Combined Cycle Gas Turbine Generation - Thermal · PDF fileCombined Cycle Gas Turbine Generation Jonathan Ayres ... Gas Turbine selected was a GE ‘Aero Derivative’:-Engine from

Combined Cycle Gas Turbine Generation

Jonathan AyresMechanical Engineer

12th November 2010

1

Content

• CCGT – The heart of WissingtonCCGT Ad• CCGT Advantages

• Flexibility RequirementsFlexibility Requirements• SPRINT• Further Heat Utilisation• Carbon FootprintCarbon Footprint

2

CHP Plant (70MWe)at Wissingtonat WissingtonSugar Factory

CHP- the heart of the Wissington bio refinery

New CHP Plant

Old Boiler House

General Electric LM6000 PD Gas Turbine

Gas Turbine selected was a GE ‘Aero Derivative’:-

Engine from a Boeing 747Engine from a Boeing 747 was taken & converted to run on gas and liquid fuels.g

f fModifications to shafts togenerate ‘rotational power’ rather than a thrust. Rotational powerthan a thrust. Rotational power can be used to drive agenerator to make electricity.

LM6000PD Gas Turbine

Content



8

Old Boiler house Based CHP

Old Boilers x 3

N tt Effi i MW (O t) (16 85) 82 8%Nett Efficiency = MW (Out) = (16+85) = 82.8%MW (In) (122)

EvapsFuel Input 122MW

Evaps 85MW

Old St

122MW

Old Steam Turbine

16MW electricity

New Combined Cycle Gas Turbine

Nett Efficiency = MW (Out) = MW (I )

(42+24+85) = 78.7%(110 82)

(42+24+85+8) = 82.8%(110+82)

110MW

MW (In) (110+82)(110+82)

Air110MW

Fuel Evaps85MW

8MW heat

42MW electricity 24MW electricity82MW Fuel

8MW heat

Gas Turbine Boiler Steam Turbine

Conventional Generation vs. CHP

11

Theoretical Thermal to Power Conversion Efficiency

• Theoretical efficiency defined as

• Th – Inlet temperature• Tc – Outlet temperature

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Theoretical Thermal to Power Conversion Efficiency

1,600

1 200 B il GT CCGT1,200

elvi

n

Gas Turbine Combined

Cycle Gas

Boiler GT CCGT

Hot Temperature (°K) 923 1,673 1,673

Steam Raisingboiler

800

Deg

ree

Ke TurbineCold Temperature (°K) 293 723 293

Theoretical Efficiency (°K) 43.7% 34.3% 58.2%

400

D

0

Rankine (steam) and Brayton (gas turbine) Cycles Combined

13

Conventional gas based steam generation

Stack Loss

PRDS

MW

S T Electricity

Exhaust Steam

EVAPS

S.T. Electricity

Process

HP Steam

Conventional gas fired boiler

Boiler house DA

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Conventional gas based steam generation

Stack Loss

PRDS

MW

S T Electricity

Exhaust Steam

EVAPS

S.T. Electricity

Process

HP Steam

Boiler house DA

15

CCGT based steam generation

Stack Loss

PRDS

MW

S T Electricity

Exhaust Steam

EVAPS

S.T. Electricity HP Steam

EVAPSGas or OilProcess

Gas or Oil

MW

G.T. Electricity

Boiler house DA

16Boiler house DA

CCGT based steam generation

PRDSPhoenix

Glass House

Bio Fuels Stack LossCondenser

MWExhaust Steam

S T Electricity

EVAPSProcess

HP SteamS.T. Electricity

Gas or Oil

Gas or Oil

MW

G.T. Electricity

Boiler house DA

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Content



18

Flexibility

• Campaign with GTC i i h GT• Campaign without GT

• Juice Run with GTJuice Run with GT• Juice Run without GT• Off Season with GT + HRSG• Off Season with GT only – (Open Cycle)Off Season with GT only (Open Cycle)

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Flexibility

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Supplementary Firing

• Gas Turbine output fixed• Essential for high efficiency• High oxygen content in gas turbine exhaust (15% vol) results in high• High oxygen content in gas turbine exhaust (15% vol) results in high

stack losses: poor boiler efficiency• Low gas temperature results in low steam temperature: poor cycle

efficiency

15% O28% O2

efficiency

• Gas burners within wind box– More stable with dual fuelMore stable with dual fuel– Rapid response if GT trips

380°C520°CGas or Oil

380 C520 C

MW

G T Electricity

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G.T. Electricity

Content


• Flexibility RequirementsFlexibility Requirements • SPRINT• Further Heat Utilisation• Carbon FootprintCarbon Footprint

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SPRINT Technology

• SPRay INTercooling of GT compressor inlet air3• Uses ~ 4 M3/Hr cold ‘demin’ water

• Boosts power output by up to 7 MW• Available for Gas fuel and Liquid standby fuel

Water & AirWater & AirWater & AirWater & AirManifoldsManifolds HPC SPRINTHPC SPRINT

NozzlesNozzlesLPC SPRINTLPC SPRINT NozzlesNozzlesLPC SPRINTLPC SPRINT NozzlesNozzles

24x HPC SPRINTNozzles

&23x LPC Water & AirManifolds

23x LPC SPRINT Nozzles

LM6000 ‘SPRINT ‘- Additional Power Output Curves:

48000

50000LM6000-PD Sprint (tm)

LM6000-PD

HPC Sprint On HPC Sprint On

44000

46000

LPC Sprint OnLPC Sprint On~2 MW~2 MW

40000

42000

(kW

e)

LPC Sprint On LPC Sprint On

~5 MW~5 MW

~2 MW~2 MW

36000

38000

Pow

er (

~6 MW~6 MW

32000

34000 ~7 MW~7 MW

28000

30000

32000

28000-10.0 -5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0

Inlet Temperature ºC

Content



28

Further Utilising Energy

• The UK's largest single tomato glasshouse

• Covers an area of 11 hectares ≈ 11 football pitches (currently being extended)

• Produce between 80 million tomatoes each year

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Using the Glasshouse to Utilise Waste Heat

Stack Loss

PRDS (100% ST Bypass)Phoenix

Glass House

Bio Fuels

MW

S T Electricit

Exhaust Steam

EVAPS

S.T. Electricity

Gas or OilProcess

HP Steam

Gas or OilCO2 +

MW

+ waste heat

G.T. Electricity

30Condensate heat exchanger

Glasshouse Condensate Loop

Booster Pump

75°CSteam Top-up Heater

BoilerhouseReturn Condensate HeatCondensate Heat Recovery

GlasshouseGlasshouse LoopsPhoenix Heat

Recovery

Flue gas C l

Booster Pump

45°C

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Cooler 45 C

Content



32

Manufacturing Processes

O2

Lime Stone

C

Bulk Sugar CO2

Manufacturing

LimeKilnOther Sugar

Bioethanol Chemicals

FuelBurnt Lime

Manufacturing Process

Bioethanol

BetaineBeet

Electricity

BoilerHouse

Co products Steam Fuel

ulp Condensate ElectricityHouse

Pulp ProcessCO2

Animal Feed

Electricity

Fuel

Pu

Electricity 2

CO2

Carbon Footprint for Manufacturing Process improved by electricity exports from CHP

Lime StoneBulk Sugar

s

Other Sugar

BioethanolChemicals f i

nput

s

vale

nt

s by

c

valu

e

Bioethanol

Betaine Beet

alen

t of

O2

equi

vou

tput

son

omic

Co productsFuel

equi

vaCO

of o

eco

Electricity Credit

Electricity CO

2

Difference between CO2 intensity of CHP electricity and ave grid electricity

Animal Feed AF Fuel etcCO2 equivalent CO2 equivalent

ave. grid electricity

Questions?

[email protected]

35

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Combined Cycle Gas Turbine Generation - Thermal · PDF fileCombined Cycle Gas Turbine Generation Jonathan Ayres ... Gas Turbine selected was a GE ‘Aero Derivative’:-Engine from