Gas Turbine Philosophy

8/17/2019 Gas Turbine Philosophy

1/55

Gas Turbine ControlPhilosophy


2/55

Gas Turbine

Rotating Blow Torch

Designed to Run at the

Ragged Edge of Self Destruction

TC G


3/55

Speedtronic Control SystemSpeedtronic Control System


4/55

Control System for Gas TurbineControl System for Gas Turbine

Gas turbine is controlled Speedtronic control system

Control loops includes Start-up

Acceleration

Speed

Temperature

Shutdown and

Manual Control functions


5/55

Speedtronic Control loopsSpeedtronic Control loops Major Control loops Secondary control loops

Start-up Acceleration

Speed and Manual FSR and Temperature Shutdown

Output of these control loops is fed to a minimum alue !atecircuit

Start "p

Shut #own

Manual

M

!#isplay

Speed

To Turbine

Fuel

"SR

#isplay

#isplay

AccelerationRate

Temperature


6/55

Speedtronic Control loopsSpeedtronic Control loops

Fuel Stro$e Reference %FSR&

Command si!nal for fuel flow

Controllin! FSR 'owest of the si( control loops

)stablishes the fuel input to turbine * rate re+uired by systemwhich is in control

Only O,) control loop will be in control at anytime The control loop which controls FSR is displayed in operator

friendly CRT


7/55

Startup#Shutdown Se$uence and ControlStartup#Shutdown Se$uence and ControlStartup control brin!s the !as turbine

.ero speed up to Operatin! speed

Allows proper fuel to establish Flame / Accelerate the turbine in such a manner as to

minimi0e the 'ow cycle Fati!ue of the hot !as path partsdurin! the se+uence

Software Se+uencin! inoles Command si!nals to Turbine Accessories1 Startin! deice and

Fuel control system

Safe and successful start-up

depends on proper functionin! of GT e+uipment Software Se+uencin! ensures safe operation of Turbine


8/55

Startup#Shutdown Se$uence and ControlStartup#Shutdown Se$uence and ControlControl lo!ic circuitry is associated not only with

actuatin! control deices1 but enables protectie circuits

and obtains permissie conditions before proceedin!

Control settin!s play a ital role in determinin! the

proper se+uencin! Actual site specific control settin!s are !enerated by M2s

G)3CS1"SA

Speed detection - by ma!netic pic$ups '456R .ero-Speed %Appro( 78 T,6& '456M Min Speed %Appro( 498 T,6& '456A Acceleratin! Speed %Appro( :78 T,6& '456S Operatin! speed %Appro(;:8 T,6&


9/55

Startup#Shutdown Se$uence and ControlStartup#Shutdown Se$uence and Control Actual settin!s of speed relays are listed in Control

specification

The control constants are pro!rammed in ROM

Always ensure correct site specific1 machine specific

control specification

Consult your system desi!ner for any +ueries


10/55

Start%up Control % "SRS&Start%up Control % "SRS&

Open loop control

"ses preset leels of fuel command

?arious Fuel leels .ero1 Fire1 @arm-up1 Accelerate and Ma(

Typical alues for Frame-9

Fire 4:98

@arm-up 4498

Accelerate 4;B8 Ma(imum 4778

Open 'oop ControlOpen 'oop Control


11/55

Start%up Control % "SRS&Start%up Control % "SRS&

Startup control FSR %FSRS"& si!nal operates

throu!h the M3, alue !ate to ensure other controlfunctions can limit FSR as re+uired

"SRS&"SRS&

FSRACCFSR,

FSRT

FSRS,

FSRMA,

M!

"SR"SR

"SR ' "SRS&"SR ' "SRS&


12/55

Start%up Control % "SRS&Start%up Control % "SRS&Speedtronic Control Start-up software

!enerates Fuel command si!nal %FSR&

Speedtronic Control Software also sets the MAD

and M3, limits for FSR for Manual Control FSR

E FSRMIN


13/55

(cceleration Control % "SR(CC(cceleration Control % "SR(CC

Acceleration control software compares the present alue of Speed si!nal with the alue at the

last sample time

#ifference between these two numbers is a measure of acceleration

@hen actual acceleration is !reater acceleration reference1

FSRACC is reduced1 which reduces FSR1 thus reduction in

fuel supply to turbine#urin! startup-acceleration reference is a function of turbine

speed

Acceleration control ta$es oer after @arm-up state


14/55


Acceleration reference is a Control constant

pro!rammed in ROMS

T!)

7H: 82sec

*++,+,

747 82sec

-+, .+, /., 0.,

TypicalTypical


15/55


M!

"SR"SR

FSRS"

"SR(CC"SR(CC

FSR,

FSRT

FSRS,

FSRMA,

"SR ' "SR(CC"SR ' "SR(CC


16/55

Speed Control % "SR!Speed Control % "SR!

Speed Control System software

controls the speed and load of the !as turbine!enerator

in response to the actual turbine speed si!nal %T,6&and the called-for speed reference%T,R&

T!)

T!R

"SR!


17/55

Speed#1oad ControlSpeed#1oad Control

Speed2'oad ReferenceI

Speed control software will chan!e FSR in proportion to thedifference the actual turbine !enerator speed %T,6& and the

called-for reference %T,R&

Reference Speed %T,R& ran!e

;:8 %min& to 47J8 %ma(& for a !enerator drie turbine

Start-up speed reference is 477H8

This is preset when START si!nal is initiated

Turbine follows 477H8 T,6 for synchroni0ation


18/55

Speed#1oad ControlSpeed#1oad Control

Turbine Speed is held constant when Generator rea$er is

closed onto >ower !rid

Fuel flow in e(cess of the necessary to maintain FS,' will

result in increased power produced by the !enerator

Thereby Speed control becomes 'oad control loop

Speed ControlI

3sochronous Speed control

#roop Speed Control


19/55

sochronous Speed Controlsochronous Speed Control

T!)

T!R

"SR!

M!"SR"SR

FSRS"

FSRACC

"SR! 2or "SR!3"SR! 2or "SR!3

FSRT

FSRS,

FSRMA, "SR ' "SR!"SR ' "SR!

S C


20/55

Droop Speed ControlDroop Speed Control#roop Control is a proportional control

Any chan!e in actual speed %!rid fre+uency& will cause a

proportional chan!e in unit load

This proportionality is adjustable to the desired re!ulation or

K#roopL

*+- ,

Sp

eed

Refere

nceT

!R

*++ ,

1ow Speed Stop

"S!1

* + + , S e t p o i n t

D r o o p *+ - , s e t t i n g

R a t e d " S R

" u l l S p e e d ! o

1 o a d " S R

"SR

0.,

Min T!R

S # CS d#1 d C t l l


21/55

Speed#1oad Control loopSpeed#1oad Control loop

SPEED

C4!TR41

M(!&(1

SETP4!T

14G

SETP4!T

Speed Target

Raise

1ower

Rate

Rate

Speed Ref5

Command

Preset

Power

Speed

Error

Speed

1oad Setpoint

Mechanical

4s

Ememrgency 4s

Primary 4s

14G

SET

P4!T

1oad Raise

1oad 1ower

1oad Rate

Rate

1oad Ref5

Cmd

Preset

M(!&(1SET

P4!T

S d C t l S h tiS d C t l S h ti


22/55

Speed Control SchematicSpeed Control SchematicSPEED C4!TR41SPEED C4!TR41 6RST7

"S!1

T!R

SPEEDRE"5

ERR4R

SG!(1

-

"SR!"SR!

T!)

SPEED

DR44P

SPEED C)(!GER 14(D SET P4!TSPEED C)(!GER 14(D SET P4!T

T!R

S>))#

R)F

M(85 1MT'BHS#

RAT)

'J7R

RA3S)

'J7'

'O@)R'BH>R)S

>R)S)T 'OG3C

PRESET

4PER(T!G

ST(RT%&P

or S)&T D49!

'BHT,RO>

M3, S)')CT 'OG3C

M3,

MED(!

SE1ECT

6RST7RST7

S h i i "SRS:!


23/55

Synchronising % "SRS:! Automatic synchroni0ation software

Al!orithms pro!rammed into rotectie core

= 3solation transformers are built into = core


24/55

(uto Synchronisation(uto Synchronisation

SpeedSpeed

MatchingMatching

Speed

System

"re$uency

Raise Speed

1ower Speed

;oltage;oltage

MatchingMatching

Speed

System ;olts

Raise ;olts

1ower ;olts

Generator ;olts

S h i i S h


25/55

Synchronising Scheme

68:.Brea=eBrea=e

CloseClose

RE"

RE"

Gen ;olts(

(7B

B

(!D1?@(S1?@(S

(uto Synch

PermissiAe

(

(7BB

6RST76RST7(&T4 S:!C)

PERMSS;E

1ine ;olts

T t C t l "SRTTemperature Control "SRT


26/55

Temperature Control % "SRTTemperature Control % "SRTTempControl software2al!orithms

limit fuel flow to the turbine to maintain internal operatin!temperatures within desi!n parameters of turbine hot !as

path parts

6i!hest temperature is in the flame 0one of

combustion chambers

TT8M

TTRE"

"SRT

"iring Temperature"iring Temperature


27/55

"iring Temperature"iring TemperatureFirin! temperature - temperature of !as as it e(its the

first sta!e no00le

Speedtronic limits this firin! temperature

Firin! temperature is calculated by thermodynamic relation ships GT performance calculations1 and site conditions as a function of )(haust Temp%T(& and C>#

fuel

TCair

3SO F3R3,G T)M> TC

sothermalC o n s t " i r i n g T e m p 2 1 i n e a r i B e d 3

Compressor Discharge Pressure 2CPD3 E C h a u s t t e m p e r a t u r e 2 T C 3



28/55


Firin! temperature can also be appro(imated as a function of T( and Fuel flow %FSR& and

as a function of T( and Generator M@ output

'ine of constant firin! temperature are used in controlsoftware to limit the !as turbine operatin! temp

whereas the constant e(haust temperature limit protects the

e(haust system durin! start-up

T( 7 TB 7 TC

T( TB TCsothermalC o n s t " i r i n g T

e m p 2 1 i n e a r i B e d 3

"uel Stro=e Reference 2"SR3 E C h a u s t t e m

p e r a t u r e 2 T C 3

E h t T t l ftE h t T t l ft


29/55

Ehaust Temp control softwareEhaust Temp control software

Series of application pro!rams written to

perform critical e(haust temperature control and monitorin!

Major function is

N )(haust temperature control

Software is >ro!rammed for

Temperature control command

Temperature control bias calculations

Temperature reference selection

Temperature Control SchematicTemperature Control Schematic


30/55

Temperature Control SchematicTemperature Control Schematic

TT8DRS4RTS4RT

)G)EST)G)EST

T4T4

149EST149EST

TT8D>TT8D>

6RST7

(;ER(GE(;ER(GE

REM(!!GREM(!!G

REECTREECT

)G))G)

(!D(!D

149149

REECTREECT

149149

TCsTCs

TT8DS

TT8M

To Comb5

Monitor TT8DT

F&(!TT:F&(!TT:6RST76RST7

3f O,) Controller should fail1 this

pro!ram i!nore the readin!s from the

failed Controller TTDM is based on

remainin! controllers thermocouples

Alarm will be !enerated

of TCs &sedof TCs &sed

S4T)ERM(1

C4R!ER

C4R!ER

S14PE

S14PEM!5M!5

SE1ECTSE1ECT

%

%

%

%

"SRM!

"SRM(8

TTR8B

TT8M

"SR

G(!

-

MED(!MED(!

SE1ECTSE1ECT

Temperature ControlTemperature Control 6RST76RST7

CPD

"SR

"SRT

Temp Control Ref Temp Control Ref

The temp-control-command pro!ram in


31/55

Temperature Control Bias programTemperature Control Bias program

TTHnICTTHnIC

TTHnITTHnI

T T H n IB

T T H n IB T T H n I

M

T T H n IM

TTHnIHTTHnIHsothermalsothermal

" S R B ( S

" S R B ( S

C P D B (

S

C P D B (

S

E C h

u a s t

T e m

p e r a

t u r e

CPD

"SR

Ehaust Temp Control Setpoints

DGT(1

!P&T

D(T(

C4MP&TER

MEM4R:

TEMPER(T&RE

C4!TR41

B(S

PR4GR(M

C4MP&TER

MEM4R:

C4!ST(!T

ST4R(GE

SE1ECTED

TEMPER(T&RE

RE"ER(!CE

T(B1E

Temperature Control BiasTemp control ias pro!ram calculates the )(haust

temp control setpoint TTRD based on C># datastored in computer memory and constants from the

selected temp-reference table

This >ro!ram also calculates another setpoint based

on FSR and constants from another temperature-

reference table

TTnPC %C># bias corner& and TTnPS %C># bias slope&

are used with the C># data to determine the C>#bias e(haust temperature setpoint

TTnP %FSR bias corner& and TTnPM %FSR bias slope&

are used with the FSR data to determine the FSR

bias e(haust temperature setpoint

>ro!ram also selects isothermal setpoint"inal temp control Ref'M!2"SR biasJ CPD biasJ sothermal setpoint 2TTHnI"inal temp control Ref'M!2"SR biasJ CPD biasJ sothermal setpoint 2TTHnI

Temperature Control Bias ProgramTemperature Control Bias Program


32/55

Temperature Control Bias ProgramTemperature Control Bias Program This >ro!ram selects the minimum of the three set points1 C># bias1 FSR bias1 or

isothermal setpoint for the final e(haust temperature control reference

#urin! normal operation with Gas or li!ht #istillate fuels1 this selection results in a C>#

bias control with an isothermal limit

C># bias setpoint is compared with the FSR bias setpoint by the pro!ram and an alarm

occurs when the C># setpoint e(ceeds the FSR bias setpoint

#urin! normal operation with 6eay fuels1 FSR bias setpoint will be selected to minimi0e

the turbine no00le plu!!in! on firin! temperature

FSR bias setpoint is compared with C># bias setpoint and an alarm occurs when the

FSR bias setpoint e(ceeds the C># bias setpoint

A ramp function is proided in the pro!ram to limit the rate of setpoint chan!e oth Ma(

%TTRDR4& and Min %TTRDR& chan!e in ramp rates %slopes& are pro!rammedTypical

rate chan!e limit is 4:de! F

The output of this ramp function is the )(haust tempcontrol setpoint which is stored in the

computer memory

Temperature Reference Select ProgramTemperature Reference Select Program


33/55

Temperature Reference Select ProgramTemperature Reference Select Program

)(haust temperature control function selects control set points toallow GT operation at firin! temperatures

Temperature-control-select pro!ram determines the operationalleel for control set points based on #i!ital input informationrepresentin! temperature control re+uirements

Three di!ital input si!nals are decoded to select one set ofconstants which defines the control set points necessary to meet

the demand

Typical di!ital si!nals areAS) S)')CT1>)A S)')CT and

6)A? F")' S)')CT

Q @hen appropriate set of constantsare selected they are stored in theselected-temperature-referencememory

Constant

Storage

Temperature

Reference

Select

Digital

nput Data

Selected

Temperature

Reference

Table

TemperatureTemperature

ReferenceReference

Select ProgramSelect Program

"uel Control system"uel Control system


34/55

"uel Control system"uel Control system

Turbine fuel control system will chan!e fuel flow to the combustors

in response to the fuel stro$e reference si!nal%FSR&

FSR actually consists of two separate si!nals added

to!ether

FSR FSR4 FSR

FSR4 Called-for li+uid fuel flow

FSR Called-for !as fuel flow

Standard fuel systems are desi!ned for operation with 'i+uid

fuel and2or !as fuel

SerAo DriAe SystemSerAo DriAe System


35/55

SerAo DriAe SystemSerAo DriAe System

SerAo driAe System


36/55

SerAo driAe System The heart of Fuel Control System

H coil )lectro 6ydraulic Sero ?ale

Sero ale is the interface between the electrical andmechanical systems

Sero ale controls the direction and rate of motion of ahydraulic actuator based on the input current to the sero

Sero ale contains three electrically isolated coils on thetor+ue motor

)ach coil is connected to one of the three controllers


37/55

1i$uid "uel System1i$uid "uel System'i+uid Fuel system consists of

Fuel handlin! components N >rimary fuel oil filter %low pressure&

N Fuel oil stop ale - Fuel pump

N Fuel bypass ale - Fuel oil pressure relief ale

N Secondary fuel oil filter %6i!h pressure&

N Flow diiders - Combined Selector ale

N False start drain ale- Fuel lines / fuel no00les

)lectrical Control components

N 'i+uid fuel press sw %upstream& 9HF'- N Fuel oil stop ale limit sw HHF'

N Fuel pump clutch solenoid 7CF

N 'i+uid fuel pump bypass ale Sero ale 9:F>

N Flow diider ma!netic pic$ups JJF#-411H and

N Speedtronic Control cards TCC and TCA

1i$uid "uel System PKD1i$uid "uel System PKD


38/55

1i$uid "uel System PKD1i$uid "uel System PKD

6RST7

Conn5"or Purge

9hen Re$uired

(tomiing(ir

Typical

"uel !oles

Combustion

Chamber

"FR4&T

"F*

TCF(

TCFC

L@"1%>

4"

"uel

Stop

;alAe

4";

Diff Press

Guage

"SR*

T!)1-

1>+"18

6RST7 6RST7

TCF(

PR#(

To Drain

"alse Start

Drain ;alAe

Chamber 4"D

(D

//"D%*

//"D%>

//"D%@

By%pass ;alAe (sm

(ccessory

Gear

DriAe

Main "uel Pump

"low

DiAider

@@"1

41T%

Control

4il

;R-

L."P

"uel oil Control % Software"uel oil Control % Software


39/55

"uel oil Control Software"uel oil Control SoftwareControl system chec$s the permissie '5 and '7F'D to allow FSR4

for closin! the ypass ale %closin! bypass ale sends fuel tothe combustors&

These si!nals control the openin! and closin! of the fuel oil stop ale Fuel pump clutch solenoid %7CF& is ener!ised to drie the pump when

the Stop ale opens

Fuel splitter al!orithm ensures re+uisite FSR when FSR4 is actie

FSR4 is multiplied by T,6 - to ma$e it a function of speed %animportant parameter of Turbine& to ensure better resolution at the lower1 more critical speeds where air flow

will be low ,et result is FRO"T- a di!ital li+uid fuel flow command At Full speed1 T,6 does not chan!e

Therefore FRO"T FSR

"uel oil Control % Software"uel oil Control % Software


40/55

"uel oil Control Software Analo! si!nal is conerted to di!ital counts and is used in the

controllersL software to compare to certain limits as well as for

display in CRTThe chec$s performed by software pro!ram

'97FF'6 - )(cessie fuel flow on start-up

'H'F'T - 'oss of '?#T position feedbac$

'H'FS - ypass ale is not fully open when the stop ale

is closed 'H'FSC - Sero Current is detected when stop ale is closed

'H'FT - 'oss of flow diider feedbac$

%'97FF'6 persists for sec and this fault initiates trip1 'H'FT also initiates trip

durin! start-up&

"uel Gas System"uel Gas System


41/55

yy

Fuel !as is controlled by Gas Speed ratio2stop ale %SR?& Gas Control ?ale %GC?&%oth are sero controlled by si!nals from Speedtronic control panel and

actuated by sprin! actin! hydraulic cylinders moin! a!ainst sprin!-loaded ale plu!s&

GC? controls the desired !as fuel flow in response to the

FSR command si!nal SR? is desi!ned to maintain a predetermined pressure %>&at the inlet of the GC? as a function of turbine speed

SR; GC;

P* P> P@

"uel Supply To Turbine

"uel Gas System"uel Gas System


42/55

yy

Gas Fuel System consists of

Fuel handlin! components

N Gas Strainer - Speed Ratio2Stop ?l assembly

N Control ale assembly - #ump ales

N Three pressure !au!es -

N Gas manifold with Lpi!tailsL to respectie fuel no00les

)lectrical control components N Gas supply press sw 9HFG - Fuel !as press (ducer%s& ;9FG

N Gas fuel ent sol ale 7?G -'?#Ts ;9GC-41 / ;9SR-41

N )lectro hydraulic sero l ;7SR / 9:GC

N Speedtronic control cards T and TCC

"uel Gas System PKD"uel Gas System PKD


43/55

yy

TCFC

SPEED R(T4

;(1;E C4!TR41

TCFC

G(S

C4!TR41

;(1;E SER;4

TCFC

G(S C4!TR41

;(1;E P4ST4!

"EEDB(CH

TBFB

Stop

Ratio

;alAe

G(S

L@"G%@

"PRG

P4S>

"PG

P4S*

"SR>

0L"G%>(

0L"G%>C

0L"G%>B

;E!T

Gas

Control

;alAe

C4MB&ST4!C)(MBER

TR(!SD&CERS

G(S

M(!"41D

P>

>+

;G

0+SR SER;4 0+GC SER;4

) draulic Su l

1;DTS0LGC%*5>

1;DTS0LSR%*5> TRP

;h.%* Dump Relay

Gas Control ;alAeGas Control ;alAe


44/55

Gas Control ?ale GC? position is proportional to FSR%Actuation of sprin!-loaded GC? is by a hydraulic cylinder controlled by an

)lectro-hydraulic sero ale& GC? will open only when permissie '51 '7FGD and 'T?D

%pur!e complete& are true N Stro$e of the ale is proportional to FSR

"SR

SerAo

;alAe

GC;G(S

P>

1;DTS

0LGC %*J%>

(nalog

#4

))

SE1SE1

"SR4&T

TBFC6RST7

4""SET

G(!

"SR>

1-

1@GC;

6RST7

GC; Position 1oop

Calibration

1 ; D T

P o s i t i o n

FSR !oes throu!h Fuel splitter al!orithm

TCC conerts FSRO"T to an analo! si!nal

GC? stem position is sensed by '?#Ts andfed bac$ to an op-amp on TCC card to compare

with FSRO"T input si!nal at summin! junction

Op-amp on TCC conerts error si!nal and sends

to sero ale to drie GC? accordin!ly

Speed Ratio#Stop ;alAeSpeed Ratio#Stop ;alAe


45/55

p pp p

"PRG

6RST7

)SE1 P4S>

#

A

4""SET

G(!

1-

1@GC;

6RST7T!)

-

TBFB

Analo!

32O

Module

0L"G%>B0L"G%>C

0LSR%*J>

0L"G%>(

Op Cyl

>osn

G(S

Dump

RelayTrip Oil

SR;

1;DTs

SerAo

;alAe6ydraulic

Oil

"PG

>

T,6

SR; Pres Calibration

3t is dual function ale %3t seres as a pressure re!ulatin! ale to hold a

desired fuel !as pressure ahead of GC?&

As a Stop ?ale- inte!ral part of protection system

Speed Ratio2Stop ?l has Two control loops >osition loop similar to GC? >ressure control loop

Q Fuel !as pressure > at the inlet of GC? iscontrolled by the pressure loop as a function of

turbine speed %in proportion to the turbine speed

T,6& to become Gas fuel press Ref F>RGQ TCC card conerts F>RG to analo! si!nal>

%F>G& is compared to the F>RG and the error

si!nal is in turn compared with the ;9SR '?#T

feedbac$ to reposition the ale as in GC? loop

N #urin! a trip or no-run condition1 a posie olta!e

bias is placed on sero coils holdin! them in the

Uale closedV position

> F>G,G ( T,6 F>G,O

GC; K SR; schematicGC; K SR; schematic


46/55

GAS CO,TRO' ?A'?)

COMMA,#

G(S

C4!TR41

;(1;E

4&TP&T

GAS F")' R)F)R),C)SER;4

4&TP&T

FRO"T

GAS CO,TRO' ?A'?) >OS3T3O,

G(S "&E1 C4!TR41 ;(1;E

S>))# RAT3O ?A'?)

COMMA,#

G(S

C4!TR41

;(1;E

4&TP&T

S>))#

SER;4

4&TP&T

R)"3R)# >R)SS"R)

M3#?A'?) GAS F")' >R)SS"R)

S>))# RAT3O ?A'?) >OS3T3O,

G(S R(T4 ;(1;E C4!TR41

Duel "uel ControlDuel "uel Control


47/55

Turbines desi!ned to operate on both li+uid and !aseous fuelsystems are e+uipped with Control software accordin!ly

Control software performs the followin!I N Transfer of one fuel to other on command N Allow time for fillin! lines with the type of fuel to which turbine operation is

bein! transferred N Mi(ed fuel operation N Operation of li+uid fuel no00le pur!e when operatin! totally on !as fuel

Software pro!rammin! inolesI Fuel splitter Fuel transfer- 'i+uid to Gas 'i+uid fuel pur!e Fuel transfer-Gas to 'i+uid Mi(ed fuel operation lo!ics and al!orithms

"uel splitter % software"uel splitter % software


48/55

FSR is splitter into two si!nals FSR4 / FSR to proidedual fuel operation

A

6RST76RST7

"&E1 SP1TTER"&E1 SP1TTER 1?-TG

Total Ga

1?-T1

Total 1FM(851MT

M!51MT

MED(!MED(!SE1ECTSE1ECT

R(MP

1?@"G

Gas Select

1?@"1

1i$uid Select

1?@"<

PermissiAes

Rate

"SR

1F Ref"SR*"SR*

"SR>"SR>

G(S Ref

A

"SR is multiplied by the li$uid fuel

fraction "8* to produce "SR*signal

"SR* is then subtracted from the"SR signal to generate "SR> signal

"SR ' "SR* "SR>"SR ' "SR* "SR>

"uel Transfer % 1i$uid to GasJ Gas to 1i$uid"uel Transfer % 1i$uid to GasJ Gas to 1i$uid


49/55

Transfer from "ull Gas to "ull 1i$uid

Transfer from "ull 1i$uid to "ull Gas5

Transfer from "ull 1i$uid to Miture5

& ! T S

& !

T S

S)')CT #3ST3''AT)

>"RG)

"SR*

TMETME

& ! T S

& ! T S

>"RG)

"SR>

& ! T S

& ! T S

>"RG)

"SR>

S)')CT GAS

S)')CT GAS

FSR4

FSR4

FSR

TMETME

TMETMESELECT MIX

"uel transfer from 1i$uid to GasGT runnin! on 'i+uid %FSR4& and GAS transfer

selectedFSR4 will remain at its initial alue1

FSR will step-up to sli!htly !reater than

.ero alue %7:8& This opens the GC?

sli!htly to bleed down the inter ale olume

The presence of a hi!h pressure than thatre+uired by the SR? would cause slow

response in initiatin! !as flow

After delay of H7 sec to bleed down the >

pressure and fill the !as supply line1 the

software pro!ram ramps the fuel commands

FSR to increase and FSR4 to decrease at

a pro!rammed rate throu!h median select

!ate Fuel transfer completes in H7 sec

"uel Control System"uel Control System


50/55

1i$uid fuel Purge

To preent the co$in! of the li+uid fuel no00lesMied fuel 4peration

Gas Turbine can be operated on both GAS / '3 in any

proportion when operator choses to be on M3D mode

'imits of fuel mi(ture are re+uired to ensure proper combustion1!as fuel distribution and !as no00le flow elocities

8 of !as flow must be increased as load is decreased to

maintain the minimum pressure ratio across the fuel no00le

Modulated nlet Guide ;ane SystemModulated nlet Guide ;ane System


51/55

3G? system an!-an! type % position&

Modulated 3G? modulates durin!

acceleration of turbine at rated speed1

loadin! and unloadin! of the !enerator

deceleration of !as turbine

3G? modulation maintains proper flows and pressures1 and thus the stresses in the compressor Maintains minimum pressure drop across fuel no00les in Combined cycle operations maintains hi!h e(haust temperatures at

low loads

Modulated nlet Guide ;ane ControlModulated nlet Guide ;ane Control


52/55

):D5

S&PP1:

6RST7

;)@%*

4R"CES 2>3

41T%*TRP 41C

(

C>

!

4

&

T

")L

%*

> *

4D

D

R P

)M @%*

C14SEC14SE

4PE!4PE!

0+T;%*

CSRG;

6RST7

CSRG; G;

RE"D#(

CSRG;4&T

)G)

SE1ECT

(nalog

#4

G; 4perationN

#urin! start-up 3G? is fully closed %H5W&

from 78 to BH8 of corrected speed

Turbine speed is corrected to reflect the air

conditions at B7WF1 this compensates

for chan!es in air density as ambient conditions

chan!e

At AmbTemp =B7WF T,6COR < T,6

At AmbTemp


53/55

"or Simple Cycle operation

3G? moe to full open position at pre-selectede(haust temperature1

usually J77WF

"or Combined Cycle operationJ

3G? be!ins to moe to full open pos

as e(htemp approaches Temp

Control ref temperature

%,ormally 3G?s be!in open when T( is within

H7WF of temp control Ref&

"uel 4pen Ma5 (ngle

Simple Cycle

2CSHG;SSR3

Combined

Cycle

2TTR83

M! "ull Speed (ngle

Startup

ProgramRegion 4f !egatiAe

.th Stage Etraction

Pressure

Corrected Speed %,

2T!C)4R3

+ *++

+ *++

"S!1 B(SE 14(D

E8)&(ST TEMPER(T&RE

G ;

( ! G 1 E

% D E

G 2

C S R G ; 3 3

y not allowin! the !uide anes to close to an an!le less than thanthe min full speed an!le at 4778T,61 a min press drop is maintained

across the fuel no00les1 thereby lessenin! combustion systemresonance

G; Control SchematicG; Control Schematic


54/55

nlet

Guide

;aneRef5

SerAo

4utput

G;

Part

Speed

Ref5

Temp5 Control"eedbac=

Temp5 Control

Reference

Manual

Command

G; Part Speed Ref5

Compressor

nlet Temp5

Speed

G; Position

G; Reference

G;

Command

9et 1ow !4 Control9et 1ow !4 Control


55/55

Select

I

nOection

"low

Steam

"low

nOection

"low

Gas

"low

Dead band

Controller

Gas dP

Gas Press

Gas Temp

Gas "uel "low

1i$ "uel "low

)umidity

Power (ugmentation

"low

BasicnOection "low

1ower

nOection "low

Re$uired

nOection

"low

Steam

9ater "low

Steam Press

Steam Temp

Documents

Gas Turbine Philosophy