154863764-Mitsubishi-Boiler-Control (1).pdf

6 1 1 N K 9 9 1 . O 5 N N G

Revised according to owner comment after software FAT in KM. (28 Jan. 2005) KS 1

Y. Ono

Y.Ono

N I W A R D

RP0

(DNV)

A4

94

A3

0

TOTAL 95 SHEETS WITH COVER

DAEWOO H.NO.2227 / 2228 / 2235 T. Yuki

MAIN BOILER(MB-4E-NS2)

Y. Ono K. Saito

Functional Design Specification for Boiler Control DRAWING NO.

K1A32/38/44

61500 G377

N51-99K-N116

MITSUBISHI HEAVY INDUSTRIES, LTD. NAGASAKI SHIPYARD & MACHINERY WORKS DRAWN 25 Nov. 2004 ISSUED

1

Kongsberg Functional Design Document (KFDD) Boiler Control System DSME 2227/2228/2235

Project:

7069

Product Synopsis:

This document describes the scope and functions of the Kongsberg Maritime Vessel Control System SVC delivered to the specified vessel. Functions within other systems are not described in this document. This document when “as built” will serve also as operator documentation together with KM standard SVC Operator Manual

Document number:

1001854

Revision:

0D

Customer doc number:

Document version:

0.4

Contract number:

Number of pages:

93

Rev.

Date

Reason for issue

Made by

Checked

Approved

A

28.04.2004

For internal comments

BA

HAE

HAE

B

13.05.2004

For Approval

OHJ

HAE

HAE

C

15.07.2004

Reissue for approval

SN

MS

EW

D

26.01.2005


OHJ

GM

OSL

E

Kongsberg Maritime AS

Kongsberg Functional Design Document (KFDD) Boiler Control System DSME 2227/2228/2235

Project:

7069

Product Synopsis:

This document describes the scope and functions of the Kongsberg Maritime Vessel Control System SVC delivered to the specified vessel. Functions within other systems are not described in this document. This document when “as built” will serve also as operator documentation together with KM standard SVC Operator Manual

Document number:

1001854

Revision:

0D

Customer doc number:

Document version:

0.4

Contract number:

Number of pages:

93

Rev.

Date

Reason for issue

Made by

Checked

Approved

A

28.04.2004


BA

HAE

HAE

B

13.05.2004

For Approval

OHJ

HAE

HAE

C

15.07.2004


SN

MS

EW

D

26.01.2005


OHJ

GM

OSL

E



History Revision

Description of Change

A


B

For Approval

C

Re-i Re-iss ssue ue for for app appro rova val, l, inse insert rt com comme ment ntss fro from m MHI MHI,, dat dated ed 10 July July 2004 2004 K.Saito / MHI Marine Boiler Re-issue for approval, insert comments after FAT, January 05

References Doc No

Description

1001854 / 0D / Page 2 of 93


Table of contents 1

GENERAL ITEMS ..................................................................................................5

1.1

Definitions/Abbreviations .....................................................................................5

1.2

Flowchart symbols.................................................................................................8

2

RESPONSIBILITIES..............................................................................................9

3

BOILER GENERAL ...............................................................................................9

3.1

General ..................................................................................................................9

3.2

Burner Management ............................................................................................13

3.3

CPU Redundancy ................................................................................................13

3.4

Power Distribution...............................................................................................14

4

BURNER SEQUENCES........................................................................................15

4.1

Fuel Oil Burning..................................................................................................16

4.2

Gas burning .........................................................................................................24

4.3

Burner Auto Mode...............................................................................................29

4.4

Burner Automatic Increase/Decrease ..................................................................30

4.5

Fuel Mode Changeover .......................................................................................34

4.6

Fuel Oil Boost UP ...............................................................................................42

4.7

Nitrogen Purge of Gas Supply Lines...................................................................43

5

4.7.1

N2 Purging of Main Line to Vent............................................................... 44

4.7.2

N2 Purge of Gas Header to Vent ................................................................ 45

4.7.3

N2 Purge of Gas Burner to Furnace ........................................................... 46

4.7.4

N2 Purge of Gas Header & Burner to Furnace........................................... 46

4.7.5

Main Line Vent Valves .............................................................................. 48

BOILER CONTROL.............................................................................................49

5.1

Drum Water Level Control..................................................................................49

5.2

Main Steam Temperature Control .......................................................................51

5.3

Atomizing Steam Pressure Control .....................................................................52

5.4

Steam Purge Pressure Control .............................................................................53

5.5

FO Pump Discharge Pressure Control.................................................................54

5.6

Steam Pressure Control .......................................................................................55

5.7

Steam Dump Control ...........................................................................................62

5.8

Flame Eyes ..........................................................................................................65

5.9

FDF STBY Fan....................................................................................................66

1001854 / 0D / Page 3 of 93


5.10

Hot Start Valve....................................................................................................67

5.11

Viscometer Outlet Valve .....................................................................................68

5.12

Fuel/Atomizing Valve Abnormal ........................................................................69

5.13

Output to Main Turbine.......................................................................................70

6

BOILER TRIP .......................................................................................................71

7

BOILER OPERATION PANELS ........................................................................78

7.1

BGB Graphic Panel .............................................................................................78

7.2

Manual Loader Functions....................................................................................82

7.3

Emergency Operation..........................................................................................84

8

7.3.1

No.1 or No.2 part........................................................................................ 84

7.3.2

Common Part.............................................................................................. 85

SOOT BLOWING SEQUENCES ........................................................................85

8.1

Long Soot Blower Sequence ...............................................................................87

8.2

Rotary Soot Blower Sequence.............................................................................87

8.3

Boiler & Economizer Soot Blower Sequence .....................................................88

8.4

Economizer Soot Blower Sequence ....................................................................90

9

ATTACHMENTS ..................................................................................................93

1001854 / 0D / Page 4 of 93


1 GENERAL ITEMS 1.1 Definitions/Abbreviations Local control

Operation of the equipment is outside the IAS system (Switchboard or local panels).

Remote control

Operation of the equipment is performed from the IAS system.

Manual control

Operation of the equipment is performed manually by the operator from the IAS operator stations or BGB.

Automatic control

Operation of the equipment is performed by IAS control logic (remote mode only).

ABC

Automatic Boiler Control

AVR

Automatic Voltage Regulation

BGB

Boiler Gauge Board

BNP

Burner Operation Panel

CCR

Cargo Control Room

CTR

Custody Transfer System

DG

Diesel generator

DP

Differential Pressure

E/R

Engine room

ECR

Engine Control Room

EOP

Emergency Operator Panel

EOT

Engine Order Telegraph

ESD

Emergency Shutdown

F&G

Fire and Gas

FDF

Forced Draft Fan

FDS

Functional Design Specification

FO

Fuel oil

FS

Field Station (Cabinet with controller and/or RIO modules)

1001854 / 0D / Page 5 of 93


FV

Forcing Vaporizer

FW

Fresh water

GMS

Gas Management System

HD

High Duty Compressor

HS

Hand Switch

HT

High Temperature

HV

High voltage (6.6 kV systems)

I/O

Input / output

IAS

Integrated Automation System

IGC code

International Code for the Construction and Equipment of Ships carrying Liquefied Gases in Bulk.

IGV

Inlet Guide Vane

KM

Kongsberg Maritime

LD

Low Duty Compressor

LNG

Liquefied Natural Gas

LO

Lubrication oil

LR

Lloyds Register

LT

Low temperature

LV

Low Voltage (440V / 220 V systems)

MCC

Motor Control Center

MCR

Maximum Continuous Rate

MHI

Mitsubishi Heavy Industries

MLP

Manual Loader Panel

MV

Main Vaporizer

MT

Main Turbine

NDU

Net Distribution Unit

OS

Operator Station

PMS

Power Management System

PV

Process Variable

RCS

Remote Control System

RCU

Remote Controller Unit

1001854 / 0D / Page 6 of 93


RIO

Remote Input Output Unit

SBRP

Soot Blower Relay Panel

SP

Set Point

SVC

Simrad Vessel Control

SW

Sea water

TG

Turbine Generator

VDU

Video Display Unit

1001854 / 0D / Page 7 of 93


1.2 Flowchart symbols Symbols

Description

Condition for next step

Action Failed (Timout)

Accomplished OR Failed (Timout)

This symbol represents any kind of processing function.

Accomplished

This symbol represents a decision or switching type function

This symbol represents a named process, such as a subroutine.

This symbol represents data input by manual means

This symbol represents a process performed by operator or automatically by process event.

Indicates a crossreference within the same page of the flow chart.

This symbol represents the end of a program flow.

This symbol represents a data that is displayed for human use.

This symbol represents a delay/timer

1001854 / 0D / Page 8 of 93


2 RESPONSIBILITIES Kongsberg Maritime is responsible for this document.

3 BOILER GENERAL 3.1 General Two main boilers are installed, both with the following specifications: Maker:

Mitsubishi Heavy Industries.

Type:

MB-4E-NS2.

Steam pressure:

60.3 bar.

Steam temperature:

515 °C.

Evaporation:

Normal: 50,000 kg/h , max: 61,500 kg/h

Feed water temperature at ECO outlet:

139,8 °C.

Efficiency Fuel Oil:

88,5 %

Boiler design pressure:

76,5 bar

Auxiliary de super heater outlet: Steam quantity: Temperature:

Max: 40,000 kg/h Max: 350 °C , normal: 288.5 °C.

1001854 / 0D / Page 9 of 93


Figure showing general arrangement: IAS Ethernet HUB A

IAS Ethernet HUB B

MB2 Control Cabinet

MB1 Control Cabinet

Boiler Common / Soot blowers Cabinet

RCU

RCU

RCU

RCU

RCU

RCU

HUB

HUB

HUB

HUB

HUB

HUB

RIO

Analogue control sensors

RIO

Analogue control sensors

RIO

Common AI/AO

RIO

Flame scanner #1 MT Trip/Pwr Reduction

RIO

Flame scanner #1 MT Trip/Pwr Reduction

RIO

Common DI/DO

RIO

Flame scanner #2

RIO

Flame scanner #2

RIO

Common DI/DO

RIO

Analogue Control Se nsors

RIO

Analogue Control Sen sors

RIO

Analogue Control Sensors

Analogue Control Vlv' s

Analogue Control Vl v's

Analogue Control Vlv's

RIO

Manual Loader

RIO

Manual Loader

RIO

Manual Loader

RIO

Manual Loader Operator Panel

RIO

Manual Loader Operator Panel

RIO

Div control

RIO

Common Vlv's Operator Panel Others

RIO

Common Vlv's Operator Panel Others

RIO

Soot Blower Control

Common Vlv's Operator Panel

RIO

RIO

Soot Blower Control

RIO

Soot Blower Control

RIO

Soot Blower Control

RIO

RIO

RIO

Operator Panel

RIO

No1 Burner Control

RIO

Common Vlv's Operator Panel

Operator Panel

No1 Burner Control

SBP RIO

No2 Burner Control

RIO

No2 Burner Control

RIO

No3 Burner Control

RIO

No3 Burner Control

BGB

1001854 / 0D / Page 10 of 93


BGB, Boiler Gauge Board The local board including graphic operator panel, manual loader functions, emergency operator function, some instruments. panels including BNP, MLP & EOP. BGB is MHI supply. Graphic Operation Panel This panel is located at the BGB. It contains lamps and switches for local boiler control also manual loader functions are included. Graphic Operator panel is MHI supply.

EOP, Emergency Operation Panel This panel is located locally at the BGB. From this panel FO burners can be started/stopped in case of emergency. EOP is MHI supply.

Soot Blower Relay Panel This cabinet is delivered by MHI. The cabinet controls soot blowing sequences of the two boilers. ABC RIO units are installed here for soot blower control. ABC Cabinets ABC cabinets consists of three cabinets . •

FS-11, Main boiler no1 control

•

FS-13, Main boiler no2 control

•

FS-12, Boiler common & soot blower control

1001854 / 0D / Page 11 of 93


Boiler main functions: •

Start / stop of oil burners

•

Start / stop of gas burners

•

Nitrogen purge of gas lines

•

Fuel mode changeover

•

Burner automatic increase/decrease according to boiler load

•

Automatic FO backup

•

Automatic FO boost up in case of gas supply failure

•

Drum water level control

•

Steam temperature control

•

Atomizing steam pressure control

•

Purge steam pressure control

•

FO pump pressure control

•

Steam pressure control, including: - Boiler master control with load ratio control - Air flow control including O2 control - FO flow control - GAS flow control

•

Steam dump control

•

Local panels with operation.

•

Boiler safety.

•

Emergency operation.

1001854 / 0D / Page 12 of 93


3.2 Burner Management Burner sequence control and boiler control loops are integrated in the ABC process stations. Data exchange between the process stations is done via the dual Ethernet.

All commands and parameters are available from IAS/ABC operator stations. In addition commands and control can be made from the Boiler Gauge Board, via local/remote switches.

Emergency operation of burner can be done from the EOP, which is totally independent from IAS. When emergency operation is selected, both ABC and BMS are changed to emergency mode.

Boiler shutdown system is mostly within the IAS boiler control system. Some shutdowns are hardwired (by MHI).

3.3 CPU Redundancy Each of the ABC process stations are equipped with a redundant CPU. Normally the main CPU runs and activates the process outputs. The slave CPU is running in parallel with the main CPU but process output are disabled (hot backup). In case of main CPU fails, the process outputs to the AO/DO cards are controlled by the slave CPU.

1001854 / 0D / Page 13 of 93


3.4 Power Distribution Each of ABC cabinets are supplied with redundant power system. See figure below, indicating the power supply principle. Each of the UPS & AC/DC converters contains sufficient capacity to supply the system.

Process Station Cabinet Main Supply Emerg Supply

220V AC UPS 1

RCU A 24V DC 220V AC

UPS 2

RCU B 24V DC

RIO Units

220V AC

BGB

24V DC RIO Units 220V AC 24V DC

SBRP

RIO Units

1001854 / 0D / Page 14 of 93


4 BURNER SEQUENCES General.

Starting / stopping of burners are made by a sequencer system within the IAS. This is applicable for either IAS control or BGB local control. A selector switch at the BGB decides which control place to be active. In case of any trouble during sequence execution a sequence jam status is issued. In case of sequence jam the running sequence will perform a clean up (error treatment). All sequences except stop sequences will be blocked until operator resets the sequence jam (reset button at IAS monitor, acknowledge button at BGB).

Burner Start.

FO / GAS start buttons are prepared separately which means operator freely can decide each burner firing mode. Burner asynchronous firing is allowed in manual mode.

Burner Stop.

FO / GAS stop buttons are prepared separately.

NOTE: 1 burner firing at gas only is not recommended for safety reasons.

Burner Auto mode.

In order to select auto mode the burners must be firing in synchronous mode. Burner manual sequences is then inhibited.

The following sequences are then available: •

Burner automatic increase, starts automatically.

•

Burner automatic decrease, starts automatically.

•

Mode change FO => Dual, need operator intervention to start.

•

Mode change Dual => GAS, need operator intervention to start.

•

Mode change GAS => Dual, need operator intervention to start.

•

Mode change Dual => FO, need operator intervention to start.

•

FO auto backup (GAS => Dual), starts automatically

•

FO boost up (GAS => FO), starts automatically.

1001854 / 0D / Page 15 of 93


4.1 Fuel Oil Burning Starting fuel oil burners:

The individual fuel oil burners can be started and stopped either from the operator station (IAS control) or from the BGB (local control). •

•

If all flames are off and operation position is BGB then first burner starting must be done from BGB. Operation position transfer BGB => IAS is blocked during boiler stopped condition. If all flames are off and operation position is IAS then first burner starting can be done from IAS.

In addition burners can be started and stopped from EOP (not described here since this is an independent system). •

Start FO burner 1 (by activating the “start FO 1” pushbutton).

•


•


1001854 / 0D / Page 16 of 93


Operator Preparations: •

Reset of all FO trip conditions.

•

Reset of all boiler trip conditions.

•

Start of FO supply pump.

•

Start of FDF

•

Open FO shutoff valve.

Sequence Description:

At the time all interlocks are lifted the start FO sequence can be started. The starting will be carried out by a sequence controller according to following description. First the corresponding burner atomizing steam valve is opened. Furnace purge will then be carried out by opening of all burner air slide dampers and FDF vane is set to purge position. Furnace purge will be continued for 90 seconds (confirmed by air volume). When the furnace purge is completed the not starting burner air registers will closed and FDF vane will be set to start position. Fuel oil control valve will be set to start position. The igniter will be inserted and the spark activated. When igniter spark and position is confirmed the burner FO valve will be opened. Furnace purge sequence uses air flow signal from differential press transmitter (247B) for detection of sufficient air volume. Differential press transmitter for air flow detects press between wind box and furnace. And air flow is calculated based on measured press.

1001854 / 0D / Page 17 of 93


Flowchart for starting fuel oil burners, the first FO burner: SEQ-1 Start Oil Burner (Initial FO Burner)

Note : Only One Burner Can Be Started At The Time Condition for next step

Start Start Permissive Terminate

Action

- Atm Steam Vlv Opened & - Steam Purg Vlv Closed

Open Bnr Atm Steam Valve & Close Steam Purge Valve Timeout : 10 sec

Error

- Boiler Purged Status Set

Start Furnace Purge Sequence (SEQ-2) Timeout : 6 min

Error

- Fd Fan Vane In Start Pos(2-6%)

Force Fd Fan Vane To Start Pos. (5%) Timeout : 10 sec

Error

- Selected Bnr Register Opened & - Not Selected Registers Closed

Close Bnr Register which are not set for start Timeout : 10 sec

Error

Close FO Recirc Valve Timeout : 10 sec

Error

Set FO Ctrl Vlv To Start Pos(18%) Timeout : 20 sec

Error

Check Air Rate & FO Press & FO Temp Timeout : 60 sec

Error

Check All Flames are OFF Timeout : 5 sec

Error

Open FO Valve 223B & Insert Igniter Timeout : 20 sec

Error

- FO Recirc Valve Closed

- FO Ctr Vlv In Start Pos(15-21%)

- Air Rate Normal (8000-4000kg/h) & - FO Press Ok(>10bar) & - FO Temp Ok or Temp byps On OR

- Burner On from BGB(local) if all Bnr off - Burner On from Monitor(IAS) if all Bnr off and OR IAS Mode established

- Boiler FO Shutoff Valve Opened - All Bnr Fo Valves Closed - Not Fo Trip - All Burner Register Closed & - Not F/E Abnormal - All Bnr GAS Shutoff Valves Closed - If ignitor is bypassed then portable ignitor must be inserted(Limit Switch) - Not boiler trip - Stop Seq Not active - FDF Run - Not Seq Jam

- Boiler FO Shutoff Vlv Close Cmd - Boiler Trip - FO Trip OR

Waiting timer 10s

- All Flames OFF Waiting Timer: 1s

- FO Valve opened & - Igniter inserted

- Igniter In Down Position Activate Retractable Igniter if Not & Spark On Portable igniter Selected & Portable Igniter Not Selected OR Or - Igniter In Down Position Activate Portable Igniter if Selected & Portable Igniter Selected & Spark On Timeout : 10 sec Waiting Timer: 2s

- Falme Fail Waiting Timer: 5s

- Set Alarm - Close Burner Fo Valve's

- Burner Fo Valve 1 Opened & - Burner Fo Valve 2 Opened & - Flame Detected Direct Error if:

Error

Open Burner Fo Valve 225B Timeout : 10 sec (Flame fail is activated 7s afterFO vlv open cmd)

- Deactivate & Retract Igniter Error

- Close Burner Register If Gas Burner Is Not Active - Close Atomize Steam Valves

- Igniter Deactivated & - Igniter Retracted Waiting timer 7s

Deactivate & Retract Igniter Timeout : 10 sec

Error

- Open Stm Purge Vlv if Any Bnr is ON - Release FDF Vane

- Fd Fan Vane Released & - FO Control Valve Released Note:

FO Valv e 223B is Slow Acting Downstream side FO Valve 225B is Fast Acting

Release Fd Fan Vane & FO Control Valve Timeout : 5 sec

Error

End

1001854 / 0D / Page 18 of 93

- Release FO Ctr Vlv - Open FO Recirc Valve


Flowchart for furnace purging:

SEQ-2

Start Start Permiss ive Terminate

Furnace Purging Condition for nex t step - Burner 1 Register Opened & - Burner 2 Register Opened & - Burner 3 Register Opened

- FDF in Furn Prg Pos +/- 3% & - A ir Flow > 40.000 Kg/h

- Air volume > 900 m3 & - Minimum Timer 60 sec

Ac tion Open All Burner Registers Timeout : 15 sec

- Start fr om Burner Start seq. or - Manual Purge from BGB in Local mode or - Manual Purge from IAS in IAS mode

Error - All Bnr FO Vlv's Closed & - FDF Run

Force Fd Fan Vane Fully Open Timeout : 30 sec

Purging ( min 60s ) Timeout : 300 sec

Set

- Purge Status > 1min Or - FDF Not RunOr - Any FO Vlv Open Command Or - FO Shut Valve Open & A ny Bnr On

Reset

Error

Error

Set Boiler Purged Status (No Set if Man Purge)

- FDF Stopped - Boiler Manual Trip

Furnace Purge Seq Failed - Release FD Fan Vane - Close All Burner Registers

End

Manual Purge.

At the BGB there is a switch for purge request. This switch will activate the above mentioned sequence if boiler is stopped.

1001854 / 0D / Page 19 of 93


Starting fuel oil burners, when another burner is on:

In manual mode operator is responsible for checking FO pressure and boiler master demand by him self. Auto mode is described in the chapter for burner automatic increase / decrease. The individual fuel oil burners can be started and stopped either from the operator station (IAS control) or from the BGB (local control). •


•


•



The sequence starts by open the burner atomizing steam valve and closing of steam purge valve. Then igniter is lowered and simultaneously burner FO valve’s (up stream 225B & down stream 223B) are opened. The burner flame should be detected within 7 seconds after FO valves are opened if not burner will trip.

1001854 / 0D / Page 20 of 93


Flowchart for starting fuel oil burners, when another FO burner is on: SEQ-3

Note : Only One Burner Can Be Started At The Time Condition for next step - Atm Steam Vlv Opened & - Steam Purge Vlv Closed &

- FO Press OK OR - FO Mode OR - BMS Manual Mode

- FO Recirc Valve Closed

- FO Control Vlv in Start Pos OR - Any FO Bnr On

- Igniter In Down Position & Spark On & Portable Igniter Not Selected OR - Igniter In Down Position & Portable Igniter Selected & Spark On Or - Corresponding Gas Bnr On

- Burner FO V(223B) Open Cmd & - Burner FO V(225B) Open Cmd

-Flame Detected Waiting timer 5s

Start Oil Burner (Next FO Burner)


Action Open Atm Steam Vlv & Close Steam Purge Vlv Timeout : 10 sec

Error

Adjust FO Press if Auto & Dual Timeout : 10 sec

Error

Close FO Recirc Vlv Timeout : 10 sec

Set FO Control Vlv to Start Pos if No FO Bnr On Timeout : 10 sec

Insert and activate Retractable Igniterif Not Portable igniter Selected Or Activate Portable Igniter if Selected

Error

- Burner On from BGB(local) if any flame on - Burner On from Monitor(IAS) if any fl on OR - Start Request from Bnr auto inc (SEQ-9 step 2 , SEQ-9 step 5)

- Any Burner Is Active - Burner FO Valves Closed & - Burner Register Closed if Gas Burner is Off - Not Seq Jam - FO Press > 10 bar if Auto Mode

Error

-

FO Shutoff Vlv Close Cmd Burner Fo Piston Valve Shutdown Boiler Trip FO Trip OR Note : If all burner flame on signals are llost before before a flame is detected on the burner being ignited the start sequence will be terminated.

Error

If Corresponding GAS Bnr is Off Timeout : 30 sec

Open Bnr FO Vlv (223B) & Open Bnr FO Vlv (225B) Timeout : 10 sec (Flame fail is activated 7s afterFO vlv open cmd)

Open Burner Register after 2 s Timeout : 10 sec

Error

Error

FO Burner Ignition Seq Failed

Close Burner FO Valves Deactivate & Retract Igniter

- Ignitor Deactivated & - Ignitor Retracted Waiting timer 7s

Deactivate & Retract Ignitor Timeout : 20 sec

Error

Close Burner Register If Gas Burner Is Not Active Close Atomize Steam Valve Open Steam Purge Valve

End

1001854 / 0D / Page 21 of 93


Stopping fuel oil burners:

The individual fuel oil burners can be stopped either from the operator station (IAS control) or from BGB (local control). • • •

Stop FO burner 1 (by activating the “stop FO 1” pushbutton). Stop FO burner 2 (by activating the “stop FO 2” pushbutton). Stop FO burner 3 (by activating the “stop FO 3” pushbutton).

The stop of burners is always available and will terminate any start attempt.

The following commands are executed: • • • • •

•

Closing individual fuel oil piston valves. De-energizing igniter (if energized). Retracting Igniter (if inserted). Closing burner register if gas burner is not active (individual gas valve closed). Steam purging of burner, atomizing steam valve will close (if no other burner is active). In case of stopping last burner a furnace purge will be carried out.

1001854 / 0D / Page 22 of 93


Flowchart for stopping fuel oil burners:

1001854 / 0D / Page 23 of 93


4.2 Gas burning Start up of gas burning can be done either by manually starting each burner or by using the automatic sequence.

Operator Preparations:

The operator must prepare the following conditions before GAS firing can start: •

FO firing must be established.

•

Reset of all GAS trip conditions.

•

Open Master GAS valve.

•

Open boiler GAS valve.

Manual Mode

The individual fuel gas burners can be started and stopped from the IAS operator station or from BGB in local control. •

Start GAS burner 1 (by activating the “GAS 1 ON” pushbutton).

•


•


•

Stop GAS burner 1 (by activating the “GAS 1 OFF” pushbutton).

•

Stop GAS burner 2 (by activating the “GAS 2 OFF” pushbutton).

•

Stop GAS burner 3 (by activating the “GAS 3 OFF” pushbutton)

Auto Mode:

The operator may select “FO/Dual/ GAS” mode from the IAS operator stations. The transfer between modes is then made by a sequence program. Number of burners is decided by boiler load.

1001854 / 0D / Page 24 of 93



Gas burners can be started once the corresponding FO burner is in operation. In addition the master gas valve and boiler GAS valve must be opened, the burner GAS valves must be closed. The vent valves are controlled automatically by the sequences or by GAS valves positions. During GAS burner ON/OFF operations the N2 purging of lines/burners will be performed automatically when needed. At the end of gas firing the operator must manually close boiler GAS valve and master GAS valve. Flowchart for starting fuel gas burners:

Note : Only One Burner Can Be Started At The Time Condition for next step - Gas Ctrl Valve In Start Position Or - Any Other Gas Burner Is Active

- Waiting Timer 3 sec

- Burner Gas Valve 1 Opened & - Burner Gas Valve 2 Opened &

SEQ-5 Start Gas Burner


- Gas Burner On f rom BGB (Local Mode) - Gas Burner On from Monitor(IAS) OR - Start Req from Bnr auto inc/dec s eq. (SEQ-9 step 3, SEQ-9 step 6)

Ac tion Check Gas Ctrl Vlv To Start Pos. If No Other Gas Burner Is A ctive Timeout : 10 sec

Error

Set Air Bias Timeout : 10 sec

Open Burner Gas Valves Timeout : 10 sec

Error

- Master Gas Valve Open - Boiler Gas shutoff valve Opened - Burner Gas V alve1 Closed - Burner Gas V alve2 Closed - Not Boiler Trip - Not FO Trip - Not Gas Trip - Master N2 Purge Sequence Not Active - Header N2 Purge Sequence Not Active - Header N2 Purge Valve Closed - Burner N2 Purge V alve Closed - Not Seq Jam - Corresponding FO Bnr On

&

- Master Gas V alve Closed - Gas Trip Note : If Corresponding Oil Burner "Flame On" Signal Is Lost Before Gas Flame Is Detected, The Start Sequence Will Be Terminated.

Release Gas Control Valv e

GAS Burner Ignition Seq Failed - Close Burner Gas V alves

Reset Air Bias

End

1001854 / 0D / Page 25 of 93

- Reset Air Bias A djustment

OR


Flowchart for stopping fuel gas burners:

SEQ-6 Stop Gas Burner Condition for next step

Start Start Permissive

Ac tion

- Burner Gas Valve 1 Closed & - Burner Gas Valve 2 Closed

Close Burner Gas Valves Timeout : 10 sec

Error

- Air Bias Adjustment is Reset

Reset Air Bias Adjus tment Timeout : 10 sec

Error

Furn Purge Req If Last Bnr Timeout : 10 sec

Error

Start Burner N2 Purge If Any Bnr Firing Timeout : 10 sec

Error

- Any Burner Is Active Or - Furn Purge Run

- Stop from BGB (Local Mode) - Stop from Monitor(IAS) - Stop request f rom burner inc/dec OR (SEQ-10 step2, SEQ-10 step4) - Stop request from Dual=>FO seq - Bnr Falme Fail - Burner Gas Valve's Not Close Cmd

Waiting Timer 10 sec

- Burner N2 Purge V Opened Or - Furn Purge Seq Run

Gas Burner Extinguish Seq Failed - Bnr register Closed Or - FO Bnr On Or - Furn Purge in Progerss

Close Bnr Register If FO Bnr is Off & Not Furn Purge Timeout : 10 sec

Error

- Close Burner Gas Valves - Close Air Register if FO Burner is Not A ctive - Close Burner N2 Purge Valve

End

1001854 / 0D / Page 26 of 93


Flowchart for Boiler Gas Valve Open: SEQ-7 Blr Gas Valve Open Condition for next step - Blr Gas Vlv Opened


- Gas Control Vlv in Ign Pos

OR

Action Open Blr Gas Valve. Timeout : 10 sec

Error

- Master Gas Valve Open - All Bnr Gas Vlv's Closed - All Bnr N2 Purge Vlv's Closed - Not Boiler Trip - Not FO Trip - Not Gas Trip - Hdr N2 Purge Seq Not Active

Timer 5 sec

- Hdr N2 Vent Vlv Closed

- Open from Monitor(IAS)

Close Hdr N2 Vent Vlv Timeout: 10 sec

Error

Set Gas Control Vlv to Ignition Pos. Timeout : 10 sec

Error

&

- Master Gas Valve Closed - Gas Trip OR

Boiler Gas Valve Open Seq Failed - Close Boiler Gas Valve - Open Header Vent Valve - Release Gas Control Vlv

End

1001854 / 0D / Page 27 of 93


Flowchart for Boiler Gas Valve Close: SEQ-8 Blr Gas Valve Close Condition for next s tep

Start Start Permiss ive

- Close from Monitor(IAS) - Close if Gas Trip

Ac tion

- Blr Gas Vlv Closed

- Gas Ctr Vlv Fully Closed(<1%)

Close Blr Gas Vlv Timeout: 10 sec

Error

Set Gas Ctr Vlv Fully Closed Timeout: 10 sec

Error

- Blr Gas Vlv Not Closed

FO Burning On ?

No

Yes - Hrd/Bnr N2 Purge to Furn Seq Run

If FO Burning: Start Hrd/Bnr N2 Purge to Furn (SEQ-19) Timeout : 1 0 sec

Error

A

Yes Start Hdr N2 Purge to Vent (SEQ-17) Timeout : 1 0 sec

- Hdr N2 Purge to Vent Run

Error

Boiler Gas Valve Close Seq Failed - Close Boiler Gas Valve - Close Hdr N2 Purge Valve - Open Header Vent Valve - Close All Burner Gas Valves - Release FDF A

End

1001854 / 0D / Page 28 of 93

OR


4.3 Burner Auto Mode Burner auto mode can be selected when the burning burners are burning in the same fuel mode e.g. FO, Dual or FG. Base burner is required in order to establish auto mode. In case of burner manual mode, any burner can be operated. For example, one gas burner firing can be made at gas only mode. Burner automatic increase / decrease, fuel mode changeover sequence is cancelled during burner manual mode. When operator selects burner manual mode, operator must also take care of suitable burner number to be matched with boiler load and general boiler safety. FO Mode Bnr1 FO Burning Bnr2 FO Burning Bnr3 FO Burning

&

&

Bnr1 GAS Bnr2 GAS Burning Bnr3 GAS Burning Burning

OR

& OR

Dual Mode Bnr1 FO Burning Bnr1 GAS Burning

& & OR

Bnr2 FO Burning Bnr2 GAS Burning

& &

OR

OR

&

OR

Auto Mo de Pos sible

& Bnr3 FO Burning Bnr3 GAS Burning

&

GAS Mode Bnr1 GAS Bnr2 GAS Burning Bnr3 GAS Burning Burning

Bnr1 FO Burning Bnr2 FO Burning Bnr3 FO Burning

&

OR

&

& OR

FO Trip Ctr Pos IAS FO Shut V Open Bnr1 Flame Fail Bnr2 Flame Fail Bnr3 Flame Fail

OR &

Bnr1 FO or Gas Burning Bnr1 Gas Burning Bnr2 Gas Burning Bnr3 Gas Burning

&

OR

&

FO Trip

1001854 / 0D / Page 29 of 93


4.4 Burner Automatic Increase/Decrease Burner Increase:

When burner auto mode is selected, the number of burners is controlled automatically according to the boiler demand. This mode is not applicable in gas only firing of one gas burner.

The system will monitor the boiler demand e.g. output from master pressure controller and the FO pressure or total fuel calorie. Also during manoeuvring a minimum numbers of burners are considered.

The priority for starting is predefined as follows: No.1 burner => No.2 burner => No.3 burner.

The priority for stopping is predefined as follows: No.3 burner => No.2 burner => No.1 burner.

Burner Increase:

Request for next burner will be calculated as follows:

Mode

FO

Dual

GAS

No Of Bnr

Limit

Result

1 bar

Boiler demand > 13,5 Gcal/h & FO pressure > 13 bar

1 => 2 bnr

2 bnr

Boiler demand > 27,0 Gcal/h & FO pressure > 12 bar

2 => 3 bnr

1 bnr

Boiler demand > 14,0 Gcal/h & total fuel calorie > 14,0 Gcal/h & FO press > 12 bar

1 => 2 bnr

2 bnr

Boiler demand > 28,5 Gcal/h & total fuel calorie > 28,5 Gcal/h & FO press > 10 bar

2 => 3 bnr

2 bnr

Boiler demand > 25,0 Gcal/h & GAS Press > 0,1 bar

GAS=>Dual

Note: In case of burner increase in GAS mode, the GAS => Dual sequence will be activated. Then dual burner will increase if required. 12,4 Gcal/hr is equivalent to 1200kg/hr of fuel oil, 20,6 Gcal/h is equivalent to 2000 kg/h.

1001854 / 0D / Page 30 of 93


Burner Decrease:

Request for stopping burner will be calculated as follows: Mode

FO

Dual

GAS

No Of Limit Bnr

Result

3 bnr

Boiler demand < 16,0 Gcal/h & FO pressure < 5,5 bar

3 => 2 bnr

2 bnr

Boiler demand < 8,0 Gcal/h & FO pressure < 5,0 bar & M/T stop for 15 min.

2 => 1 bnr

3 bnr

Boiler demand < 16,0 Gcal/h & total fuel calorie < 18,0 Gcal/h

3 => 2 bnr

2 bnr

Boiler demand < 9,0 Gcal/h & total fuel calorie < 10,2 Gcal/h & M/T stop for 15 min.

2 => 1 bnr

3 bnr

Boiler demand < 17 Gcal/h & GAS hdr pressure < 0,12 bar

3 => 2 bnr

2 bnr

Boiler demand < 6,0 Gcal/h & GAS hdr pressure < 0,1 bar

GAS=>Dual

Main Turbine Interaction:

In case of main turbine trip the numbers of burners are limited to maximum 2 burner. TimerOff

MT Vlv Lift > 50%

Crash Astern, Crash Stop (Burner No3 Auto Decrease) (By SEQ-10)

30s

&

MT Telegraph Stop OR MT Telegraph Astern MT Vlv Lift Astern Full

&

TimerOff

MT Vlv Lift Astern Full

30s

& OR MT Telegraph Stop MT Telegraph Astern

&

MT Vlv Lift > 50%

1001854 / 0D / Page 31 of 93

Crash Ahead, Crash Stop (Burner No3 Auto Decrease) (By SEQ-10)


Flowchart for Burner Automatic Increase:


SEQ-9 Burner Increase


- No of burners are 1 or more - Not MT Interlock by Crash Astern/Ahead/MT Trip - Auto mode selected - Bnr decrease Seq Off - FO => Dual Seq Off - Dual => GAS Seq Off - GAS => Dual Seq Off - Dual => FO Seq Off - FO Boost Up Seq Off - Not Seq Jam - Not Burner Abnormal

Action

- Burner 2 is OFF - Burner 2 Ready*1)

Check Burner 2 is OFF: Timeout : 1sec

- FO Mode: Boiler Demand & FO Prs - Dual Mode: Boiler Demand & Tot Calorie Input - GAS Mode: Boiler Demand & GAS Press

No

OR

&

1 OR

Start FO Burner 2 (SEQ-3) if FO or Dual mode Timeout : 60sec

- FO Burner 2 is ON & - Ignition Seq Compleate

Start GAS Burner 2 if: Dual Mode & GAS Bnr2 is OFF (SEQ-4) Timeout : 60sec

- FO Mode, OR - Burner2 is Dual Firing

Stop FO Burner 2 (SEQ-4)

Error

7 2

Stop GAS Burner 2 (SEQ-6)

Error

8

3


Action

- Burner 3 is OFF - Burner 3 Ready

Check Burner 3 is OFF: Timeout : 1sec

No 4

- FO Burner 3 is ON - Ignition Seq Compleate

- FO Mode, OR - Burner 3 is Dual Firing OR GAS mode

Start FO Burner 3 (SEQ-3) if FO or Dual Mode GAS>Dual seq (SEQ-13) if GAS mode 5 Timeout : 60sec Start GAS Burner 3 if: Dual Mode & GAS Bnr3 is OFF (SEQ-4) Timeout : 60sec

Error

Stop FO Burner 3 (SEQ-4) 9

Error 6

Stop GAS Burner3 (SEQ-6) 10

Alarm: Burner Increase Failed

End

* 1) Re ad y:

F O Mo de ; F O B ur ne r S ta rt Pe rm is si ve OK Dual Mode; FO Burner & Gas Burner Start Permissive OK

1001854 / 0D / Page 32 of 93


Flowchart for Burner Automatic Decrease: SEQ-10 Burner Decrease

Condition for next step - Burner 3 is ON

-FO Mode: Boiler Demand & FO Prs - Dual Mode: Boiler Dem & Tot Calorie OR - GAS Mode:Boiler Demand & GAS Prs - MT Chrash Ast/Ahd if 3 Bnr Firing - MT Trip & 2bnrs or More Firing


Action Check Burner 3 is ON: Timeout : 1sec

- Number of burners are 2 or more - Telegraph Stop + 15min - Auto Mode Selected - Bnr increase Seq Off - FO => Dual Seq Off - Dual => GAS Seq Off - GAS => Dual Seq Off - Dual => FO Seq Off - FO Boost Up Seq Off - Not Burner Abnrmal - Not Seq Jam

No 1

- FO Burner 3 is OFF & - GAS Burner 3 is OFF

Stop FO Burner 3 if: FO or Dual Mode (By SEQ-4) & Stop GAS Burner 3 if: Dual or GAS mode (By SEQ-6) Timeout : 60sec

Error

&

2

Condition for next step - Burner 2 is ON

Action Check Burner 2 is ON: Timeout : 1sec

No 3

- FO Burner 2 is OFF& - GAS Burner 2 is OFF

Stop FO Burner 2 if: FO or Dual Mode (By SEQ-4) & Stop GAS Burner 2 if: Dual mode (By SEQ-6) & GAS=>Dual (SEQ-13) if GAS mode Timeout : 60sec

Error

4

Alarm: Burner Dec. Failed 5 End

1001854 / 0D / Page 33 of 93


4.5 Fuel Mode Changeover There are three different modes of fuel selection. Fuel Oil Only:

Only oil burners ON.

Dual Fuel:

Both gas and oil burners ON

Fuel Gas Only:

Only gas burners ON

Available sequence for change-over is:

Fuel oil => <= Dual fuel => <= Fuel Gas.

Special Mode: Low Load Gas Mode

Low Load Gas mode can be selected either in dual mode condition or in gas mode condition. This mode enables gas only firing during main turbine in maneuvering zone.

FO => Dual Fuel:

If activated the system will start up gas burners where oil burner is already on.

1001854 / 0D / Page 34 of 93


Flowchart for Changeover FO => Dual: Start Start Permissive Terminate

SEQ-11 Mode: FO => Dual

Condition for next step - GAS Control Vlv in Start Pos

- Air Flow Controller Add Air Set

Action Set GAS Control valve to start position Timeout : 1sec 1

Set Add Air to Air Flow Controller Timeout : 1sec

No

Error 2

- (Bnr1 GAS Bnr is ON &

Open Bnr1 GAS Valves (1&2)

- (Bnr2 GAS Bnr is ON or Bnr2 FO Bnr is OFF) &

Open Bnr2 GAS Valves (1&2) if FO Bnr On Error

- (Bnr3 GAS Bnr is ON or Bnr3 FO Bnr is OFF) Wating Timer 20 sec

- IAS mode: OR Dual button from Monitor is pressed.

Open Bnr3 GAS Valves (1&2) if FO Bnr On Timeout : 60sec

-

All Bnr's GAS vlv's closed Master GAS valve open Boiler GAS vlv open Burner mode = Auto Bnr Increase Seq Off Bnr Decrease Seq Off Dual => GAS Seq Off GAS => Dual Seq Off Dual => FO Seq Off FO Boost Up Seq Off Not Burner Abnormal Not Seq Jam

-Boiler Trip - FO Trip - GAS Trip

OR

3

Reset Add Air to Air Flow Controller Timeout : 1sec 4

Reset FG Control Vlv Start Position Timeout : 1sec 5

FO => Dual Seq Failed

- Stop GAS Burner 1 (SEQ-6) - Stop GAS Burner 2 (SEQ-6) - Stop GAS Burner 3 (SEQ-6) - Reset Add Air to Air Flow Controller - Reset GAS Control Vlv Start Position 6 End

1001854 / 0D / Page 35 of 93

&


Dual => GAS:

When mode switch is changed from dual to GAS, the system will stop oil firing. SEQ-12 Mode: Dual => GAS


- FO Press < 3 bar

- FO Burner 1 is OFF - FO Burner 2 is OFF - FO Burner 3 is OFF


Action Set FO Burner Extinguish Request to FO Flow Controller Timeout: 120sec

- Stop FO Bnr1 (SEQ-4) - Stop FO Bnr2 (SEQ-4) - Stop FO Bnr3 (SEQ-4) if Dual Bnr ON Timeout: 60sec

Error

Error

Reset FO Burner Extinguish Request to FO Flow Controller

- IAS mode: GAS button from Monitor is pressed.OR

- Master GAS valve open - Number of Dual bnr's are 2 or more - Boiler GAS vlv open - Bnr mode = Auto - Bnr Increase Seq Off - Bnr Decrease Seq Off & - FO => Dual Seq Off - GAS => Dual Seq Off - Dual => FO Seq Off - FO Boost Up Seq Off - Not Bnr Abnormal - Not Seq Jam - GAS Press > 0.1 bar - LD Comp 1 or 2 Running - Not FO Auto Backup Order Active - Boiler trip - FO Trip - GAS Trip - Auto Backup Order - FO Boost Up Order

Dual => Gas Sequence Failed

End

1001854 / 0D / Page 36 of 93

OR


GAS => Dual Fuel:

When mode switch is changed from GAS to dual, the system will start up oil burners where gas burners are firing. Some process conditions will start GAS => dual sequence automatically by means of FO auto backup order. In case of LD compressor stop no3 burner will stop automatically

FO Auto Backup. Cargo Tk Press L Manouvering Zone Low Gas Mode

FO Auto Backup Order

& OR

Both LD Comp Stop Only Base Gas Bnr Firing No3 Bnr Stop & Gas Mode

‘

1001854 / 0D / Page 37 of 93


Flowchart for Changeover GAS => Dual: SEQ-13 Mode: GAS => Dual

Condition for next step - Air Bias OK

- FO Control Vlv in Start Pos


Total Timeout: 5Min

Action

Set Air Bias Timeout : 1sec

Error

Set FO Ctr Vlv To Start Pos Timeout : 10sec

Error

- Open Bnr1 Atm Steam Vlv & - Close Bnr1 Stm Purg Vlv if GAS Bnr1 is ON

- Bnr1 Atm Stm vlv Opened or Bnr1 is OFF - Open Bnr2 Atm Steam Vlv & & - Close Bnr2 Stm Purg Vlv - Bnr2 Atm Stm vlv Opened or if GAS Bnr2 is ON Bnr2 is OFF & - Open Bnr3 Atm Steam Vlv & - Bnr3 Atm Stm vlv Opened or - Close Bnr3 Stm Purg Vlv Bnr3 is OFF if GAS Bnr3 is ON

Error

- IAS mode: Dual button from Monitor is pressed. - FO Auto backup Order OR - FG Inc Order (SEQ-9 Step 5, SEQ-10 Step 4)

- GAS Mode - Boiler FO Vlv Opened - FO Burners no interlock active. - Burner mode = Auto - Number of GAS bnrs are 2 or more - Bnr Increase Seq Off - Bnr Decrease Seq Off - FO => Dual Seq Off - Dual => GAS Seq Off - Dual => FO Seq Off - FO Boost Up Seq Off - Not Bnr Abnormal - Not Seq Jam - GAS PRESS > 0.1 bar

-Boiler Trip - FO Trip - GAS Trip

Timeout : 10sec

- Bnr1 Stm Purge vlv Clsed or Bnr1 is OFF & - Bnr2 Stm Purge vlv Clsed or Bnr2 is OFF & - Bnr3 Stm Purge vlv Clsed or Bnr3 is OFF

- FO recirc Valve Close Cmd

- Bnr1 Dual Burning or Bnr1 is OFF & - Bnr2 Dual Burning or Bnr2 is OFF & - Bnr3 Dual Burning or Bnr3 is OFF & Waiting Timer 10sec

- Check Steam Purg Vlv is Closed

Error

Timeout : 10sec

Close FO Recirc Valve Timeout : 10sec

Error

- Open Bnr1 FO Vlv 1&2 if GAS Bnr1 is ON - Open Bnr2 FO Vlv 1&2 if GAS Bnr2 is ON

Error

- Open Bnr3 FO Vlv 1&2 if GAS Bnr3 is ON Timeout : 10sec GAS => Dual Seq Failed Reset FO Control Valve to Start Position

-Reset Air Bias -Reset FO Ctr V Start Pos

End

1001854 / 0D / Page 38 of 93

&

OR


Dual => FO:

When mode switch is changed from dual to FO, the system will stop gas firing.

Flowchart for Changeover Dual => FO: SEQ-14 Mode: Dual =>FO

Condition for next step - GAS Press < 50mbar


Action Set Gas Extinguish Request to Gas Flow Controller Timeout : 180sec

Error

Stop GAS Bnr1 - GAS Burner 1 is OFF & Stop GAS Bnr2 - GAS Burner 2 is OFF &

- IAS mode: FO button from Monitor is pressed. OR

- Any FO burner On - Burner mode = Auto - Bnr Increase Seq Off - Bnr Decrease Seq Off - FO => Dual Seq Off - Dual => GAS Seq Off - FG => Dual Seq Off - FO Boost Up Seq Off - Not Bnr Abnormal - Not Seq Jam

&

Error Stop GAS Bnr3

- GAS Burner 3 is OFF Timeout : 30sec

-Boiler Trip - FO Trip

Reset Gas Extinguish Request to Gas Flow Controller

Dual => FO Seq Failed - Reset Gas Extinguish Request to Gas Flow Controller

End

1001854 / 0D / Page 39 of 93

OR


Low Load Gas Mode:

Low Load Gas mode can be selected either in dual mode condition or in gas mode condition. This mode enables gas only firing during main turbine in maneuvering zone.

Dual => Low Load Gas Mode: When LL gas mode is activated at dual mode, the boiler master will increase the calorie demand in order to increase gas pressure to over 0.1bar. When gas pressure is over the limit for changing to gas mode, then “dual=>gas” sequence is activated. After change to gas mode is complete boiler master low limit will be set depending on number of burners.

Gas => Low Load Gas Mode: When LL gas mode is activated at gas mode, boiler master low limit will be set depending on number of burners.

Note:

Since Low Load Gas Mode sets a minimum boiler master demand main steam pressure might increase. In case main steam pressure is increased the dump control valve will open and keep the pressure at dump set point.

Low Load Gas Mode Available: •

BMS Auto &

•

2 or 3 Bnr Firing &

•

Dual or Gas Mode

1001854 / 0D / Page 40 of 93


Low Load Gas Mode Exit: •

FO Mode Pushbutton Depressed, or

•

Dual Mode Pushbutton Depressed or

•

Gas Mode Pushbutton Depressed or

•

Steam Press Over 62.9bar or

•

Dump control valve over 70% or

•

Gas mode dropout (Fuel mode is changed from gas to other mode due to FO boost-up or back-up.)

Boiler Master Low Limit: •

During changeover at dual 2 bnr: 17 Gcal/h

•

During changeover at dual 3 bnr: 26 Gcal/h

•

At low load gas mode and gas only firing: 13 Gcal/h

1001854 / 0D / Page 41 of 93


4.6 Fuel Oil Boost UP FO boost up sequence is available in GAS mode. The sequence is initiated in case of GAS master valve trip conditions. SEQ-15 Fuel Oil Boost Up

Condition for next step - If Bnr1 GAS firing: Bnr1 Atm Stm V Opened Bnr1 FO Vlv 1&2 Opened Bnr1 Prg Stm V Closed & - If Bnr2 GAS firing: Bnr2 Atm Stm V Opened Bnr2 FO Vlv 1&2 Opened Bnr2 Prg Stm V Closed & - If Bnr3 GAS firing: Bnr3 Atm Stm V Opened Bnr3 FO Vlv 1&2 Opened Bnr3 Prg Stm V Closed & - FO Recirc V Opened


Action

- Burners Firing in GAS mode - All Bnr FO Valves Closed - FO Shutoff Vlv Opened - Boiler in Auto Mode

Open: Bnr1 Atm Stm V if Bnr firing Bnr2 Atm Stm V if Bnr firing Bnr3 Atm Stm V if Bnr firing Bnr1 FoVlv1&2 if Bnr firing Bnr2 FoVlv1&2 if Bnr firing Bnr3 FoVlv1&2 if Bnr firing

-FO Trip Close: Bnr1 Prg Stm V if not firing Bnr2 Prg Stm V if not firing Bnr3 Prg Stm V if not firing FO Recirc Vlv

Error

Close Bnr1 FO Vlv's & Air register if No Flame or Purge steam vlv not closed or Atomize steam vlv not open

Force FO Control Vlv to "FO Boost Up Order" Position Timeout: 6 sec

Close Bnr2 FO Vlv's & Air Register if No IR Flame or Purge steam vlv not closed or Atomize steam vlv not open

Wait 15 Sec

- All Bnr GAS Vlv's Closed - Boiler Gas Valve Closed

-FO Boost Up Order From Shd System

Close: - All Bnr GAS Vlv's - Boiler GAS Valve Timeout: 10 sec

Close Bnr3 FO Vlv's & Air Register if No IR Flame or Purge steam vlv not closed or Atomize steam vlv not open Error

Relaease FO Boost Up Order Force Control

Relaease FO Boost Up Order Force Control

Alarm: Fuel Oil Boost Failed

End

1001854 / 0D / Page 42 of 93

&


4.7 Nitrogen Purge of Gas Supply Lines Purging of gas supply lines can be done from the IAS operator stations. The following sequences are available: •

N2 Purge Master Line to Vent

•

N2 Purge No1/2 Boiler Gas Header to Vent

•

N2 Purge No1/2 Boiler Gas Burner to Furnace( by gas burner stop sequence).

•

N2 Purge No1/2 Boiler Gas Header & Burner to Furnace

Vent Mast Master gas valve

Gas Supply GAS main line N2 purge valve

Vent

Vent

N2 Supply GAS Control

GAS Control

Valve

Valve

Hdr N2 Purge Vlv

Boiler

Boiler

GAS

GAS

Valve

Valve Bnr 3 N2 Purge Valve

Bnr 1 N2 Purge Valve

Bnr 2 N2 Purge Valve

FWD (2)

CNTR (1)

Hdr Vent Vlv

AFT (3)

FWD (2) r e l i o B d b t S n o s r e n r u B

r e l i o B t r o P n o s r e n r u B

CNTR (1)

1001854 / 0D / Page 43 of 93

AFT (3)

Hdr Vent Vlv


4.7.1 N2 Purging of Main Line to Vent When the main line is purged, the line from the master gas valve outlet to each of the boiler gas valve inlets is purged with N2. Master N2 purging can be started when there are no gas burners firing in any boiler, the master gas valve is closed and both boiler gas valves are closed. The system will open the master vent valves and then open the master N2 purge valve. After purge time has elapsed the master N2 purge valve will close again. The main line vent valves will remain open. A status indication “Master N2 purged” will be set after successful sequence is performed. This status will be reset when the master gas valve closed indication disappears. This sequence will be performed automatic when the master gas valve is closed, but can also be manually started from a pushbutton on the IAS operator stations.

Flowchart: SEQ-16 Nitrogen Purging Main Line Condition for next step - Master Gas Valve Closed

Start Start Permissiv e Terminate

- Master N2 purge from monitor(Remote) - Master GAS V alve Close Cmd

Ac tion Check Master Gas Valve Closed Timeout : 50 sec

Error

- Master Vent Valve 1 Opened & - Master Vent Valve 2 Opened

Open Master Vent Valves Timeout : 10 sec

Error

- Master N2 Purge Valve Opened

Open Master N2 Purge Valv e Timeout : 10 sec

Error

- Master GAS V alve Close Command - Boiler 1 GAS Valve Closed - Boiler 2 GAS Valve Closed - No Gas Burners Active

- Master GAS Valve Not Closed

Wait 90 Seconds

- Master N2 Purge Valve Closed

OR

Close Master N2 Purge Valv e Timeout : 10 sec

Error

Master N2 Purge Seq Failed

Set - Master GAS Valve Not Closed

Reset

Set Master N2 Purged Status

End

1001854 / 0D / Page 44 of 93

- Master Vent Valve 1 Open - Master Vent Valve 2 Open - Master N2 Purge Valve Close

&

OR


4.7.2 N2 Purge of Gas Header to Vent When the gas header is purged, the line from each boiler gas valve outlet to each burner gas valve inlet is purged with N2. The gas header can be purged when no gas burners are firing in that boiler and the boiler fuel gas valve is closed. The system will open the boiler header N2 vent valve and then open the header N2 purge valve. After purge time has elapsed the N2 purge valve will close again. The header N2 vent valve will remain open. A status indication “header purged” will be set. This status will be reset when the boiler fuel gas valve closed indication disappears. This sequence will be performed automatic when the boiler gas valve is closed and purge to furnace is not succeeded. The sequence can be manually started from a software pushbutton on the IAS operator stations if required.

Flowchart: SEQ-17 Nitrogen Purging Boiler Header Condition for next step - Boiler Header N2 Vent Valve Opened


- Purge boiler hdr/bnr from monitor(Remote) - Boiler GAS Valve Close(SEQ-8,step4)

Action Open Boiler Header N2 Vent Valve Timeout : 10 sec

Error Error - Boiler GAS Vlv Closed - All Bnr GAS Closed

- Boiler Header N2 Purge Valve Opened

Open Header N2 Purge Valve Timeout : 10 sec

- Boiler GAS Valve Not Closed

Close Header N2 Purge Valve Timeout : 10 sec

Set - Boiler GAS Valve Not Closed

Reset

&

Error

Wait 35 Seconds

- Boiler Header N2 Purge Valve Closed

OR

Error

Set Boiler Header Purged Status

End

1001854 / 0D / Page 45 of 93

Header N2 Purge Seq Failed - Header Vent Valve Open - Header N2 Purge Valve Close

OR


4.7.3 N2 Purge of Gas Burner to Furnace When the gas burner is purged, the line from each burner gas valve outlet to each gas burner is purged with N2. Burner purge is performed automatically as a part of the gas burner stop sequence (SEQ-6). When the burner gas valve is closed and there is at least one flame in the furnace, the burner N2 purge valve will be opened. After purge time has elapsed the burner N2 purge valve will close again. A status indication “Burner purged” will be set. This status will be reset when the burner gas valves closed indication disappears.

4.7.4 N2 Purge of Gas Header & Burner to Furnace After gas firing is shut off the header and burners are purged to furnace. When the gas header is purged, the line from each boiler gas valve outlet to each burner gas valve inlet is purged with N2. The gas header can be purged when no gas burners are firing in that boiler and the boiler gas valve is closed. The master N2 purge valve and the burner N2 purge valves must also be closed. The system will open all burner gas valves and then open the header N2 purge valve. After purge time has elapsed the N2 purge valve and all burner gas valves will close again. The header N2 vent valve will be opened. A status indication “header purged” will be set. This status will be reset when the boiler fuel gas valve closed indication disappears. This sequence will be performed automatic when the boiler gas valve is closed, but can also be manually started from a software pushbutton on the IAS operator stations.

1001854 / 0D / Page 46 of 93


Flowchart:

Condition for next step - Boiler Header Vent Valve Closed

- Bnr1 GAS Valve 1&2 Opened OR FO Bnr1 Off & - Bnr2 GAS Valve 1&2 OpenedOR FO Bnr2 Off & - Bnr3 GAS Valve 1&2 OpenedOR FO Bnr3 Off

SEQ-19 Nitrogen Purging Boiler Header & Bnr


Close Boiler Header Vent Valve Timeout : 10 sec

Error

- Purge boiler hdr from monitor(Remote) - Purge request from Boiler Gas Vlv Close sequence (SEQ-8 step3)

Action

- Any FO Bnr On - Boiler Gas Vlv Closed - All Bnr Gas Valves Closed - Burner N2 Purge Valves Closed

&

- Boiler Gas Vlv Not Closed

OR

- Open Bnr1 GAS Valves if : FO Bnr1 On - Open Bnr2 GAS Valves if : FO Bnr2 On

Error

- Open Bnr3 GAS Valves if : FO Bnr3 On Timeout : 10 sec

- Boiler Header N2 Purge Valve Opened

Open Header N2 Purge Valve Timeout : 10 sec

Error

Wait 25 Seconds

- Boiler Header Vent Vlv Opened - All Bnr GAS Valves Closed - Boiler N2 Valve Closed

OR

Open Header Vent Valve After 5 sec All Bnr GAS Valve Close After 10 sec Header N2 Valve Close Timeout :30 sec

Error

Header N2 Purge Seq to Furn Failed Set - Boiler GAS Vlv Not Closed

Reset

Set Boiler Header/ Burner Purged Status

End

1001854 / 0D / Page 47 of 93

- All Gas Bnr Valves Close - Header N2 Purge Valve Close - Header Vent Valve Open


4.7.5 Main Line Vent Valves Master vent valves are performed automatically as follows.

Master vent valves are automatically closed when: •

10 sec after master gas valve open command

•

Master gas valve open limit switch is active.

Master vent valves are automatically opened when: •

15 sec after master gas valve close command, or

•

Master gas valve closed limit switch is active, &

•

Both boiler gas valves closed

Master gas valve open command is as follows: •

Master gas valve open order is selected from monitor. This is possible when master gas valve interlock is not active (Not master gas valve trip).

Master gas valve close command is as follows: •

Master gas valve close order is selected from monitor.

•

Master gas valve interlock is active (Master gas valve trip)

•

Both boilers gas valve interlock are active (Both boiler gas valve trip)

1001854 / 0D / Page 48 of 93


5 BOILER CONTROL 5.1 Drum Water Level Control The purpose of this controller is to keep the water level in boiler drum constant. This is done by controlling the feed water flow to the boiler in accordance with the steam flow from the boiler and with a correction from drum level measurement. The flow measurement and the level measurement are weighed, and then given as set point to the flow controller.

In case of feed water flow transmitter is faulty, the backup controller will take over the control of the valve. The backup controller is a 2 element control based upon level measurement and steam flow measurement. The backup controller can also be activated by the operator if wanted.

The level controller has following two set points and wanted set point can be selected from the IAS operator stations: • Fixed level set point. • Variable level set point dependent on the steam flow.

Super Htr

167B Steam Flow #1

158B Safety Sensor

FI

FI

LI

High Sel

Sel Switch

Boiler Drum

Feed Fwd

LC (PI) LI F1

Setp

FC (PI)

Setp

Par Select

Error

166B Drum Water Level

167B Steam Flow #2

Switch

Fixed level Setp

Backup Controller

LC (PI)

Switch to backup if Feed w flow is faulty

Feed Fwd

Setp

F2

Valve char

FI Economizer Feed Water Pumps

1001854 / 0D / Page 49 of 93


Failsafe handling Cause

Effect

Comments:

Steam flow signal failure

Steam flow value freeze

Both sensors failed

Feed water flow signal failure

Switch to backup controller

Level measurement signal fail

Switch to safety sensor.

Difference between No effect valve Command and ABU feedback > 10%

If both control & safety sensor is failed then controller is set to manual mode, and operator must manually control the FW valve. Alarm

1001854 / 0D / Page 50 of 93


5.2 Main Steam Temperature Control The purpose of this system is to maintain the main steam temperature constant at set point. The temperature controller set point can be selected from the IAS operator stations. Superheated outlet temperature is measured by two sensors and a high selector is used as process value for the controller. Steam flow and super heater 5 pass inlet temperature is used a feed forward action in order to obtain quick response at load changes. 129B SH Outlet Temp 1

129B SH Outlet Temp 2

TI

119B SH 5 Pass In Temp

TI

TI

167B Steam Flow 1 FI

Hi Sel Steam Flow => Vlv Opening

Steam Temp => Vlv Opening

Man Mode 500 C

Setp

PID

+

Fuel Calorie Input

FI

FI

Hi Sel

Normal 515 C

Sw

167B Steam Flow 2

Cal Inp => Vlv Min Op.

Hi Sel

Feed Fwd

20%

3rd Burner start 180 s

Hi Sel

0

130B Steam Temp C/V (Large)

1

FO or Dual Mode

133B Small Steam Temp C/V

Two steam temperature control valves are provided parallel. One is large, another is small. Small control valve is provided additionally with considering of boiler capacity. Additional small control valve is operated by fuel mode as initial plan. Action of small control valve is decided by function generator which is located between high selector and switch, as above figure.

1001854 / 0D / Page 51 of 93



Effect

Comments:

SH Outlet Temp Sensor Failure

Temp Controller to “Manual”

Both sensors failed

SH 5 pass inlet temp sensor failure

Value frozen in last readable value

Steam flow sensor failure


FO flow sensor failure


GAS flow sensor failure


Both sensors failed

5.3 Atomizing Steam Pressure Control The purpose of this system is to control the atomizing steam pressure at the most suitable levels according to FO pressure. This system consist of a PID controller where set point is derived from the FO pressure.

242B Atom Press

231B FO Press

PI

PI

DO Press => Atom Setp

FO Press => Atom Setp

PID

Swit ch

Ign Val FO (6bar) FO Bnr's Off

Swit ch

DO Use

Swit ch

Ign Val DO (6bar) FO Bnr's Off

Setp Follow

Tracking 50% at Gas Mode

226B Atomiz Press C/V

1001854 / 0D / Page 52 of 93



Effect

Comments:

Atom Press signal fault

Controller is set to “Manual”

FO press signal fault

No effect

5.4 Steam Purge Pressure Control The purpose of this system is to control the purge steam pressure at the most suitable levels. 362B Purge Press 2bar 1bar

PI 0

1

2bar

0

1

Burner Purge SP down at Burner Purging (SEQ-4 Status 8-12)

Any Burner Purge V/V Open

Setp

PID


Effect

Comments:

Purge Press signal fault


1001854 / 0D / Page 53 of 93


5.5 FO Pump Discharge Pressure Control The FO pump outlet pressure is maintained by controlling the recirculation. Set point to the controller is a high selection of main boiler 1 and main boiler 2 FO burner pressure.

MB1 FOPress (from Fuel Oil Control Loop)

MB2 FOPress (from Fuel Oil Control Loop)

200B FOPump Press PI

Hi Sel FO Press => Setpoint

All FO Bnr Stopped (8,5bar)

Setp

Switch

PID

FO Pump Stopped (80%) Switch

FO Boost Seq Run

10% 20 s

215B FOPump Press C/V


Effect

Comments:

FO pump pressure signal fail


MB1 FO pressure signal fail

No effect

If both boiler FO press signal fails then set point will be fixed.

MB2 FO pressure signal fail

No effect

If both boiler FO press signal fails then set point will be fixed.

1001854 / 0D / Page 54 of 93


5.6 Steam Pressure Control The purpose of this system is to maintain the steam pressure at outlet super heater at a constant value according to set point, normally at 60.3 bar. Set point is adjustable from IAS operator stations. The pressure control is done by controlling the total fuel flow and the combustion air flow to all burners. The air flow controller will lead during increasing demand At boiler start, steam up controller will bring boiler pressure up to set point at predefined rate. When 2 boilers are brought up to set point (steaming up finished) the master controller will automatically activate and take control.

Boiler Master Controller.

The boiler master controller consists of 3 controllers. • Boiler 1 controller: - Steaming up, 1 boiler operation, FO ,Gas or air flow in manual. • Boiler 2 controller: - Steaming up, 1 boiler operation, FO ,Gas or air flow in manual. • Master controller: - 2 boilers parallel operation and FO ,Gas and air flow in auto.

Load ratio

A load ratio function is applied at master control. Operator may select a percentage load rate between the two boilers. This will affect the master calorie demand to FO, Gas and air flow controllers.

Master Set point.

Master set point is set manually, normally 60.3 bar. Dump controller set point is given a bias from master set point, normally master set point + 1 bar. In case of maneuvering mode or excess BOG mode master set point is automatically set down to master set point – 1 bar (set down ramp is rapid, return to master ramp is slow).

1001854 / 0D / Page 55 of 93


165B MB1 Sream Press 1

165B MB1 Steam Press 2

PI

PI


PI

Hi Sel


167B MB1 Steam Flow 1




PI

FI

FI

FI

FI

Hi Sel

Hi Sel

Hi Sel

Swit ch

Steam Up Rate Master Setpoint Auto Set Down Set Down Bias

Set

PID

c T r

Swit ch

Hi Sel

d w F d e e F

Set

Gas Cal Input

+

0-50 Gcal/h

Load Ratio

Bias 1.1

+

MB2 Master Demand

Ratio Set Ratio Feedback

0-50 Gcal/h

Swit ch

Other Boiler

Low Load Gas Mode Tracking Master : NOT (2 boiler paralell operation and FO,GAS,Air in Auto) Steam Up: FO or GAS or Air i n Manual or Master Active

0.00075 Gcal/kg Air Flow (kg/hr)

Trc

Master 0-100 Gcal/h

Steam-Up

Low Lim

Press => Max Load

d w F d e e F

PID

0-50 Gcal/h FO Cal Input

Hi Sel

*

Low Sel

* 0,5

Low Lim

Boiler Demand


Effect

Comments:

MB1 steam pressure signal failed


Both signals failed

MB2 steam pressure signal failed


Both signals failed

MB1 steam flow signal failed

Value freeze

Both signals failed

MB2 steam flow signal failed

Value freeze

Both signals failed

1001854 / 0D / Page 56 of 93


Fuel Oil Flow Controller

Fuel flow controller set point is made by : Boiler master demand – Actual Gas heat input. Burner min and max protection is made by set point limitation of flow controller. FO boost up function is implemented in order to decide correct FO flow in case of Gas trip. 231B FO Press 1

231B FO Press 2

PI

To Atomiz Press Control Loop To FO Pump Discharge Press Control Loop

PI

HI Sel

Swit ch

A Swit ch

All FO Bnr Off 0

Gas Flow (from Gas flow control loop)

Master Cal Demand Gas Cal Input 0 FO Boost Up Order

FG Flow => FO Flow

FO Press => FO Flow

Swit ch

Lo Sel

X

/

With Up/dwn Ramp

X

No Of FO Bnr

-

A

PID

Min Press Control

Swit ch

X FO Cal Value FO Boost Up Order

PID

Setp

Lo Sel

FO Cal Value

Swit ch

FO Ctr Vlv Force Swit ch

FO Recirc Vlv Opened FO Ignition , FO FO Ignition, Dual 1bnr FO Ignition, Dual 2bnr FO Ignition, Dual 3bnr

1001854 / 0D / Page 57 of 93

2nd FO Ign Set Req 3rd FO Ign Set Req Dual Mode

Max FO Bnr Flow No Of FO Bnr

FO Bnr Exting Req

Swit ch

FO Cal Inp

OR

FO Cal Value

Hi Sel

FO Flow

&

X

Min FO Flow 1 Bnr FO Min FO Flow 2 Bnr FO Min FO Flow 3 Bnr FO Min FO Flow 1 Bnr Dual Min FO Flow 2 Bnr Dual Min FO Flow 3 Bnr Dual Min FO Cal Inp



Effect

Comments:

FO press signal failed

Manual mode

Both sensor failed

Gas press signal failed

No effect

Fuel Gas Flow Controller

Gas Flow is measured by differential press transmitter for Gas flow input (differential pressure between burner/Hdr), BOG pressure and BOG temperature. Controller set point is set from boiler master. Set point is defined as “boiler master” – “FO minimum flow”. A separate minimum controller is provided in order to maintain Gas minimum flow FO boost up function is implemented in order to keep gas supply steady during FO ignition when master gas valve trip is activated.

1001854 / 0D / Page 58 of 93


249B Gas Press

238B BOG Temp

230B BOG Press

TI

PI

PI

Gas Press => Gas Flow Master Cal Demand

X

FO Min Cal Input FO Cal Input

X

Swit ch

-

No Of Gas Bnrs

FO control Manual Gas Control Manual

OR

OR

&

2nd FO Ign Set Req 3rd FO Ign Set Req Dual Mode

Lo Sel Swit ch

0

X

Max Gas Bnr Flow No Of Gas Bnr

All Gas Bnr Stop

/ To Air Flow Control To Fuel Oil Flow Control

With Up/Dwn Ramp Flt

Gas Flow

Swit ch

Gas Cal Value

Gas Bnr Exting Req

Gas Cal Inp

Hi Sel

X

Min Gas Flow 1 Bnr

Swit ch

Min Gas Flow 2 Bnr Min Gas Flow 3 Bnr Min Gas Flow At Bnr Inc

Gas Cal Value

PID

Min Flow Controller

Setp

Flow Controller

Hi Sel

FO Boost Up Order

Swit ch Gas Shut Vlv Closed Gas Ignition, 1bnr, Free Flow

Gas Ctr Vlv Force

Swit ch

Gas Ignition, 2bnr, Free Flow Gas Ignition, 3bnr, Free Flow Gas Ignition, 1bnr, LD Run Gas Ignition, 2bnr, LD Run Gas Ignition, 3bnr, LD Run

208B Gas Flow C/V

1001854 / 0D / Page 59 of 93

PID



Effect

Comments:


Switch to flow control

BOG press signal failed

No effect

BOG temp signal failed

No effect

GAS Flow signal failed

Switch to pressure control

Air Flow Controller

The set point for the air controller is calculated by the total calorie input (FO flow + Gas flow) multiplied by an air ratio. A feed fwd from boiler master demand is used in order to quickly response to load changes. The air ratio is automatically adjusted by an O2 controller. The O2 controller set point is variable with the boiler load. If wanted the air/fuel ratio can be adjusted manually. The air controller is built to lead during load increase.

1001854 / 0D / Page 60 of 93


FO Flow

GAS Flow

17.47

X

14

Burner Load

Flue Gas O2

Air Flow

Air Flow

O2

PI

PI Hi Sel

Bnr Load => O2 Content

X

Sel Sw

+

Calc mbar => Kg/h

A Excess R atio

X Fuel/Air Ratio Set 0.5 - 1.5

X

Soot Blow Running 1.1

X

Air Bias ( Bnr Seq) 1.05

Not Man Zo ne Steam Flow > 80% 3 Bnr Run

Setp

0 . 1 w o l l o F

PID Range 0.9-1.1 Setp

> 40000

Furn Prg OK

> 4000 & < 8000

Ign OK

PID

& Sw i tch

Ignition Set Furn purge Fdf Stop

X Vane Char

X

Boiler Master

1 bnr On (1.05) 2 bnr On (1.03) 3 bnr On (1.00)

Sw i tch

X

Note:

Stby Fan Air Fl ow

+ A

X2

Low Sel

O2 trim control is activated when the following conditions are established: Steam flow > 80% & 3 burners firing.


Effect

Comments:

Air flow sensors failed

Air flow controller to manual

Both sensors failed

FO press signal failed

No effect


No effect

O2 Sensor failed

O2 trim is bypassed

1001854 / 0D / Page 61 of 93


5.7 Steam Dump Control The main purpose of this system is to force the boilers to burn excess boil of gas generated in the cargo tanks. Secondary function is to prevent overpressure in the boilers. In case pressure at the steam outlet is above set point, the steam dump valves will start to open dumping the excess steam to the main condenser

Excess BOG Controller.

FO flow and Recommended BOG rate is calculated and transformed to an estimated steam flow equivalent which will be defined as the controller set point. The controller will use the dump control valves to keep the steam flow at set point.

Max Gas Valve Controller.

The excess dump controller output will be limited in case Gas control valve exceeds the max value (90%).

Maneuver Dump Controller.

Set point of this controller is made by master controller set point + bias. The controller will remain passive until boiler pressure exceeds the set point. When controller is activated it will remain active until boiler pressure is normal and output is 0.

1001854 / 0D / Page 62 of 93


167B 167B MB1 MB2 Steam Flow Steam Flow FI BOG DUMP MODE

&

GAS BNR RUNNING

Lo Sel

GCal => Stm Flow Set

Swit ch

Load Limit

Hi Sel

MB1 FG Vlv Pos MB2 FG Vlv Pos

Hi Sel

Dump PID Controller

PID

BOG Controller

Rec BOG 0-130 t/h

Hi Sel

Lo Sel

Swit ch

PID t S e

Max FG Vlv Pos 95%

Dump Order => Spary V1 Contr

0

Max FG Controller

165B MB2 Steam Press PI

Hi Sel

+

MB2 Min FO Flow

PI

FI

Not

0

MB1 Min FO Flow

165B MB1 Steam Press

Swit ch

0

Set

Crash Ast Boiler Master

MT Trip

Dump Pist Vlv Closed Dump C/V Lead/Follow Change Over

Dump Order => Spary V2 Contr

1

Master Setpoint Bias 1bar

+

Hardware Function Generator by MHI

0

1

0

1

0

1

To IAS for Spray Vlv Control 331B Dump C/V #1 332B Dump C/V #2

Valve Valve Outpu t 10 0

Spray1

90

Spray2

Dump1

Dump2

80

70

60

50 40

30

20

10 Dump Controller Output 10

20

30

40

50

60

70

80

90

1 00

1001854 / 0D / Page 63 of 93


Dump Piston Valve.

Prior to steam dump control valves opening, the dump piston valve must be opened. This logic is calculated within the ABC by using dump dump control loop internal variables. In addition input from MT RCS is used. IAS calculates a “dump available” signal. If this signal is not present the dump piston valve will shut down. Dump Controller: Set - Pv < 0.5 bar Dump controller output > 1%

&

Off Delay 3min

OR

MT manovering zone MT Trip

Dump Available From IAS


E ff ec t

Comments:

Steam press sensors failed

Controllers is set to “Manual”

4 sensors failed

Steam flow sensors failed

No effect

MB1 Gas control vlv pos feedback failed

No effect

MB2 Gas control vlv pos feedback failed

No effect

MB1 FO flow signal failed

No effect

MB2 FO flow signal failed

No effect

1001854 / 0D / Page 64 of 93

Dump Piston Vlv Open Order


5.8 Flame Eyes There are four flame eyes for each of the burners. Two flame eyes for both IR sensing and two for UV sensing. Flame is detected if one of the flame eyes is activated. When FO burning or GAS burning is active, then if one flame failure is detected then one flame eye fail alarm is provided. If four flame eyes failure are detected then FO and GAS burners are tripped. (Refer to "6 BOILER TRIP") IR flame fail alarm is suppressed if burner is only gas firing. UV flame fail alarm is suppressed if burner is FO or dual firing. Flame eye rack “power fail” and “fan failure” is sent to ABC for alarm.

Principle drawing:

Timer Off 0 sec Flame Scanner 1 IR On Flame Scanner 2 IR On OR

Flame ON

Flame Scanner 1 UV On Flame Scanner 2 UV On

FO burner burning

& OR

GAS burner burning

Timer On

& All Burner Stopped

1001854 / 0D / Page 65 of 93

OR

F/E #1 IR Abnormal


5.9 FDF STBY Fan Each main boiler has it’s own FDF which is normally used for combustion air supply. In addition there is a stby FDF which can be used in case normal FDF is failed. The stby FDF is common for the two boilers and can be used for only one boiler at the time. The ABC receives certain inputs for detecting that sbty fan and damper is selected and OK. Air flow sensors for stby FDF is input to common FS and the ABC logic will use these sensors for air flow control when stby FDF is selected. The output for vane control is switched to stby FDF vane by hardwired logic by MHI

No1 STBY Fan Mode No1 Side STBY Fan Dmr Open

No1 STBY Fan Mode(DO)

&

STBY FDF Run Low Or High OR Normal FDF Run

1001854 / 0D / Page 66 of 93

Blr FDF Run


5.10 Hot Start Valve At hot start of boiler (steam press < 15 bar) the start-up valve is opened.

When steam flow is low at boiler hot start (Steam up controller active) the start up valve is controlled according to steam flow.

After steam up is finished the start up valve is permanently closed.

Boiler condition

Steam up valve

Boiler stopped

Closed

No burners firing Opened

Cold start of boiler

Cold start needle valve opened & Boiler firing & steam press < 15bar Opened

Hot start of boiler

Boiler firing & steam press > 15bar & steam flow < 2.5 t/h Closed

Hot Start of boiler

Boiler firing & steam press > 15 bar & steam flow > 4 t/h Set

Boiler Firing Staem Press < 15 bar

&

Staem Press > 15 bar

&

OR

Reset

Steam Flow < 2.5 t/h

OR

Staem Flow > 4.0 t/h

&

Timer ON 3 min

1001854 / 0D / Page 67 of 93

RS

Hot Start Valve Open Order


5.11 Viscometer Outlet Valve When total (No.1 and No.2) FO flow is less than 900kg/h or No.1 boiler is gas mode or No.2 boiler is gas mode, viscometer outlet valve is opened. 1200 kg/hr

No.1 Blr FO Flow

+

LSE

No.2 Blr FO Flow No.1 Blr Gas Mode

Set 1200kg/hr Reset 1700 kg/hr

No.2 Blr Gas Mode

1001854 / 0D / Page 68 of 93

OR

Viscometer Valve Open


5.12 Fuel/Atomizing Valve Abnormal HFO supply manual valve close LS DO supply manual valve close LS Atomizing steam supply manual valve close LS Atomizing air supply manual valve close LS

No. HFO

DO

Steam

Air

Remark

Close

Close

Close

Close

1

X

X

X

X

Alarm

2

X

X

X

O

Alarm

3

X

X

O

X

Alarm

4

X

X

O

O

Alarm

5

X

O

X

X

Alarm

6

X

O

X

O

Normal case 1 (Hot start condition)

7

X

O

O

X

Normal case 2 (Transition condition)

8

X

O

O

O

Alarm

9

O

X

X

X

Alarm

10

O

X

X

O

Trip case

11

O

X

O

X

Normal case 3 (Cold start condition)

12

O

X

O

O

Alarm

13

O

O

X

X

Alarm

14

O

O

X

O

Alarm

15

O

O

O

X

Alarm

16

O

O

O

O

Alarm X: open, O: close

In case of No.10, FO shut off valve will be closed. In case of No. 6,7 and 11, condition is normal. In other case, alarm will be set.

1001854 / 0D / Page 69 of 93


5.13 Output to Main Turbine The boiler control calculates some outputs for the main turbine system. Main Boiler 1

Drum Water Level Transmitter

CompHi 220mm

10 s

CompHi 200mm

10 s

CompHi 180mm

10 s

CompLo -200mm

10 s

MT Trip

MT Slow dow n

MT Program Interlock

MT Slow dow n

Main Boiler 2


CompHi 220mm

10 s

CompHi 200mm

10 s

CompHi 180mm

10 s

CompLo -200mm

10 s

MT Trip

MT Slow dow n

MT Program Interlock

MT Slow dow n

Bo i l e r Co m m o n

MB1 Logick

Boiler Firing

&

MB2 Logick

Both Boiler Trip

&

Boiler Firing

&

1001854 / 0D / Page 70 of 93

OR

One Boiler Trip


6 BOILER TRIP The trip system is divided into five different categories. •

FO trip.

•

Boiler trip.

•

Boiler GAS trip.

•

Master GAS trip.

•

Burner flame fail trip.

Once the trip circuit is activated a holding circuit is activated and corresponding trip cause is flickering. Acknowledge button must be operated in order to confirm the trip cause, corresponding lamp is then steady lit. Trip circuit is still active. Acknowledge can be done from IAS or BGB whichever location is in command. When trip cause is acknowledged and trip cause is brought to normal, then trip can be reset by operating the respective system stop pushbutton. Trip circuit is de-activated. In case drum water level safety transmitter is faulty the control sensor can be selected for safety functions. This operation must be manually initiated by the operator. FO Trip.

In case of FO trip condition is activated the FO supply to the boiler is tripped. Cause

Action

Reset

Atomizing steam press LL (3bar)

- Boiler FO Shut Vlv Close

FO temp LL (have bypass switch) (80 deg/C)

- No1 burner FO vlv1&2 Close

Acknowledge push button and

FO Press LL (1bar)


FO Pump Stop Fuel/Atomize Valve Abnormal


1001854 / 0D / Page 71 of 93

Boiler FO shutoff vlv close push button


Logic Diagram. Atm Steam Pres s LL

&

FO Temp LL FO Temp Bypass Sw itch

FO Trip

&

FO Press LL

OR

&

FO Pump Stop &

Any FO Bnr On Emergency Mode Fuel/Atomiz Valve Abnormal

Set

FO Trip OR Boiler trip Control position IAS IAS Blr FO Shutoff Vlv Close Push b utton Control position BGB BGB Blr FO Shutoff Vlv Close Push b utton

Reset

RS

BoilerFO Shutoff Vlv Shutdow n Order Bnr1 FO Vlv1&2 Shutdow n Order Bnr2 FO Vlv1&2 Shutdow n Order

& OR &

1001854 / 0D / Page 72 of 93

Bnr3 FO Vlv1&2 Shutdow n Order


Boiler Trip.

In case boiler trip condition occur is both FO and Gas system is tripped. Cause

Action

Reset

Drum water level HH (+240mm + 10s) by analogue sensor

- Activate FO trip


- Activate Gas trip

Boiler FO shutoff vlv close push button resets FO trip

Drum water level LL (-240mm) by switch OR Drum water level LL (-240mm + 5s) by analogue sensor FDF stop


All burner flame fail Emergency manual trip ECR

Boiler Gas vlv close push-button reset Gas trip.

Emergency manual trip BGB Main steam temp H (545deg/c) by analogue sensor

1001854 / 0D / Page 73 of 93



CompHi 240mm

10 s

CompLo -240mm

5s

OR

Drum Water Lev el LL Float Sw itch

Boiler Trip

No1 FD Fan Run

&

Stby Fan Mode On

OR

Stby FD Fan Run High or Low &

Stby FD Fan Air Dmp OK

&

OR

Stby FD Fan Selected All Bnr Flame Fail Emerg Manu Trip ECR Emerg Manu Trip BGB Steam Temp Transmitter

CompHi 545C

Boiler Gas Trip.

In case of Gas trip condition is activated the Gas supply to the boiler is tripped. Cause

Action

Reset

BOG Press L (7mbar)

- Boiler Hdr Vent Vlv Open

BOG Press H (736mbar)

- Boiler Gas Shut Vlv Close


Boiler Trip Condition

- No1 burner Gas vlv1&2 Close

Master Gas Valve Trip On + 15s

- No2 burner Gas vlv1&2 Close - No3 burner Gas vlv1&2 Close

1001854 / 0D / Page 74 of 93

Boiler Gas shutoff valve close push button


BOG Press Transmitter

CompLo 0,007bar

&

CompHi 0,736bar

&

90 s

OR Any Bnr Gas V lv Opened

Boiler GAS Trip

10 s

Boiler Trip On 15 s

Master GAS Vlv Trip On

Set

GAS Trip OR Boiler trip

Reset

RS

Boiler Vent vlv Open Order Boiler GAS Vlv Shutdow n Order Bnr1 GAS Vlv1&2 Shutdow n Order

Blr GAS Vlv Close Pushbutton

Bnr2 GAS Vlv1&2 Shutdow n Order Bnr3 GAS Vlv1&2 Shutdow n Order

Master GAS Valve Trip.

In case of Master GAS trip condition is activated the GAS supply to both boilers is tripped. Simultaneously FO boost up order is sent to each boiler. Cause

Action

Reset

E/R Vent Fan Failure

- Master GAS Vlv Shutdown

Gas Duct Exh Fan Stop

- Master N2 Vent Vlv Oppen

Acknowledge push button and Master GAS Vlv close push-button

Gas leak detected Fire Detected BOG Temp LL (5deg/c) Master GAS Vlv Manu Trip Vapor Hdr Press LL BOG Htr Abnormal Master Gas Close Push Button Both Boiler trip

1001854 / 0D / Page 75 of 93


E/R Vent Fan Failure Gas Duct Exh Fan Stop

On-delay

10 s

FO Boost Up Order

Gas Leak Detected Fire detected BOG Temp LL

Master GAS Vlv Trip

Master Gas Vlv Manu Trip (ECR)

OR

OR

Master Gas Vlv Manu Trip (BGB) Vapour Hdr Press LL BOG Htr Abnormal Master Gas Vlv Close PB

Both Boiler Trip Both Blr GAS Vlv's Closed LS GAS Master Vlv Trip

Set Reset

RS

GAS Master Vlv Close Pushbutton

1001854 / 0D / Page 76 of 93

Master Vent vlv Open Order Master GAS Vlv Shutdown Order


Burner Flame Fail.

In case flame is lost during burner firing, the burner FO and GAS supply is tripped. Control Mode Manual Control Position IAS Control Position BGB Base Bnr IR 1&2 Failed

&

Base Bnr UV1&2 Failed

Set Reset

& IAS Base Bnr OFF PB

RS

Base Bnr Flame1 Fail Base FO Bnr Valve Close Base GAS Bnr Valve Close Base Bnr Atmise Valve Close Base Bnr Air Reg Close

OR

& BGB Base Bnr OFF PB No.2 Bnr IR1&2 Failed

&

No.2 Bnr UV1&2 Failed

Set Reset

& IAS No.2 Bnr OFF PB

RS

No.2 Bnr Flame1 Fail No.2 FO Bnr Valve Close No.2 GAS Bnr Valve Close No.2 Bnr Atmise Valve Close No.2 Bnr Air Reg Close

OR

& BGB No.2 Bnr OFF PB No.3 Bnr IR1&2 Failed

&

No.3 Bnr UV1&2 Failed

Set Reset

& IAS No.3 Bnr OFF PB

RS

No.3 Bnr Flame1 Fail No.3 FO Bnr Valve Close No.3 GAS Bnr Valve Close No.3 Bnr Atmise Valve Close No.3 Bnr Air Reg Close

OR

& BGB No.3 Bnr OFF PB

&

Base Bnr Flame ON

&

No.2 Bnr Flame ON No.3 Bnr Flame ON &

1001854 / 0D / Page 77 of 93

OR

All Bnr Flame Fail


7 BOILER OPERATION PANELS 7.1 BGB Graphic Panel The BGB graphic panel contains buttons for control of sequences and lamps for feedback. The buttons activates the same sequences as those used when operating from the IAS operator stations.

Command transfer.

In order to use the functions from the panel, command must be transferred from the control room to the BGB.

BGB graphic panel lamp and switch functions.

Description

Type

Function

Orginator

By-pass Condition No1 or No2 Emerg Mode

MB1 + MB2

Lamp

Switch on BGB for selection of “Emergency Mode”

BGB (by MHI)

Common Emerg Mode

MB1 + MB2

Lamp

Switch on BGB for selection of “Emergency Mode”

BGB (by MHI)

AC 220V Source

MB1 + MB2

Lamp

Lamp on BGB

BGB (by MHI)

DC 24V Source

MB1 + MB2

Lamp

Lamp on BGB

BGB (by MHI)

MB1 x 3 +

Switch/Lamp Swich: Starts GAS Burner when Local Contr Position &

NoX Burner NoX Gas BNR On

MB2 x 3

manual mode.

FS-10(MB1), FS-11(MB2)

Lamp: - Flicker during start seq, - Fast Flicker when start error - Steady when burner is On NoX Gas BNR Off

MB1 x 3 + MB2 x 3

Switch/Lamp Swich: Stops GAS Burner when Local Contr Position & manual mode. Also reset of start/stop error Lamp: - Flicker during stopt seq, - Fast Flicker when stopt error - Steady when burner is On

1001854 / 0D / Page 78 of 93

FS-10(MB1), FS-11(MB2)


Description NoX FO BNR On

Type MB1 x 3 +

Function

Orginator

Switch/Lamp Swich: Starts FO Burner when Local Contr Position &

MB2 x 3

manual mode.

FS-10(MB1), FS-11(MB2)

Lamp: - Flicker during start seq, - Fast Flicker when start error - Steady when burner is On NoX FO BNR Off

MB1 x 3 +

Switch/Lamp Swich: Stops FO Burner when Local Contr Position &

MB2 x 3

manual mode. Also reset of start/stop error

FS-10(MB1), FS-11(MB2)

Lamp: - Flicker during stopt seq, - Fast Flicker when stopt error - Steady when burner is On Flame Signal

MB1 x 2 +

Indicator

Indicator

Flame condition indicator

BGB (by MHI)

MB2 x 2

FO Shut V/V Open

MB1 + MB2

Switch/Lamp Swich: Send open command to FO shut valve Lamp: - Flicker during open time,

FS-10(MB1), FS-11(MB2)

- Fast Flicker if open failed - Steady when valve is open Close

MB1 + MB2

Switch/Lamp Swich: Send close command to FO shut valve, also used for FO/Boiler trip reset

FS-10(MB1), FS-11(MB2)

Lamp: - Flicker during close time, - Fast Flicker if close failed - Steady when valve is closed

Furnace Purge Request

MB1 + MB2

Switch/Lamp Switch : Lamp:

Activates furnace purge sequence Switch On

FS-10(MB1), FS-11(MB2) Lamp: BGB(by MHI)

In Progress

MB1 + MB2

Lamp

Lamp On: Furnace purge in progress

FS-10(MB1), FS-11(MB2)

Complete

MB1 + MB2

Lamp

Lamp On: Furnace purge compleate OR Purge Status

1001854 / 0D / Page 79 of 93

FS-10(MB1),


Description

Type

Function

Orginator FS-11(MB2)

BMS Position BGB Manual

MB1 + MB2

Switch/Lamp Switch: Change burner operation to BGB location Lamp: Burner operation at BGB On

IAS

MB1 + MB2

Switch/Lamp Switch: Change burner operation to IAS Lamp

Burner operation at IAS On

FS-10(MB1), FS-11(MB2) FS-10(MB1), FS-11(MB2)

Al arm Boiler Trip

MB1 + MB2

Lamp

Boiler trip active or nor reset

FS-10(MB1), FS-11(MB2)

Atm Press Low

MB1 + MB2

Lamp

Atm press low active

FS-10(MB1), FS-11(MB2)

FO Press Low

MB1 + MB2

Lamp

FO press low active

FS-10(MB1), FS-11(MB2)

Manual trip

MB1 + MB2

Lamp

Boiler Manual Trip active

FS-10(MB1), FS-11(MB2)

AB C Pos it io n BGB

MB1 + MB2

Switch/Lamp Switch: Change control loop operation to BGB location Lamp: Control loop operation at BGB On

IAS

MB1 + MB2

Switch/Lamp Switch: Change control loop operation to IAS Lamp

GAS Firing

MB1 + MB2

Lamp

Control loop operation at IAS On

GAS firing condition

FS-10(MB1), FS-11(MB2) FS-10(MB1), FS-11(MB2)

FS-10(MB1), FS-11(MB2)

Feed water motor valve Open

MB1 + MB2

Switch/Lamp Switch: Send open command to feed water motor valve control panel. Lamp: - Flicker during open time - Fast flicker if opened failed

1001854 / 0D / Page 80 of 93

FS-10(MB1), FS-11(MB2)


Description

Type

Function

Orginator

- Steady when valve is open Close

MB1 + MB2

Switch/Lamp Switch: Send close command to feed water motor valve control panel.

FS-10(MB1), FS-11(MB2)

Lamp: - Flicker during close time - Fast flicker if closed failed - Steady when valve is closed FS-10(MB1), FS-11(MB2), FS12,(Com) FDF Start

MB1 + MB2 + Switch Common

Stop

IAS.

MB1 + MB2 + Switch Common

Run

Switch: Send start command to group starter panel via

Switch: Send stop command to group starter panel via IAS.

MB1 + MB2 + Lamp

Lamp: Steady when FDF is Running.

Common

Au x Feed Water Pum p Start

Common

Switch

Switch: Send start command to group starter panel via

FS12,(Com)

IAS. Stop

Common

Switch

Switch: Send stop command to group starter panel via

FS12,(Com)

IAS. Run

Common

Switch

Lamp: Steady when motor is Running.

FS12,(Com)

Common

Lamp

Lamp: Steady when fan is Running.

FS12,(Com)

Seal Ai r Fan Run (No1/2)

1001854 / 0D / Page 81 of 93


7.2 Manual Loader Functions The graphic panel at the BGB contains functions for manual control of each control valve. The IAS output (4-20mA) for control valves are connected to an ABU (Analogue Backup Unit).

Normal mode.

Each control valve or FDF vane can be manually controlled from either BGB graphic panel or from IAS operator stations. In normal mode the 4-20mA control signal from IAS is passed to the actuator. (Except for purge C/V and small Steam temp C/V)

Emergency mode.

In this case the IAS 4-20mA control signal is neglected and BGB increase/decrease order is operating the ABU output directly.

The following control loops can be controlled from the local control panels • Control of atomizing stem control valves.(MB1 & MB2) • Control of the super heater temperature control valves.( MB1 & MB2) • Control of Fuel gas control valves. (MB1 & MB2.) • Control of the fuel oil control valves. (MB1 & MB2.) • Control of the fd-fan inlet vanes. (MB1 & MB2) • Control of the feed water valves. (MB1 & MB2.) • Control of dump control valve (common for both boiler) • Control of FO pump pressure control valve (common for both boilers)

Note: ABU units are MHI supply.

1001854 / 0D / Page 82 of 93


ABC Po si ti on IAS

Set

BGB

Reset

IAS

RS Not

OR

BGB

Emerg mode

Manual/Auto Selectio n ABC Position "BGB"

Set

&

OR

BGB A

Reset

Auto

RS Not

Manual

&

BGB M

OR

ABC Position "IAS" &

IAS A (Sow button)

&

IAS M (Sow Button) Emerg mode

Inc / Dec Prinsipple Manual

Man/Auto Selection "Manual" ABC Position "BGB"

PID

t l e c e S c T r

&

T r c V a l u e

+ -

&

+/-

Inc

& Dec Emerg mode ABU Feedback(4-20mA)

Sel Sw

Output to ABU 4-20mA

1001854 / 0D / Page 83 of 93


7.3 Emergency Operation Note: This is outside of IAS, MHI supply

7.3.1 No.1 or No.2 part case of failure of both controllers (active/standby) for No.1 or No.2 part, emergency operation mode is performed in following manner. 1)

Air flow control valve should be fully closed. And the forced draft fan shall be started.

2)

If emergency mode switch for common part is selected to emergency mode then FO pump discharge press control valve should be opened at about 50%. And the FO burning pump shall be started. After starting of FO burning pump, FO pump discharge press should be adjusted at a suitable pressure (15-20bar).

3)

Change operation mode switch from "NOR" to "PURGE". Open fully (above 70%) air flow control valve. Differential press between wind box and furnace should be confirmed (above 15mbar). Furnace purge should be conducted until turning "Purge Finish" lamp on.

4)

Change emergency mode from "PURGE" to "BURN".

5)

Air flow control valve should be set at ignition position. (About 5%)

6)

FO flow control valve should be set at ignition position. (About 20%)

7)

Atomizing press control valve should be set at suitable position. (About 30%)

8)

Turn FO shut V/V switch from "CLOSE" to "OPEN".

9)

Turn igniter switch from "OFF" to "ON".

10) Turn FO V/V switch from "CLOSE" to "OPEN". FO V/V "OPEN" position should be kept until establishment of flame. However, it must not exceed 10 seconds. 11) Atomizing press should be kept at 8bar. 12) FO and Air flow should be adjusted manually, to keep safe combustion. 13) When second burner start, fuel oil press should be exceeded 10bar. And same as above item 12) and 13).

Note : If burner does not ignite by the above process, repeat operation from the above 3). Note : If drum water level low-low with float switch is detected, acknowledge button on BGB should be depressed.

1001854 / 0D / Page 84 of 93


7.3.2 Common Part In case of failure of both (active/standby) controllers for common, emergency operation mode is performed in following manner. 1) Change operation mode switch from "NOR" to "EMERG". 2) FO pump discharge press should be adjusted at suitable pressure (15-25bar). 3) If dump control is needed, dump control valve should be adjusted at a suitable position.

8 SOOT BLOWING SEQUENCES The soot blower sequences are provided within the IAS. Operations are done from the IAS monitors. Each boiler are equipped with 2 sequence possibilities, “Boiler & economizer” or “economizer”. In addition each blower can be started locally. The software consists of many subsequence’s, one for each blower. A main sequence call up respective subsequence during auto operation. Local operation call each subsequence directly.

Operation.

Operation is done from IAS monitors. Following operation modes are prepared: • “NO1 MAIN BOILER” • “NO2 MAIN BOILER” • “BOTH BOILERS”

After selection of operation mode the sequence can by started. Following sequence selections are prepared: • “SEQ START” • “ECO START”

Bypass Function

Bypass function is performed manually or automatically. Manual function is active by selecting the corresponding bypass push buttons of IAS. Auto function is as follows. When "SEQ START" or "ECO START" function is running, if trouble occurs then corresponding soot blower is bypassed automatically.

1001854 / 0D / Page 85 of 93


Emergency retract

If long soot blower forward sequence is active then the sequence is stopped. And the long soot blower retract sequence is stated. If long soot blower is not active or complete then "steam supply valve" is closed and "drain valve" is opened. If rotary soot blower sequence is active then the sequence is continued to the end position.

Local Control.

Local control is active by changing the control location from IAS to Local. Then start order will be active by depressing the "BOTH BLR" push button of IAS. After depressing the "BOTH BLR" push button of IAS, "steam supply valve" open and "drain valve" close. Operator can start the soot blower by depressing the corresponding Soot Blower push button. The subsequence’s “Long Soot Blower” and “Rotary Soot Blower” as described below is activated directly by the operator.

1001854 / 0D / Page 86 of 93


8.1 Long Soot Blower Sequence This sequence can be called from “SEQ START” sequence or by local command. The blower will first run fwd until retract position is received. Then reverse rotation order is active until stop limit switch is received. An emergency retract function is applied. If emergency retract command is activated the run fwd order is cancelled and retract order is activated. Retract order will remain until stop limit switch is received. A maximum timer for retract order is applied. Start

Condition for next step - Blower Fwd Running ON & - Stop position OFF

- Blower Retract Position ON & - Blower Fwd Running OFF

- Blower Rev Running ON & - Retract Position OFF

- Blower Stop Position ON - Blower Rev Running OFF


- Start Req from Soot Blow Auto Seq - Start Req from Local.

OR

Action Start Fwd Timeout : 5 sec

Reset Fwd Start Start at Retract position

Error - Staem Valve Open - Not Emerency Retract On - Not Reverse Position - Not Steam Press Low - Not Emergency - Not Motor Overload - Not Reverse Run if Auto Seq - Boiler Load < 50 %

Error

Timeout : 250 sec

Start Reverse

&

Error

Timeout : 5 sec

Reset Rev Start at Stopt position

- Emergency Retract ON - Steam press low & 30 Sec After Vlv Open - Steam supply valve abnormal if Auto Seq OR - Boiler trip - Auto Seq Fail - Motor Overload

Error

Timeout : 250 sec

- Reset Run Fwd Order - Set Rev Order if not stop position - Set Alarm - Set Bypass if Auto Seq

End

8.2 Rotary Soot Blower Sequence This sequence can be called from “SEQ START” sequence, “ECO START” sequence or by local command. command. The blower will run until stop position is received. Then run order will be switched off.

1001854 / 0D / Page 87 of 93


Start

Condition for next step - Blower Running ON & - Stop Position OFF

- Stop Position ON & - Blower Running OFF


- Start Req from Soot Blow Auto Seq - Start Req from Local.

OR

Action Start Blower Timeout : 5 sec

Error

Stop Blower at Stop position Error Timeout : 60 sec

- Motor Overload - Boiler Load < 50 %

- Motor Overload - Boiler Trip - Auto Seq Fail

&

OR

- Reset Run Order - Set Alarm - Set Bypass if Auto

End

8.3 Boiler & Economizer Soot Blower Sequence This sequence makes use of “Long soot blower sequence” and “rotary soot blower sequence” in order to make a complete soot blower sequence. Each boiler can be soot blower separately or both boilers can be blower in serial. Once Steam supply valve opens, this valve keep open until all sequence finish AND all long soot blower in normal stop position. When long soot blower is stuck in travelling, steam supply valve keep open.

1001854 / 0D / Page 88 of 93


Flowchart for No.1 or No.2 boiler sequence Start Start Permissive Terminate

Start

Condition for next step - Steam Vlv Opened

- Other Boiler Drain Valve Closed

- L1 Seq Run OR - Bypass ON - L1 Seq Run for 364 sec OR - L1 Seq Not Run - L2 Seq Run OR - Bypass ON - L2 Seq Run for 388 sec OR - L2 Seq Not Run

- R1 Seq Run OR - Bypass ON - R1 Seq Run for 38 sec OR - R1 Seq Not Run

- R2 Seq Run OR - Bypass ON - R2 Seq Run for 38 sec OR - R2 Seq Not Run - R3 Seq Run OR - Bypass ON - R3 Seq Run for 18 sec OR - R3 Seq Not Run

Open Steam Vlv Timeout : 40 sec Close Other Blr Drain Valve Timeout : 10 sec

Error

Error

Check Steam Pressure OK Timeout : 2 sec

Error

Start L1 If not Bypass ON Timeout : 2 sec

Bypass

Wait, L1 blowing Timeout : 500 sec

Error

Start L2 If not Bypass ON Timeout : 2 sec

- Control position IAS - No1 or No2 Boiler Select - Not ECO START - Not other BLR SEQ START - Not other BLR ECO START - Not motor over load - Not Soot Blower abnormal - Not Emergency retract ON - Not Steam supply valve abnormal - Boiler Load < 50 %

- Emergency Retract ON - Steam press low & 30 sec after eam valve open - St eam supply valve abnormal - Boiler Trip - AC 440V Failure

Bypass

Wait, L2 blowing Timeout : 500 sec

Error

Start R1 If not Bypass ON Timeout : 2 sec

Bypass

Wait, R1 blowing Timeout : 60 sec

Error


Bypass


Error


Bypass


Error


Bypass


Error


Bypass


Error

- R6 Seq Run OR - Bypass ON


Bypass

- Terminate all soot blower sub sequences

- R6 Seq Not Run


Error

- Close steam Vlv if all long blower in normal stop position

Close Steam Valve if all long blower in normal stop position & Open Drain Vlv 1&2 Timeout : 10 sec

Error


- Steam Vlv Closed & - No1 MB Drain Vlv Opened & - No2 MB Drain Vlv Opened

OR

Action

Timer 180s

- Steam Press OK

- Start from Monitor(IAS)

- Open No1 MB Drain Vlv - Open No2 MB Drain Vlv - Set Alarm

End

1001854 / 0D / Page 89 of 93

&

OR


Flowchart for both boiler sequence Start

Condition for next step - Steam Vlv Opened &

- No.2 Blr Drain Valve Closed


Open Steam Vlv Timeout : 40 sec

Close No.2 Blr Drain Valve Timeout : 10 sec

Error

Error


Error

No1 Boiler Blower Sequence L1,L2,R1,R2,R3,R4,R5,R6

- No.2 Blr Drain Valve Opened

OR

Action

Timer 180s

- Steam Press OK


Open No.2 Boiler Drain Vlv Timeout: 10 sec

Error

- Control position IAS - Both Boiler Select - Not ECO START - Not other BLR SEQ START - Not other BLR ECO START - Not motor over load - Not Soot Blower abnormal - Not Emergency retract ON - Not Steam supply valve abnormal - Boiler Load < 50 %

- Emergency Retract ON - Steam press low & 30 sec after steam valve open - Steam s upply valve abnormal - Boiler trip - AC 440V Failure

&

OR

Timer 180s

- Steam Press OK


Error

No2 Boiler Blower Sequence L1,L2,R1,R2,R3,R4,R5,R6 - Steam Vlv Closed & - No1 MB Drain Vlv Opened & - No2 MB Drain Vlv Opened

Close Steam Valve if all long blower in normal stop position & Open Drain Vlv 1 & 2 Timeout : 10 sec

- Terminate all soot blower sub sequences Error

- Close steam Vlv if all long blower in normal stop position - Open No1 MB Drain Vlv - Open No2 MB Drain Vlv - Set Alarm

End

8.4 Economizer Soot Blower Sequence This sequence makes use of “rotary soot blower sequences” in order to make a complete soot blower sequence. Each boiler can be soot blower separately or both boilers can be blower in serial.

1001854 / 0D / Page 90 of 93


Flowchart for No.1 or No.2 boiler sequence Start


- Other Boiler Drain Valve Closed




Open Steam Vlv Timeout : 40 sec Close Other Boiler Drain Valve Timeout : 10 sec

Error

Error

Check Steam Press OK Timeout : 2 sec

Error


Bypass


Error


Bypass


Error


Bypass


Error



Bypass

- R6 Seq Not Run


Error Error

- R5 Seq Run for 38 sec OR - R5 Seq Not Run

- Control position IAS - Not SEQ START - Not other Blr SEQ START - Not other Blr ECO START - Not moter over load - Not soot blower abnormal - Not Emergency Retract ON - Not Steam supply valve abnormal - Boiler Load < 50 %

- Emergency Retract ON - Steam press low & 30 sec after steam valve open - Steam s upply valve abnormal - Boiler Trip - AC440V Failure

- Terminate all soot blower sub sequences - Close steam Vlv

- Steam Vlv Closed & - No1 MB Drain Vlv Opened & - No2 MB Drain Vlv Opened

OR

Action

Timer 180s

- Steam Press OK

- Start from Monitor(IAS).

Close Steam Valve & Open Drain Vlv 1 & 2 Timeout : 10 sec

Error

- Open No1 MB Drain Vlv - Open No2 MB Drain Vlv - Set Alarm

End

1001854 / 0D / Page 91 of 93

&

OR


Flowchart for both boiler sequence Start


- No.2 Blr Drain Valve Closed


Open Steam Vlv Timeout : 40 sec

Error

Close No.2 Blr Drain Valve Timeout : 10 sec

Error


Error

No1 Boiler Blower Sequence R3,R4,R5,R6

- No.2 Blr Drain Valve Opened

Open No.2 Boiler Drain Vlv Timeout: 10 sec

Error

- Control position IAS - Not ECO START - Not other BLR SEQ START - Not other BLR ECO START - Not motor over load - Not Soot Blower abnormal - Not Emergency retract ON - Not Steam supply valve abnormal - Boiler Load < 50 %

- Emergency Retract ON - Steam press low & 30 sec after steam valve open - Steam s upply valve abnormal - Boiler Trip - AC 440V Failure

Timer 180s

- Steam Press OK


Error

No2 Boiler Blower Sequence R3,R4,R5,R6 - Steam Vlv Closed & - No1 MB Drain Vlv Opened & - No2 MB Drain Vlv Opened

OR

Action

Timer 180s

- Steam Press OK


Close Steam Valve & Open Drain Vlv 1 & 2 Timeout : 10 sec

- Terminate all soot blower sub sequences Error

- Close steam Vlv - Open No1 MB Drain Vlv - Open No2 MB Drain Vlv - Set Alarm

End

1001854 / 0D / Page 92 of 93

&

OR

154863764-Mitsubishi-Boiler-Control (1).pdf

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