Numerical investigation of the water transport and performance of proton exchange membrane fuel cell with an imitating river flow field

The cathode flow field design of proton exchange membrane fuel cell (PEMFC) could improve water management, avoiding local material failure, increasing oxygen transport and power output. In this study, a novel cathode flow field that imitates river diversion drainage is proposed for settling the issue of channel drainage, under-rib porous layers drainage and balanced water management. A numerical model of the 3D multiphase flow is built for comparative study to reveal the water transport and performance of PEMFC. In the novel flow field, the opened-trap diverts the liquid water of cathode channel to auxiliary channel and increases the gas velocity in cathode channel to drain more water, thereby, 50% liquid water in cathode channel is removed compared to conventional flow field. Micro flume design in auxiliary channel is used to provide the drainage path for underrib porous layers, meanwhile collected liquid water for convenience to auxiliary channel drainage. The balance water management of novel flow field promotes the downstream drainage and upstream water retention. Effective water management can enhance mass transfer and PEMFC performance. Compares with the conventional flow field, the novel flow field does not increase pressure drop, improves the PEMFC net power and CCL/ PEM oxygen concentration by 13.3% and 1.23 times, respectively.

Automated summary

A novel cathode flow field design, resembling river diversion drainage, is proposed to solve the issues of channel drainage and under-rib porous layers drainage, and to achieve balanced water management. Compared to the conventional flow field, this new design does not increase pressure drop and improves the net power and oxygen concentration of the proton exchange membrane fuel cell (PEMFC).