A Parametric Study on the Planar SOFC Performance Using the Three-Dimensional Transport Equations With Electrochemical Reaction

A three-dimensional heat/fluid flow analysis procedure to predict the planar SOFC performance has been developed. The continuity, Navier-Stokes, energy and species equations, coupled with the electro-chemical relation models, are solved for the single periodic module of a unit cell which is composed of the anode/cathode channels, the porous electrodes, the electrolyte, and the interconnect. Using the FVM method of SIMPLE type, the local current density, which is proportional to the rate of chemical reaction, is determined iteratively by forcing the local current density and the mass-transfer rate at the reacting surface match. The Butler-Volmer equation is used to estimate the activation overpotential while the diffusion in the porous electrodes is simulated to accurately predict the concentration overpotential. Upon validation of the procedure, the average current density and voltage relation has been successfully obtained for the given structure. The cell characteristics, which include the local current density, temperature, and concentration distributions, are presented and discussed. The effects of various parameters, namely, the inlet temperature, the electrode thickness, and the channel/rib width, on the cell performance are carefully examined for different electric loads.