Performance analysis of planar-type unit SOFC considering current and temperature distributions

The solid oxide fuel cell(SOFC) is expected to be a candidate for distributed power sources in the next generation, due to its high efficiency, high-temperature waste heat utilization and low emission of pollutants to the environment. In this study, a quasi-two- (co- and counter-flow) and three- (cross-flow) dimensional simulation program for planar-type SOFC was made considering mass, charge and heat balances along the flow directions and perpendicular to the electrolyte membrane, in order to obtain temperature and current density distributions along the flow direction. Numerical results from this simulation with adiabatic boundary conditions show that the temperature increases along the flow direction in the co-flow case and the temperature profile has a maximum near the fuel inlet in the counter-flow case. The effects of the gas re-circulation ratio, operating pressure and physical properties on current and temperature distributions were also studied. The temperature distribution is uniform irrespective of flow type under the boundary condition of radiative exchange between the outer interconnector and the electric furnace surface with a realistic view factor. Temperature and current density profiles are discussed considering the Nernst potential and overvoltage changes along the flow direction. (C) 2000 Elsevier Science B.V. All rights reserved.