Novel design and numerical investigation of a windward bend flow field for proton exchange membrane fuel cell

Abstract

3D flow field design usually improves the performance of proton exchange membrane fuel cell (PEMFC) with the penalty of a dramatically increasing pressure drop. To surmount this issue, a novel windward bend flow field that exhibits superior mass transfer performance under a constant pumping power is proposed in this study. The performance of PEMFC with windward bend flow field is numerically compared with two canonical 3D flow fields, namely 3D wave flow field and cutting cylindrical baffles flow field. Results demonstrated that compared with two canonical 3D flow fields, windward bend flow field gets a better water management capability. The optimal distance, tilt angle and direction for the windward bend structure embedded in channel are 2.0 mm, 15° (at the direction of the front section of the windward bend structure tilts towards membrane electrode assembly). Furthermore, the average enhancement rate of the maximum power density of PEMFC with optimal windward bend flow field is 7.6 % and 12.4 % compared with cutting cylindrical baffles flow field and 3D wave flow field owing to the larger Sherwood number of optimal windward bend flow field under the specified pumping power range.