Recent Developments In Small Gas Turbines Siemens

Recent Developments in Small Industrial Gas turbines Ian Amos Product Strategy Manager Siemens Industrial Turbomachinery Ltd Lincoln, UK

Copyright © Siemens AG 2009. All rights reserved.

Content


Gas Turbine as Prime Movers
Applications
History


Technology
thermodynamic trends and drivers
core components


Future requirements
Market developments

Page 2

Nov 2010

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1

Gas Turbine as Prime Mover Prime mover : A machine that transforms energy from thermal, electrical or pressure form to mechanical form; typically an engine or turbine. Gas Turbines vary in power output from just a few kW more than 400,000 kW. The shaft output can be used to generate electricity from an alternator or provide mechanical drive for pumps and compressors. Page 3

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Nov 2010

Siemens Industrial gas turbine range Utility Turbines

Figures in net MW

SGT5-8000H

375

SGT5-4000F

287

SGT6-8000H

266

Industrial Turbines

SGT6-5000F SGT5-2000E SGT6-2000E SGT-800 SGT-700 SGT-600 SGT-500 SGT-400 SGT-300 SGT-200 SGT-100

Page 4

198 168 113 47 31 25 17 13 8 7 5

Nov 2010

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Industrial Gas Turbine Product Range Portfolio (MW)

SGT-100-1S

47 SGT-800 30 SGT-700 SGT-600 25 SGT-500 17 SGT-400 13 SGT-300 8 SGT-200 7 SGT-100 5

SGT-100-2S

SGT-200-2S

SGT-200-1S

SGT-300

SGT-400

SGT-500

Page 5

SGT-600

Nov 2010

SGT-700

SGT-800

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Industrial Gas Turbine Product applications Power Generation

Pumping

An SGT-100 generating set is installed on Norske Shell's Troll Field platform in the North Sea

Thirty SGT-200 driven pump sets on the OZ2 pipeline operated by Sonatrach, Algeria

Page 6

Nov 2010

Compression

Two SGT-700 driven Siemens compressors for natural gas liquefaction plant owned by UGDC at Port Said, Egypt.

CHP

Comb. Cycle

An SGT-800 CHP plant for InfraServ Bavernwerk’s chemical plant in Gendork, Germany.

Two SGT-400 generating sets operating in cogeneration/ combined cycle for BIEP at BP’s Bulwer Island refinery, Australia

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Gas Turbine Refresher Comparison of Gas Turbine and Reciprocating Engine Cycle AIR INTAKE

FUEL

COMBUSTION EXHAUST

COMPRESSION

Continuous

Intermittent AIR/FUEL INTAKE Page 7

COMPRESSION

Nov 2010

COMBUSTION

EXHAUST

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Gas Turbine as Prime Mover

Gas Turbine Characteristics Size and Weight
High power to weight ratio giving a very compact power source

Operation and Maintenance
No Lubricating oil changes
High levels of availability

Vibration
Rotating parts mean vibration free operation requiring simple foundations

Fuel flexibility
Dual fuel capability
Burn Lean gases (high N2 or CO2 mixtures)
Varying calorific values

Emissions
Very low emissions of NOx Page 8

Nov 2010

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Brayton Cycle

1-2 2-3 3-4

Air drawn from atmosphere and compressed Fuel added and combustion takes place at constant pressure Hot gases expanded through turbine and work extracted

(in single shaft approx 2/3 of turbine work is used to drive the compressor) Copyright © Siemens AG 2009. All rights reserved. Energy Sector

Nov 2010

Page 9

Ideal Engine Cycle: Efficiency

Ideal thermal efficiency

   1  Simple cycle efficiency = 1 −    P1   P2 

( γ −1) / γ

Cycle efficiency is therefore only dependant on the cycle pressure ratio. Assumption : Ideal cycle with no component or system losses.

0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0

10

20

30

40

50

Pressure Ratio Page 10

Nov 2010

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Engine Cycle: The Real Engine Deviations from Ideal Cycle

‘Real’ Efficiencies

•Aerodynamic losses in turbine and compressor blading

• Practical simple cycle gas turbines achieve 25 to 40 % shaft efficiency

• Working fluid property changes with temperature • Pressure losses in intakes, combustors, ducts, exhausts, silencers etc.

• However, heat rejected in the exhaust can be used :-

• Air used for cooling hot components • Parasitic air & hot gas leakages • Mechanical losses in bearings, gearboxes, seals, shafts • Electrical losses in alternators Page 11

• Complex gas turbine cycles can achieve shaft efficiencies up to 50%

•Large combined cycle GT can achieve close to 60% shaft efficiency •Cogeneration (Heat and Power) can exceed 80% total thermal efficiency Copyright © Siemens AG 2009. All rights reserved. Energy Sector

Nov 2010

Energy Cost Savings GT cycle parameter study 43.0 25

42.0

Shaft Efficiency (%)

22

41.0 20

40.0

18

39.0

PRESSURE RATIO

16

38.0 14

37.0 1300ºC

1350ºC

1400ºC

1450ºC

1250ºC

36.0 1200ºC

FIRING TEMPERATURE

35.0 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 480 Shaft Specific Output (kJ/kg)

Increase Pressure ratio and firing temperatures for higher simple cycle efficiencies Page 12

Nov 2010

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Design Drivers : Low Specific Fuel Consumption Higher Pressure Ratios • Increased Cycle Efficiency • Increased number of compressor / turbine stages and therefore cost Complex Cycles • Increased Cycle Efficiency and/or Specific Power • Can impact operability, cost and reliability Higher Firing Temperature • Requires increased sophistication of cooling systems • Can impact life and reliability and combustor emissions

Page 13

Nov 2010

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Design Drivers : Availabilty, Cost and Emissions
High reliability.
Moderates the trend to increase firing temperature and cycle complexity.
Low Emissions (Driven by environmental legislation)
More difficult to achieve with high firing temperatures and combustion pressures
Lowest possible cost.
Encourages smallest possible frame size, i.e. high specific power high firing temperature.
Reduced Pressure ratios (< 20:1) to avoid auxiliary fuel compression costs

Compromise is required in the concept design to get the best balance of parameters Page 14

Nov 2010

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Future Machines

SGT-400

SGT-300

TB

TD

TG

TF

TE

TA

16 15 14 13 12 11 10 9 8 7 6 5 4 3

1300 ttiioo RRaa rree u u s s

es Pr

1200

urree

t aatu eerr mpp eem T T g

1100

inng FFiir

1000 900 800

Firing Temperature °C

Pressure Ratio

3CT

Centrifugal Compr.

SGT-100

SGT-200

Core Engine Trends: Key Parameter Trends

700 1950

1960

1970

1980

YEAR Year

2000

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Nov 2010

Page 15

1990

Engine Trends: Thermal Efficiency 40 SGT-400

38

300 36 34

250

SGT-100

32

SGT-200

200

Specific Power Output Thermal Efficiency

150 TB5000

30

Thermal Efficiency (%)

Specific Power (kJ/kg)

350

28 26

100 1975

1980

1985

1990

1995

2000

24 2005

Year

Dramatic impact of increased TET and pressure ratio over last 25 years:

• • • Page 16

Specific Power increased by almost 100% Specific Fuel Consumption reduced by over 30% reduced airflow for a given power output and has resulted in smaller engine footprints, reduced weight and reduced engine costs Nov 2010

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Product Evolution

SGT-300 Introduced 1995 7,900 kWe 30.5% eff

TA Introduced 1952 750kW

17.6% eff

Developed to 1,860kW

Page 17

Nov 2010

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Gas Turbine Layout - single shaft or twin shaft

Single Shaft Expansion through a single series of turbine stages. Power transmitted through rotor driving the compressor and torque at the output shaft

Twin Shaft Expansion over 2 series of turbines. Compressor Turbine (CT) provides power for compressor Useful output power provided by free Power Turbine (PT) Page 18

Nov 2010

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SGT-400 Industrial gas turbine

Compressor

Page 19

Combustion system

Nov 2010

Gas Generator Turbine

Power Turbine

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Combustion

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Environmental Aspects Pollutants and Control Pollutant

Effect

Method of Control

Carbon Dioxide

Greenhouse gas

Cycle Efficiency

Carbon Monoxide

Poisonous

DLE System

Sulphur Oxides

Acid Rain

Fuel Treatment

Nitrogen Oxides

Ozone Depletion Smog Poisonous Greenhouse gas Visible pollution

DLE System

Hydrocarbons Smoke

DLE System DLE System

DLE - Dry Low Emissions

Page 21

Nov 2010

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Exhaust Emission Compliance
Emissions control:
Two types of combustion configuration need to be considered:
Diffusion flame
Dry Low Emissions (DLE or DLN) using Pre-mix combustion


Diffusion flame
Produces high combustor primary zone temperatures, and as NOx is a function of temperature, results in high thermal NOx formation
Use of wet injection directly into the primary zone to lower combustion temperature and hence lower NOx formation


Dry Low Emissions
Lean pre-mixed combustion resulting in low combustion temperature, hence low NOx formation
With good design and control <25ppm NOx across a wide load and ambient range possible Page 22

Nov 2010

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Combustion NOx Formation 1000

NOx Formation Rate [ ppm/ms ]

100 10 1 0.1

Diffusion Flame

0.01 0.001

Lean Pre-mix 0.0001 0.00001 0.000001 1300

1500

1700

1900

2100

2300

2500

Flame Temperature [ K ]

Flame temperature affects thermal NOx formation Page 23

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Nov 2010

Combustion NOx Formation Flame Temperature as a function of Air/Fuel ratio Diffusion flame reaction zone temperature

Lean burn

Flame temperature

Diffusion flame

Lean Pre-mixed (DLE/DLN)

Lean

Page 24

Nov 2010

Stoichiometric FAR

Rich

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Combustor Configuration NOx product is a function of temperature

Diffusion Combustion - high primary zone temperature

Cooling

Dry Low Emissions Combustion -low peak temperature achieved with lean pre-mix combustion Page 25

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Nov 2010

DLE Lean Pre-mix Combustor (SGT-100 to SGT-400 configuration) Igniter

Liquid Core

Pilot Burner

Main Burner Radial Swirler


Robust design involving no moving parts
Fixed swirler vanes
Variable fuel metering via pilot and main fuel valves

Main Gas Injection Igniter

Pilot Gas Injection

Pre Chamber

Air

Gas/Air Mix

Gas

Air Double Skin Impingement Cooled Combustor

Page 26

Nov 2010

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Lean Pre–Mix combustion
Simple fuel system
Variable fuel metering via pilot and main fuel valves
Low NOx across a wide operating range of load and ambient conditions BLOCK VALVE

BLOCK VALVE

M

MAIN FLOW CONTROL VALVE

MAIN MANIFOLD BLEED VALVE

PILOT MANIFOLD PILOT FLOW CONTROL VALVE

Page 27

Nov 2010

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Combustion DLE Lean Premix System

Key to success
good mixing of fuel and air
multiple injection ports around swirler


long pre-mix path
fuel injection as far from combustion zone as possible


good air flow distribution
can annular arrangement with top hats


use of pilot burner
CO control & flame stability


use of guide vane modulation/air bleed
air flow management

Page 28

Nov 2010

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14

DLE System : Siemens experience


15million operating hours across the range (SGT-100 to SGT-800)
Approximately 1000 DLE units
About 90% of new orders DLE

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Nov 2010

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Experience Stable load accept/reject Daily profile for unit running more than 8000hrs DLE operation on liquid fuel.

kW

Daily variations Load Shed and Accept

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Nov 2010

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15

Gas Fuel Flexibility BIOMASS & COAL GASIFICATION

3.5

Other gas

High Hydrogen Refinery Gases

Associated Gas

37

Landfill & Sewage Gas

49

65 LPG

Siemens Diffusion IPG Ceramics

Off-shore lean Well head gas

Operating Experience

Off-shore rich gas

Siemens DLE Units operating DLE Capability Under Development Pipeline Quality NG Low Calorific Value (LCV)

Medium Calorific Value (MCV)

10

20

‘’Normal’’

30 40 50 Wobbe Index (MJ/Nm³)

60

SIT Ltd. Definition

70

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Nov 2010

Page 31

High Calorific Value (HCV)

The change in WI by the addition of inert species to pipeline quaility gas

50 UK Natural Gas

45

CO2 N2

Wobbe MJ/m

3

40 35 Medium CV Fuel

30

MCV Rangedevelopment Definition

25 20 15 10 5

LCV Burner

0 0

10

20

30

40

50

60

70

80

90

100

CO2 or N2 content of UK Natural Gas Page 32

Nov 2010

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Examples of Siemens SGT Fuels Experience NON DLE Combustion
Natural Gas
Wellhead Gases
Landfill Gas
Sewage Gas
High Hydrogen Gases
Diesel
Kerosene
LPG (liquid and gaseous)
Naphtha
‘Wood’ or Synthetic Gas
Gasified Lignite

Sewage gas standard burner Gasified Biomass Special Diffusion burner

5

10

Landfill gas Special Diffusion burner

15

20

25

High Hydrogen gas standard burner UK Natural Gas

30

35

40

45

50

Liquified Petroleum gas modified MPI

55

60

65

70

Wobbe Index MJ/m3 standard gases

Gaseous Fuel Range of Operation


DLE experience on Natural Gas, Kerosene and Diesel
DLE on fuels with high N2 and CO2 content.
DLE Associated or Wellhead Gases Page 33

Nov 2010

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Turbine

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Aerodynamic optimised design !

Minimised loss
optimum pitch/width ratio across whole span.
low loading


High speed




high stage number


low Mach numbers
thin trailing edges
low wedge angle
zero tip clearance Page 35

Nov 2010

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Aerodynamics High Load Turbine

Computational Fluid Dynamics (CFD) used to complement experimental testing of advanced components. Page 36

Nov 2010

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Analytical optimised design !

Reduce blade stresses
Minimal shroud


shroud may still be desirable for damping purposes.


High hub/tip area ratio
Low rotational speed. Maximise life
Low temperatures
Low unsteady forces Page 37

Nov 2010

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Mechanical Design Improved analysis software (grid and solver) and improved hardware allow traditional ‘postdesign’ to be carried out during design iterations. Meshing of complex cooled blade could take many man months in early 90’s - now down to minutes. More sophisticated analysis for detailed lifing studies still required after design.

Page 38

Nov 2010

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19

Fatigue Life of Rotating Blades Positions of Concern

Blade Vibration response
Predicted by FE and measured in Lab.
Identifies critical blade frequencies and modes (Campbell Diagram)

Aerofoil

High Cycle Fatigue
Fillet Radii between aerofoil & platform
Top neck of firtree root

Fillets

Low Cycle Fatigue
In areas of highest stress
Eg - blade root serrations Root Serration (including skew effects) Copyright © Siemens AG 2009. All rights reserved. Energy Sector

Nov 2010

Page 39

Mechanical Design - Vibration analysis Campbell Diagram for LPT Blade (Blade only) EO20

6000

EO18

EO19

EO17

mode 6

EO11 EO10

3000

mode 4

EO9

mode 3 EO6

2000

mode 2

1000

mode 1

0 15000

15500

Iteration 3 version 10

Page 40

100%

4000

105%

mode 5

95%

Frequency (Hz)

5000

Nov 2010

EO3

16000

16500

17000

17500

18000

Engine Speed (rpm)

18500

19000

19500

20000

D G Palmer 3-8-01

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Cooling optimised design !!

Large LE radius
minimise stagnation htc thick trailing edge thickness and large wedge angle for cooling thickness distribution to suit cooling passages. Minimise gas washed surface.

Page 41

Nov 2010

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Cooled Blading Designs SGT100 > SGT300 > V2500 Aeroengine

Page 42

Nov 2010

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SGT400 First Vane Cooling Features

Impingement Cooling

Film Cooling Turbulators

Cast 2 Vane Segment

Page 43

Nov 2010

Trailing Edge Ejection

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SGT-400 13MW Industrial Gas Turbine First Stage Cooled Vane Hot Blades are life limited. -Oxidation - Thermal fatigue - Creep

Life typically 24,000 hrs. Life can be increased or decreased depending on duty and environment. Page 44

Nov 2010

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SGT-300 First Stage Cooled Rotor Blade Ceramic Core forming Cooling Passages

Page 45

SGT300 8MW Industrial Gas Turbine Multi-Pass Cooled First Stage Rotor Blade

Nov 2010

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HP Turbine Blade Coatings Hot Gas Surface Coatings for Corrosion & Oxidation protection
Aluminide,
Silicon Aluminide (Sermalloy J)
Chromising
Chrome Aluminide, Platinum Aluminide
MCrAlY Internal Coatings on Cooled Blades operating in poor environments

Ceramic Thermal Barrier Coatings
Yttria stabilised Zirconia
Plasma Spray Coatings used on Vanes
EBPVD Coatings used on rotating blades
More uniform structure for improved integrity

Page 46

Nov 2010

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23

Turbine Validation Process Analysis

Design

Assess evaluation and calibration of methods

Prototype

Test

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Nov 2010

Page 47

New technology incorporated into existing engine platforms SGT-100 Product Development New ratings have been released

Compressor Blade • Stator stages S1& S2 • Rotor stages R1 & R2

Aerodynamic modifications to compressor and turbine. HP Rotor blade • SX4 material • Triple fin shroud • Step Tip seal

Power generation, 5.4MWe (launch rating 3.9MW previously 5.25MWe)

Mechanical Drive,

5.7MW

(previously 4.9MW)

T

Page 48

P

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Industrial Gas Turbines Advanced Materials & Manufacturing

SGT400 PT 2 Nozzle Ring Page 49

Nov 2010

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Bladed Turbine Disc

Page 50

Nov 2010

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25

The Gas Turbine Package In addition to the main package, the following is also required:
Combustion air intake system
Gas turbine exhaust system
Enclosure ventilation system (if enclosure fitted)
Control system
UPS or battery and charger system

Page 51

Nov 2010

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SGT-300 Industrial gas turbine Package design – The latest Module Design
Available as a factory assembled packaged power plant for utility and industrial power generation applications
Easily transported, installed and maintained at site
Package incorporates gas turbine, gearbox, generator and all systems mounted on a single underbase
Preferred option to mount controls on package, option for off package.
Common modular package design concept
Acoustic treatment to reduce noise levels to 85 dB(A) as standard (lower levels available as options) Page 52

Nov 2010

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Typical Compressor Set

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Nov 2010

SGT-400 New Package Design Minimised customer interfaces reducing contract execution/installation costs 1 1

Combustion Air Intake

2

Enclosure Air Inlet

3

On-Skid Controls

4

Fire & Gas System

5

Interfaces

6

Lub Oil Cooler

7

Enclosure Air Exit

7

6

2 3

4 5


Highly flexible modular construction
Customer configurable solutions based upon pre-engineered options
Standard module interfaces to allow flexibility and inter-changeability
Additional functionality provided dependent upon client needs
Base design provides common platform for on-shore and off-shore PG and MD Page 54

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Future direction

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Future Trends - guided by market requirements Universal demand for further increases in efficiency and reliability, and reduction in cost. Oil & Gas (Mech drive and Power Gen)
Fuel flexibility - associated gases, off-gases, sour gas
Remote operation
Emissions -inc CO2 Independent Power Generation
Fuel flexibility - syngas, biofuels(?), LPG
Flexible operation - part load operation
Distributed cogeneration (rather than centralised generation)
Emissions - inc CO2

Page 56

Nov 2010

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28

Oil and Gas remote operations / fuel flexibility •First application of its kind in Russia (Western Siberia) burning wellhead gas which was previously flared •Solution: Three SGT-200 gas turbine •Output 6.75 MWe each •DLE Combustion system •Guaranteed NOx and CO emission levels of 25ppm •Min. air temp. (-57oC) •Max. air temp. (+34oC) •Gas composition with Wobbe Index >45MJ/m3 •Total DLE hours approximately 22,300 hours for each unit •Significant reduction of emissions : 80-90% reduction of NOx level •Siemens has supplied 135 gas turbines for Power Generation , Gas compression and pumping duty throughout the Russian oil & gas industry Page 57

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Nov 2010

Power Generation re-emergence of cogeneration WATER

GRID

FUEL

BOILER OR DRIER

PRODUCT / STEAM

~ Page 58

Nov 2010

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Thank You

Page 59

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