Volume 50

The effect of channel height on the performance of PEM electrolyzer Ziwei Bai, Wenzhuo Yao, Gendi Li, Jie Song, Guizhi Xu, Yuting Zhu, Jianguo Liu, Zhenlan Dou, Chunyan Zhang

Abstract

PEM electrolysis have fast load-following capability and is suitable to provide services to the power grid. The dynamic performance of electrolysis stack needs to be further improved under fluctuating renewable energy power directly input and is discussed in this work by modifying channel height of flow field. A numerical dynamic models of different field channels are implemented with CFD and both I-V curves, temperature distribution, pressure drop, and oxygen content in outlet water are discussed separately. It is found that the channel height has significant impact on the electrolysis characteristics including response delay, and pressure drop. Electrolyzer with flow field of 0.5mm channel height has the best dynamic performance. Under this condition, the electrolyzer`s current density reaches 3A/cm2 at 2.15V, and the response delay of single channel flow field decreased by 26% to 0.28s. This work can provide simulation support for the designation of PEM electrolyzers’ flow fields.

Keywords electrolyzer, channel height, dynamic response characteristics, computational fluid dynamics analysis.