Numerical investigation and experimental verification of liquid water dynamic transfer characteristics in the flow field of PEMFC with dead-ended anode during gas purging

Abstract

Water accumulation in the anode during the operation of a proton exchange membrane fuel cell with the dead-ended anode (DEA) has a significant impact on its performance. In this study, numerical simulation and experimental verification were combined to investigate the water accumulation and water dynamic transfer characteristics in the anode flow field during dead-ended operation and gas purging, respectively. The effects of placement orientation, surface wettability, and purge time on the water dynamic transfer characteristics are investigated. The results show that the placement orientation has significant effects on the water distribution characteristics and drainage for PEMFC. When placed vertically and with a purging time of 50 ms, the liquid water saturation in the channel is 5.52 %, which drains 14.91 % more water than that of horizontal placement. Besides, Water discharge velocity and water removal ratio should be considered comprehensively in the development of the purge strategy, the optimal purging time is 70 ms with the water discharge velocity and water removal rate are 0.39 μl/ms and 97.34 %, respectively. Finally, the transfer process of liquid water in the flow field with DEA mode is observed by visual experiment, and the results of the numerical simulation are verified.