Numerical investigation of influence of cross-sectional dimensions of flow channels on PEM fuel cell performance

Proton exchange membrane fuel cell (PEMFC) has acquired increasing importance because of operating at higher efficiency and producing environmentally friendly power at low temperatures over the past decade. Flow channel as a vital part of PEMFC plays a critical role for augmenting the performance of PEMFC. In this paper, a single phase, 3-D model is generated to examine impact of the channel cross-section geometry on the cell performance. 15 different simulation cases were gained by altering the flow channel width and depth from 0.2 to 1.6 mm for the fixed depth and width of 1 mm, respectively. In the base case, the channel dimensions are 1.0 mm width and depth. The results revealed that decreasing depth and width of the channel enhanced the current density thanks to increasing gas velocity in the flow channels of the anode and cathode at the expense of increased pressure drop. The cases having the channel cross-sectional dimensions of 0.2 x 0.1 mm and 0.1 x 0.2 mm (channel width x depth) enhanced the current density about 57% and 45% at 0.4 V compared to the base case. Besides, oxygen consumption and water production in the cathode side are also remarkably increased in these cases. However, the channel cross-sectional size of 0.8 x 1 mm case which increases the current density 2.5% at 0.4 V in comparison with the base case can be best option by taking into consideration pressure drop into the flow channels.