Feb 10, 2003
An Introduction to Boiler Design Basics JC Foucher
Boiler design basics Summary
z z z z z
History Thermodynamics for beginners Boiler design Utilily versus Industrial boilers Boiler Construction, Examples, and Troubles
Date of last change
Reference/Name of Presentation/SN
2
Boiler design basics Summary
z z z z z
History Thermodynamics for beginners Boiler design Utilily versus Industrial boilers Boiler Construction, Examples, and Troubles
Date of last change
Reference/Name of Presentation/SN
3
History : Steam as a resource The most significant series of events shaping today’s world is the late 17th century industrial revolution. However, the first steam reaction turbine, illutrated here, has been invented in 200 BC by Hero from Greece. Steam Technology is an old invention its future is still brilliant, based on the same fundamentals : - GENERATE HEAT - TRANSFER THE HEAT to WATER - PRODUCE STEAM and - CONVERT TO ENERGY Source : ALSTOM Indonesia Boiler Seminar, April 2002
Date of last change
Reference/Name of Presentation/SN
4
History : First Application of Steam Power
Steam Industries develop after inventors designed safe and efficient steam devices useful to man activities : Alexandro Branca from Italy invented in the 16th century a device, illustrated here, which marked the beginning of Steam Turbine Development. It was used for milling wheat grains effortlessly. Source : ALSTOM Indonesia Boiler Seminar, April 2002
Date of last change
Reference/Name of Presentation/SN
5
Modern Use of Steam Power
z z z z z
Power Generation Industrial Processes Sea and land transportation District Heating Other special uses
Source : ALSTOM Indonesia Boiler Seminar, April 2002
Date of last change
Reference/Name of Presentation/SN
6
A Typical Power Station
Source : ALSTOM Indonesia Boiler Seminar, April 2002
Date of last change
Reference/Name of Presentation/SN
7
Boiler design basics Summary
z z z z z
Date of last change
History Thermodynamics for beginners Boiler design Utilily versus Industrial boilers Boiler Construction, Examples, and Troubles
Reference/Name of Presentation/SN
8
Thermodynamics for beginners - 1 z
z
z
z
A vessel is filled with an amount of water ( ) and warmed at constant pressure up to boiling a continuing supply of heat changes water phase from liquid to gas (steam), the temperature remains constant result : a steam at temp. Tp, pressure Pp, volume Vp and energy stored as internal heat or enthalpy Qp one m3 of water is transformed under such conditions into 1700 m3 of steam Source : ALSTOM Indonesia Boiler Seminar, April 2002
Date of last change
Reference/Name of Presentation/SN
9
Thermodynamics for beginners - 2
z
z z
A vessel is filled with the same water amount ( ) and warmed at constant volume up to boiling a continuing supply of heat changes water phase from liquid to gas (steam), result : – steam temperature Tv >Tp, – pressure Pv > Pp, – Vv =Vp volume unchanged – energy stored as internal heat or enthalpy Qv > Qp
Source : ALSTOM Indonesia Boiler Seminar, April 2002
Date of last change
Reference/Name of Presentation/SN
10
Thermodynamics for beginners - 3
z
Steam generation is a phase change or water from liquid to gas, thanks to a continuous supply of heat,
z
the higher both pressure and temperature are, the higher is the energy stored in the steam,
z
the steam turbine purpose is to convert this thermal energy into rotational mechanical energy
z
the purpose of the generator is to convert this rotational mechanical energy into electric energy
Date of last change
Reference/Name of Presentation/SN
11
Thermodynamics for beginners - 4 The Water-Steam Cycle inside the boiler z
Temp.
– liquid water warm-up
K B
From F to A to B
z
C
z
B : evaporation begins B to C : – mixture of water (decreasing) and steam (increasing) called saturated steam
A F Entropy Source : J. Goalvoueden in Les Techniques de l ’Ingénieur, B 124
Date of last change
Reference/Name of Presentation/SN
12
Thermodynamics for beginners - 5 The Water-Steam Cycle inside the boiler (cont) D Temp.
z
completed, steam still saturated
K B
C : evaporation
C
z
– steam is superheated z
A F Entropy
C to D
D – superheated steam sent to turbine
Source : J. Goalvoueden in Les Techniques de l ’Ingénieur, B 124
Date of last change
Reference/Name of Presentation/SN
13
Thermodynamics for beginners - 6 The Water-Steam Cycle outside the boiler z
D Temp.
– expansion in the steam turbine
K B
z
C
E to F – steam is condensed and cooled in the condenser
A F
D to E
E Entropy
z
F – water available for a new cycle
Source : J. Goalvoueden in Les Techniques de l ’Ingénieur, B 124
Date of last change
Reference/Name of Presentation/SN
14
Thermodynamics for beginners - 7 Single Rankine Reheat Steam Cycle D
Temp.
K C
B
A E
F
Entropy
Source : J. Goalvoueden in Les Techniques de l ’Ingénieur, B 124
Date of last change
Reference/Name of Presentation/SN
15
Thermodynamics for beginners - 8 Double Reheat Steam Cycle D Temp.
z
K
– expansion in the HP steam turbine
K B
C
z
I to K – steam returns to the boiler and is reheated
I z
A F
D to I
L Entropy
K to L – expansion in the IP/LP steam turbine
Source : J. Goalvoueden in Les Techniques de l ’Ingénieur, B 124
Date of last change
Reference/Name of Presentation/SN
16
Flows and Heat Exchange in the Boiler
Source : Combustion, Fossil Power J.G. Singer 1991, ch 5 p 7 fig 2
Date of last change
Reference/Name of Presentation/SN
17
The Complete Water-Steam Cycle
Source : ALSTOM Indonesia Boiler Seminar, April 2002
Date of last change
Reference/Name of Presentation/SN
18
Boiler design basics Summary
z z z z z
Date of last change
History Thermodynamics for beginners Boiler design Utilily versus Industrial boilers Boiler Construction, Examples, and Troubles
Reference/Name of Presentation/SN
19
Boiler design basics Summary
z
Boiler design – – – – –
Date of last change
various boiler designs type of operation fuels, solid, liquid, gaseous firing systems steam water circulation
Reference/Name of Presentation/SN
20
Various Boiler Designs Based on :
z
Intended use
industrial, power generation,
z
construction
shop or field assembled
z
firing system
grate, suspension, fluidized bed
z
boiler arrangement
hanged or bottom supported
z
water circulation
natural, controlled, forced
z
fuel
solid, liquid, gas, waste heat
Date of last change
Reference/Name of Presentation/SN
21
Boiler design basics Summary
z
Boiler design – – – – –
Date of last change
various boiler designs type of operation fuels, solid, liquid, gaseous firing systems steam water circulation
Reference/Name of Presentation/SN
22
Utility plants and boilers : three types of operation z
Base load : 100% capacity 24/7/365 – highest capacities (up to 1000 MWe), high efficiency – no load-follow requirement
z
Peak load – – – –
z
ultra-fast startup time, suitable for «golden hours» competition with open cycle gas turbines a few hundred hours per year no high efficiency requirement
Intermediate load – in between, high load-follow capability - customized design versus type of operation -
Date of last change
Reference/Name of Presentation/SN
23
Boiler design basics Summary
z
Boiler design – – – – –
various boiler designs type of operation fuels, solid, liquid, gaseous firing systems steam water circulation
Note : this seminar is targeted to an area where use of coal is limited. Consequently, the information provided for coal firing is purposedly limited.
Date of last change
Reference/Name of Presentation/SN
24
Solid Fuels, Fossil z
Coal (from 15 to 30 MJ/Kg)
Source : Combustion, Fossil Power J.G. Singer 1991, ch 2
Date of last change
Reference/Name of Presentation/SN
25
Solid Fuels, Non-Fossil z
Coke – fused solid residue from chemical processes involving coal or oil
z
Petroleum coke (petcoke) – petrochem byproduct (32-36 MJ/Kg, 3-6% sulfur)
z z z z
Wood (20 MJ/Kg) Bark (mainly from paper mills) Food processing wastes Municipal and industrial refuses (7 to 15 MJ/Kg)
Source : Combustion, Fossil Power J.G. Singer 1991, ch 2
Date of last change
Reference/Name of Presentation/SN
26
Liquid Fuels z
Crude petroleum – high amount of volatile compounds
z
Fuel oil
Fuel Oil Grade
FO n°1
FO n°2
FO n°4
FO n°5
FO n°6
Distillate Very Light Light Type Kérosene Distillate Residual Residual Residual Light Amber Black Black Black Color 46,4 45,5 43,4 43,4 42,5 MJ/Kg 0,1 0,4 - 0,7 0,4 - 1,5 2.0 2.8 Sulfur content,% 50°C 93°C Atomizing temp Ambient Ambient -4°C min
- Oil fired boilers can be converted to crude firing 1 lb/USgal x 119.8 = Kg/m3 1 BTU/Usgal x 278.72 = KJ/m3 KJ/m3 / (volumic mass Kg/m3) =KJ/Kg
Date of last change
Reference/Name of Presentation/SN
Source : Combustion, Fossil Power J.G. Singer 1991, ch 2
27
Gaseous Fuels z z z z
Natural gas Liquefied Petroleum gas (LPG) Refinery and oil gas, Gas from steel processing : coke oven and blast furnace gas Gas Propane MJ/Kg
Butane
Natural Gas
LPG
C33H88
C44H10 10
mix
mix
50
46
47
45
- Oil fired boilers can be converted to gas firing -
1 lb/USgal x 119.8 = Kg/m3 1 BTU/Usgal x 278.72 = KJ/m3 KJ/m3 / (volumic mass Kg/m3) =KJ/Kg
Date of last change
Reference/Name of Presentation/SN
Source : Combustion, Fossil Power J.G. Singer 1991, ch 2
28
Fuels, Typical Problems z z z z z z z
Degradation of fuel quality with time Exhaustion of fuel resource with time, leading to fuel switching High quality fuel exported, low quality burned domestically Cost increase, leading to fuel switching NOx generation properties Sulfur content, inducing acid dew point corrosion Particulates content
Date of last change
Reference/Name of Presentation/SN
29
Boiler design basics Summary
z
Boiler design – – – – –
Date of last change
various boiler designs type of operation fuels, solid, liquid, gaseous firing systems steam water circulation
Reference/Name of Presentation/SN
30
Firing systems
z
Firing on a travelling grate – suitable to un-pulverized solid fuels
z
Suspended firing – suitable to pulverized coal, liquid and gaseous fuels
z
Fluidized bed combustion – suitable to coarse pulverized solid low grade fuels
Date of last change
Reference/Name of Presentation/SN
31
Firing solid fuels on a travelling grate Solid crushed fuel
Air
Ash
Drive shaft
Air
Date of last change
Ash
Reference/Name of Presentation/SN
32
Suspension firing
z z
Solid pulverized fuels – solid fuel ground to the fineness of face powder
Air + pulverized fuel
Date of last change
z z z z
Liquid fuels Gases
Reference/Name of Presentation/SN
33
Fluidized Bed Combustion, principle
Flue gas
Fluidized Bed
z z z z
Fuel & sorbent
z z
Tube Bundle
z z z z
Ability to burn low-grade fuels Fuel flexibility Immune to ash properties NOx limited production In-situ SOx capture
Air
Date of last change
Reference/Name of Presentation/SN
34
Fluidized Bed Combustion, Types Bubbling Fluidized Bed
Circulating Fluidized Bed gas
gas
Air Fuel & sorbent
Fuel & sorbent Air
Date of last change
Ash
Air
Reference/Name of Presentation/SN
Ash
35
Boiler design basics Summary
z
Boiler design – – – – –
Date of last change
various boiler designs type of operation fuels, solid, liquid, gaseous firing systems steam water circulation
Reference/Name of Presentation/SN
36
The Natural Circulation Boiler
z z
z
Date of last change
No circulation pump circulation driven by density differences between water and steam/water mixture pressure increase detrimental to circulation : low pressure boilers only
Reference/Name of Presentation/SN
37
Controlled Circulation boiler z z
z z z z
Date of last change
circulation pump allow higher pressure levels and hence, capacities better load follow capability more complex auxiliary consumption drum thickness increase
Reference/Name of Presentation/SN
38
Forced Circulation Boiler
z z z z
z
Date of last change
No drum once-through circulation fast start-up/shutdown invented by Sulzer of Switzerland, now within ALSTOM the « tower » type boiler
Reference/Name of Presentation/SN
39
Evaporator Design
z
z
Date of last change
Reference/Name of Presentation/SN
Goal : avoid any departure from safe nucleate boiling (DNB) as tube integrity is therefore at risk
40
Steam - Water Separation : The Drum Dry saturated steam towards superheaters Tertiary separators Feedwater inlet
Secondary separator Water/steam mixture from evaporator
Primary separator Water level
Pure Water Downcomers Source : Combustion, Fossil Power J.G. Singer 1991, ch 7 p 16 fig 7
Date of last change
Reference/Name of Presentation/SN
41
Boiler design basics Summary
z z z z z
Date of last change
History Thermodynamics for beginners Boiler design Utilily versus Industrial boilers Boiler Construction, , Examples, and Troubles
Reference/Name of Presentation/SN
42
Utility vs Industrial boilers
z
Except size, no basic design difference between both : a boiler is quite always (1) a combination of a furnace where the combustion occurs, and, downstream, a series of heat exchangers where the combustion heat is transferred to the water and steam
z
Utility boilers, whose final purpose is electricity generation, must provide high reliable service, and show good efficiency
1 - Except HRSGs Date of last change
Reference/Name of Presentation/SN
43
Utility vs Industrial boilers (+)
z
Industrial boilers (whose final purpose is not electricity generation) must often show a great flexibility to meet quick load swings
z
Both uses are mixed in combined heat-andpower stations such as desalination plants, pulp & paper, petrochemical, steel processing, food industries
1 - Except HRSGs Date of last change
Reference/Name of Presentation/SN
44
Shop vs site boiler construction z
Shop construction – integrated package with preassembled auxiliaries – shipping routes from shop to site must be carefully investigated – all construction by shop staff – option limited to small boiler
z
Site construction – – – –
Date of last change
shop-assembled components easy to ship significant amount of work by local staff option required for large utility boilers strong site construction supervision Reference/Name of Presentation/SN
45
Typical boiler specification z
Boiler – Information related to the water and steam generating equipment and unit designation
z
Furnace – Dimensions / Total Volume
z
Superheater and reheater design – mono/multistage, layout, pendant/panel/platen
z
Air Heater – regenerative bi/tri sectors, cold end plate material
z
Economizer – tube type, finned or plain,
Date of last change
Reference/Name of Presentation/SN
46
Typical boiler specification (+)
z z
Fuel specification Combustion system – fuel preparation and handling, burners type
z
Operating Conditions – Controll point, lowest load ensuring normal steam temp – Maximum Continuous Rating (MCR) – Guaranteed load, base for overall unit efficiency guarantee
Date of last change
Reference/Name of Presentation/SN
47
Typical boiler specification (++)
z
Boiler Capacity – steam flow rate at MCR – control load : steam temp achieved and controlled
z
Boiler Efficiency – Efficiency of xx% means that xx% of the heat supplied by the fuel is transferred to the water / steam mixture, and 100 - xx% is lost – 100% efficiency is not achievable in a cost effective way
Date of last change
Reference/Name of Presentation/SN
48
Boiler design basics Summary
z z z z z
History Thermodynamics for beginners Boiler design Utilily versus Industrial boilers Boiler Construction, Examples, and Troubles
Date of last change
Reference/Name of Presentation/SN
49
Small / Medium size Boilers z z
z
z
z Date of last change
Bottom supported Can be shop constructed (package boilers) All heat furnace and heat exchangers rest on ground thermal expansion lateral and upwards restrained sensitive to earthquakes
Reference/Name of Presentation/SN
50
Small / Medium size Boilers The ALSTOM« D » Package Boiler – – – – –
Date of last change
compact small capacity 100% shop assembled shipped on train or barges fast erection
Reference/Name of Presentation/SN
51
Small / Medium size Boilers
zThe
ALSTOM/CE « D » type VP package boiler
– compact size – small capacity – 100% shop assembled – shipped on train or barges – fast erection
Date of last change
Reference/Name of Presentation/SN
52
Small / Medium size Boilers
zThe
ALSTOM/CE « VU60 » D type package boiler zup to 270 t/hr (approx 90 MWe power)
Date of last change
Reference/Name of Presentation/SN
53
Large size Boilers
z z z
z
z z Date of last change
Large Utility boilers Top supported/hanged All heat furnace and heat exchangers hanged from the top Allow easy thermal expansion both lateral and downwards resistant to earthquakes footprint minimized
Reference/Name of Presentation/SN
54
Large size Boilers z z z z z z z z z
Germany Niederaussem K 1012 MWe (gross) lignite once-through forced circulation supercritical operation: 2002 Fuel: lignite Steam 274 bar, 580°C/600°C 94.4 % efficiency
Date of last change
Reference/Name of Presentation/SN
55
Large size Boilers z z
USA Red Hills 2 x 250 MWe
z z z z z
Date of last change
lignite Circulating Fluidized Bed operation: 2002 Steam 184 bar, 541°C Bechtel
- Largest lignite-fired CFB in the world Reference/Name of Presentation/SN
56
Large size Boilers z z z z z z
Menu Date of last change
Shoaiba, 3 x 350 MWe in Saudi Arabia Oil-fired 2 pass - subcritical Controlled Circulation Operation: 2002 Fuel: Oil & gas Steam 182 bar, 540°C/540°C
Sub Reference/Name of Presentation/SN
57
Large size Boilers z z z z z
z z z
Date of last change
Egypt Suez 3 & 4 (and Aboukir) 2 x 325 MWe Oil or gas-fired drum boiler, 2 coupled pass Controlled Circulation Operation: 1987 Fuel: Oil & gas Steam 181 bar, 541°C/541°C
Reference/Name of Presentation/SN
58
Large size Boilers Heat Exchangers Arrangement
RH SH SH
RH RH EC0
Vaporizer
Date of last change
Reference/Name of Presentation/SN
59
Large size boiler Glossary, top Furnace steam-cooled roof
Structural steel framing
Pressure-part support steel
Hanger rods Rear pass steamcooled roof
Drum U bolts Riser tubes Steam drum
Finishing (High temp) Superheater or reheater
Superheater panels Superheater or reheater platens Radiant wall reheater
Buckstays Convection Superheater or reheater
Reheater inlet header
Source : Combustion, Fossil Power J.G. Singer 1991, ch 7 p 21 fig 11
Date of last change
Reference/Name of Presentation/SN
60
Large size boiler Glossary, middle Radiant wall reheater Reheater inlet header
Convection Superheater or reheater Economiser
Furnace side wall Furnace front wall
Furnace rear wall Economiser inlet Windbox
Downcomers Burners
Economiser ash hoppers Ljungstrom® Regenerative Air heater
Boiler water circulating pump
Source : Combustion, Fossil Power J.G. Singer 1991, ch 7 p 21 fig 11
Date of last change
Reference/Name of Presentation/SN
61
Large size boiler Glossary, bottom
Boiler water circulating pump
Lower waterwall ring header
Ljungstrom® Regenerative Air heater
Bottom-ash hopper
Primary air fans
Forced draft fans
Source : Combustion, Fossil Power J.G. Singer 1991, ch 7 p 21 fig 11
Date of last change
Reference/Name of Presentation/SN
62
Boiler Construction : furnace Tube wall (membrane) Insulation
Mineral Ribbed liner fibre outer casing double Galvanized layer hex mesh
lagging Insulation pins
Tube wall
Pourable Insulation Date of last change
Reference/Name of Presentation/SN
Horizontal Buckstay Corner closure plate 63
Boiler Construction : Combustion Area z
Two firing types – tangential firing
– Front/wall firing
Date of last change
Reference/Name of Presentation/SN
64
Boiler Furnace : T / front firing Tangential firing
Burners are located in the furnace angles No individual flames but a rotating fireball Date of last change
Reference/Name of Presentation/SN
65
Boiler furnace : T / front firing Front firing Burners are located on one furnace wall or two facing walls. Flames stay individual
Date of last change
Reference/Name of Presentation/SN
67
Tangential and wall fired VU 60 industrial boilers
Date of last change
Reference/Name of Presentation/SN
68
Combustion System Issues z z z z z z z z
Incomplete/bad combustion : yellow flame, black smoke Lack of combustion air, insufficient excess air Flame too long (front firing) Flame too close from the wall (T firing) Flame instability at low loads Poor fuel oil pulverization Superheater / reheater burned on gas firing Emissions of NOx, SOx and particulates
Date of last change
Reference/Name of Presentation/SN
69
Boiler Tube issues
z z z z z z
Date of last change
Tube cleanliness Tube corrosion by combustion byproducts Tube overheating Tube pitting Hydrogen-induced tube embrittlement Tube ductile gouging
Reference/Name of Presentation/SN
70
Heat Transfer and Tube Cleanliness
Energy Loss, clean tube
•
Loss in the tube wall only
Energy Loss, fouled tube
• • •
Date of last change
Loss in external deposits Loss in the tube wall Loss in internal deposits
Reference/Name of Presentation/SN
71
Heat Transfer and Tube Cleanliness
Date of last change
Reference/Name of Presentation/SN
72
Heat Transfer and Tube Cleanliness
Remove external deposits by sootblowing
Date of last change
Avoid internal deposits by water treatment; remove by acid cleaning
Reference/Name of Presentation/SN
73
Corrosion of Heat Exchangers by Combustion Byproducts z
High temperature corrosion in superheaters and reheaters – promoted by sodium and vanadium compounds – sensitive if metal temp. above 600°C
z
Medium temp. Corrosion in evaporators – fixed through combustion system adjustment
z
Low temp. Corrosion in cold areas – promoted by sulfur, which turns into sulfuric acid below dew point : keep temperature above 150°C
Date of last change
Reference/Name of Presentation/SN
74
Tube failures - Overheating Cross section of a tube exposed to short time overheating Cause : often DNB excursion Short time overheating failure
Long time overheating failure Long time overheating failure
Date of last change
Reference/Name of Presentation/SN
75
Tube failures - Pitting Electromechanical corrosion
Fix : appropriate water chemistry Date of last change
Reference/Name of Presentation/SN
76
Tube failures - Others Hydrogen-induced tube burst : occurs beneath a relatively dense deposit Fix : appropriate water chemistry Ductile gouging : irregular wastage of the tube meteal beneath a porous deposit Fix : appropriate water chemistry
Date of last change
Reference/Name of Presentation/SN
77
Boiler Construction : Drum Dry saturated steam towards superheaters Feedwater
Water/steam mixture from evaporator
Date of last change
Reference/Name of Presentation/SN
78
Troubles associated to drums
z z z z z z z
Date of last change
Loss of level gauges water level controllers out of service corrosion moisture carry-over in the steam safety valves leaking leaks of roll-expanded evaporator tubes plugging of evaporator tubes
Reference/Name of Presentation/SN
79
Boiler Auxiliary : Ljungstrom® Regenerative Air Heater Hot flue gas from boiler
Cold flue gas to stack Date of last change
Reference/Name of Presentation/SN
Hot Air to Burners
Cold Air 80
Ljungstrom® Regenerative Air Heater, Glossary Hot Air to burners
Hot flue gas from boiler
Radial seals Heat transfer Elements
Rotor Housing or t Ro
Pin rack
Date of last change
Cold flue gas to chimney
Hot End
So otb low Axial seals er Cold air
Intermediate s
Cold End Source : Combustion, Fossil Power J.G. Singer 1991, ch 14 p 29 fig 27
Reference/Name of Presentation/SN
81
Ljungstrom® Regenerative Air Heater Issues z z z z z
Leakages due to damaged axial or circumferential seals Cold end baskets damaged by acid corrosion, Poor sootblowing, triggering fires Standby pneumatic or DC motor not working or absent Broken / missing pins on the pin rack
- Heavy impact on boiler efficiency Date of last change
Reference/Name of Presentation/SN
82
Boiler auxiliary : Sootblowers
Source : Combustion, Fossil Power J.G. Singer 1991, ch 14 p 39 fig 34
Date of last change
Reference/Name of Presentation/SN
83
Sootblowers Issues
z z z z z
Date of last change
Locked, unable to travel in the furnace Auxiliary steam not available Insufficient number of sootblowers Wear and tear of the steam nozzles etc.
Reference/Name of Presentation/SN
84
Boiler Auxiliary : fans Discharge
Inlet vanes
Inlet (Suction) Inlet (Suction)
Source : Combustion, Fossil Power J.G. Singer 1991, ch 14 p 8 fig 5
Date of last change
Reference/Name of Presentation/SN
85
Boiler Auxiliary : fans
Source : Combustion, Fossil Power J.G. Singer 1991, ch 14 p 8 fig 6
Date of last change
Reference/Name of Presentation/SN
86
Boiler Auxiliary : Circulation Pump Inlet (Suction)
Discharge Impeller Pump-End Journal Bearing Rotor Motor Casing Thrust Bearing Terminal Gland Electrical Terminal Box Source : Combustion, Fossil Power J.G. Singer 1991, ch 14 p 43 fig 37
Date of last change
Filter Reference/Name of Presentation/SN
Discharge Pump-End Bearing Housing Heat-Exchanger Inlet Connection Stator Windings Stator laminations Cover-End Journal Bearing Thrust Disc and Auxiliary Impeller Heat-Exchanger Outlet Connection Reverse Thrust Bearing 87
Boiler Operation Improvement : Training
Source : Combustion, Fossil Power J.G. Singer 1991, ch 21 p 32
Date of last change
Reference/Name of Presentation/SN
88
Safe Operation of Large Boilers z
Protection against pressure surges – safety relief valves on drum, reheaters and superheaters
z
Lack of water in the drum – automatic trip if level comes too low to avoid operation of boiler without water
z
Protection against explosions in furnaces – boilers on-off safeties : burner management system – flame scanners
z
Environmental issues
Date of last change
Reference/Name of Presentation/SN
89
Power Generation Glossary z
Capacity Factor – energy generated by the unit during the reference period divided by the energy that could have been generated had the unit run at its full rating over the entire period
z
Net Plant Heat Rate [ NPHR ] – the fuel-heat input required to generate one KWhr of energy delivered to the grid
z
Auxiliary Power Charges – in-house power requirement of the installation (pumps, fans, motors, etc.)
Date of last change
Reference/Name of Presentation/SN
90
Power Generation Glossary (+) z
Gross Plant Heat Rate – net plant heat rate plus the fuel-heat input needed to cover the auxiliary power charges
z
Replacement Power Cost – the cost of purchasing the replacement energy if the concerned installation is not operating, due to a scheduled or forced outage
z
Black Start Capability – in-house auxiliary generating station (diesel, generally) to cover the auxiliary power charges necessary to start the plant
Date of last change
Reference/Name of Presentation/SN
91
A introduction to Boiler Design Basics
Boiler Design Basics Introduced !
Thank you for your attention Date of last change
Reference/Name of Presentation/SN
92
www.alstom.com