For an anode-supported planar SOFC, a single-unit with double channels was
modeled for a counter-flow pattern, and the concentration polarization at t
he anode was estimated. The flow phenomena were simulated using the finite
volume method and the distribution of the gaseous species was calculated. I
n the model, it was assumed that the gas flow in the porous anode is govern
ed by Darcy's Law, and the reactant species are transported to the electrol
yte/anode interface mainly by diffusion in a multicomponent mixture system.
For binary H-2-H2O and CO-CO2 systems, the calculated concentration polari
zation was found comparable to the experimental results. As an example for
a multicomponent system, a model using steam-reformed methane as a fuel was
employed to simulate the concentration polarization at a high fuel utiliza
tion. From the simulated results, it was evident that the shift reaction ef
fectively reduces the concentration polarization when the fuel utilization
is high. (C) 2000 Elsevier Science S.A. All rights reserved.