Gas Turbine30.06.09.ppt

30 June 09

VMG/AG1 of 119

GAS TURBINES

Vivek GhateGMS – CPP

[email protected]

30 June 09

VMG/AG2 of 119

Index

1. Basics of Gas Turbines.

2. Major Components of Gas Turbines.

3. Categories of Gas Turbines.

4. Performance Comparison of various makes of Gas

Turbines.

5. GE’s range of Gas Turbines.

6. Factors affecting the performance of Gas turbines.

7. Gas Turbines at RIL.

8. Maintenance factors of Gas Turbines based on the

fuel used.

9. The Hot gas path components & its metallurgy.

10. Gas Turbine Control Systems.

11.Performance Benchmarking.

30 June 09

VMG/AG3 of 119

GAS TURBINE

A gas turbine, also called a combustion turbine, is a rotary engine that extracts energy from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamber in-between.

30 June 09

VMG/AG4 of 119

GAS TURBINEBy heating up compressed air, expanding it in

nozzles mechanical/rotational energy is obtained.

Buckets

30 June 09

VMG/AG5 of 119

Brayton Cycle

30 June 09

VMG/AG6 of 119

Ideal Brayton cycle:

• (1-2) Isentropic Compression - Ambient air is drawn into the compressor, where it is pressurized.

• (2-3) Isobaric Process - The compressed air then runs through a combustion chamber, where fuel is burned, heating that air—a constant-pressure process, since the chamber is open to flow in and out.

• (3-4) Isentropic Expansion - The heated, pressurized air then gives up its energy, expanding through a turbine (or series of turbines). Some of the work extracted by the turbine is used to drive the compressor.

• (4-1) Isobaric Process - Heat Rejection (in the atmosphere).Actual Brayton Cycle:

• Adiabatic process - Compression.• Isobaric process - Heat Addition.• Adiabatic process - Expansion.• Isobaric process - Heat Rejection.

30 June 09

VMG/AG7 of 119

GT Cutaway Showing Casing Cross Section

30 June 09

VMG/AG8 of 119

Simple Cycle Single Shaft Gas Turbine

• Compressor & Turbine are coupled to common single shaft.• Normally used in process where less speed variation is required.• Due to larger rotor mass the speed can be easily kept constant.• Extremely suitable for generator drives.

30 June 09

VMG/AG9 of 119

Simple Cycle Two Shaft Gas Turbine

• In 2 shaft machines turbine is divided into High Pressure (HP) turbine & Low Pressure (LP) turbine.• HP turbine & compressor are attached to one shaft & LP turbine is attached to another shaft.• These machines provide wide speed range with sufficient power & efficiency.• Well suited for mechanical drives & compressors.

30 June 09

VMG/AG10 of 119

Open Cycle Gas Turbine Typical Performance

30 June 09

VMG/AG11 of 119

Combined Cycle Power Plant

30 June 09

VMG/AG12 of 119

Cogen Cycle Power Plant

30 June 09

VMG/AG13 of 119

Gas Turbine Major

Components

30 June 09

VMG/AG14 of 119

Gas Turbine Major Components

Compressor

Turbine

Combustion chamber

Starting means

30 June 09

VMG/AG15 of 119

COMPRESSOR• 17 stage axial flow compressor. • Extractions 5th stage: bearing cooling and sealing air.• 11th stage: Air bleed valves for surge control.• 17th stage: Atom air compressor and pulse air.

TURBINE• 3 Stage Impulse Turbine

COMBUSTION CHAMBER

• 10 combustors in annular space.• 2 nos. Igniters in combustor no 1 & 10.• 4 nos. Flame scanners in the combustor no 2,3 & 7,8.

Gas Turbine Major Components

30 June 09

VMG/AG16 of 119

Gas Turbine Major Components

GT ANNULAR FIRING

CROSS FIRE TUBE

2+3+7+8 HAVE SCANNERS 1&10 HAVE IGNITORS

30 June 09

VMG/AG17 of 119

Categories of Gas Turbines

30 June 09

VMG/AG18 of 119

GAS TURBINE CATEGORIES

The Simple Gas Turbine is classified into five broad groups:

Frame Type Heavy - Duty Gas Turbines: Large power generation units ranging from 3 MW to 480 MW in a simple cycle configuration. Efficiency – 30 to 39 %.

Aircraft - Derivative Gas turbines: These are power generation units, which are prime mover of aircraft in the aerospace industry. Efficiency – 35 to 45%.

Industrial Type - Gas Turbines: In the range of 2.5-15 MW. Used extensively for compressor drive trains. Efficiency – Less than 30%.

Small Gas Turbines: In the range from about 0.5-2.5 MW. They often have centrifugal compressors & radial inflow turbines. Efficiency – 15 to 25%.

Micro - Turbines: In the range from 75 - 650 kW. Efficiency – 15 to 20%.

30 June 09

VMG/AG19 of 119

Frame Type Heavy - Duty Gas Turbines

Gas Turbines up to 20 MW.

Various Manufacturers are:

Solar Turbine Rolls Royce Siemens MHI GE

30 June 09

VMG/AG20 of 119

MODEL MakeOutpu

t (MW)

Heat Rate(kcal/kwh)

Efficiency%

Pressure

Ratio

Turbine

Speed(rpm)

Flow(kg/sec)

Exhaust

Temp (C)

Saturn 20

Solar 1.2 3535 24.3 6.82251

66.55 504

501-KB5S

Rolls Royce

3.897 2960 29.1 10.31420

015.4 560

SGT 100

Siemens 4.35 2865 30 131650

017.7 527

MF-61 MHI 5.925 3001 28.7 8.41540

027.3 496

Mars 100

Solar 10.69 2650 32.5 17.41116

842 488

LM1600PE

GE14.89

82544 33.8 21.3 7900 49.8 479

SGT 500

Siemens 17 2671 32.2 12 3000 92.5 375

UGT-15000+

ZoryaMashpro

ekt20 2389 36 19.4 3000 72.2 412

Gas Turbine

30 June 09

VMG/AG21 of 119

Gas Turbine

Gas Turbines up to 60 MW.

Various Manufacturers are:

Rolls Royce Siemens Alstom IHI Mitsubishi

30 June 09

VMG/AG22 of 119

Rolls Royce Gas Turbine

MODEL YEAR

ISO BASE

RATING(MW)

HEAT RATE(kcal/kwh)

EFFICIENCY%

PRESS

RATIO

FLOW(kg/sec)

TURBINE

SPEED(rpm)

EXHAUST

TEMP(Deg C)

RB211 6761 DLE

2000

32 2188 39.3 21.5 94.55 4850 503.33

TRENT 60 DLE

1996

51 2043 42 33151.8

23000 444.44

TRENT 60 WLE

2001

58 2104 40 36165.9

13000 423.33Siemens Gas

Turbine

MODELYEA

R

ISO BASE

RATING

(MW)

HEAT RATE(kcal/

kwh)

EFFICIENCY

%

PRESS

RATIO

FLOW(kg/

sec)

TURBINE

SPEED(rpm)

EXHAUST

TEMP(Deg C)

SGT 700

1999

29.062389.7

236 18 91.36 6500 517.78

SGT 800

1998

452322.9

134 19.3

130.45

66001093.8

9

SGT 900

1982

49.52634.2

332.7 15.3

175.45

5425 513.89

30 June 09

VMG/AG23 of 119

IHI Gas Turbine

MODELYEA

R

ISO BASE

RATING(MW)

HEAT RATE(kcal/

kwh)

EFFICIENCY

%

PRESS

RATIO

FLOW(kg/

sec)

TURBINE

SPEED(rpm)

EXHAUST

TEMP(Deg C)

LM 6000 PC SPRINT

1997

46 2123.3 40.5 30130.4

53000 445

LM 6000 PD SPRINT

1997

45.48 2123.5 40.5 30130.9

13000 450Mitsubishi Gas

Turbine

MODELYEA

R

ISO BAS

E RATING

(MW)

HEAT RATE(kcal/

kwh)

EFFICIENCY

%

PRESS

RATIO

FLOW(kg/

sec)

TURBINE

SPEED (rpm)

EXHAUST

TEMP(Deg C)

MF221 199

430

2689.69

32 15108.1

87200 532.78

30 June 09

VMG/AG24 of 119

Gas Turbines more than 60 MW

30 June 09

VMG/AG25 of 119

Alstom Gas TurbineMODE

LYEA

R

ISO BASE

RATIN

G(MW)

HEAT RATE(kcal/kwh)

EFFICIENCY%

PRESS

RATIO

FLOW(kg/sec)

TURBINE

SPEED (rpm)

EXHAUST

TEMP(Deg C)

GT8C21998

56.3 2722 33.9 17 197 6219 508

GT11N2

1993

115.4 2559 33.6 16 400 3000 531

GT13E2

1993

172.2 2363 36.4 15 538 3000 522

GT261994

288 2246 38.3 32 633 3000 615

30 June 09

VMG/AG26 of 119

Ansaldo EnergiaMODE

LYEAR

ISO BASE

RATIN

G(MW)

HEAT RATE(kcal/kwh)

EFFICIENCY%

PRESS

RATIO

FLOW(kg/sec)

TURBINE

SPEED(rpm)

EXHAUST

TEMP(Deg C)

V64.3A

1996 68.5 2364.51 34.7 15.8 191.4 3000 588.89

V 94.2 1981 166 2500.63 34.4 11.8 510.0 3000 546.11

V 94.3 A2

1995 272 2233.43 38.5 17.4 657.3 3000 575.00

V 94.3 A4

2004 279 2200.66 39.1 17.7 668.2 3000 577.22Mitsubishi Gas Turbine

Model

Type

ISO BASE

Eff Heat Rate

Pressure

Flow Turbin

eExhaus

t

RATING %(kcal/kwh)

Ratio(kg/sec)

Speed Temp

(MW)       (rpm)(Deg

C)

M701 SC 144 34.8 2473 14 442 3000 542

M701F

CC 273+142 59 1464 17 651 3000 600

M701G

SC 334 39.5 2175 21 739 3000 587

30 June 09

VMG/AG27 of 119

Siemens Gas Turbine

MODELYEA

R

ISO BASE

RATIN

G(MW)

HEAT

RATE(kcal/kwh)

EFFICIENCY%

PRESS RATIO

FLOW(kg/sec)

TURBINE

SPEED (rpm)

EXHAUST

TEMP(Deg C)

SGT 1000F

1996

67.72452.

7435.1 15.8

191.82

5400 582.78

SGT 5 2000E

1981

163.32496.

8534.5 11.8

528.18

3000 542.22

SGT 6 3000E

1997

188.22359.

4736.5 13.4

520.00

3000 581.11

SGT 6 4000F

1995

2782199.

9039 17.2

672.27

3000 582.22

SGT 5 3000E

1997

2901509.

0354.9 (CC) 3000

SGT 5 4000F

1995

4071434.

9757.7 (CC) 3000

30 June 09

VMG/AG28 of 119

GE’s range of Gas Turbines

30 June 09

VMG/AG29 of 119

Model Type

O/P(M

W)

Freq(Hz)

Kcal/

kwh

MS9001H

CC 520 501434.

3

MS9001FB

SC 412.9 501481.

2

MS9001FA

CC 390.8 501517.

5

SC 255.6 502331.

7

MS9001E

CC 193.2 501656.

2

SC 126.1 502546.

0

MS6001FA

CC 117.7 501573.

0

CC 75.9 502460.

3

MS6001B

CC 64.3 501752.

0

SC 42.1 502682.

6

MS6001C

CC 67.2 501583.

3

SC 45.4 502348.

1

The world demands a reliable supply of clean, dependable power. GE offers a wide array of technological options to meet the most challenging energy requirements.

GE Heavy Duty Gas Turbine

30 June 09

VMG/AG30 of 119

GE H-System

First gas turbine ever to achieve the milestone of 60% fuel efficiency.

30 June 09

VMG/AG31 of 119

109H System Combined Cycle Power Plant

520 MW; Single shaft.

Firing Temperature Class: 1430˚C (2600˚F)

Heat Rate: 1435 kcal/kwh.

Efficiency: 60%

18 Stage Compressor; 23:1 Pressure Ratio;

Airflow 687 kg/sec.

NOx emissions: < 25 ppm.

Steam Turbine: GE design; Reheat, Single flow

exhaust.

Generator: GE 550 MW LSTG; 660 MVA Liquid

cooled.

HRSG: 3 Pressure level reheat.

S 109H

30 June 09

VMG/AG32 of 119

The F Class Comparison

  GE (MS9001

FA)

Siemens

(SGT5-4000F)

Alstom

(GT26)

SIMPLE CYCLEOutput 255.6 MW 278 MW 288 MW

Heat Rate 2332 kcal/kwh 2200 kcal/kwh

2246 kcal/kwh

Efficiency 36.90% 39.10% 38.3%

Pressure Ratio 17 17.2

32

Flow 642.2 kg/sec 672.2 kg/sec 633 kg/sec

Exhaust Temp. 602 Deg C 582 Deg C

615 Deg C

COMBINED CYCLEOutput 390.8 MW 407 MW 410 MW

Heat Rate 1517.5 kcal/kwh 1435 kcal/kwh

1488 kcal/kwh

Efficiency 56.70% 57.70% 57.8%

30 June 09

VMG/AG33 of 119

H Class Comparison

  GE (S109H)

Siemens

(8000H)

Combined Cycle

Output 520 MW 530 MW

Heat Rate 1435 kcal/kw

h

1435 kcal/kwh

Efficiency 60 % 60 %

Pressure Ratio

23 19.2

Flow 687 kg/sec 820 kg/sec

30 June 09

VMG/AG34 of 119

GE Aero derivative Gas Turbine

30 June 09

VMG/AG35 of 119

MODELOUTPUT

(MW)

HEAT RATE(kcal/kwh)

PRESSURE

RATIO

TURBINE

SPEED(rpm)

FLOW(kg/sec)

EXHAUST TEMP.

(C)

LMS100PA 102.9981960.4

2 41.01 3000 213 407

LMS100PB 98.441906.4

8 40 3000 207 417

LM6000PC sprint 50

2132.85 31.5 3627 137 434

LM6000PC 42.892060.2

5 29.2 3627 129 436

LM6000PD sprint 46.9

2085.20 30.9 3627 132 446

LM6000PD 41.72110.9

2 29.3 3627 127 448

LM2500RC 32.912238.4

7 28.5 3600 92 524

LM2500RD 32.682243.7

6 23 3600 91 525

LM2500PH 26.462186.2

9 23 3000 76 497

GE 10 - 2 11.982 2557 15.5 11000 47 480

GE Aero derivative Gas Turbine

30 June 09

VMG/AG36 of 119

Factors Affecting the Gas Turbine

Performance

30 June 09

VMG/AG37 of 119

Gas Turbine Performance

Influences on Gas Turbine

Output:

Compressor Fouling Size Influence Thermodynamic Influence Ambient condition Influence GT Speed Inlet & Exhaust Pressure Loss

30 June 09

VMG/AG38 of 119

Fouling rate is a function of

Environment

Wind Direction

Filtration System

Compressor Fouling

30 June 09

VMG/AG39 of 119

Size Influence

Greater Dimensions

Higher Air flow

Higher Output

30 June 09

VMG/AG40 of 119

Mainly determined by the design of the engine

Main Component Efficiency Compressor Pressure Ratio Turbine Inlet Temperature

The combination of gas temperature and pressure ratio gives a specific output, exhaust temperature and thermal efficiency, which also are influenced by the components efficiency.

Thermodynamic Influence

30 June 09

VMG/AG41 of 119

Ambient Conditions Influence

Ambient Air Pressure (P0)Ambient Air Temperature (T0)Ambient Air Relative Humidity (RH)

The gas turbine nominal performance is related to:P = 1,013 barT = 15°CRH = 60%

Ambient Conditions Influence

30 June 09

VMG/AG42 of 119

At constant gas temperature INCREASED ambient air pressure gives:

Increased OutputUnchanged Unit Efficiency

Ambient Air Pressure (PO)

The air density reduces

as the site elevation

increases. While the resulting airflow and

output decrease proportionately,the heat rate and

other cycle parameters are

not affected.

30 June 09

VMG/AG43 of 119

The gas turbine is an air-breathing engine, its performance is changed by Air Temperature that affects the density or mass flow of the air intake to the compressor.

The following graph shows effect of Ambient Air temperature on output, heat rate, heat consumption, and exhaust flow.

Ambient Air Temperature (TO)

30 June 09

VMG/AG44 of 119

At constant gas temperature, INCREASED ambient air relative humidity gives:

Decreased Output

Ambient Air Relative Humidity

Humid air, which is less dense than dry air, affects output and heat rate, as shown in Graph.

30 June 09

VMG/AG45 of 119

GT - MW change with speed at different ambient temperature range

32.433.15

33.7534.35

34.9535.4 35.7 35.925 36 36.075 36.075

3030.75

31.532.1

32.733.3 33.6 33.9 34.05 34.2 34.35

28.8

29.62530.3

30.97531.65

32.25 32.55 32.85 33.075 33.3 33.45

27.628.35

29.129.85

30.4531.05

31.5 31.8 32.1 32.34 32.46

26.47527.225

27.97528.65

29.430

30.45 30.75 31.05 31.35 31.5

25.3526.1

26.8527.6

28.228.875

29.4 29.7 30 30.3 30.6

24.324.975

25.6526.4

27.1527.75

28.228.65 29.025

29.325 29.55

23.17523.925

24.625.35

26.02526.7

27.1527.6

27.975 28.35 28.65

22.12522.8

23.5524.3

24.925.575

26.126.55

27 27.3 27.6

202122232425262728293031323334353637

95 96 97 98 99 100 101 102 103 104 105

speed %

MW

5degC 15degC 20degC 25degC 30degC35degC 40degC 45degC 50degC

Ref: GE perf.curveGTF6SP

GT Speed

30 June 09

VMG/AG46 of 119

Inlet & Exhaust Pressure Loss

Pressure Drop Effects for Frame -

6:

4 Inches H2O Inlet Drop Produces:

• 1.50% Power Output Loss• 0.50 % Heat rate Increase• 1.2 Deg F Exhaust temperature increase.

4 Inches H2O Exhaust Drop Produces:

• 0.50% Power Output Loss• 0.50 % Heat rate Increase• 1.2 Deg F Exhaust temperature increase.

30 June 09

VMG/AG47 of 119

Gas Turbines with

RELIANCE

30 June 09

VMG/AG48 of 119

MODEL MakeOutput (MW)

Heat Rate(kcal/kwh)

Efficiency%

Pressure Ratio

Turbine Speed(rpm)

Flow(kg/sec)

Exhaust

Temp (0C)

GE 10 - 2

GE 11.982 2557 33.3 15.5 11000 47 480

Fr - 5 GE 26.30 3022 28.5 10.5 5100 123 487.2

Fr - 6 GE 37.5 2752 32.1 12.2 5100 146 544

SGT 700 SIEMENS 29.06 2390 36 18 6500 91.36 518

LM6000PC

GE 45.48 2123 40.5 30 3000 131 450

LM2500+

GE 30.057 2169 39.7 21.4 6100 84 500.5

Fr – 9EGE 126.1 2548 33.8 (sc) 12.6 3000 418 543

GE 193.20 1656 52.0 (cc) 12.6 3000 418 543

Fr – 9 FA

GE 255.6 2334 36.9 (sc) 17 3000 642 602

GE 390.80 1517 56.7 (cc) 17 3000 641 602

RIL Gas Turbines

30 June 09

VMG/AG49 of 119

Performance Curves for Gas

Turbine

30 June 09

VMG/AG50 of 119

ModelISO

Output

Heat

Rate

Efficiency %

Flow(lb/sec)

Power consumed

by Compress

or%

Firing Temp (Deg

C)

Fr – 5 26.33022

28.5 273 63.86 957

MS – 6541

37.52752

32.1 294.8 61.96 1104

Fr – 9E 126.12548

33.8 919.6 57.93 1124 

Fr – 9FA

255.62334

36.9 1412.4 54.29 1327

Performance Curve for Gas Turbine

30 June 09

VMG/AG51 of 119

Gas Turbine Compressor Power

NETOUTPU

T(MW)

T1(C)

T2(C)

T3(C)

T4(C)

WORK

RATIO

TURBINE

WORK(MW)

COMPRESSOR

POWER(MW)

%

Fr - 5 26.3 15315

957487

0.361

73 4663.8

6

MS-6541

37.5 15362

1104

544

0.380

99 6161.9

6

Fr-9E 126.1 15340

1104

543

0.421

300 17457.9

3

Fr-9FA 255.6 15407

1327

605

0.457

559 30454.2

9 

LM6000

PC45.48 15

535

1260

450

0.358

127 8264.2

0

SGT 700

29.06 15416

1140

518

0.355

82 5364.4

7

30 June 09

VMG/AG52 of 119

Effect of Power Consumed by Compressor

0

10

20

30

40

Fr - 5 MS-6541 Fr-9E Fr-9FAMODEL

EF

FIC

IEN

CY

, %

40

50

60

70

80

% P

OW

ER

CO

NS

UM

ED

BY

T

HE

CO

MP

RE

SS

OR

Efficiency % %

30 June 09

VMG/AG53 of 119

Effect of Firing Temperature

0

10

20

30

40

Fr - 5 MS-6541 Fr – 9E Fr - 9FAModel

Eff

icie

ncy

, %

0

250

500

750

1000

1250

1500

Fir

ing

Tem

p,

Deg

C

Efficiency % Firing Temp (Deg C)

30 June 09

VMG/AG54 of 119

ModelISO

OutputHeatRate

Efficiency %

Flow(lb/sec)

Power consumed by Compressor %

Firing Temp

(Deg C)

MS-6541

37.5275

232.1 294.8 61.96 1104

Fr – 9FA

255.6233

436.9 1412.4 54.29 1327

• For every 100 Deg F/55.5 Deg C increase in firing temperature, the efficiency increases about 1.5%. So, 223 Deg C rise in firing temp increases the efficiency by 6%. Leading to improvement in heat rate by 165 kcal/kwh.

• 7 % reduction in compressor power consumption improves the heat rate by 211 kcal/kwh.

• Remaining 2 % improvement in Heat rate as a result of: GTD-222 Stage 2 Nozzle

Stage – 2 & 3 Honey Comb Shrouds

86i IGV setting

Higher RPM Load Gear

High Pressure Packing Brush Seal

Improved Cooling Stage 1 Nozzle

Comparison

30 June 09

VMG/AG55 of 119

• Approximately 20% of the Inlet Air to the Axial Flow Compressor gets lost to the Thermal cycle due to losses associated with cooling hot gas path parts or losses due to Large Clearances.

• Most uprates on Gas Turbines typically are achieved by Higher Airflow or Higher Firing Temperatures.

30 June 09

VMG/AG56 of 119

Maintenance Factors of Gas

Turbine

30 June 09

VMG/AG57 of 119

Combustion System ComponentsEfforts to advance the combustion system are driven by the need for higher firing temperatures and for compliance with regulatory requirements to reduce exhaust emissions.

30 June 09

VMG/AG58 of 119

Combustion System Components

Requirements:

Withstanding Higher Firing Temperature.

Low Emissions etc. NOx & CO.

Life Time Extension.

Maintenance Interval Extension.

30 June 09

VMG/AG59 of 119

Factors Affecting the Combustion Components Life

Type of fuel

Firing Temperature

Cyclic Effects

Steam or Water Injection

Quality of Air

30 June 09

VMG/AG60 of 119

Maintenance factors – Hot gas path (Buckets & Nozzles)

30 June 09

VMG/AG61 of 119

Fuel vs. Component life

Estimated Effect of Fuel Type on Maintenance

30 June 09

VMG/AG62 of 119

Fuel vs. Component life

Various fuels used areRFG, Naphtha, HSD&

LCO. Liquid fuel High radiant energy Impurities (Na, K, Va)

Results Thermal fatigue failure Hot corrosion 1 hr of Liquid Fuel = 1.5 hrs of Gas Fuel

Operation Operation at Base Load

30 June 09

VMG/AG63 of 119

The Firing Temperature

Firing temperature Thermal efficiency Power output

Results Creep Distortion Reduced life 1 hr of peak load = 6 hours of base load operation. operation.

30 June 09

VMG/AG64 of 119

Cyclic Effects during Start/Stop

30 June 09

VMG/AG65 of 119

Cyclic Effects

Each stop and start of a gas turbine subjects the hot gas path to significant thermal cycles. Control systems are designed and adjusted to minimize this effect. The severity is phenomenal in the case of emergency start and trips.

1 Emergency Trip = 8 Normal Shutdown Cycles

30 June 09

VMG/AG66 of 119

Steam or Water Injection

30 June 09

VMG/AG67 of 119

Steam or Water Injection

Steam or water is injected in to the combustion system for:  

• NOx Reduction• Power Augmentation

This steam or water Injection used causes higher dynamic pressure and due to higher specific heat capacity of steam with respect to the gas, causes higher transfer of heat to bucket and nozzle resulting in higher metal temperature of these components reducing their life.

30 June 09

VMG/AG68 of 119

Hot Gas Path Components &

its Metallurgy

30 June 09

VMG/AG69 of 119

Combustion Liners (FR1G/FR1H) The original combustion liner was Louvered which was cooled through louvered punches in liner body (Experiencing cracking in punches during operation) Replaced with a slot-cooled liner - provides a more uniform distribution of cooling air flow for better overall cooling. Air enters the cooling holes, impinges on the brazed ring and discharges from the internal slot as a continuous cooling film.

30 June 09

VMG/AG70 of 119

The Mechanism of Slot Cooled Liner

Advantage• 139 C lower metal Temp.• Lower Temp. gradient.• Short length provide more stiffness and reduced cooling air.

30 June 09

VMG/AG71 of 119

TBC Coated Liner

Advantage•The 380 micron TBC thick provide 38 °C lower temp. in base metal.• For firing temp. 1124 °C the thickness of liner is 15 mil thicker.

30 June 09

VMG/AG72 of 119

• The Material Hastelloy-X replaced by Nimonic 263 because of superior to creep life time.

• The wall thickness is thicker and TBC coated.

• T.P was lengthened 15 in to relocate the wear of Liner-T.P interface induced by compressor discharge air.

• Increasing inspection interval to 12000 E.O.H.

• Redesign of aft bracket allowing the T.P pivot during the thermal cycling.

Transition piece Changes

30 June 09

VMG/AG73 of 119

Turbine Components

There have been significant design and material improvements made to the turbine components to improve component designs which can withstand higher firing temperatures due to advanced materials and coatings, as well as the addition of air cooling for some of the components.

30 June 09

VMG/AG74 of 119

BUCKETSStage 1 Bucket (FS2H)DesignThe original design’s sharp leading edge has been blunted to allow more cooling air to flow to the leading edge, which reduces thermal gradients and cracks.MaterialsThe original stage 1 bucket was IN- 738 is changed to an Equiaxed (E/A) GTD-111, a precipitation hardened, nickel-base super alloy, a greater low cycle fatigue. It also provides the industry standard in corrosion resistance.CoatingsIn 1997 the coating was changed again to GT-33 INCOAT. GT-33 is a vacuum plasma spray coating, an increased resistance to through cracking. “INCOAT” refers to an aluminide coating on the cooling holes passages.

30 June 09

VMG/AG75 of 119

Stage 2 Bucket (FS2F)CoolingThe new stage 2 buckets contains internal air cooling ,allows for higher firing temperatures. Tip ShroudShroud leading edge was scalloped & tip was thickened & shroud tapered. It resulted in 25% reduction in stress and 80% increase in creep life.

Materials The original bucket was made

of U-700, the material was changed to GTD-111, also a precipitation-hardened, nickel- Scalloping of bucket shroud base super alloy, to improve rupture Coating strength. In addition it has higher low GT 33 INCOAT cycle fatigue strength

BUCKETS

30 June 09

VMG/AG76 of 119

Stage 3 Bucket (FS2K)DesignThe trailing edge was thickened, and the chordlength increased, the shroud leading edge was scalloped, the shroud tip was thickened between the seal teeth, and the underside of the shroud was tapered. These design changes resulted in an increase in creep life of the bucket.MaterialsThe stage 3 bucket was originally made of U-500, it was changed to IN-738, a precipitation hardened, nickel-based super alloy.Process ChangeA new process for the bucket which eliminates the need for the cold straightening step, thus eliminating the process induced strain in the material.

BUCKETS

30 June 09

VMG/AG77 of 119

NOZZLESStage 2 Nozzle (FS1P)

30 June 09

VMG/AG78 of 119

SHROUD BLOCKSStage 1 Shroud Blocks (FS2C)The stage 1 shroud block was redesigned for the 2055°F/ 1124°C firing temperature. The two piece design is film cooled using airflow from the stage 2 nozzle to inhibit cracking. The film cooling required additional flow which translates into a performance loss. The main advantage of the two piece design is that it allows the damaged caps to be replaced without Having to remove the shroud block bodies or turbine nozzles. The body and hook fit are made of310 stainless steel and the cap is made of FSX-414.

30 June 09

VMG/AG79 of 119

Stage 2 & 3 Shroud Honey Comb Seal• Honey Comb Shroud:i. Reduces Leakageii. Greater Rub Tolerance• Requires Buckets with Cutter Teeth• Provides a performance improvement up

to 0.6% in both output and heat rate.

SHROUD BLOCKS

30 June 09

VMG/AG80 of 119

MATERIALSTurbine Blades

Turbine Nozzles

30 June 09

VMG/AG81 of 119

MATERIALSCombustors

Turbine Wheels

30 June 09

VMG/AG82 of 119

MATERIALSCompressor Blades

30 June 09

VMG/AG83 of 119

Improvement in Firing Temperature with Blade

Material

30 June 09

VMG/AG84 of 119

Gas Turbine Control Systems

30 June 09

VMG/AG85 of 119

RIL Gas Turbine Control System

Due to non-availability of spares, Mark IV system at RIL sites are under proposal for upgrade to Mark VI. Expected cost is Rs. 200 lacs per unit.

30 June 09

VMG/AG86 of 119

System Type Mark I Mark II Mark II ITS Mark IV Mark V Mark VI

Introduced 1966 1973 1976 1982 1991 2004

Total Shipped 850 1825 356 1080 530 Ongoing

Sequencing Relays Discrete Solid State ComponentsTMR

MicroprocessorTMR

MicroprocessorTMR

Microprocessor

ControlDiscrete Solid

StateICs ICs & MPs

TMR Microprocessor

TMR Microprocessor

TMR Microprocessor

Protection RelaysRelays &

Solid StateICs & micro-

processorTMR

MicroprocessorTMR

MicroprocessorTMR

Microprocessor

DisplayAnalog Meters

& Relay Annunciator

Analog and Digital Meters; Solid State Annunciator

CRT & LED Aux. Display

VGA Color Graphics

VGA Color Graphics

Input Push buttons and bat handled switchesMembrane Switches

Keyboard &/or CPD

Keyboard &/or CPD

Fault Tolerance

Manually Rejects Failed Exhaust Thermocouples

Automatic Rejects Failed T/Cs.

Hardware Based

SIFT, Software Implemented

Fault Tolerance

SIFT, Software Implemented

Fault Tolerance

Enhancement Integrated Circuits Micro-ProcessorTMR & CRT

DisplaySIFT, VGA Graphics

Remote I/O capability

GE Control System Advances

30 June 09

VMG/AG87 of 119

Introduction to Control Philosophy

Control systemCommunicates with the turbine toMeasure, adjust the parameters

It also protects the turbine from abnormal operations

30 June 09

VMG/AG88 of 119

Gas Turbine Controls

1. Basic Control Parameters of GT

2. Minimum Gate Concept of

Six Control Loop

Start up

Speed/Load

Temperature

Acceleration

Manual

Shut down

Main

Auxiliary

Introduction to Control Philosophy

30 June 09

VMG/AG89 of 119

UNIT CONTROL DISPLAY

CRANK MOTOR

GEAR

BOX

GENERATOR WATTS VARS PF FREQ

IGV

NAP/KER

HSD

NORMAL RUN STATUSSELECT2 PRESELSTATUS_FLD UNLOADINGFSER_CONTROL SPEED-DROOPSPEED_LVL 14HSFLAME # A # B # C # DGT_SPEED 98.75 %TNR 102.57 %SPREAD_1 30 deg CFSR 64 %MSG_FLD1 SIMPLE CYCLEMSG_FLD2 IGV FULL OPENSC43 AUTOSC43F NAPTHALIQUID FUEL 100 % RT NAP/KER

MasterSelect

MasterControl

LoadControl

FuelSelect

OFF

FIRE

STOP

FAST START

START

MWSETPOINT

PRESEL

BASELOAD

NAP

HSD

GAS

CRANK

CO-GEN DROOP LOAD CONTROL

SIMPLE ISOCH

RAISE LOWER

100

50

25

0

LUBE OIL

EXHAUST BREAKER OPEN

AUTO

CPD8.55 barg

84 dga

Max. Vib7.0 mm/secAIR INLET

75

30 June 09

VMG/AG90 of 119

Mark-V

Panel

BOI

Turbine Generator

Sta

ge L

ink

<I> Station

Backup operatorInterface

Controlling and Monitoring

30 June 09

VMG/AG91 of 119

< QD1 >

MARK-V CONTROL PANEL LAYOUT

< R > < C >

< T > < P > < PD >

< CD >

< S >

IONET

DENET

POWER

< I >

Station

STAGE LINK

30 June 09

VMG/AG92 of 119

The MARK-V Control System Description

• The Mark-V control system has TMR (Triple Modular Redundant) configuration. <R>, <S> and <T> control processor. <C> communication processor. <P> protective processor. <PD> power distribution processor. <QD1> & <CD> input & output processor. The < I > station is used to control the turbine. The <BOI> may be used to control the Turbine, whenever loss of communication between the < I > station and Mark-V panel.

30 June 09

VMG/AG93 of 119

Simple Cycle Package Power Plant Starting Time

* Time is in Minutes

30 June 09

VMG/AG94 of 119

Gas Turbine Generator Controls & Limit

30 June 09

VMG/AG95 of 119

Dual Fuel transfer Characteristics- Gas to Liquid

30 June 09

VMG/AG96 of 119

Gas Turbine Fuel Control

30 June 09

VMG/AG97 of 119

Gas Fuel Control System

30 June 09

VMG/AG98 of 119

Liquid Fuel Control System

30 June 09

VMG/AG99 of 119

Typical Gas Turbine Starting Characteristics

30 June 09

VMG/AG100 of 119

Exhaust Temperature Control

The firing temperature is difficult tomeasure and hence the Controller uses the exhaust thermocouplesas reference which is directly proportional to Firing Temperature.

Tf = Tx (Pcd/Pa)k

Temperature Controller ensuresthat the Turbine internals are protected from over heat and Optimum poweris produced.

30 June 09

VMG/AG101 of 119

Exhaust/Firing Temperature Relation

The firing temperature remains constant even with increase in MW, FSR & CPR ratio with less exhaust temperatures.

Curve comparing the load

at different ambient.

30 June 09

VMG/AG102 of 119

Acceleration Control functions during sudden Load Changes and Start Up

TNH

0.35 %/sec

100%0%

0.10 %/sec

40% 50% 75% 95%

Acceleration Control

30 June 09

VMG/AG103 of 119

Manual Control Loop Can be used to limit fuel to prevent over firing and over riding active control.

Manual Control

30 June 09

VMG/AG104 of 119

Shut down control loop reduces the fuel at a predetermined during shut down to reduce thermal stresses.

FSRSD is the minimum of Six Control Loops

Shut Down Control

30 June 09

VMG/AG105 of 119

IGV Control

IGV Control Loop

• Controls air fuel ratio

• Prevents Compressor Pulsations

30 June 09

VMG/AG106 of 119

Maintains higher Exhaust Temperature at partial loads for Combined Cycle Operation

IGV Schedule

IGV scheduling is requiredto ensure the protection fromPulsation/Stall by excessive opening at lower speeds/loads and negative pressures at partial loads by less opening

IGV Control

30 June 09

VMG/AG107 of 119

Maintains higher Exhaust Temperature at partial loads for Combined Cycle Operation

IGV control reference

The exhaust temp. variesfor simple and combined cycle operations.IGV temperature control neverexceeds the base temperature control set point.

Exh

au

st T

em

pera

ture

CPD

Isothermal

CPD BIASCPD BIASCPD BIAS

Base temp control set point

CC IGV temp control set point

SC control set point

IGV Control

30 June 09

VMG/AG108 of 119

Performance Benchmarking

30 June 09

VMG/AG109 of 119

Purpose of Benchmarking

• Gives feed back on relative performance.

• Indicating opportunities for improvement.

• Un-earth and explore the outstanding Reliability issues.

• Highlight the areas for improvement.

• Target the initiatives for sustainable development.

30 June 09

VMG/AG110 of 119

Gas Turbine Key Performance Indicators

% Reliability accounting for - No. of Emergency trips - No. of Forced shutdowns - No. of Unplanned shutdowns hrs% Availability accounting for - Outage duration - MTBFKey performance indicators - Heat rate (Open cycle/Co-gen) - Efficiency (Open cycle/Co-gen) - Fuel efficiency improvement IndexFuel , Power , Steam Costs & Grid Power Bill

- Percentage increase in Grid Power Consumption

- Fuel, Power & Steam Cost- Fuel & Grid Power Bill

30 June 09

VMG/AG111 of 119

Benchmarking at a Glance

• Number of Emergency Trips

• Number of forced shutdowns

– These are numbers which indicate the number of equipment trips in each category.

– RIL benchmark for not more than 1 trip/year for one equipment.

30 June 09

VMG/AG112 of 119

Benchmarking at a Glance

• Number of unplanned shut down hours

– This is number which indicates the number of unplanned shutdown hours in each category.

– RIL has a systematic budget approach targeting planned shutdown hours for all the equipment.

– The Down time hours include planned and unplanned shutdown hours.

30 June 09

VMG/AG113 of 119

Benchmarking at a Glance

• GT open cycle heat rate

Total direct fuel fired in GT in Kcal Power generated from GT in kwh

• GT/HRSG Co-gen Efficiency GT/HRSG Co-gen efficiency =

((A+B)/(C+D))*100where• A= GT power generation in thermal units• B= HRSG steam generation in thermal units• C= Fuel input to GT in thermal units• D= Fuel input to HRSG supp firing in thermal units

30 June 09

VMG/AG114 of 119

Benchmarking at a Glance

STG Cycle Efficiency

This is the efficiency in % for STG.

STG Efficiency = (A+B/C)*100where• A = ST power generation in thermal

units• B = Steam generation in thermal units• C = Steam energy input at Steam turbine

inlet in thermal units

30 June 09

VMG/AG115 of 119

Benchmarking at a Glance

Auxiliary Boiler Thermal Efficiency

This is the efficiency in % for Auxiliary Boiler.

Aux Boiler Efficiency = (A/B)*100where• A = Aux boiler steam generation in thermal

units• B = Fuel energy input to boilers in thermal

units

30 June 09

VMG/AG116 of 119

Benchmarking at a Glance

• Overall fuel utilization efficiency

– This is the combined efficiency of the CPP in %

– Overall Fuel utilization efficiency =((A+B+C)/(D+E+F))*100

• where• A= GT power generation in thermal units• B= ST power generation in thermal units• C= Steam extraction+PRDS steam energy in thermal units• D= GT input fuel in thermal units• E= HRSG input suppl. fuel in thermal units• F=Aux boiler input fuel in thermal units

30 June 09

VMG/AG117 of 119

Benchmarking at a Glance

• Fuel efficiency improvement index– This is the number in %, that indicates fuel

efficiency improvement to reference period.

• Fuel efficiency improvement index is then = A / B

where A = Fuel efficiency for the current periodB = Fuel efficiency for the reference period overall

30 June 09

VMG/AG118 of 119

RIL - CPP Benchmarking Criteria

Based on Key performance indicators, Ranking allotted to plants

Sr. No.

2008-’09 2007-’082006-’0

7

1 Jamnagar BarodaPatalgan

ga

2 Hazira HaziraJamnaga

r

3 Nagothane Jamnagar Hazira

4 BarodaNagothan

eGandhar

5 Gandhar Gandhar Baroda

6Patalgang

aPatalgang

aNagotha

ne

30 June 09

VMG/AG119 of 119

Thank

You