13.2.2
Check and make sure that lubricate oil temperature is normal and sealing oil check is completed.
6.13.2.3
Close isolation valve from lubricate oil and HV standby oil to sealing oil, start AC lubricate oil pump. Check and make sure that vibration, sound and pressure are normal.
6.13.2.4
Check and make sure there is no oil leakage in lubricate oil system.
6.13.2.5
Stop AC lubricate oil pump, start DC emergency oil pump and hydrogen sealing oil pump. Check and make sure that vibration, sound and pressure are normal. Start DC emergency oil pump. Start hydrogen sealing oil pump for standby.
6.13.2.6
Check and make sure that all indications on pressure meters and thermometers are right.
6.13.2.7
Test oil cooler switching; make sure that oil pressure does not fluctuate during switching.
6.13.2.8
Start all jacking oil pumps in sequence; check and make sure that the vibration, sound, outlet pressure and all jacking oil pressures are normal.
6.13.2.9
Check and make sure there is no oil leakage in jacking oil devices.
6.13.2.10
Stop jacking oil pump.
6.13.2.11
Stop smoke discharging air fan of main oil tank.
6.13.3 Lubricate oil system start 6.13.3.1
It should be ensured that all checks are completed before starting lube oil system.
6.13.3.2
Start smoke discharging air fan of main oil tank.
6.13.3.3
Start AC lube oil pump and hydrogen sealing oil pump. Check and make sure that all the indications of pressure meters are right.
6.13.3.4
Put DC lubricate oil pump interlock switch into operation.
6.13.3.5
Check valve installed at oil injector outlet should be regulated by maintenance person for first start system and system after major maintenance. After regulation, fix it by 140
locking the handle. 6.13.3.6
Check oil flow in bearing returning oil watch hole is normal.
6.13.3.7
Check and make sure bearing lubricate oil temperature is normal. If oil temperature is too low, put oil heater of main oil tank into operation.
6.13.4 Lubricate oil system stop 6.13.4.1
Turning gear should continue to run until highest temperature point of turbine cylinder is lower than 150℃; turbine lubricate oil system only can be stopped when cylinder highest temperature point is lower than 120℃ and sealing oil system is working normally.
6.13.4.2
After turbine turning gear stops, release turbine DC oil pump from interlock and stop jacking oil pump according to cylinder temperature. Pay attention to oil level rise of main oil tank, when oil level is too high, it should overflow into oil storage tank out of turbine hall.
6.13.4.3
Close cooling water inlet & outlet valves of oil cooler.
6.13.4.4
Stop turbine lubricate oil purifying device if it is necessary.
6.13.4.5
Two hours after stopping lubricate oil system and sealing oil system, smoke discharging air fan of main oil tank can be stopped.
6.13.5 Turbine turning gear regulations 6.13.5.1
Turning gear must be put into operation four hours before starting turbine; during continuous turning gear, if main bearing stops due to turning gear fault or necessary for work, turbine can only be started after four (4) hours continuous running of turning gear.
6.13.5.2
During turning gear running, lubricate oil, jacking oil and sealing oil must be ensured not to intermit and be with sufficient pressure and rotor eccentricity does not exceed 0.075mm.
6.13.5.3
After turbine stops, turning gear and lubricate oil should run continuously for at least 48 hours until rotor is cooled to be lower than 150℃. All the relevant parameters of turbine should be supervised.
6.13.5.4
When cylinder first stage metal temperature is lower than 150℃, turning gear can be stopped; after turning gear stops, lubricate oil system should continuously run.
6.13.5.5
If jacking oil pump can not be put into operation, turning gear must be continuously turned. If „Block-skid‟ happens to turning gear, following measures should be done until jacking oil pump recovers to normal operation: a. Start DC emergency oil pump to increase lubricate oil amount and decrease oil temperature as much as possible but no less than 27℃. b. Wait for one minute, if „Block-skid‟ still exists, stop the turning gear for 15min and then start it again. c. If „Block-skid‟ still exists, stop the turning gear and turn rotor for 180°every 10min. Repeat the above method until „Block-skid‟ disappears and turning gear runs normally.
6.13.5.6
During unit stop and turning gear period, maintenance related to turbine proper is prohibited to avoid cold steam and cold water entering into turbine. Pay attention to supervise cylinder metal changing trend, temperature difference of up and down cylinder, temperature difference of main & reheating steam pipes, up 7 down temperature difference of steam extraction pipes, vessel water levels, pressures and temperatures. If up and down temperature difference increase acutely, reason should be found out immediately and cut off the water, steam sources.
6.13.5.7
During continuous turning gear, turning gear stop due to work necessity or turning gear 141
fault should be approved by chief engineer and following principles should be obeyed: a. If turning gear needs to be stopped due to turning gear fault or other necessity, after turning gear stops, corresponding position should be marked on rotor and stop time should be remembered. b. After turning gear stops, turn the rotor for 180°before recover continuous running. Pay attention to rotor eccentricity and there should no over current or current swing. 6.13.5.8
During continuous running of turning gear and under special condition, jacking oil device may be stopped, but turning gear current must be supervised; when its increase does exceed 120% of normal value, jacking device can be stopped and continue to run turning gear.
6.13.5.9
During continuous turning gear, if there is obvious metal friction sound in cylinder and turning gear current swing (it is not turning gear device fault), turning gear should be stopped immediately and manual turning according to above statute should be done until it recovers.
6.14 Turbine oil cooler start and stop 6.14.1 Oil cooler standby 6.14.1.1
During operation, standby oil cooler should be fulfilled with oil; oil cooler after maintenance only can be in standby after filling oil. Inlet and outlet oil valves are open and cooling water is stopped.
6.14.1.2
Check and make sure that oil level in main oil tank is above 0; otherwise oil should be supplemented to main oil tank.
6.14.1.3
When one oil cooler is running and the other is filled with oil after maintenance, oil filling valve of oil cooler should be slightly open. Supervise the changing of lubricate oil pressure and close oil filling valve after air at oil side in oil cooler is completely discharged.
6.14.2 Put water side of oil cooler into operation 6.14.2.1
Close oil cooler bottom water side discharging valve, close outlet valve of oil cooler.
6.14.2.2
Open oil cooler water side air discharging valve.
6.14.2.3
Make sure that isolation valves before and after oil cooler cooling water regulation valve are open and its bypass valve is closed.
6.14.2.4
Slightly open oil cooler inlet water valve, fill water and discharge air for oil cooler. Close air discharging valve when water is seen.
6.14.2.5
Open outlet valve of oil cooler.
6.14.2.6
Confirm that control air source of oil cooler cooling water regulation valve is working and regulation is normal.
6.14.3 Oil cooler switching 6.14.3.1
When switching oil coolers during operation, main oil tank oil level, lubricate oil pressure and temperature should be paid attention to.
6.14.3.2
Confirm the running states of oil cooler A, B.
6.14.3.3
After standby oil cooler is fulfilled with oil, put standby oil cooler cooling water into operation.
6.14.3.4
Turn the handwheel of switching valve. After turning 90°, indication screw on handwheel point middle, oil coolers run in parallel.
6.14.3.5
Continue to turn handwheel 90°to standby oil cooler direction, check and make sure indication screw on handwheel points to standby oil cooler, i.e. standby pump is switched for running. Pay attention to cooling water regulation valve action and make 142
sure oil cooler outlet oil temperature is within 43～49℃ and lubricate oil pressure is normal. 6.14.3.6
After normal switching, former running oil cooler cooling water and former running oil cooler switches into standby state.
6.14.4 Oil cooler stop 6.14.4.1
Check and confirm oil cooler A, B running state.
6.14.4.2
Switch the switching valve of oil cooler to the position of another oil cooler running, cut off the oil line of oil cooler to be stopped.
6.14.4.3
If maintenance is necessary after stop for oil cooler, open the bottom oil discharging valve and air discharging valve at oil side to completely discharge oil from oil cooler.
6.14.4.4
Close inlet & outlet water valve of oil cooler, open oil cooler button water discharging valve and air discharging valve at water side to discharge water.
6.15 EH oil system start and stop 6.15.1 Check before EH oil system 6.15.1.1
Confirm that EH oil tank level is slightly higher than normal oil level and oil is qualified.
6.15.1.2
Confirm that all tests in EH oil system are qualified and all interlock protections are working.
6.15.1.3
Open primary and secondary valves of all pressure switches, close all oil & water discharging valve.
6.15.1.4
Control power is working and signal is normal.
6.15.1.5
Start isolation valve and put one EH oil cooler into operation.
6.15.1.6
Confirm that closed cooling water system is working and air is completely discharged.
6.15.2 System leakage check 6.15.2.1
EH oil pump, cooling oil pump and filtering pump motor are sent with power.
6.15.2.2
Start cooling oil pump with following operation process: 1) Open cooling oil pump oil inlet valve. 2) Open oil cooler inlet valve. 3) Start cooling oil pump and make sure that there is no vibration and sound. 4) Check and make sure that cooling oil pump pipeline system has no oil leakages. 5) Stop cooling oil water, if oil temperature inside oil tank is lower than 37℃, heating pump should be stopped.
6.15.2.3
Start and stop fire resistant oil regeneration pump 1) Start regenerating pump inlet oil valve. 2) Start diatomite filter bypass valve. 3) Start regenerating pump, check and make sure that vibration and sound are normal. 4) Open diatomite strainer inlet oil valve slowly. 5) Close diatomite strainer bypass valve gradually. 6) Make sure that diatomite strainer differential pressure is normal and lower than 0.24MPa. 7) Confirm that fire resistant oil regenerating system has no oil leakage and no abnormity. 8) Stop fire resistant oil regeneration pump. 143
6.15.2.4
Start and stop EH oil pump 1) Confirm that oil tank oil temperature is within 21℃～37℃. 2) Start EH oil pump inlet oil valve, fill oil and discharge air for EH oil pump. 3) Confirm that following valves are fully open: a. EH oil pump outlet valve. b. Manual valve on head pipe supplying EH oil to turbine. 4) Start EH oil pump A or B, check and make sure that vibration, sound and pressure are normal and there is no oil leakage. 5) Check whether oil tank oil level is normal; otherwise supplement oil. 6) Check whether EH oil pipeline system has oil leakage or not. 7) Stop EH oil pump. 8) Start and stop the other EH oil pump with same operation processes.
6.15.3 Check for nitrogen accumulator 6.15.3.1
Make sure that inlet valves are fully closed and oil drainage valves are fully open.
6.15.3.2
Check and make sure that nitrogen has been charged to set pressure; if pressure is lower than set value, nitrogen should be charged continuously.
6.15.3.3
After check, close oil drainage valve and open inlet valve of accumulator.
6.15.4 EH oil system start and stop 6.15.4.1
Make sure that closed cooling circulating is working.
6.15.4.2
Make sure that cooling pump is at „Automation‟ position, if EH oil temperature is lower than 21℃, heater starts automatically.
6.15.4.3
Start one EH oil pump and put the other pump into „Standby‟ from CRT after complete check.
6.15.4.4
Check and make sure that all indications of pressure meters in EH oil system device panel normal.
6.15.5 EH oil system stop 6.15.5.1
Except for that there is work in EH oil system, otherwise the system should not be stopped.
6.15.5.2
Release standby EH oil pump on CRT from „Standby‟ and stop EH oil pump.
6.15.5.3
Close oil cooler cooling water inlet valve.
6.15.6 EH oil pump switching 6.15.6.1
Check and make sure that system is running stably and standby pump is in fine condition.
6.15.6.2
Start standby pump, check and make sure that everything is normal.
6.15.6.3
Stop former running pump, confirm that the pump is stopped and output head pipe pressure is normal.
6.15.6.4
Stop EH oil pump on „CRT‟ and put it into „Standby‟.
6.15.6.5
Check and make sure that EH oil system runs normally.
6.15.7 Oil system operation and maintenance 6.15.7.1
Lighting around the equipment is sufficient, oil tank level is normal and all indications of pressure meters are right.
144
6.15.7.2
EH oil system has no oil leakage.
6.15.7.3
Oil tank temperature is normal.
6.15.7.4
Oil pump and system pipeline vibrate and sound is abnormal.
6.16 Generator sealing oil system start and stop 6.16.1 Check before starting generator sealing oil system 6.16.1.1
All control power, signal power are in operation, all instrumental meters are complete and in operation.
6.16.1.2
Measure insulation for motors and send power after mechanical parts are ready.
6.16.1.3
Put closed circulating cooling water system into operation.
6.16.1.4
All the valves of pressure meters, differential pressure meters and regulators are open, isolation valve for detecting oil level is open and all strainers rotate freely.
6.16.1.5
Inlet valve of sealing oil pump at hydrogen side is open.
6.16.1.6
Outlet re-circulating valve of sealing oil pump at air side and hydrogen side are properly open (fix it after regulation).
6.16.1.7
Inlet valves, outlet cooling water valves of oil coolers at air side and hydrogen side to be put into operation are open; standby cooler inlet valve is closed, outlet valve is open and outlet strainer at air side is open.
6.16.1.8
Inlet valves of sealing oil strainer at air side and hydrogen side are open and bypass valve is closed.
6.16.1.9
Manual valve after sealing oil #1 pressure balance valve at hydrogen side is closed; sealing oil pressure meter valves at air side and hydrogen side are closed.
6.16.1.10 Manual valve after sealing oil #2 pressure balance valve at hydrogen side is closed; sealing oil pressure meter valves at air side and hydrogen side are closed. 6.16.1.11
Exit the manual screw of oil level regulation bobber valve of returning oil tank at hydrogen side and make the two ball cocks be at free status.
6.16.1.12
Close pressure meter oil discharging valve at hydrogen side of main differential pressure regulator.
6.16.1.13
Close pressure meter oil discharging valve at hydrogen side of standby differential pressure regulator.
6.16.1.14
Open inlet valve of sealing oil pump at air side.
6.16.1.15
Open outlet head pipe manual valve of sealing oil pump at air side.
6.16.1.16
Oil returning check valve from hydrogen side to air side and oil discharging valve from hydrogen-oil separating tank to sealing oil tank are at automatic regulation state. Oil supplement valve of oil tank at hydrogen side is properly open and forcing oil discharging valve at hydrogen side is closed.
6.16.1.17
Following valves should be regulated according to regulations before sealing oil system works normally: 1) Pressure balancing valve at two ends of sealing oil at hydrogen side. 2) Air side sealing oil main differential pressure regulation valve and standby differential pressure regulation valve. 3) Oil supplying depressurized valve of turbine main oil pump and safety valve after the valve. 4) Outlet re-circulating valve of sealing oil pump at air side. 5) Outlet re-circulating valve of sealing oil pump at hydrogen side. 145
6.16.2 Regulations of sealing oil system operation 6.16.2.1
Sealing oil system should be put into operation before turning gearing running and generator gas displacement.
6.16.2.2
When generator is charged with hydrogen or rotor is running, sealing oil pressure must be maintained.
6.16.2.3
When generator is charged with hydrogen, smoke remove machine of hydrogen-oil separating tank at air side should run continuously.
6.16.2.4
Turbine lubricate oil system should be put into operation before starting sealing oil system.
6.16.2.5
Before discharging oil from main lubricate oil tank, hydrogen inside generator must be completely discharged firstly.
6.16.3 System start 6.16.3.1
Make sure that start conditions of sealing oil pump at air side are satisfied, start sealing oil pump at air side and make sure it runs well.
6.16.3.2
Regulate re-circulating valve of pump outlet and keep oil pressure after oil filter be at 0.8MPa and oil temperature be within 27～50℃.
6.16.3.3
Oil smoke removing machine should starts automatically by interlock, put standby oil smoke removing machine into interlock.
6.16.3.4
Open balancing valve at hydrogen side and oil side of pressure regulator, put differential pressure valve into operation. If differential pressure valve is in failure, use pump outlet re-circulating valve to keep normal oil pressure for operation.
6.16.3.5
Supplement oil to returning oil tank at hydrogen side to normal level.
6.16.3.6
Open sealing oil supplying valve at air & hydrogen sides of balancing valve at two sides of sealing oil and put balancing valve into operation.
6.16.3.7
Put AC sealing oil pump at hydrogen side into operation, use pump outlet re-circulating valve to keep oil pressure after oil filter at 0.8MPa; make sure that sealing oil differential pressure at air side and hydrogen side should not exceed 0.5KPa.
6.16.3.8
Have sealing oil system protection test and oil pump interlock test according to regulations.
6.16.3.9
If during putting balancing valve and pressure differential regulator into operation, required oil pressure can not be ensured, bypass valve should be used to keep oil pressure, put them into operation after finding out the reason.
6.16.4 System operation and maintenance 6.16.4.1
Normal supervision during operation 1) Hydrogen pressure should be kept at 0.4MPa during unit normal operation. 2) Keep hydrogen-oil differential pressure within 0.084±0.01MPa. 3) Sealing oil supplying differential pressure at hydrogen side and air should be within 0.5KPa. 4) Sealing oil cooler outlet oil temperature should be kept within 27～49℃. 5) Air side sealing oil returning oil temperature ≤56℃. 6) Hydrogen side sealing oil returning oil temperature ≤64℃. 7) Oil pump and motor bearing oil level, temperature and vibration. 8) Oil tank level at hydrogen side and air side. 9) Air side returning oil tank vacuum should be kept within -250～-500Pa. 146
10) Turbine main oil source supplying pressure. 11) Oil smoke removing machine runs well. 6.16.4.2. Oil system operation 1) Air-side seal oil system operation a Main operating oil source: the normal working oil source of the air-side seal oil is supplied by the AC electric seal oil pump. The outlet pressure of seal oil pump is 0.25- 0.8 MPa. Oil-supply of the shaft seal ring uses the by-pass differential pressure regulator to adjust the difference of hydrogen and seal oil. The differential pressure regulator adjusts the air-side oil pressure automatically according to the hydrogen pressure in the generator to ensure that the normal operation of the shaft seal ring and the difference of hydrogen and seal oil is 0.084MPa. b The first spare oil source (that is the main spare oil source) is the 1.6～1.7MPa hydraulic oil from the main oil pump of the steam turbine. This spare oil is supplied for the air-side shaft seal ring after pressure is reduced through the pressure-relief valve on the pipeline. The outlet oil pressure at the pressure-relief valve is 0.7~0.8MPa. And the oil mass is 250L/min. when the operating oil source is out of order and the difference of hydrogen and seal oil reduces to 0. 056MPa, the spare differential pressure regulator installed in the pipe will open automatically and the spare oil source will be also in operation automatically. c The second spare oil source is also supplied by the steam turbine oil system, that is, the spare AC electric seal oil pump in the main oil tank of the steam turbine. The oil pressure is 1.0MPa. Since it is in the same pipeline as the first one, this spare oil source enters the shaft seal ring through the spare differential pressure regulator and is put into operation when the differential pressure reduces to 0.056MPa. When the coaxial rotational speed of the steam turbine exceeds 2/3 of the specified speed, the main shaft oil pump of the steam turbine can supply oil with the first oil source; when it is lower than that number or when it is out of order, only the second oil source can be in operation. d The third spare oil source is supplied by the self-contained DC electric oil pump in the seal oil system. The DC electric oil pump and the alternate current electric oil pump are merged in the same pipeline, when differential pressure reduces to 0.035MPa, the DC oil pump will start, and hydrogen oil differential pressure will come back to 0.084MPa. This oil source can only work for about 2 hour, so the alternate current oil pump should be checked and repaired as soon as possible. e The fourth spare oil source is also supplied by the stream turbine oil system. The oil is supplied by the bearing lubricating oil pump of the stream turbine, and the oil pressure is relatively low, that is, 0.035～0.105MPa. So at this time the hydrogen pressure in the turbine should be reduced to 0.014MPa. 2) Hydrogen-side seal oil system operation Normal working oil source of hydrogen-side seal oil is supplied by AC seal oil pump, when AC seal oil pump has fault, DC seal oil pump will supply seal oil to it. 6.16.5 System stop 6.16.5.1
Stop conditions 1) Make sure that gas displacement in generator has already finished, air in generator has been exhausted. 2) Turning gear stops. When rotor runs, sealing oil system has to stop; otherwise it will damage sealing pad.
6.16.5.2 Stop seal oil system 1) Insolate pressure difference meter of compensation valve in air-side, hydrogen-side. 2) Close HP and LP spare oil source manual valve from lube oil to seal oil. 147
3) Close front & back manual valve of seal oil standby pressure difference valve. 4) Release interlock of hydrogen-side DC seal oil pump, stop AC seal oil pump in hydrogen-side. 5) Release interlock of air-side DC seal oil pump, stop AC seal oil pump in air-side. When seal oil system stopped, release interlock of oil scavenger tank standby draft fan in air-side, stop draft fan.
6.17 Generator hydrogen cooling system start and stop 6.17.1 Check before generator gas replacement and notices for replacement 6.17.1.1
Sealing oil system runs reliably and oil-hydrogen differential pressure maintains within about 0.084MPa.
6.17.1.2
Gas displacement should be operated when generator is stop, and turning gear speed is lower than 1000r/min.
6.17.1.3
Relevant meters and alarming devices are tested and calibrated to be qualified.
6.17.1.4
All fire works in turbine hall are completed.
6.17.1.5
There is a certain pressure inside generator.
6.17.1.6
Confirm that sealing oil differential pressure regulation valve characteristic test is qualified. Pressure inside generator during gas replacement keeps at about 50KPa.
6.17.1.7
Inform hydrogen generator station to prepare sufficient hydrogen before charging hydrogen; make sure that hydrogen supplying stops before discharging hydrogen. There is sufficient CO2 at site for gas replacement and its purity is qualified. B
B
6.17.1.8
Generator gas tightness test is qualified.
6.17.1.9
Valves in hydrogen system should be opened or closed slowly, operate it manually if it is possible, and copper spanner can be used under special conditions. During operation, hydrogen should be prevented from sudden washing which may cause fire.
6.17.1.10
Check the switches status in system according to H2 system valve check card （before replacing CO2 by air）. B
B
6.17.2 Replacing air inside generator with CO2 B
B
6.17.2.1
Close isolation valve to generator compressed air.
6.17.2.2
Close general valve from hydrogen generating station to hydrogen head pipe.
6.17.2.3
Close hydrogen cylinder supplying general valve.
6.17.2.4
Close check valve before hydrogen pressure regulation valve, check valve after hydrogen pressure regulation valve and bypass valve of hydrogen pressure regulation valve.
6.17.2.5
Close hydrogen supplying pipe general valve.
6.17.2.6
Open hydrogen replacement valve.
6.17.2.7
Close CO2 replacement valve.
6.17.2.8
Open CO2 supplying general valve.
6.17.2.9
Open general valve of CO2 supplying pipe of CO2 cylinder.
B
B
B
B
B
B
B
B
6.17.2.10
Open and regulate gas replacement general air discharging valve and keep pressure inside generator be within 40～50KPa. Make sure sealing oil pressure is 84KPa higher than pressure inside generator.
6.17.2.11
When purity inside generator is higher than 90％, clean generator and discharge with CO2 totally, open liquid leakage detector discharging valve of stator air-side & supervision cabinet inlet discharging valve of generator working condition & B
B
148
supervision cabinet outlet discharging valve of generator working condition & star-point liquid leakage detector discharging valve & outlet box liquid leakage detector discharging valve & hydrogen dryer inlet discharging valve & hydrogen dryer outlet discharging valve in sequence once time for about 2 minutes. 6.17.2.12
Open valve from hydrogen to hydrogen purity analysis meter. Close it after CO2 purity is qualified.
6.17.2.13
Open valve from hydrogen to hydrogen purity analysis meter. Open hydrogen humidity meter air inlet manual valve and hydrogen humidity meter discharging air manual valve.
6.17.2.14
Open hydrogen discharging valve. Close hydrogen humidity meter air inlet manual valve and hydrogen humidity meter discharging air manual valve after CO2 purity is qualified.
B
B
B
B
6.17.2.15
Open valve from hydrogen to hydrogen dryer. Close hydrogen valves and hydrogen discharging valve.
6.17.2.16
Close valve from hydrogen to hydrogen humidity meter.
6.17.2.17
When CO2 purity inside generator is higher than 95%, close general valve of CO2 supplying pipe of CO2 cylinder, CO2 supplying general valve, H2 replacement valve and replacement general discharging valve. B
B
B
B
B
B
B
B
6.17.3 CO2 replacement inside generator by H2 B
B
B
B
6.17.3.1
Check and make sure that hydrogen purity analysis meter inlet valve and returning valve are closed.
6.17.3.2
Cut off power of H2 purity analysis meter and send power when H2 purity inside generator reaches to be higher than 90％.
6.17.3.3
Make sure that manual valve from unit compressed air to hydrogen pipe is strictly closed.
6.17.3.4
Make sure that CO2 inside generator is higher than 95% and pressure inside generator is about 40 KPa.
6.17.3.5
Contact with hydrogen generating station to supply hydrogen.
6.17.3.6
Open general valve from hydrogen generating station to hydrogen head pipe.
6.17.3.7
Open check valve before hydrogen pressure regulation valve and check valve after hydrogen pressure regulation valve.
6.17.3.8
Open general valve of hydrogen supplying valve.
6.17.3.9
Check and make sure that hydrogen replacement valve is strictly closed.
B
B
6.17.3.10
Regulate hydrogen pressure regulation valve to make hydrogen supplying head pipe pressure be higher than 50KPa.
6.17.3.11
Open CO2 replacement valve.
6.17.3.12
Open and regulate gas replacement general discharging valve and keep pressure at 50KPa inside generator. Make sure that sealing oil differential pressure regulation valve actuates normally to ensure sealing oil pressure is 84KPa higher than pressure inside generator.
6.17.3.13
When H2 purity inside generator is higher than 90％, clean generator and discharge with CO2 totally, open liquid leakage detector discharging valve of stator air-side & supervision cabinet inlet discharging valve of generator working condition & supervision cabinet outlet discharging valve of generator working condition & star-point liquid leakage detector discharging valve & outlet box liquid leakage detector discharging valve & hydrogen dryer inlet discharging valve & hydrogen dryer outlet discharging valve in sequence once time for about 2 minutes.
B
B
B
B
149
6.17.3.14
Open generator discharge valve, close generator discharging valve after H2 purity is qualified.
6.17.3.15
Open valve from hydrogen to hydrogen purity analysis meter after H2 purity is qualified.
6.17.3.16
Open valve from hydrogen to hydrogen purity analysis meter. Open hydrogen humidity meter air inlet manual valve and hydrogen humidity meter discharging air manual valve.
6.17.3.17
Open hydrogen discharging valve. Close discharge valve after H2 purity is qualified.
6.17.3.18
Open valve from hydrogen to hydrogen dryer. Open hydrogen discharge valve. Close hydrogen discharge valve after H2 purity is qualified.
6.17.3.19
When H2 purity inside generator is higher than 98%, close CO2 replacement valve and gas replacement general discharging valve. Replacement is completed. B
B
6.17.4 Hydrogen cooler start 6.17.4.1
Close discharge valve of inlet & outlet pipes of cooler.
6.17.4.2
Open hydrogen cooler water inlet valve slowly, close air discharging valve when cooler air discharging pipe sees water.
6.17.4.3
Open outlet water valve of hydrogen cooler.
6.17.4.4
Open isolation valves before and after hydrogen temperature regulation valve, close bypass valve and put hydrogen cooler temperature regulation valve into „Automation‟.
6.17.5 Hydrogen cooling system supervision during generator operation 6.17.5.1
When generator is running normally, hydrogen pressure inside generator should keep within 0.38～0.42MPa, it alarms when the pressure is higher 0.43MPa than or lower than 0.385MPa. When hydrogen pressure is too high, air discharging valve can be opened to discharge part hydrogen and decrease pressure to normal value. When hydrogen pressure lower than 0.38MPa, contact chemical operator to supply hydrogen with 0.40MPa.
6.17.5.2
During unit operation, H2 purity inside generator is higher than 96％, O2 purity inside generator is lower than 1％, H2 humidity inside generator is lower than 29/M3 . if purity or temperature is unqualified, blow down should be done and hydrogen should be supplemented to generator to improve purity and decrease humidity. P
P
6.17.5.3
During generator normal operation, H2 moisture removal device should be put into operation.
6.17.5.4
During generator normal operation, hydrogen cooling system should work normally and sealing oil system must work normally.
6.17.5.5
During generator normal operation, hydrogen coolers should be working. If one of the hydrogen coolers exits, generator load limit is 80% of rated load.
6.17.5.6
During normal operation, it must be ensured that generator inlet hydrogen temperature is lower than generator stator cooling water inlet temperature. It should be kept that all the temperatures of four temperature detection points at outlet of hydrogen cooler are lower than generator stator cooling water inlet temperature.
6.17.5.7
When any detection point temperature at hydrogen outlet is higher than the average value of the other three detection points, maintenance person should be contacted for treatment.
6.17.5.8
When temperature of any detection point at generator hydrogen cooler outlet is higher than generator stator cooling water inlet temperature, hydrogen temperature or stator cooling water temperature should be checked and regulated to be normal. If it is due to wrong detection point indication, maintenance person should be contacted for treatment. 150
6.17.6 H2 replacement inside generator by CO2 B
B
B
B
6.17.6.1
Close isolation valve to generator compressed air.
6.17.6.2
Close general valve from hydrogen generating station to hydrogen head pipe.
6.17.6.3
Close hydrogen cylinder general supplying valve.
6.17.6.4
Close check valve before hydrogen pressure regulation valve, check valve after hydrogen pressure regulation valve and bypass valve of hydrogen pressure regulation valve.
6.17.6.5
Close hydrogen supplying pipe general valve.
6.17.6.6
Open hydrogen replacement valve.
6.17.6.7
Close CO2 replacement valve.
6.17.6.8
Open CO2 supplying general valve.
6.17.6.9
Open general valve of CO2 supplying pipe of CO2 cylinder.
B
B
B
B
B
B
B
B
6.17.6.10
Open and regulate gas replacement general air discharging valve and keep pressure inside generator be within 40～50KPa. Make sure sealing oil pressure is 84KPa higher than pressure inside generator.
6.17.6.11
When CO2 purity inside generator is higher than 90％, clean generator and discharge with CO2totally, open liquid leakage detector discharging valve of stator air-side & supervision cabinet inlet discharging valve of generator working condition & supervision cabinet outlet discharging valve of generator working condition & star-point liquid leakage detector discharging valve & outlet box liquid leakage detector discharging valve & hydrogen dryer inlet discharging valve & hydrogen dryer outlet discharging valve in sequence once time for about 2 minutes. B
B
B
B
6.17.6.12
Open valve from hydrogen to hydrogen purity analysis meter. Close it after CO2 purity is qualified.
6.17.6.13
Open valve from hydrogen to hydrogen purity analysis meter. Open hydrogen humidity meter air inlet manual valve and hydrogen humidity meter discharging air manual valve.
6.17.6.14
Open hydrogen discharging valve. Close hydrogen humidity meter air inlet manual valve and hydrogen humidity meter discharging air manual valve after CO2 purity is qualified.
B
B
B
B
6.17.6.15
Open valve from hydrogen to hydrogen dryer. Close hydrogen valves and hydrogen discharging valve.
6.17.6.16
Close valve from hydrogen to hydrogen humidity meter.
6.17.6.17
When CO2 purity inside generator is higher than 95%, close general valve 122 of CO2 supplying pipe of CO2 cylinder, CO2 supplying general valve, H2 replacement valve and replacement general discharging valve. B
B
B
B
B
B
B
B
6.17.7 CO2 replacement inside generator by compressed air B
B
6.17.7.1
Close general valve from hydrogen generating station to hydrogen head pipe, hydrogen cylinder supplying general valve, check valve before hydrogen pressure regulation valve, check valve after hydrogen pressure regulation valve and bypass valve of hydrogen pressure regulation valve.
6.17.7.2
Open drainage valve of gas replacement head pipe drainage valve from unit compressed air to generator, close it after water drainage.
6.17.7.3
Close hydrogen replacement valve, CO2 supplying general valve and general valve of CO2 supplying pipe of CO2 cylinder. B
B
6.17.7.4
B
B
B
Open CO2 replacement valve. B
B
151
B
6.17.7.5
Open hydrogen supplying pipe general valve.
6.17.7.6
Open and regulate gas replacement general air discharging valve and keep pressure inside generator be within 40～50KPa.
6.17.7.7
Open isolation valve to generator compressed air, keep pressure in generator about 0.04MPa. when air purity inside generator is higher than 90％, clean generator and discharge with CO2 totally, open liquid leakage detector discharging valve of stator air-side & supervision cabinet inlet discharging valve of generator working condition & supervision cabinet outlet discharging valve of generator working condition & star-point liquid leakage detector discharging valve & outlet box liquid leakage detector discharging valve & hydrogen dryer inlet discharging valve & hydrogen dryer outlet discharging valve in sequence once time for about 2 minutes. B
6.17.7.8
B
When CO2 purity inside generator is lower than 5％, close hydrogen supplying pipe general valve, CO2 replacement valve and air isolation valve to generator compressed air. B
B
B
6.17.7.9
B
Close gas replacement general air discharging valve.
6.18 Start and stop of generator stator cooling water system 6.18.1 Check stator cooling water system before putting into operation 6.18.1.1
System interlock test are satisfied and stator water system valve position is rightly.
6.18.1.2
When supplementary water for stator cooling water tank is analyzed to be qualified, start water supplement valve to supplement water to full.
6.18.1.3
Closed cooling water system is working normally.
6.18.1.4
Control power supply and dynamical power is sent and instrumental meters and alarming devices are working.
6.18.1.5
Make sure that generator hydrogen system and sealing oil system are working normally.
6.18.1.6
Make sure that hydrogen pressure inside generator reaches to 0.2MPa.
6.18.2 Filling water to stator water system 6.18.2.1
Water in system should be completely discharged before filling water to stator water system. 1) Stator water system Water is generally filled to stator water system through ion exchanger with flow of 25～40L /min. 2) Make sure that water circulating pipes before ion exchanger are flushed and clean, water in pipelines is qualified. Open manual valve before solenoid valve. 3) Prepare resin of ion exchanger and fill water into stator, start condensing water transfer pump. 4) Open ion exchanger inlet manual valve. 5) Close stator water returning valve and fill water to stator water system through water supplement solenoid valve. 6) Supplement water inlet pressure is 0.36MPa; permit maximum inlet water temperature is 50℃. 7) Supplement water to water tank to normal level. Solenoid valve closes automatically. 8) Open the air valves on stator water tank, cooler and pipeline to discharge air; then close it.
6.18.3 Stator water cooling pump start
152
6.18.3.1
Stator cooling water should be reported to be qualified by chemical and cooling water tank level is normal.
6.18.3.2
Start stator water cooling pump and open outlet valve slowly. Check and make sure that vibration, sound and all bearing temperatures are normal.
6.18.3.3
Check and make that outlet pressure is normal. When water cooler, ion exchanger air discharging valve see water, close air discharging valve, regulate re-circulating valve to keep generator stator inlet water pressure be at about 320KPa (local indication). Regulate water supplement valve of water tank and regulate ion exchanger flow to be within 25～40L /min.
6.18.3.4
After system runs normally, put the other stator water cooling pump into standby.
6.18.3.5
Put stator water cooler cooling water into operation.
6.18.4 Stator cooling water pump stop 6.18.4.1
Release standby stator water cooling pump from interlock.
6.18.4.2
Stop stator water cooling pump.
6.18.4.3
If repair is needed after stator water cooling pump stops, power should be cut off, inlet & outlet valves of the pump should be closed. Decrease the pressure and then discharge water.
6.18.5 Stator cooling water pump switching 6.18.5.1
Check and make sure that standby stator cooling water pump bearing oil cup level is normal and oil quality is good.
6.18.5.2
Start standby pump and check pump completely.
6.18.5.3
Check and make sure that stator cooling water head pipe pressure is normal.
6.18.5.4
Stop former running stator water cooling pump.
6.18.5.5
Put former running pump into standby.
6.18.6 Items should be supervised for stator water system 6.18.6.1
Stator water tank level and temperature.
6.18.6.2
Stator water pump inlet & outlet pressure and current.
6.18.6.3
Stator water pump motor and pump bearing oil level, bearing temperature, vibration and sound.
6.18.6.4
Stator water cooler outlet filter screen inlet & outlet pressure and differential pressure.
6.18.6.5
Generator stator cooling water inlet & outlet pressure difference.
6.18.6.6
Stator cooling water inlet flow.
6.18.6.7
Stator cooling water conductivity is 0.5-1.5S/cm.
6.18.6.8
Ion outlet stator water conductivity is 0.1-0.4S/cm.
6.18.6.9
Ion inlet and outlet pressure.
153
Attachment: Saturation steam pressure, temperature comparison table (listing according to pressure) Pressure （MPa）
Temperature （℃）
Pressure （MPa）
Temperature （℃）
Pressure （MPa）
Temperature （℃）
0.001
6.982
0.040
75.89
2.7
228.06
0.0015
13.034
0.050
81.35
2.8
230.04
0.0020
17.511
0.060
85.95
2.9
231.96
0.0025
21.094
0.070
89.96
3.0
233.84
0.0030
24.098
0.080
93.51
3.1
235.66
0.0035
26.692
0.090
96.71
3.2
235.66
0.0040
28.981
0.10
99.63
3.3
237.44
0.0045
31.034
0.12
104.81
3.4
239.18
0.0050
32.90
0.14
109.32
3.5
240.88
0.0055
34.6
0.16
113.32
3.6
244.16
0.0060
36.18
0.18
116.93
3.7
245.75
0.0065
37.65
0.20
120.23
3.8
247.31
0.0070
39.02
0.25
127.43
3.9
248.84
0.0075
40.32
0.30
133.54
4.0
250.33
0.0080
41.53
0.35
138.88
4.5
257.41
0.0085
42.69
0.40
143.62
5.0
263.92
0.0090
43.79
0.45
147.92
5.5
269.94
0.0095
44.83
0.50
151.85
6.0
275.56
0.010
45.83
0.60
158.84
6.5
280.83
0.011
47.71
0.70
164.96
7.0
285.80
0.012
49.45
0.80
170.42
7.5
290.51
0.013
51.06
0.90
175.35
8.0
294.98
0.014
52.58
1.0
179.88
8.5
299.24
0.015
54.0
1.1
184.06
9.0
303.31
0.016
55.34
1.2
187.96
9.5
307.22
0.017
56.62
1.3
191.6
10
310.96
0.018
57.83
1.4
195.04
11
318.04
0.019
58.98
1.5
198.28
12
324.64
0.020
60.09
1.6
201.37
13
330.81
0.021
61.15
1.7
204.30
14
336.63
0.022
62.16
1.8
207.1
15
342.12
0.023
63.14
1.9
209.79
16
347.32
0.024
64.08
2.0
212.37
17
352.26
0.025
64.99
2.1
214.85
18
356.96
154
0.026
65.87
2.2
217.24
19
361.44
0.027
66.72
2.3
219.54
20
365.71
0.028
67.55
2.4
221.78
21
369.79
0.029
68.35
2.5
223.94
22
373.68
0.030
69.12
2.6
226.03
Critical 22.115
Critical 374.12
155
Attachment: Air pressure, vacuum, relative saturation temperature comparison table ts B
B
H
B 666
668
670
672
674
676
670 665 660
678
686
682
684
7.9
11.5
13.6
16.3
9.1
12.7
15.4
17.2
19.4
21.4
7.9
11.5
13.6
16.3
18.6
20.1
22.0
236.8
25.4
655
12.7
15.4
17.2
19.4
21.4
23.2
24.3
25.9
27.3
28.2
650
18.6
20.1
22.0
23.8
25.4
26.4
27.7
29.0
30.2
31.0
645
23.2
24.3
25.9
27.3
28.2
29.4
30.6
31.8
32.6
33.6
640
26.4
27.7
29.0
30.2
31.0
32.2
33.2
33.9
34.8
35.8
635
29.4
30.6
31.8
32.6
33.6
34.5
35.2
36.1
37.0
37.8
630
32.2
33.2
33.9
34.8
35.8
36.7
37.3
38.1
39.0
39.5
625
34.5
35.2
36.1
37.0
37.8
38.4
39.2
40.0
40.5
41.2
620
36.7
37.3
38.1
39.0
39.5
40.2
41.0
41.6
42.1
42.7
615
38.4
39.2
40.0
4.05
41.2
41.9
42.5
43.0
43.6
44.2
610
40.2
41.0
41.6
42.1
42.7
43.4
43.8
44.5
45.1
45.7
605
41.9
42.5
43.0
43.6
44.2
44.9
45.3
45.9
46.4
46.8
600
43.4
43.8
44.5
45.1
45.7
46.0
46.6
47.1
47.5
48.0
595
44.9
45.3
45.9
46.4
46.8
47.3
47.8
48.4
48.7
49.3
590
46.0
46.6
47.1
47.5
48.0
48.6
48.7
49.4
49.9
50.3
585
47.3
47.8
48.4
48.7
49.3
49.7
50.0
50.5
51.0
51.4
580
48.6
48.7
49.4
49.9
50.3
50.8
51.1
51.6
52.0
52.3
575
49.7
50.0
50.5
51.0
51.4
51.7
52.2
52.6
52.9
53.2
570
50.8
51.1
51.6
52.0
52.3
52.7
53.1
53.6
53.8
54.2
565
51.7
52.2
52.6
52.9
53.2
53.7
54.1
54.4
54.8
55.2
560
52.7
53.1
53.6
53.8
54.2
54.6
54.9
55.3
55.7
56.0
156
