Representative Thermal Models in VTB

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Representative Thermal Models in VTB

• Wei Jiang, Jamil Khan
• Mechanical Engineering
• University of South Carolina

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Simulations

• Simulations for Performance Evaluation
• Simulation for Design Optimization
• First Law and Second Law Analysis
• Energy and Exergy Budgets for a System
• Balance of the Plant

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System Simulation for Optimization?

• Air compressor
• Gas turbine
• Fuel cell
• Heat exchanger
• Combustor
• Reformer
• Valve
• Generator
• Pressure drop

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Heat Exchanger
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Combined Port for Fluid
Combined ports for Fluid are a combination of a
natural port and a signal matrix port. The
natural port is associated with pressure and mass
flow rate while the signal matrix port is
associated with temperature and major components
(in mass ratio) of the air.
Signal Matrix Port
Natural Port Across Pressure (Pa) Through Mass
flow rate (kg/s)
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Equations for Heat Transfer
This model represents a counter flow shell and
tube heat exchanger. Fluids are not undergoing a
phase change in the process of heat transfer and
Pressure drop of fluid is not considered for this
model.
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Simulation
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Air compressor

• First basic principle was introduced to develop
  the centrifugal compressor model with energy
  transfer taken into consideration. NASA shock
  loss theory is applied to model incident loss and
  friction loss.
• Incidence loss
• Friction loss
• Clearance loss
• Backward loss
• Volute loss.

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Simulation results of compressor
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Simulation results of compressor
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Rotary Vane Pump

• The process in the vane pump is adiabatic.
• Air is considered ideal gas.
• Efficiency is the function of mass flow rate.
• Pressure difference is the function of mass
  flow
• rate and rotational speed.

• The equations for pressure and pump efficiency
  are derived from
• experimental data for a specific pump
  (G12/04-E, see reference1).

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Mathematical Description
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Simulation Results of Pump
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Gas turbine

• Energy transfer analysis was performed to develop
  the axial compressor model. Craig Coxs theory
  is used to obtain the loss coefficient .
• Profile loss
• Secondary loss
• Tip leakage loss
• Annulus loss.

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Velocity triangles for gas turbine
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• Thank you