Numerical investigation of baffle shape effects on performance and mass transfer of proton exchange membrane fuel cell

Abstract

Flow channels with baffles can enhance the transport of reactants and improve the performance of proton exchange membrane fuel cell (PEMFC). In this study, five different structures of flow channels with baffles are proposed, and the mass transfer and cell performance of PEMFC with different baffled channels are compared by CFD method. The results show that the PEMFC with a cutting cylindrical baffle has the best performance with an output current density of 1.82 A/m2 when the voltage is 0.4 V. Baffle design can promote reaction gas transmission while also increasing reaction gas concentration in the channel. Due to the circular arc surface design of the cylindrical section, the mass transfer enhancement effect of cutting baffles is better. When the fluid passes through the baffles, the velocity magnitude also changes abruptly due to the disturbance effect, and the more effective convection brought about by the reactants being pushed into the catalytic layer can enhance the mass transfer in the PEMFC and obtain better performance. The presence of baffles will increase the accumulation of water, the smaller the cross-sectional area, the better the water removal effect. Vortex generation will result in large parasitic power, which is detrimental to the performance of the PEMFC.