Numerical study on the effect of bi-polar plate geometry in the SOFC heating-up process

Structural failure often occurs in the heating-up process of a solid oxide fuel cell (SOFC) due to thermal shock. The bi-polar plate of a planar-SOFC, which consists of gas channels and current collectors, significantly affects the temperature rise and distribution in the SOFC unit. Thus, in this work, a 3D transient heating-up model is developed to study the effect of the bi-polar plate geometry on the SOFC heating-up process and the model results agree well with the results reported in the literature. The effects of the ratios of channel width to height (alpha) and channel width to rib width (beta) on the temperature increasing rate and temperature distribution in a single-channel SOFC unit are numerically studied. The results show that the volume of bi-polar plate dominates the temperature increasing rate and heating-up time due to its largest theoretical heat absorption quantity. The max temperature gradient both parallel to the channel and perpendicular to the electrolyte decreases with the increase in beta, due to the decrease in the bi-polar plate volume, but the max temperature gradient perpendicular to the channel increases with the increase in alpha and beta (except beta = 0.5) due to the rib effect. These different relations are important for the optimization of bi-polar plate geometry. Published under license by AIP Publishing.