biomass combined heat & power th ltechnology– stirling engine – fuel cell 6. rankine cycle...
TRANSCRIPT
BiomassCombined Heat & Power
T h lTechnology
1Morris A. PierceNovember 5, 2009
Why CHP/Cogeneration?• Typical thermal electric plants have a
thermal efficiency of 25 to 30%thermal efficiency of 25 to 30%• 70 to 75% of the energy input into an
l t i l t i j t d i t thelectric plant is rejected into the atmosphere as waste heat
• Wasted heat = wasted money, higher emissions
• Biomass CHP plants can achieve efficiencies above 90%
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US Electric System Energy Flow
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US Electric System Energy Flow
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Biomass Fuel & Technology
CHP 5 000 MBH
Heating 1,000 – 20,000 MBH
CHP >5,000 MBH Green Wood Chips>30% moisture
180 4 000 MBHDry Wood Chips 180-4,000 MBH<30% moisture
50 - 300 MBHPellets
5MBH 100 1,000 10,000 100,000Sq Ft 4,000 40,000 400,000 4,000,000
CHP Technologies• Rankine Cycle
Steam turbine– Steam turbine– Organic Rankine Cycle
• Brayton CycleBrayton Cycle– Gas turbine
• Otto CycleOtto Cycle– Reciprocating engine
• OtherOther– Stirling engine– Fuel cell
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Rankine Cycle
Heat SourceHeat Source
WorkingFluid
Turbine orEngine Power
Heat SinkHeat Sink
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Steam Turbine CHP
Boiler
900 psig875°F
SteamSteam CondensingTurbine
ElectricGenerator
13 psiaSteam
Condenser 200°FCondenserHot Water
Very efficient above 5 MW less efficient at smaller sizes
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Very efficient above 5 MW, less efficient at smaller sizes
Steam Turbines
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Organic Rankine Cycle CHP
Currently available for 300 kW to 2,200 kW
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ySmaller units down to 10 kW are being tested
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Organic Rankine Cycle CHP Module
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Brayton & Otto Cycles• Gas turbines & reciprocating engines
require a liquid or gaseous fuelrequire a liquid or gaseous fuel• Biomass gasification technology to support
t bi & i i t t t b tturbines & engines is not yet mature, but continued development could make it
i ll i bl i th f tcommercially viable in the near future.• Gasification usually requires a consistent,
dry feedstock
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CHP/Cogeneration• More complicated than a heat-only or
electric only projectelectric-only project• Significant stimulus incentives available• Use of standardized, modular technology
will help reduce costs
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For more information:
Morris A Pierce, PhDUniversity of RochesterUniversity of Rochester
585 275-4331mapi@mail rochester [email protected]
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