Effects of Channel Cross-Section Geometry on the Performance of Polymer Electrolyte Membrane Fuel Cells

Abstract

Abstract. In this study, the effects of the flow-field cross-section geometry on the polymer electrolyte membrane fuel cell's performance were investigated by using a three-dimensional numerical model. For this purpose, the fuel cells with rectangular, triangular, trapezoidal, and semi-elliptical channel cross-section geometries were modeled. When changing the channel geometry, one or more of the channel cross-sectional area sizes, channel height, channel width, flow collecting plate shoulder width, and cell width sizes changed. Therefore, the influence of the flow-channel cross-section geometries was examined for four cases. With the change in channel geometry, the cross-sectional areas are unequal in the first case. In the second case, by varying channel heights, the flow-field areas were equalized. To equalize the flow-field area sizes, in the third case, the channel and shoulder widths of the current-collector plate were set differently for each geometry. Lastly, in the fourth case, the channel and cell widths were treated differently. Among the four investigated cases, the influence of channel cross-sectional geometry was found to be most pronounced in Case-4. In Case-4, the cell voltage and power values obtained for varying channel-section geometries can be sorted as triangular > semi-elliptical > trapezoidal > rectangular.