Numerical Simulation of Single Solid Oxide Fuel Cell Performance By Coupling Dynamics of Electrochemical Flows with Thermal Impact on Solid Electrolytes

Monday, October 12, 2015: 09:20
106-A (Phoenix Convention Center)
T. N. Chaudhary (Heriot Watt University) and B. Chen (Heriot Watt University)
It has been recognized that the thermal impact is the major concern for the electrolyte of Solid Oxide fuel cells (SOFC) due to the high temperature operating conditions. Therefore, it is necessary for engineering design to understand the mechanism of heat transfer from fuel/air reacting to the anode and cathode for cell designs. A numerical model has been developed for a single solid oxide fuel cell by coupling dynamics of electrochemical reacting flows, heat transfer, and thermal strengths of solid porous electrodes for analysing the cell performance. The Finite element method (FEM) is used for numerically solving the set of transportation equations. The developed model is applied to simulate the bench mark case of International Energy Agency (IEA) for both the co-flow and counter flow. The comparison shows a good agreement with the errors of 13% in current density value and 4% in maximum temperature with those of bench mark case. In case of co-flow the maximum temperature about 1109 °C is found at fuel outlet side. In case of counter flow the maximum temperature is 1118 °C and is observed at fuel inlet side.  Predicted temperature distribution is applied to estimate the thermal stresses developed in the cell. Modelling results from simulations of a single unit of the SOFC cell operated at temperature of 900 °C, pressure of 1.01 bar, and the Reynolds number of 44.7 and 0.646 for air and fuel flows under adiabatic boundary condition, show that the maximum thermal stress produced in the cell is about 2600 MPa in the electrolyte at about 5mm away from the fuel inlet. Another case is simulated by considering convective heat flux boundary condition at top and bottom of the cell. The maximum thermal stress produced in this case is about 1820 MPa. The details of model development and the more results from the simulations will be reported in the full paper for predicting the effects of the thermal deformation of anode and cathode on the performance of a SOFC.