mitsubishi boiler control

PLAN RECORD REVISIONS AP- CHECK-

ISO METRIC SCREW THREDS NO. DESCRIPTION (DATE)PROVED ED

1

Revised according to owner comment aftersoftware FAT in KM. (28 Jan. 2005) KS

Y. Ono Y.Ono

DR

AW

ING

NO

.

N51

-99K

-N11

6

係ｺｰﾄﾞ

RP0

A4× 94A3× 0

TOTAL 95 SHEETS WITH COVERMARINE BOILER DESIGNING SEC.

TURBO & MARINE MACHIN. DESIGN DEPTDAEWOO H.NO.2227 / 2228 / 2235

APPROVED T. YukiY. Ono

CHECKED -DRAWN K. Saito

CONFERRED SCALE ～

MAIN BOILER(MB-4E-NS2)

Functional Design Specificationfor Boiler Control

ORDER ITEM DRAWING NO. REV.NO

K1A32/38/4461500G377 N51-99K-N116 1

MITSUBISHI HEAVY INDUSTRIES, LTD.NAGASAKI SHIPYARD & MACHINERY WORKS

DRAWN 25 Nov. 2004 ISSUED

ＣＲ

客先 12

協会

メーカ

機装設

電装設

機装課

電武装課

香運

香検

船検

香検

生内風舶

生缶Ｇ

飽

香二ム

深

ＳＺ

品保

機品(香)

物流

材料

長菱設計

不設

不技

舶ボ設計

舶ボ計装

舶ボ計画

控

計 12

出図先

(DNV)

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 KongsbergMaritime Vessel Control System SVC delivered to the specifiedvessel. Functions within other systems are not described in thisdocument. This document when “as built” will serve also asoperator documentation together with KM standard SVC OperatorManual

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 Reissue for approval OHJ GM OSL

E


1001854 / 0D / Page 2 of 93

History

Revision Description of Change

A For internal comments

B For Approval

C Re-issue for approval, insert comments from MHI, dated 10 July 2004K.Saito / MHI Marine Boiler

Ｄ Re-issue for approval, insert comments after FAT, January 05

References

Doc No Description


1001854 / 0D / Page 3 of 93

Table of contents

1 GENERAL ITEMS..................................................................................................51.1 Definitions/Abbreviations .....................................................................................51.2 Flowchart symbols.................................................................................................8

2 RESPONSIBILITIES ..............................................................................................9

3 BOILER GENERAL ...............................................................................................93.1 General ..................................................................................................................93.2 Burner Management ............................................................................................133.3 CPU Redundancy ................................................................................................133.4 Power Distribution...............................................................................................14

4 BURNER SEQUENCES........................................................................................154.1 Fuel Oil Burning..................................................................................................164.2 Gas burning .........................................................................................................244.3 Burner Auto Mode...............................................................................................294.4 Burner Automatic Increase/Decrease ..................................................................304.5 Fuel Mode Changeover .......................................................................................344.6 Fuel Oil Boost UP ...............................................................................................424.7 Nitrogen Purge of Gas Supply Lines...................................................................43

4.7.1 N2 Purging of Main Line to Vent............................................................... 444.7.2 N2 Purge of Gas Header to Vent ................................................................ 454.7.3 N2 Purge of Gas Burner to Furnace ........................................................... 464.7.4 N2 Purge of Gas Header & Burner to Furnace........................................... 464.7.5 Main Line Vent Valves .............................................................................. 48

5 BOILER CONTROL.............................................................................................495.1 Drum Water Level Control..................................................................................495.2 Main Steam Temperature Control .......................................................................515.3 Atomizing Steam Pressure Control .....................................................................525.4 Steam Purge Pressure Control .............................................................................535.5 FO Pump Discharge Pressure Control.................................................................545.6 Steam Pressure Control .......................................................................................555.7 Steam Dump Control ...........................................................................................625.8 Flame Eyes ..........................................................................................................655.9 FDF STBY Fan....................................................................................................66


1001854 / 0D / Page 4 of 93

5.10 Hot Start Valve ....................................................................................................675.11 Viscometer Outlet Valve .....................................................................................685.12 Fuel/Atomizing Valve Abnormal ........................................................................695.13 Output to Main Turbine.......................................................................................70

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

7 BOILER OPERATION PANELS ........................................................................787.1 BGB Graphic Panel .............................................................................................787.2 Manual Loader Functions....................................................................................827.3 Emergency Operation..........................................................................................84

7.3.1 No.1 or No.2 part........................................................................................ 847.3.2 Common Part.............................................................................................. 85

8 SOOT BLOWING SEQUENCES ........................................................................858.1 Long Soot Blower Sequence ...............................................................................878.2 Rotary Soot Blower Sequence.............................................................................878.3 Boiler & Economizer Soot Blower Sequence .....................................................888.4 Economizer Soot Blower Sequence ....................................................................90

9 ATTACHMENTS ..................................................................................................93


1001854 / 0D / Page 5 of 93

1 GENERAL ITEMS

1.1 Definitions/Abbreviations

Local control Operation of the equipment is outside the IAS system (Switchboard orlocal 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 fromthe IAS operator stations or BGB.

Automatic control Operation of the equipment is performed by IAS control logic (remotemode 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 6 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 7 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 8 of 93

1.2 Flowchart symbolsSymbols Description

Condition for next step Action

AccomplishedOR

Failed (Timout)

Accomplished

Failed (Timout)This symbol representsany kind of processing

function.

This symbol represents adecision or switching type

function

This symbol represents anamed process, such as a

subroutine.

This symbol representsdata input by manual

means

This symbol represents aprocess performed by

operator or automaticallyby process event.

Indicates a cross-reference within the same

page of the flow chart.

This symbol representsthe end of a program flow.

This symbol represents adata that is displayed for

human use.

This symbol represents adelay/timer


1001854 / 0D / Page 9 of 93

2 RESPONSIBILITIESKongsberg Maritime is responsible for this document.

3 BOILER GENERAL

3.1 GeneralTwo 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: Max: 40,000 kg/hTemperature: Max: 350 °C , normal: 288.5 °C.


1001854 / 0D / Page 10 of 93

Figure showing general arrangement:

RIO

RCU

RIO

RIO

RCU

RIO

RIO

RIO

RIO

RIO

RIO

RIO

RIO

RIO

HUB HUB

No3 Burner Control

No2 Burner Control

No1 Burner Control

Manual Loader

Manual LoaderOperator Panel

Common Vlv'sOperator PanelOthers

Common Vlv'sOperator Panel

Operator Panel

IAS Ethernet HUBA

Analogue control sensors

Flame scanner #1MT Trip/Pwr Reduction

Flame scanner #2

Analogue Control SensorsAnalogue Control Vlv's

RIO

RCU

RIO

RIO

RCU

RIO

RIO

RIO

RIO

RIO

RIO

RIO

RIO

RIO

HUB HUB

No3 Burner Control

No2 Burner Control

No1 Burner Control

Manual Loader

Manual LoaderOperator Panel

Common Vlv'sOperator PanelOthers

Common Vlv'sOperator Panel

Operator Panel

Analogue control sensors

Flame scanner #1MT Trip/Pwr Reduction

Flame scanner #2


RIO

RCU

RIO

RIO

RCU

RIO

RIO

RIO

RIO

RIO

RIO

RIO

HUB HUB

Soot Blower Control

Manual Loader

Div control

Soot Blower Control

Soot Blower Control

Soot Blower Control

Common AI/AO

Common DI/DO

Common DI/DO


IAS Ethernet HUBB

BGB

SBP

MB1 ControlCabinet

MB2 ControlCabinet

Boiler Common /Soot blowersCabinet


1001854 / 0D / Page 11 of 93

BGB, Boiler Gauge BoardThe local board including graphic operator panel, manual loader functions, emergencyoperator function, some instruments. panels including BNP, MLP & EOP.BGB is MHI supply.

Graphic Operation PanelThis panel is located at the BGB. It contains lamps and switches for local boiler controlalso manual loader functions are included.Graphic Operator panel is MHI supply.

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

Soot Blower Relay PanelThis cabinet is delivered by MHI. The cabinet controls soot blowing sequences of thetwo boilers. ABC RIO units are installed here for soot blower control.

ABC CabinetsABC 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 12 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 13 of 93

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

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

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

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

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


1001854 / 0D / Page 14 of 93

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

Main Supply UPS 1Emerg Supply

Process Station Cabinet

BGB

RCU A220V AC

24V DC

RCU B

RIO Units

UPS 2220V AC

24V DC

RIO Units

220V AC

24V DC

220V AC

24V DC

SBRP

RIO Units


1001854 / 0D / Page 15 of 93

4 BURNER SEQUENCESGeneral.

Starting / stopping of burners are made by a sequencer system within the IAS. This isapplicable for either IAS control or BGB local control. A selector switch at the BGBdecides which control place to be active.

In case of any trouble during sequence execution a sequence jam status is issued. In caseof sequence jam the running sequence will perform a clean up (error treatment). Allsequences 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 decideeach 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. Burnermanual 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 16 of 93

4.1 Fuel Oil BurningStarting fuel oil burners:

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

• If all flames are off and operation position is BGB then first burner starting mustbe done from BGB. Operation position transfer BGB => IAS is blocked duringboiler stopped condition.

• If all flames are off and operation position is IAS then first burner starting can bedone from IAS.

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

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




1001854 / 0D / Page 17 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 startingwill be carried out by a sequence controller according to following description.

First the corresponding burner atomizing steam valve is opened. Furnace purge willthen be carried out by opening of all burner air slide dampers and FDF vane is set topurge position.

Furnace purge will be continued for 90 seconds (confirmed by air volume). When thefurnace purge is completed the not starting burner air registers will closed and FDFvane 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 isconfirmed 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 detectspress between wind box and furnace. And air flow is calculated based on measuredpress.


1001854 / 0D / Page 18 of 93

Flowchart for starting fuel oil burners, the first FO burner:SEQ-1

Start Oil Burner (Initial FO Burner)

Condition for next step

- 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

End

Action

Open Bnr Atm Steam Valve &Close Steam Purge Valve

Timeout : 10 sec

- Atm Steam Vlv Opened & - Steam Purg Vlv Closed

Start Furnace Purge Sequence(SEQ-2)

Timeout : 6 min - Boiler Purged Status Set

- Set Alarm

- Close Burner Fo Valve's

- Deactivate & Retract Igniter

- Close Burner RegisterIf Gas Burner Is Not Active

- Close Atomize Steam Valves

- Open Stm Purge Vlvif Any Bnr is ON

- Release FDF Vane

- Release FO Ctr Vlv

- Open FO Recirc Valve

Note : Only One BurnerCan Be Started At The Time

Close Bnr Register which are not setfor start

Timeout : 10 sec

- Selected Bnr Register Opened & - Not Selected Registers Closed

Close FO Recirc ValveTimeout : 10 sec - FO Recirc Valve Closed

Set FO Ctrl Vlv To Start Pos(18%)Timeout : 20 sec - FO Ctr Vlv In Start Pos(15-21%)

Check Air Rate & FO Press & FOTemp

Timeout : 60 sec

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

Waiting timer 10s

Open FO Valve 223B &Insert Igniter

Timeout : 20 sec

- FO Valve opened & - Igniter inserted

Activate Retractable Igniter if NotPortable igniter Selected

OrActivate Portable Igniter if Selected

Timeout : 10 sec

- Igniter In Down Position & Spark On & Portable Igniter Not Selected OR - Igniter In Down Position & Portable Igniter Selected & Spark On Waiting Timer: 2s

Open Burner Fo Valve 225BTimeout : 10 sec

(Flame fail is activated 7s afterFOvlv open cmd)

- Burner Fo Valve 1 Opened & - Burner Fo Valve 2 Opened & - Flame Detected Direct Error if: - Falme Fail Waiting Timer: 5s

Deactivate & Retract IgniterTimeout : 10 sec

- Igniter Deactivated & - Igniter Retracted Waiting timer 7s

Release Fd Fan Vane &FO Control ValveTimeout : 5 sec

- Fd Fan Vane Released & - FO Control Valve Released

Error

Error

Error

Error

Error

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

Start PermissiveTerminate

StartOR

&

OR

Force Fd Fan Vane To Start Pos.(5%)

Timeout : 10 sec - Fd Fan Vane In Start Pos(2-6%) Error

Error

Error

Error

Error

Error

Error

Check All Flames are OFFTimeout : 5 sec

- All Flames OFF

Waiting Timer: 1sError

Note: FO Valve 223B is Slow ActingDownstream sideFO Valve 225B is Fast Acting


1001854 / 0D / Page 19 of 93

Flowchart for furnace purging:

SEQ-2FurnacePurging


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

- FDF Stopped - Boiler Manual Trip

End

Action

Set BoilerPurged Status(No Set if Man

Purge)

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

Open All Burner RegistersTimeout : 15 sec

- Burner 1 Register Opened & - Burner 2 Register Opened & - Burner 3 Register Opened

Force Fd Fan Vane Fully OpenTimeout : 30 sec

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

Furnace Purge Seq Failed

- Release FD Fan Vane- Close All Burner Registers

Reset

Set

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

TerminateStart Permissive

Start

ErrorPurging (min 60s)Timeout : 300 sec

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

Error

Error

Manual Purge.

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


1001854 / 0D / Page 20 of 93

Starting fuel oil burners, when another burner is on:

In manual mode operator is responsible for checking FO pressure and boiler masterdemand by him self. Auto mode is described in the chapter for burner automaticincrease / decrease.

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





The sequence starts by open the burner atomizing steam valve and closing of steampurge valve. Then igniter is lowered and simultaneously burner FO valve’s (up stream225B & down stream 223B) are opened. The burner flame should be detected within 7seconds after FO valves are opened if not burner will trip.


1001854 / 0D / Page 21 of 93

Flowchart for starting fuel oil burners, when another FO burner ison:

SEQ-3Start Oil Burner

(Next FO Burner)


- 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

- FO Shutoff Vlv Close Cmd - Burner Fo Piston Valve Shutdown - Boiler Trip - FO Trip

End

Action

Open Atm Steam Vlv &Close Steam Purge Vlv

Timeout : 10 sec

- Atm Steam Vlv Opened & - Steam Purge Vlv Closed &

FO Burner Ignition Seq Failed

Close Burner FO Valves

Deactivate & Retract Igniter

Close Burner RegisterIf Gas Burner Is Not Active

Close Atomize Steam Valve

Open Steam Purge Valve


Open Burner Register after 2 sTimeout : 10 sec

-Flame Detected Waiting timer 5s

Note : If all burner flame on signals arellost before before a flame is detected onthe burner being ignited the startsequence will be terminated.Insert and activate Retractable Igniterif

Not Portable igniter SelectedOr

Activate Portable Igniter if Selected

If Corresponding GAS Bnr is Off Timeout : 30 sec

- 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

Error

Deactivate & Retract IgnitorTimeout : 20 sec

- Ignitor Deactivated & - Ignitor Retracted Waiting timer 7s

Open Bnr FO Vlv (223B) &Open Bnr FO Vlv (225B)

Timeout : 10 sec(Flame fail is activated 7s afterFO vlv

open cmd)

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

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

StartStart Permissive

TerminateOR

&

OR

Error

Error

Error

Adjust FO Press if Auto & DualTimeout : 10 sec

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

Error

Close FO Recirc VlvTimeout : 10 sec - FO Recirc Valve Closed Error

Set FO Control Vlv to Start Pos if NoFO Bnr On

Timeout : 10 sec

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

Error


1001854 / 0D / Page 22 of 93

Stopping fuel oil burners:

The individual fuel oil burners can be stopped either from the operator station (IAScontrol) 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 23 of 93

Flowchart for stopping fuel oilburners:

SEQ-4Stop FO Burner


- FO Burner On

End

Action

Close Burner FO ValvesTimeout : 10 sec

- Burner Fo Piston Valve 1 Closed & - Burner Fo Piston Valve 2 Closed

Open All RegisterTimeout : 20 sec

- Burner 1 Register Opened & - Burner 2 Register Opened & - Burner 3 Register Opened

Set FDF to Purge Position 80%Timeout : 30 sec

- FDF in Purge psition (>80%) & - Air Flow > 40.000 Kg/h

Error

Error

Open Stm Purge Vlv &Open FO Recirc V if Last FO Bnr

Timeout : 30 Sec

- Stm Purge Vlv Opened & - Any FO Bnr On Or FO Recirc V Closed

- Burner Off from BGB(in Local) - Burner Off from Monitor (in Remote) - Stop Request from Bnr auto dec Seq (SEQ-10 step 2 or SEQ-10 step 4). - Bnr Flame Fail(FO or Dual)

Start PermissiveStart

OR

Last Bnr & not gas firing(All Bnr FO & GAS Vlv's

Closed)

Timer 30 seconds

Release FDFTimeout : 20 sec

- FDF Released Error

Close All RegisterTimeout : 20 sec

- Burner 1 Register Closed & - Burner 2 Register Closed & - Burner 3 Register Closed

Error

A

A

No

Yes

Close Bnr Atm Stm VlvOpen FO Recirc Vlv

Close All Stm Purge Vlv'sTimeout : 20 sec

- Bnr Atm Stm Vlv Closed & - FO Recirc Vlv Opened & - All Stm Purge Vlv Closed

Timer 5 sec

Close Bnr Registerif Gas firing is offTimeout : 20 sec

-Bnr Register Closed OR - Gas firing is on

Error

Timer 30 sec

Close Bnr Atm Stm VlvTimeout : 20 sec

-Bnr Atm Stm Vlv Closed

Error

Error

Error

FO Burner Extinguish Seq Failed

- Close Burner FO Valves

- Deactivate & Retract Igniter

- Close Air Register if Gas Burner isNot Active

- Close Atomize Steam Valve

- Open Steam Purge Valve if AnyBurner On

- Release FDF Vane

- Open FO Re-circ Valve if All FOBurners are Off

Error


1001854 / 0D / Page 24 of 93

4.2 Gas burningStart up of gas burning can be done either by manually starting each burner or by usingthe 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. Thetransfer between modes is then made by a sequence program. Number of burners isdecided by boiler load.


1001854 / 0D / Page 25 of 93


Gas burners can be started once the corresponding FO burner is in operation. In additionthe master gas valve and boiler GAS valve must be opened, the burner GAS valvesmust be closed.

The vent valves are controlled automatically by the sequences or by GAS valvespositions.

During GAS burner ON/OFF operations the N2 purging of lines/burners will beperformed automatically when needed.

At the end of gas firing the operator must manually close boiler GAS valve and masterGAS valve.

Flowchart for starting fuel gas burners:

SEQ-5Start Gas Burner


- Master Gas Valve Open - Boiler Gas shutoff valve Opened - Burner Gas Valve1 Closed - Burner Gas Valve2 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 Valve Closed - Not Seq Jam - Corresponding FO Bnr On

- Master Gas Valve Closed - Gas Trip

End

Action

GAS Burner Ignition Seq Failed

- Close Burner Gas Valves

- Reset Air Bias Adjustment


Check Gas Ctrl Vlv To Start Pos.If No Other Gas Burner Is Active

Timeout : 10 sec

- Gas Ctrl Valve In Start Position Or - Any Other Gas Burner Is Active

Release Gas Control Valve

Set Air BiasTimeout : 10 sec - Waiting Timer 3 sec

Open Burner Gas ValvesTimeout : 10 sec

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

Note : If Corresponding Oil Burner"Flame On" Signal Is Lost Before GasFlame Is Detected, The Start SequenceWill Be Terminated.

Reset Air Bias

- Gas Burner On from BGB (Local Mode) - Gas Burner On from Monitor(IAS) - Start Req from Bnr auto inc/dec seq. (SEQ-9 step3, SEQ-9 step6)


StartOR

&

OR

Error

Error


1001854 / 0D / Page 26 of 93

Flowchart for stopping fuel gas burners:

SEQ-6Stop Gas Burner


- Burner Gas Valve's Not Close Cmd

End

Action

Close Bnr RegisterIf FO Bnr is Off & Not Furn Purge

Timeout : 10 sec

- Bnr register Closed Or - FO Bnr On Or - Furn Purge in Progerss

ErrorClose Burner Gas ValvesTimeout : 10 sec

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

Furn Purge Req If Last BnrTimeout : 10 sec

- Any Burner Is Active Or - Furn Purge Run

Waiting Timer 10 sec

Error

- Stop from BGB (Local Mode) - Stop from Monitor(IAS) - Stop request from burner inc/dec (SEQ-10 step2, SEQ-10 step4)- Stop request from Dual=>FO seq - Bnr Falme Fail


OR

Reset Air BiasAdjustment

Timeout : 10 sec - Air Bias Adjustment is Reset Error

Start Burner N2 PurgeIf Any Bnr FiringTimeout : 10 sec

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

Error

Gas Burner Extinguish Seq Failed

- Close Burner Gas Valves

- Close Air Register if FO Burner isNot Active

- Close Burner N2 Purge Valve

Error


1001854 / 0D / Page 27 of 93

Flowchart for Boiler Gas ValveOpen:

SEQ-7Blr Gas Valve Open


- 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

- Master Gas Valve Closed - Gas Trip

End

Action

Close Hdr N2 Vent VlvTimeout: 10 sec - Hdr N2 Vent Vlv Closed Error

Set Gas Control Vlv to Ignition Pos.Timeout : 10 sec - Gas Control Vlv in Ign Pos Error

- Open from Monitor(IAS)Start PermissiveTerminate

Start

Open Blr Gas Valve.Timeout : 10 sec - Blr Gas Vlv Opened Error

OR

&

OR

Timer 5 sec

Boiler Gas Valve Open Seq Failed

- Close Boiler Gas Valve

- Open Header Vent Valve

- Release Gas Control Vlv


1001854 / 0D / Page 28 of 93

Flowchart for Boiler Gas ValveClose:

SEQ-8Blr Gas Valve Close


- Blr Gas Vlv Not Closed

End

Action

ErrorClose Blr Gas VlvTimeout: 10 sec - Blr Gas Vlv Closed

If FO Burning:Start Hrd/Bnr N2 Purge to Furn

(SEQ-19)Timeout : 10 sec

- Hrd/Bnr N2 Purge to Furn Seq Run Error

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


OR

Set Gas Ctr Vlv Fully ClosedTimeout: 10 sec - Gas Ctr Vlv Fully Closed(<1%) Error

Start Hdr N2 Purge to Vent(SEQ-17)

Timeout : 10 sec - Hdr N2 Purge to Vent Run Error

FO Burning On ?No

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

Yes

Yes

A

A


1001854 / 0D / Page 29 of 93

4.3 Burner Auto ModeBurner auto mode can be selected when the burning burners are burning in the samefuel 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 gasburner firing can be made at gas only mode. Burner automatic increase / decrease, fuelmode changeover sequence is cancelled during burner manual mode. When operatorselects burner manual mode, operator must also take care of suitable burner number tobe matched with boiler load and general boiler safety.

GAS Mode

FO Mode

Dual Mode

Auto Mode Possible

Bnr1 FO BurningBnr2 FO BurningBnr3 FO Burning

OR&

&OR

Bnr1 GASBurningBnr2 GASBurningBnr3 GASBurning

OR

Bnr1 FO BurningBnr2 FO BurningBnr3 FO Burning

OR

Bnr1 GASBurningBnr2 GASBurningBnr3 GASBurning

OR

Ctr Pos IAS

Bnr2 FO BurningBnr2 GAS Burning



&

&

OR

OR

OR

&

&

&

&

&

&

&

&

Bnr1 Flame FailBnr2 Flame FailBnr3 Flame Fail

Bnr1 FO or Gas Burning

Bnr2 Gas BurningBnr3 Gas Burning

FO Trip

Bnr1 Gas Burning&

&

OR

&OR

FO Shut V Open

FO Trip

&


1001854 / 0D / Page 30 of 93

4.4 Burner Automatic Increase/DecreaseBurner Increase:

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

The system will monitor the boiler demand e.g. output from master pressure controllerand the FO pressure or total fuel calorie. Also during manoeuvring a minimum numbersof 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 No OfBnr

Limit Result

1 bar Boiler demand > 13,5 Gcal/h & FO pressure > 13 bar 1 => 2 bnrFO

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

Dual2 bnr Boiler demand > 28,5 Gcal/h & total fuel calorie >

28,5 Gcal/h & FO press > 10 bar2 => 3 bnr

GAS 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 beactivated. 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 2000kg/h.


1001854 / 0D / Page 31 of 93

Burner Decrease:

Request for stopping burner will be calculated as follows:

Mode No OfBnr

Limit Result

3 bnr Boiler demand < 16,0 Gcal/h & FO pressure < 5,5 bar 3 => 2 bnrFO 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

Dual2 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

GAS2 bnr Boiler demand < 6,0 Gcal/h & GAS hdr pressure < 0,1

barGAS=>Dual

Main Turbine Interaction:

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

MT Vlv Lift > 50%

MT Telegraph Stop

MT Telegraph Astern

MT Vlv Lift Astern Full&

OR

30s

&

MT Vlv Lift Astern Full

MT Telegraph Astern

MT Vlv Lift > 50%

&

OR&

MT Telegraph Stop

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

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

TimerOff

TimerOff

30s


1001854 / 0D / Page 32 of 93

Flowchart for Burner Automatic Increase:

SEQ-9Burner 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

End


Action

Check Burner 2 is OFF:Timeout : 1sec

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

Start GAS Burner 2 if:Dual Mode &

GAS Bnr2 is OFF(SEQ-4)

Timeout : 60sec

- FO Mode, OR- Burner2 is Dual Firing

Start FO Burner 2(SEQ-3)

if FO or Dual modeTimeout : 60sec

- FO Burner 2 is ON & - Ignition Seq Compleate

Check Burner 3 is OFF:Timeout : 1sec

- Burner 3 is OFF- Burner 3 Ready

Start GAS Burner 3 if:Dual Mode &

GAS Bnr3 is OFF(SEQ-4)

Timeout : 60sec

- FO Mode, OR- Burner 3 is Dual FiringORGAS mode

Start FO Burner 3(SEQ-3)

if FO or Dual ModeGAS>Dual seq (SEQ-13)

if GAS modeTimeout : 60sec

- FO Burner 3 is ON - Ignition Seq Compleate

Alarm: Burner Increase Failed


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

Start

Stop GAS Burner 2(SEQ-6)Error

Stop GAS Burner3(SEQ-6)

No

Error

No

Error

OR

&

OR

Error Stop FO Burner 2(SEQ-4)

Stop FO Burner 3(SEQ-4)

*1) Ready: FO Mode; FO Burner Start Permissive OKDual Mode; FO Burner & Gas Burner Start Permissive OK

1

2

3

4

5

6

7

8

9

10


1001854 / 0D / Page 33 of 93

Flowchart for Burner Automatic Decrease:

SEQ-10Burner Decrease


- 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

End


Action

Check Burner 3 is ON:Timeout : 1sec- Burner 3 is ON

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

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

Check Burner 2 is ON:Timeout : 1sec- Burner 2 is ON

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 modeTimeout : 60sec

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

Alarm: Burner Dec. Failed


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

Start

OR

&

Error

Error

No

No

1

2

3

4

5


1001854 / 0D / Page 34 of 93

4.5 Fuel Mode ChangeoverThere 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 modecondition. 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 35 of 93

Flowchart for Changeover FO => Dual:

End

SEQ-11Mode: FO => Dual


- 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

End


ActionSet GAS Control valve to start

positionTimeout : 1sec

- GAS Control Vlv in Start Pos

Set Add Air to Air FlowController

Timeout : 1sec- Air Flow Controller Add Air Set

Open Bnr1 GAS Valves (1&2)

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

Open Bnr3 GAS Valves (1&2)if FO Bnr On

Timeout : 60sec

- (Bnr1 GAS Bnr is ON &

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

- (Bnr3 GAS Bnr is ON or Bnr3 FO Bnr is OFF)

Wating Timer 20 sec

Reset Add Air to Air FlowController

Timeout : 1sec

- IAS mode: Dual button from Monitor is pressed.

Start

FO => Dual Seq Failed

- Stop GAS Burner 1(SEQ-6)



- Reset Add Air to Air FlowController

- Reset GAS Control Vlv StartPosition

OR

&

OR

Reset FG Control Vlv StartPosition

Timeout : 1sec

No

Error

Error

1

2

3

4

5

6


1001854 / 0D / Page 36 of 93

Dual => GAS:

When mode switch is changed from dual to GAS, the system will stop oil firing.

SEQ-12Mode: Dual => GAS

Condition for next step- 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

End


Action

- Stop FO Bnr1(SEQ-4)



if Dual Bnr ONTimeout: 60sec

- FO Burner 1 is OFF



Error

- IAS mode: GAS button from Monitor is pressed.

Start

OR

&

OR

Set FO Burner ExtinguishRequest to FO Flow

ControllerTimeout: 120sec

- FO Press < 3 bar

Reset FO Burner ExtinguishRequest to FO Flow

Controller

Dual => Gas Sequence Failed

Error


1001854 / 0D / Page 37 of 93

GAS => Dual Fuel:

When mode switch is changed from GAS to dual, the system will start up oil burnerswhere gas burners are firing.

Some process conditions will start GAS => dual sequence automatically by means ofFO auto backup order.

In case of LD compressor stop no3 burner will stop automatically

FO Auto Backup.

Cargo Tk Press L

Manouvering Zone

Both LD Comp Stop

FO Auto Backup Order

Only Base Gas Bnr Firing

OR

&

Gas Mode

No3 Bnr Stop

&Low Gas Mode

‘


1001854 / 0D / Page 38 of 93

Flowchart for Changeover GAS => Dual:

- 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

SEQ-13Mode: GAS => Dual


-Boiler Trip- FO Trip- GAS Trip

End


Action

Set Air BiasTimeout : 1sec- Air Bias OK

- Open Bnr1 Atm Steam Vlv &- Close Bnr1 Stm Purg Vlv

if GAS Bnr1 is ON


if GAS Bnr2 is ON


if GAS Bnr3 is ON

Timeout : 10sec

- Bnr1 Atm Stm vlv Opened or Bnr1 is OFF

& - Bnr2 Atm Stm vlv Opened or Bnr2 is OFF

& - Bnr3 Atm Stm vlv Opened or Bnr3 is OFF

- Check Steam Purg Vlv isClosed

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

Close FO Recirc ValveTimeout : 10sec- FO recirc Valve Close Cmd

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

Start

OR

&

OR

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



Timeout : 10sec

- Bnr1 Dual Burning or Bnr1 is OFF

& - Bnr2 Dual Burning or Bnr2 is OFF

& - Bnr3 Dual Burning or Bnr3 is OFF

& Waiting Timer 10sec

Set FO Ctr Vlv To Start PosTimeout : 10sec- FO Control Vlv in Start Pos

Error

Error

Error

GAS => Dual Seq Failed

-Reset Air Bias-Reset FO Ctr V Start Pos

Total Timeout: 5Min

Error

Error

Reset FO Control Valve toStart Position

Error


1001854 / 0D / Page 39 of 93

Dual => FO:

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

Flowchart for Changeover Dual => FO:

SEQ-14Mode: Dual =>FO

Condition for next step - 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

-Boiler Trip- FO Trip

End


Action

Stop GAS Bnr1

Stop GAS Bnr2

Stop GAS Bnr3

Timeout : 30sec

- GAS Burner 1 is OFF &

- GAS Burner 2 is OFF &

- GAS Burner 3 is OFF

Error

- IAS mode: FO button from Monitor is pressed.

Start

Set Gas Extinguish Requestto Gas Flow Controller

Timeout : 180sec- GAS Press < 50mbar

Error

Reset Gas ExtinguishRequest to Gas Flow

Controller

&

OR

OR

Dual => FO Seq Failed

- Reset Gas ExtinguishRequest to Gas Flow

Controller


1001854 / 0D / Page 40 of 93

Low Load Gas Mode:

Low Load Gas mode can be selected either in dual mode condition or in gas modecondition. 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 caloriedemand in order to increase gas pressure to over 0.1bar. When gas pressure is over thelimit for changing to gas mode, then “dual=>gas” sequence is activated. After change togas mode is complete boiler master low limit will be set depending on number ofburners.

Gas => Low Load Gas Mode:

When LL gas mode is activated at gas mode, boiler master low limit will be setdepending on number of burners.

Note:

Since Low Load Gas Mode sets a minimum boiler master demand main steam pressuremight increase. In case main steam pressure is increased the dump control valve willopen 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 41 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 FOboost-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 42 of 93

4.6 Fuel Oil Boost UPFO boost up sequence is available in GAS mode. The sequence is initiated in case ofGAS master valve trip conditions.

SEQ-15Fuel Oil Boost Up

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

-FO Trip

End


ActionOpen:

Bnr1 Atm Stm V if Bnr firingBnr2 Atm Stm V if Bnr firingBnr3 Atm Stm V if Bnr firingBnr1 FoVlv1&2 if Bnr firingBnr2 FoVlv1&2 if Bnr firingBnr3 FoVlv1&2 if Bnr firing

Close:Bnr1 Prg Stm V if not firingBnr2 Prg Stm V if not firingBnr3 Prg Stm V if not firing

FO Recirc Vlv

Force FO Control Vlv to "FOBoost Up Order" Position

Timeout: 6 sec

Alarm: Fuel Oil Boost Failed

-FO Boost Up Order From Shd SystemStart

Close Bnr1 FO Vlv's &Air register

if No Flame orPurge steam vlv not closed orAtomize steam vlv not open

Close Bnr2 FO Vlv's &Air Register

if No IR Flame orPurge steam vlv not closed orAtomize steam vlv not open

Close Bnr3 FO Vlv's &Air Register

if No IR Flame orPurge steam vlv not closed orAtomize steam vlv not open

Relaease FO Boost Up OrderForce Control

Close:- All Bnr GAS Vlv's- Boiler GAS Valve

Timeout: 10 sec

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

Relaease FO Boost Up OrderForce Control

&- 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

Error

Wait 15 Sec

Error


1001854 / 0D / Page 43 of 93

4.7 Nitrogen Purge of Gas Supply LinesPurging of gas supply lines can be done from the IAS operator stations. The followingsequences 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

VentMast

Gas Supply

N2 Supply

Hdr Vent Vlv Bur

ners

on

Stbd

Boi

ler

Bur

ners

on

Port

Boi

ler

Master gas valve

GAS main lineN2 purge valve

Vent Vent

BoilerGASValve

Bnr 3 N2 Purge Valve

Hdr Vent Vlv

BoilerGASValve

GAS ControlValve

CNTR(1)

FWD(2)

AFT(3)

CNTR(1)

FWD(2)

AFT(3)

Hdr N2 Purge Vlv

GAS ControlValve




1001854 / 0D / Page 44 of 93

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 theboiler gas valve inlets is purged with N2.

Master N2 purging can be started when there are no gas burners firing in any boiler, themaster 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 linevent valves will remain open.

A status indication “Master N2 purged” will be set after successful sequence isperformed. This status will be reset when the master gas valve closed indicationdisappears.

This sequence will be performed automatic when the master gas valve is closed, but canalso be manually started from a pushbutton on the IAS operator stations.

Flowchart:SEQ-16

Nitrogen PurgingMain Line


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

- Master GAS Valve Not Closed

End

Action

Check Master Gas Valve ClosedTimeout : 50 sec - Master Gas Valve Closed

Open Master N2 Purge ValveTimeout : 10 sec - Master N2 Purge Valve Opened

Error

Error

Wait 90Seconds

Close Master N2 Purge ValveTimeout : 10 sec - Master N2 Purge Valve Closed

Set Master N2Purged Status

- Master GAS Valve Not Closed Reset

Set

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


StartOR

&

OR

Error

Master N2 Purge Seq Failed

- Master Vent Valve 1 Open- Master Vent Valve 2 Open

- Master N2 Purge Valve Close

Open Master Vent ValvesTimeout : 10 sec

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


1001854 / 0D / Page 45 of 93

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 burnergas valve inlet is purged with N2.

The gas header can be purged when no gas burners are firing in that boiler and theboiler fuel gas valve is closed.

The system will open the boiler header N2 vent valve and then open the header N2purge valve.

After purge time has elapsed the N2 purge valve will close again. The header N2 ventvalve will remain open.

A status indication “header purged” will be set. This status will be reset when the boilerfuel gas valve closed indication disappears.

This sequence will be performed automatic when the boiler gas valve is closed andpurge to furnace is not succeeded. The sequence can be manually started from asoftware pushbutton on the IAS operator stations if required.

Flowchart:SEQ-17

Nitrogen PurgingBoiler Header


- Boiler GAS Vlv Closed - All Bnr GAS Closed

- Boiler GAS Valve Not Closed

End

Action

Open Header N2 Purge ValveTimeout : 10 sec - Boiler Header N2 Purge Valve Opened

Error

Error

Wait 35Seconds

Open Boiler Header N2 Vent ValveTimeout : 10 sec - Boiler Header N2 Vent Valve Opened

Close Header N2 Purge ValveTimeout : 10 sec - Boiler Header N2 Purge Valve Closed

Set Boiler HeaderPurged Status

- Boiler GAS Valve Not Closed Reset

Set

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


OR

&

OR

Error

Error

Header N2 Purge Seq Failed

- Header Vent Valve Open- Header N2 Purge Valve Close


1001854 / 0D / Page 46 of 93

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 gasburner 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 thefurnace, 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 <x> purged” will be set. This status will be reset when theburner 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 burnergas valve inlet is purged with N2.

The gas header can be purged when no gas burners are firing in that boiler and theboiler gas valve is closed. The master N2 purge valve and the burner N2 purge valvesmust 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 closeagain. The header N2 vent valve will be opened.

A status indication “header purged” will be set. This status will be reset when the boilerfuel gas valve closed indication disappears.

This sequence will be performed automatic when the boiler gas valve is closed, but canalso be manually started from a software pushbutton on the IAS operator stations.


1001854 / 0D / Page 47 of 93

Flowchart:SEQ-19

Nitrogen PurgingBoiler Header & Bnr


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

- Boiler Gas Vlv Not Closed

End

Action

Close Boiler Header Vent ValveTimeout : 10 sec - Boiler Header Vent Valve Closed

Open Header N2 Purge ValveTimeout : 10 sec - Boiler Header N2 Purge Valve Opened Error

Wait 25Seconds

- Open Bnr1 GAS Valves if :FO Bnr1 On



Timeout : 10 sec

- 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

Open Header Vent ValveAfter 5 sec All Bnr GAS Valve CloseAfter 10 sec Header N2 Valve Close

Timeout :30 sec

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

Error

Set Boiler Header/ BurnerPurged Status - Boiler GAS Vlv Not Closed Reset

Set

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


Start

OR

&

OR

Error

Error

Header N2 Purge Seq to Furn Failed

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

- Header Vent Valve Open


1001854 / 0D / Page 48 of 93

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 49 of 93

5 BOILER CONTROL

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

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

The level controller has following two set points and wanted set point can be selectedfrom the IAS operator stations:

• Fixed level set point.• Variable level set point dependent on the steam flow.

FC

FI

FI

Boiler Drum LC(PI) (PI)

BackupController

Super Htr

Feed Water Pumps

FI

LI

LC(PI)

SwitchSwitch tobackup ifFeed wflow isfaulty

Fixed level Setp

ParSelect

Feed Fwd

Feed Fwd

HighSel

Setp

Setp

F1

F2 Valvechar

Economizer

Setp

166BDrum WaterLevel

167BSteam Flow #1

167BSteam Flow #2

LI

SelSwitch

158BSafetySensor

Error


1001854 / 0D / Page 50 of 93

Failsafe handling

Cause Effect Comments:

Steam flow signalfailure

Steam flow value freeze Both sensors failed

Feed water flowsignal failure

Switch to backupcontroller

Level measurementsignal fail

Switch to safety sensor. If both control & safety sensor is failedthen controller is set to manual mode,and operator must manually control theFW valve.

Difference betweenvalve Command andABU feedback > 10%

No effect Alarm


1001854 / 0D / Page 51 of 93

5.2 Main Steam Temperature ControlThe purpose of this system is to maintain the main steam temperature constant at setpoint.

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 usedas process value for the controller.

Steam flow and super heater 5 pass inlet temperature is used a feed forward action inorder to obtain quick response at load changes.

Cal Inp=>Vlv Min Op.

Steam Flow=>Vlv Opening

Steam Temp=>Vlv Opening

Feed Fwd

TI TI TI FI FI FI

129BSH OutletTemp 1

PID

HiSel

HiSel

HiSel

HiSel

129BSH OutletTemp 2

119BSH 5

Pass In Temp

167BSteamFlow 1

167BSteamFlow 2

FuelCalorieInput

SetpSw

Man Mode 500 C

Normal 515 C

3rd Burner start

180 s

+ 20%

130BSteam Temp C/V(Large)

0 1

133BSmall SteamTemp C/V

FO or DualMode

Two steam temperature control valves are provided parallel. One is large, another issmall. 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 smallcontrol valve is decided by function generator which is located between high selectorand switch, as above figure.


1001854 / 0D / Page 52 of 93

Failsafe handling


SH Outlet TempSensor Failure

Temp Controller to“Manual”

Both sensors failed

SH 5 pass inlet tempsensor failure

Value frozen in lastreadable value

Steam flow sensorfailure


Both sensors failed

FO flow sensorfailure


GAS flow sensorfailure


5.3 Atomizing Steam Pressure ControlThe purpose of this system is to control the atomizing steam pressure at the mostsuitable levels according to FO pressure.

This system consist of a PID controller where set point is derived from the FO pressure.

FO Press=>Atom Setp

Setp

PI

PID

242BAtomPress

Ign Val DO (6bar)

PI

231BFO

Press

Switch

Switch

Ign Val FO (6bar)

Switch DO Use

FO Bnr's OffFO Bnr's Off

DO Press=>Atom Setp

226BAtomizPressC/V

Tracking 50% at Gas ModeFollow


1001854 / 0D / Page 53 of 93

Failsafe handling


Atom Press signalfault

Controller is set to“Manual”

FO press signal fault No effect

5.4 Steam Purge Pressure ControlThe purpose of this system is to control the purge steam pressure at the most suitablelevels.

Setp

PI

PID

362BPurgePress

0 1

0 1

1bar2bar

2bar

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

Any Burner Purge V/V Open

Failsafe handling


Purge Press signalfault



1001854 / 0D / Page 54 of 93

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

Setp

PI

MB1FOPress

(from FuelOil Control

Loop)

Switch PID

HiSel

MB2FOPress

(from FuelOil Control

Loop)

200BFOPump

Press

All FO Bnr Stopped(8,5bar)

SwitchFO Pump Stopped (80%)

10% FO Boost SeqRun

20 s

FO Press=>Setpoint

215BFOPumpPress C/V

Failsafe handling


FO pump pressuresignal fail


MB1 FO pressuresignal fail

No effect If both boiler FO press signal fails thenset point will be fixed.

MB2 FO pressuresignal fail

No effect If both boiler FO press signal fails thenset point will be fixed.


1001854 / 0D / Page 55 of 93

5.6 Steam Pressure ControlThe purpose of this system is to maintain the steam pressure at outlet super heater at aconstant value according to set point, normally at 60.3 bar. Set point is adjustable fromIAS operator stations. The pressure control is done by controlling the total fuel flow andthe combustion air flow to all burners. The air flow controller will lead duringincreasing demand

At boiler start, steam up controller will bring boiler pressure up to set point atpredefined rate. When 2 boilers are brought up to set point (steaming up finished) themaster 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 loadrate between the two boilers. This will affect the master calorie demand to FO, Gas andair flow controllers.

Master Set point.

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


1001854 / 0D / Page 56 of 93

Steam-Up Master

TrcSet

Trc

Set

Press=>Max Load

SteamUpRate

FO Cal Input

PI PIPI PI

165BMB2

SteamPress 1

PID

HiSel

+

HiSel

LowSel

165BMB2

SteamPress 2

165BMB1

SreamPress 1

165BMB1

SteamPress 2

BoilerDemand

HiSel

Gas Cal Input

Air Flow (kg/hr)

PID

LoadRatio

Ratio SetRatio Feedback

MB2 Master Demand+

Switch

FI FI

HiSel

167BMB1

SteamFlow 1

167BMB1

SteamFlow 2

Master SetpointAuto Set DownSet Down Bias

Switch

HiSel

FI FI

HiSel

167BMB2

SteamFlow 1

167BMB2

SteamFlow 2

Bias 1.1*

Switch

FeedF

wd

FeedF

wd

Other Boiler

Master : NOT (2 boiler paralell operation and FO,GAS,Air in Auto)Steam Up: FO or GAS or Air in Manual or Master Active

Tracking

0-50 Gcal/h 0-100 Gcal/h

0-50 Gcal/h0-50 Gcal/h

LowLim

Low Load GasMode

* 0,5 LowLim

0.00075 Gcal/kg

Failsafe handling


MB1 steam pressuresignal failed


Both signals failed

MB2 steam pressuresignal failed


Both signals failed

MB1 steam flowsignal failed

Value freeze Both signals failed

MB2 steam flowsignal failed

Value freeze Both signals failed


1001854 / 0D / Page 57 of 93

Fuel Oil Flow Controller

Fuel flow controller set point is made by : Boiler master demand – Actual Gas heatinput.

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 Gastrip.

FO Press=>FO Flow

Setp

PI

231BFO

Press 1

-

X

PID

Switch

Switch

All FO Bnr Off

Gas Flow(from Gas

flowcontrolloop)

0

No Of FO Bnr

Master Cal Demand

Max FO Bnr FlowNo Of FO Bnr

Min FO Flow 1 Bnr FOMin FO Flow 2 Bnr FOMin FO Flow 3 Bnr FOMin FO Flow 1 Bnr DualMin FO Flow 2 Bnr DualMin FO Flow 3 Bnr Dual

XLoSel

FO Cal Value/

Switch

Switch

FO Boost UpOrder

FO Ctr Vlv Force FO Recirc Vlv OpenedFO Ignition , FOFO Ignition, Dual 1bnrFO Ignition, Dual 2bnrFO Ignition, Dual 3bnr

FO Boost UpOrder

HiSel

Switch

FO Bnr Exting ReqSwitch

FG Flow=>FO Flow

X

FO FlowFO Cal Inp

FO Cal Value

OR 2nd FO Ign Set Req3rd FO Ign Set Req&Dual Mode

Switch

Gas Cal Input0

With Up/dwnRamp

XFO Cal Value

Min FO Cal Inp

PID

LoSel

Min PressControl

A

A

HISel

PI

231BFO

Press 2

To Atomiz Press ControlLoop

To FO Pump DischargePress Control Loop


1001854 / 0D / Page 58 of 93

Failsafe handling


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 (differentialpressure 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 FOignition when master gas valve trip is activated.


1001854 / 0D / Page 59 of 93

MinFlowControllerFlow

Controller

Gas Press=>Gas Flow

Setp

PI TI PI

249BGas

Press

-

X

PID

Switch

238BBOGTemp

230BBOGPress

Master Cal Demand

Min Gas Flow 1 BnrMin Gas Flow 2 BnrMin Gas Flow 3 BnrMin Gas Flow At Bnr Inc

HiSel

Switch

FO Boost Up Order

Gas Ctr Vlv ForceGas Shut Vlv ClosedGas Ignition, 1bnr, Free FlowGas Ignition, 2bnr, Free FlowGas Ignition, 3bnr, Free Flow

Switch

HiSel

PID

To Air Flow ControlTo Fuel Oil FlowControl

Switch0

X No Of Gas Bnrs

X

Gas Flow

Gas Cal Inp

Gas Cal Value

OR 2nd FO Ign Set Req3rd FO Ign Set Req&Dual Mode

Switch

FO Min Cal InputFO Cal Input

OR

FO control ManualGas Control Manual

/ Gas Cal Value

Max Gas Bnr FlowNo Of Gas Bnr

XLoSel

Switch

Gas Bnr Exting ReqWith Up/DwnRamp Flt

Gas Ignition, 1bnr, LD RunGas Ignition, 2bnr, LD RunGas Ignition, 3bnr, LD Run

All Gas Bnr Stop

208BGasFlowC/V


1001854 / 0D / Page 60 of 93

Failsafe handling


Gas press signal failed Switch to flow control

BOG press signalfailed

No effect

BOG temp signalfailed

No effect

GAS Flow signalfailed

Switch to pressurecontrol

Air Flow Controller

The set point for the air controller is calculated by the total calorie input (FO flow + Gasflow) multiplied by an air ratio. A feed fwd from boiler master demand is used in orderto quickly response to load changes.

The air ratio is automatically adjusted by an O2 controller. The O2 controller set pointis 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 61 of 93

FlueGasO2

SetpFollo

w 1.

0

GASFlow

+

PID&

FOFlow

Fuel/AirRatio Set0.5 - 1.5

Soot BlowRunning 1.1

Setp

Ignition SetFurn purge

X

Steam Flow > 80%

Sw itch

HiSel

X

X

PI PI

AirFlow

AirFlow

Bnr Load=>O2 Content

Calc

X

O2

PID

3 Bnr Run

Range0.9-1.1

X17.47 X14

BurnerLoad

Excess Ratio

Not Man Zone

Air Bias( Bnr Seq)1.05

X

X Sw itch

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

mbar=>Kg/h

> 40000FurnPrg OK

Ign OK> 4000 &< 8000

Fdf Stop

VaneChar

+Boiler Master X 2A

A

LowSel

SelSw

Stby FanAir Flow

Note: O2 trim control is activated when the following conditions are established:

Steam flow > 80% & 3 burners firing.

Failsafe handling


Air flow sensors failed Air flow controller tomanual

Both sensors failed

FO press signal failed No effect

Gas press signal failed No effect

O2 Sensor failed O2 trim is bypassed


1001854 / 0D / Page 62 of 93

5.7 Steam Dump ControlThe main purpose of this system is to force the boilers to burn excess boil of gasgenerated in the cargo tanks.

Secondary function is to prevent overpressure in the boilers. In case pressure at thesteam outlet is above set point, the steam dump valves will start to open dumping theexcess steam to the main condenser

Excess BOG Controller.

FO flow and Recommended BOG rate is calculated and transformed to an estimatedsteam flow equivalent which will be defined as the controller set point. The controllerwill 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 themax 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. Whencontroller is activated it will remain active until boiler pressure is normal and output is 0.


1001854 / 0D / Page 63 of 93

Dump Order=>Spary V1 Contr

Set

SetDumpController

Max FGController

BOGController

Set PID

Switch

Master Setpoint

HiSel

MB1 Min FO FlowBias 1bar

Dump Pist Vlv Closed

+MB2 Min FO Flow

+

Rec BOG0-130 t/h

LoSel

Load Limit

PID

MB1 FG Vlv Pos HiSelMB2 FG Vlv Pos

Max FG Vlv Pos95%

PID

LoSel

FI

167BMB1

Steam Flow

Hardware FunctionGenerator by MHI

Dump Order=>Spary V2 Contr

To IAS for SprayVlv Control

331B Dump C/V #1

FI

167BMB2

Steam Flow

HiSel

PI

165BMB1

Steam Press

PI

165BMB2

Steam Press

HiSel

Switch

0

Not&BOG DUMP MODEGAS BNR RUNNING

0

GCal=>Stm Flow

Crash Ast

Boiler Master

MT TripSwitch

0 1

332B Dump C/V #2

0 1 0 1

Dump C/V Lead/FollowChange Over

0 1

Dum p Cont r ol lerOut put

Valve Out put

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

1 00

1 0 2 0 3 0 40 50 60 70 80 9 0 100

Spr ay1

Dum p1

Spr ay2

Dum p2


1001854 / 0D / Page 64 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 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 pistonvalve will shut down.DumpController:Set - Pv < 0.5 bar

Dump controlleroutput > 1% OR

Dump Piston VlvOpen Order

MT manovering zone

&

MT Trip

Dump Available From IAS

Off Delay3min

Failsafe handling


Steam press sensorsfailed

Controllers is set to“Manual”

4 sensors failed

Steam flow sensorsfailed

No effect

MB1 Gas control vlvpos feedback failed

No effect

MB2 Gas control vlvpos feedback failed

No effect

MB1 FO flow signalfailed

No effect

MB2 FO flow signalfailed

No effect


1001854 / 0D / Page 65 of 93

5.8 Flame EyesThere are four flame eyes for each of the burners. Two flame eyes for both IR sensingand 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 thenone 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 issuppressed if burner is FO or dual firing.

Flame eye rack “power fail” and “fan failure” is sent to ABC for alarm.

Principle drawing:

Flame ONFlame Scanner 1 UV On

Flame Scanner 2 UV On

OR

&F/E #1 IR Abnormal

Timer On

FO burner burning

GAS burner burningOR

All Burner Stopped&

OR

Flame Scanner 1 IR On

Flame Scanner 2 IR On

Timer Off 0 sec


1001854 / 0D / Page 66 of 93

5.9 FDF STBY FanEach 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 stbyFDF 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 andOK.

Air flow sensors for stby FDF is input to common FS and the ABC logic will use thesesensors 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

STBY FDF Run Low Or High

& No1 STBY Fan Mode(DO)

Normal FDF RunOR Blr FDF

Run


1001854 / 0D / Page 67 of 93

5.10 Hot Start ValveAt 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 valveis controlled according to steam flow.

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

Boiler condition Steam up valve

Boiler stoppedNo burners firing

Closed

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

Opened

Hot Start of boiler

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

Closed

Reset

SetBoiler FiringStaem Press < 15bar

Steam Flow < 2.5 t/h

&Hot Start ValveOpen OrderOR

Staem Press > 15 bar &

Staem Flow > 4.0 t/h &

OR

RS

Timer ON3 min


1001854 / 0D / Page 68 of 93

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

No.1 Blr FO Flow

No.2 Blr FO Flow+ LSE

Set 1200kg/hrReset 1700 kg/hr

1200 kg/hr

ORNo.1 Blr Gas Mode

No.2 Blr Gas Mode

Viscometer ValveOpen


1001854 / 0D / Page 69 of 93

5.12 Fuel/Atomizing Valve AbnormalHFO 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 70 of 93

5.13 Output to Main TurbineThe boiler control calculates some outputs for the main turbine system.

MT Trip

CompHi200mm

Boiler Firing

Drum Water LevelTransmitter

CompHi220mm

&

10 s

10 s

CompHi180mm

10 s

CompLo-200mm

10 s

MT Slow dow n

MT Program Interlock

MT Slow dow n

MB1Logick

Boiler FiringMB2Logick

&

&

OR

Both Boiler Trip

One Boiler Trip

Main Boiler 1

MT Trip

CompHi200mm


CompHi220mm

10 s

10 s

CompHi180mm

10 s

CompLo-200mm

10 s

MT Slow dow n

MT Program Interlock

MT Slow dow n

Main Boiler 2

Boiler Common


1001854 / 0D / Page 71 of 93

6 BOILER TRIPThe 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 tripcause is flickering.

Acknowledge button must be operated in order to confirm the trip cause, correspondinglamp is then steady lit. Trip circuit is still active. Acknowledge can be done from IAS orBGB whichever location is in command.

When trip cause is acknowledged and trip cause is brought to normal, then trip can bereset 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 selectedfor 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)

FO temp LL (have bypassswitch) (80 deg/C)

FO Press LL (1bar)

FO Pump Stop

Fuel/Atomize Valve Abnormal

- Boiler FO Shut Vlv Close

- No1 burner FO vlv1&2Close



Acknowledge push-button and

Boiler FO shutoffvlv close push-button


1001854 / 0D / Page 72 of 93

Logic Diagram.

Reset

Atm Steam Press LL

FO Temp LLFO Temp Bypass Sw itch

FO Press LL

FO Pump StopAny FO Bnr OnEmergency Mode

&

&

&

&

FO Trip

FO Trip

Boiler trip

OR

ORSet

RSBoilerFO Shutoff Vlv Shutdow n OrderBnr1 FO Vlv1&2 Shutdow n OrderBnr2 FO Vlv1&2 Shutdow n OrderBnr3 FO Vlv1&2 Shutdow n OrderIAS Blr FO Shutoff Vlv

Close Push button

Control position IAS

BGB Blr FO Shutoff VlvClose Push button

Control position BGB

&

&

OR

Fuel/Atomiz Valve Abnormal


1001854 / 0D / Page 73 of 93

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

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

Emergency manual trip BGB

Main steam temp H (545deg/c)by analogue sensor

- Activate FO trip

- Activate Gas trip


Boiler FO shutoffvlv close push-button resets FOtrip


Boiler Gas vlv closepush-button resetGas trip.


1001854 / 0D / Page 74 of 93

No1 FD Fan Run

Stby FD Fan Run High or Low

Stby FD Fan Air Dmp OK

Stby FD Fan Selected

All Bnr Flame Fail

Emerg Manu Trip ECR

&

Boiler Trip

OR

&

CompLo-240mm

Drum Water Level LLFloat Sw itch

OR


CompHi240mm

Stby Fan Mode On

&

Emerg Manu Trip BGB

Steam TempTransmitter

CompHi545C

OR

10 s

5 s

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)

BOG Press H (736mbar)

Boiler Trip Condition

Master Gas Valve Trip On + 15s

- Boiler Hdr Vent Vlv Open

- Boiler Gas Shut Vlv Close

- No1 burner Gas vlv1&2Close




Boiler Gas shutoffvalve close push-button


1001854 / 0D / Page 75 of 93

Any Bnr Gas Vlv OpenedOR

&

Boiler Trip On

Boiler GAS Trip

Master GAS Vlv Trip On

Reset

GAS Trip

Boiler tripOR

Set

Blr GAS VlvClose Pushbutton

RSBoiler Vent vlv Open OrderBoiler GAS Vlv Shutdow n OrderBnr1 GAS Vlv1&2 Shutdow n OrderBnr2 GAS Vlv1&2 Shutdow n OrderBnr3 GAS Vlv1&2 Shutdow n Order

10 s

90 s

15 s

&CompHi0,736bar

BOG PressTransmitter

CompLo0,007bar

Master GAS Valve Trip.

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

Cause Action Reset

E/R Vent Fan Failure

Gas Duct Exh Fan Stop

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

- Master GAS Vlv Shutdown

- Master N2 Vent Vlv Oppen


Master GAS Vlvclose push-button


1001854 / 0D / Page 76 of 93

E/R Vent Fan Failure

Gas Duct Exh Fan Stop

Gas Leak Detected

Fire detected

BOG Temp LL

Master Gas Vlv Manu Trip (ECR)

Vapour Hdr Press LL

BOG Htr Abnormal

Master Gas Vlv Close PB

Both Boiler Trip

Master GAS Vlv TripOR

FO Boost Up Order

ResetGAS Master Vlv Trip Set

GAS Master VlvClose Pushbutton

RSMaster Vent vlv Open Order

Master GAS Vlv Shutdown Order

OR

Both Blr GAS Vlv's Closed LS

Master Gas Vlv Manu Trip (BGB)

10 sOn-delay


1001854 / 0D / Page 77 of 93

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

IAS Base Bnr OFF PB

BGB Base Bnr OFF PB

&

&

&

OR

RSSet

Reset Base Bnr Flame1 Fail

No.2 Bnr IR1&2 Failed

No.2 Bnr UV1&2 Failed

IAS No.2 Bnr OFF PB

BGB No.2 Bnr OFF PB

&

&

&

OR

RSSet

Reset No.2 Bnr Flame1 Fail

No.3 Bnr IR1&2 Failed

No.3 Bnr UV1&2 Failed

IAS No.3 Bnr OFF PB

BGB No.3 Bnr OFF PB

&

&

&

OR

RSSet

Reset No.3 Bnr Flame1 Fail

Base FO Bnr Valve CloseBase GAS Bnr Valve CloseBase Bnr Atmise Valve CloseBase Bnr Air Reg Close

No.2 FO Bnr Valve CloseNo.2 GAS Bnr Valve CloseNo.2 Bnr Atmise Valve CloseNo.2 Bnr Air Reg Close

No.3 FO Bnr Valve CloseNo.3 GAS Bnr Valve CloseNo.3 Bnr Atmise Valve CloseNo.3 Bnr Air Reg Close

Base Bnr Flame ON

&

&

&

OR

No.2 Bnr Flame ON

No.3 Bnr Flame ON

All Bnr Flame Fail


1001854 / 0D / Page 78 of 93

7 BOILER OPERATION PANELS

7.1 BGB Graphic PanelThe BGB graphic panel contains buttons for control of sequences and lamps forfeedback. The buttons activates the same sequences as those used when operating fromthe IAS operator stations.

Command transfer.

In order to use the functions from the panel, command must be transferred from thecontrol 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)

NoX Burner

NoX Gas BNR On MB1 x 3 +

MB2 x 3

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

manual mode.

Lamp: - Flicker during start seq,

- Fast Flicker when start error

- Steady when burner is On

FS-10(MB1),

FS-11(MB2)

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


FS-10(MB1),

FS-11(MB2)


1001854 / 0D / Page 79 of 93


NoX FO BNR On MB1 x 3 +

MB2 x 3

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

manual mode.

Lamp: - Flicker during start seq,

- Fast Flicker when start error


FS-10(MB1),

FS-11(MB2)

NoX FO BNR Off MB1 x 3 +

MB2 x 3

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

manual mode. Also reset of start/stop error

Lamp: - Flicker during stopt seq,

- Fast Flicker when stopt error


FS-10(MB1),

FS-11(MB2)

Flame Signal MB1 x 2 +

MB2 x 2

Indicator Indicator Flame condition indicator BGB (by MHI)

FO Shut V/V

Open MB1 + MB2 Switch/Lamp Swich: Send open command to FO shut valve

Lamp: - Flicker during open time,

- Fast Flicker if open failed

- Steady when valve is open

FS-10(MB1),

FS-11(MB2)

Close MB1 + MB2 Switch/Lamp Swich: Send close command to FO shut valve, also used

for FO/Boiler trip reset

Lamp: - Flicker during close time,

- Fast Flicker if close failed

- Steady when valve is closed

FS-10(MB1),

FS-11(MB2)

Furnace Purge

Request MB1 + MB2 Switch/Lamp Switch : Activates furnace purge sequence

Lamp: 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 FS-10(MB1),


1001854 / 0D / Page 80 of 93


FS-11(MB2)

BMS Position

BGB Manual MB1 + MB2 Switch/Lamp Switch: Change burner operation to BGB location

Lamp: Burner operation at BGB On

FS-10(MB1),

FS-11(MB2)

IAS MB1 + MB2 Switch/Lamp Switch: Change burner operation to IAS

Lamp Burner operation at IAS On

FS-10(MB1),

FS-11(MB2)

Alarm

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)

ABC Position

BGB MB1 + MB2 Switch/Lamp Switch: Change control loop operation to BGB location

Lamp: Control loop operation at BGB On

FS-10(MB1),

FS-11(MB2)

IAS MB1 + MB2 Switch/Lamp Switch: Change control loop operation to IAS

Lamp Control loop operation at IAS On

FS-10(MB1),

FS-11(MB2)

GAS Firing MB1 + MB2 Lamp GAS firing condition 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

FS-10(MB1),

FS-11(MB2)


1001854 / 0D / Page 81 of 93


- Steady when valve is open

Close MB1 + MB2 Switch/Lamp Switch: Send close command to feed water motor valve

control panel.

Lamp: - Flicker during close time

- Fast flicker if closed failed

- Steady when valve is closed

FS-10(MB1),

FS-11(MB2)

FS-10(MB1),

FS-11(MB2),

FS12,(Com)

FDF

Start MB1 + MB2 +

Common

Switch Switch: Send start command to group starter panel via

IAS.

Stop MB1 + MB2 +

Common

Switch Switch: Send stop command to group starter panel via

IAS.

Run MB1 + MB2 +

Common

Lamp Lamp: Steady when FDF is Running.

Aux Feed Water Pump

Start Common Switch Switch: Send start command to group starter panel via

IAS.

FS12,(Com)

Stop Common Switch Switch: Send stop command to group starter panel via

IAS.

FS12,(Com)

Run Common Switch Lamp: Steady when motor is Running. FS12,(Com)

Seal Air Fan

Run (No1/2) Common Lamp Lamp: Steady when fan is Running. FS12,(Com)


1001854 / 0D / Page 82 of 93

7.2 Manual Loader FunctionsThe graphic panel at the BGB contains functions for manual control of each controlvalve.

The IAS output (4-20mA) for control valves are connected to an ABU (AnalogueBackup Unit).

Normal mode.

Each control valve or FDF vane can be manually controlled from either BGB graphicpanel or from IAS operator stations. In normal mode the 4-20mA control signal fromIAS 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/decreaseorder 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 83 of 93

-

+

Reset

SetIAS

BGB

IAS A (Sow button)

RS

IAS M (Sow Button)

Emerg mode

&

+ / -

ABC Position

Not

IAS

BGB

ABC Position "BGB"

BGB A

BGB M&

OR

OR&

&

ABC Position "IAS"

Reset

SetRS

Not

Auto

Manual

Manual/Auto Selection

PID

Inc

Dec

Emerg mode

&

&

SelSw

Manual

Trc ValueTrc Select

ABU Feedback(4-20mA)

&ABC Position "BGB"

Man/Auto Selection "Manual"

Emerg modeOR

Output to ABU4-20mA

Inc / Dec Prinsipple


1001854 / 0D / Page 84 of 93

7.3 Emergency OperationNote: 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, emergencyoperation mode is performed in following manner.

1) Air flow control valve should be fully closed. And the forced draft fan shall bestarted.

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

3) Change operation mode switch from "NOR" to "PURGE". Open fully (above70%) air flow control valve. Differential press between wind box and furnaceshould be confirmed (above 15mbar). Furnace purge should be conducted untilturning "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" positionshould be kept until establishment of flame. However, it must not exceed 10seconds.

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 asabove item 12) and 13).

Note : If burner does not ignite by the above process, repeat operation from the above3).

Note : If drum water level low-low with float switch is detected, acknowledge buttonon BGB should be depressed.


1001854 / 0D / Page 85 of 93

7.3.2 Common Part

In case of failure of both (active/standby) controllers for common, emergency operationmode 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 suitableposition.

8 SOOT BLOWING SEQUENCESThe soot blower sequences are provided within the IAS. Operations are done from theIAS 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 sequencecall up respective subsequence during auto operation. Local operation call eachsubsequence 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 byselecting the corresponding bypass push buttons of IAS. Auto function is as follows.When "SEQ START" or "ECO START" function is running, if trouble occurs thencorresponding soot blower is bypassed automatically.


1001854 / 0D / Page 86 of 93

Emergency retract

If long soot blower forward sequence is active then the sequence is stopped. And thelong soot blower retract sequence is stated. If long soot blower is not active or completethen "steam supply valve" is closed and "drain valve" is opened. If rotary soot blowersequence 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 startorder will be active by depressing the "BOTH BLR" push button of IAS. Afterdepressing the "BOTH BLR" push button of IAS, "steam supply valve" open and "drainvalve" close. Operator can start the soot blower by depressing the corresponding SootBlower push button. The subsequence’s “Long Soot Blower” and “Rotary Soot Blower”as described below is activated directly by the operator.


1001854 / 0D / Page 87 of 93

8.1 Long Soot Blower SequenceThis 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 rotationorder is active until stop limit switch is received.

An emergency retract function is applied. If emergency retract command is activated therun fwd order is cancelled and retract order is activated. Retract order will remain untilstop limit switch is received. A maximum timer for retract order is applied.

Start


- 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 %

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

End

Action

Reset Fwd Start at Retract position

Timeout : 250 sec

- Blower Retract Position ON & - Blower Fwd Running OFF

- Reset Run Fwd Order- Set Rev Order if not stop position

- Set Alarm- Set Bypass if Auto Seq

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


Start

Start FwdTimeout : 5 sec

- Blower Fwd Running ON & - Stop position OFF Error

Error

OR

&

OR

Start Reverse

Timeout : 5 sec

- Blower Rev Running ON & - Retract Position OFF

Error

Reset Rev Start at Stopt position

Timeout : 250 sec

- Blower Stop Position ON - Blower Rev Running OFF

Error

8.2 Rotary Soot Blower SequenceThis sequence can be called from “SEQ START” sequence, “ECO START” sequenceor by local command.

The blower will run until stop position is received. Then run order will be switched off.


1001854 / 0D / Page 88 of 93

Start


- Motor Overload - Boiler Load < 50 %

- Motor Overload - Boiler Trip - Auto Seq Fail

End

Action

Stop Blower at Stop position

Timeout : 60 sec

- Stop Position ON & - Blower Running OFF

- Reset Run Order- Set Alarm

- Set Bypass if Auto

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


Start

Start BlowerTimeout : 5 sec

- Blower Running ON & - Stop Position OFF Error

Error

OR

&

OR

8.3 Boiler & Economizer Soot Blower SequenceThis sequence makes use of “Long soot blower sequence” and “rotary soot blowersequence” 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 alllong soot blower in normal stop position. When long soot blower is stuck in travelling,steam supply valve keep open.


1001854 / 0D / Page 89 of 93

Flowchart for No.1 or No.2 boiler sequence

Start


- 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 - Steam supply valve abnormal - Boiler Trip - AC 440V Failure

End

Action

Start L1 If not Bypass ONTimeout : 2 sec

- L1 Seq Run OR - Bypass ON

- Terminate all soot blower subsequences

- Close steam Vlv if all long blower innormal stop position

- Open No1 MB Drain Vlv


- Set Alarm

Wait, L1 blowing Timeout : 500 sec

- L1 Seq Run for 364 sec OR - L1 Seq Not Run

- Start from Monitor(IAS)Start PermissiveTerminate

Start

Open Steam VlvTimeout : 40 sec - Steam Vlv Opened Error

Bypass

OR

&

OR

Timer 180s

Start L2 If not Bypass ONTimeout : 2 sec

- L2 Seq Run OR - Bypass ON

Wait, L2 blowing Timeout : 500 sec

- L2 Seq Run for 388 sec OR - L2 Seq Not Run Error

Start R1 If not Bypass ONTimeout : 2 sec

- R1 Seq Run OR - Bypass ON Bypass

Wait, R1 blowing Timeout : 60 sec

- R1 Seq Run for 38 sec OR - R1 Seq Not Run Error


- R2 Seq Run OR - Bypass ON

















Wait, R6 blowing Timeout : 60 sec - R6 Seq Not Run Error

Close Steam Valve if all long blowerin normal stop position & Open Drain

Vlv 1&2 Timeout : 10 sec

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

Error

Check Steam Pressure OKTimeout : 2 sec - Steam Press OK Error

Bypass

Bypass

Bypass

Bypass

Bypass

Close Other Blr Drain ValveTimeout : 10 sec - Other Boiler Drain Valve Closed Error

Error


1001854 / 0D / Page 90 of 93

Flowchart for both boiler sequence

Start


- 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 supply valve abnormal - Boiler trip - AC 440V Failure

End

Action

No1 Boiler Blower SequenceL1,L2,R1,R2,R3,R4,R5,R6


- Close steam Vlv if all long blower innormal stop position



- Set Alarm

Open No.2 Boiler Drain VlvTimeout: 10 sec - No.2 Blr Drain Valve Opened


Start

Open Steam VlvTimeout : 40 sec - Steam Vlv Opened & Error

OR

&

OR

Timer 180s

Timer 180s


No2 Boiler Blower SequenceL1,L2,R1,R2,R3,R4,R5,R6

Close Steam Valve if all long blowerin normal stop position & Open Drain

Vlv 1 & 2 Timeout : 10 sec



Close No.2 Blr Drain ValveTimeout : 10 sec - No.2 Blr Drain Valve Closed Error

Error

Error

8.4 Economizer Soot Blower SequenceThis sequence makes use of “rotary soot blower sequences” in order to make a completesoot blower sequence.

Each boiler can be soot blower separately or both boilers can be blower in serial.


1001854 / 0D / Page 91 of 93

Flowchart for No.1 or No.2 boiler sequence

Start


- 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 supply valve abnormal - Boiler Trip - AC440V Failure

End

Action




- Close steam Vlv



- Set Alarm


- R3 Seq Run for 18 sec OR - R3 Seq Not Run

- Start from Monitor(IAS).Start PermissiveTerminate

Start


Bypass

OR

&

OR

Timer 180s











Wait, R6 blowing Timeout : 60 sec - R6 Seq Not Run ErrorError

Close Steam Valve &Open Drain Vlv 1 & 2

Timeout : 10 sec


Error

Bypass

Check Steam Press OKTimeout : 2 sec - Steam Press OK Error

Bypass

Close Other Boiler Drain ValveTimeout : 10 sec - Other Boiler Drain Valve Closed Error

Error


1001854 / 0D / Page 92 of 93

Flowchart for both boiler sequence

Start


- 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 supply valve abnormal - Boiler Trip - AC 440V Failure

End

Action

No1 Boiler Blower SequenceR3,R4,R5,R6


- Close steam Vlv



- Set Alarm

Open No.2 Boiler Drain VlvTimeout: 10 sec - No.2 Blr Drain Valve Opened


Start


OR

&

OR

Timer 180s

Timer 180s


No2 Boiler Blower SequenceR3,R4,R5,R6

Close Steam Valve &Open Drain Vlv 1 & 2

Timeout : 10 sec


Error


Close No.2 Blr Drain ValveTimeout : 10 sec - No.2 Blr Drain Valve Closed Error

Error


1001854 / 0D / Page 93 of 93

9 ATTACHMENTS- Parameter List. (will be issued later)

- ABC Operator Manual. (will be issued later)

mitsubishi boiler control

Documents