Presentazione di PowerPoint

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SOFC System Configuration through Pinch Analysis
Vittorio Verda, Michele Calì, Stefano Saroglia
Department of Energy Engineering - Politecnico di
Torino
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OUTLINES

• Characterization of the main processes (mass flow
  rate, initial and target temperature, net heat
  flux)
• 2) Determination of the available heat flux
  without varying the fuel cell operating
  condition
• Synthesis of the heat exchanger network
  corresponding to the maximum output.

• Three applications are considered
• Cogeneration heating and power
• Cogeneration cooling and power
• Power production.

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SYSTEM COMPONENTS
Exhausts
HES
LTR
HTR
Aria
Air
Water
Air plenum
Acqua
Post- combustor
SOFC Stack
Pre- reformer

Reformer
Ejector
Fuel
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PROCESS CHARACTERIZATION
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AVAILABLE HEAT FLUX

• Once the fuel cell operating conditions are
  known, the available heat can be calculated. The
  following contributions are considered
• Ohmic and activation losses
• Electrochemical reactions
• Inlet and outlet stack conditions must be known
  to calculate the available heat flux.

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Stack operating conditions
Inlet reformer and outlet stack conditions can be
used to determine the inlet stack composition.
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Reforming model
Hypothesis of chemical equilibrium (T950 C)
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Reforming model
When this model is applied to the pre-reformer,
the determined chemical composition is close to
the determined one. Adiabatic conditions are
assumed.
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Faradays law
It accounts for the contribution due to hydrogen
and carbon monoxide to the total current
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Calculation of the chemical composition stack
inlet flow
The difference between the chemical composition
calculated by using the two methods can be
plotted as the function of the contribution of
hydrogen to the total current
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Application 3 - ORC
25 kW
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Composite curve -3
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Composite curve - 1
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Composite curve - 2
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Conclusion System configuration
F 100 kW
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Acknowledgments
This work has been developed in the framework of
the EOS Project, contract 470/2004 between Gas
Turbine Technologies and Politecnico di
Torino. Authors would like to thank Siemens and
Gas Turbine Technologies.