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 distribut ed power sources in the next generation, due to its high efficiency, high-t emperature waste heat utilization and low emission of pollutants to the env ironment. In this study, a quasi-two- (co- and counter-flow) and three- (cr oss-flow) dimensional simulation program for planar-type SOFC was made cons idering mass, charge and heat balances along the flow directions and perpen dicular to the electrolyte membrane, in order to obtain temperature and cur rent density distributions along the flow direction. Numerical results from this simulation with adiabatic boundary conditions show that the temperatu re increases along the flow direction in the co-flow case and the temperatu re 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 pr operties on current and temperature distributions were also studied. The te mperature distribution is uniform irrespective of flow type under the bound ary condition of radiative exchange between the outer interconnector and th e electric furnace surface with a realistic view factor. Temperature and cu rrent density profiles are discussed considering the Nernst potential and o vervoltage changes along the flow direction. (C) 2000 Elsevier Science B.V. All rights reserved.