Abstract: Reasonable design of flow channel will effectively improve the performance of proton exchange membrane fuel cell (PEMFC). A novel stepped flow channel model was established for PEMFC, and the numerical simulation experiments were carried out according to two proposed experimental schemes. The effects of the structure parameters of the stepped flow channel on the distribution of oxygen and water mass fractions, pressure drop in the flow channel and electrochemical characteristics of PEMFC were studied by comparing with the conventional flow channel. The results show that, compared with the conventional flow channel structure, the stepped flow channel structure will effectively improve the uniformity of oxygen distribution and water distribution in the cell, and its maximum power density will be increased by 13.58%, but it will produce a big pressure drop in the flow channel. When the inlet and outlet height of flow channel of PEMFC is fixed, the pressure drop in flow channel will be reduced with the increase of the number of steps, and the maximum pressure drop can be reduced by 24.9%.

Key words: vehicle engineering; proton exchange membrane fuel cell; stepped flow channel; numerical simulation; fuel cell performance

摘要： 合理的流道设计能够有效改善质子交换膜燃料电池（PEMFC）的性能。针对PEMFC建立了一种新型的阶梯型流道模型,并根据提出的两种实验方案进行了数值模拟实验。通过与常规型流道进行对比分析,研究了阶梯型流道结构参数对PEMFC氧气和水质量分数分布、流道内的压降和电化学特性的影响。结果表明,与常规型流道结构相比,阶梯型流道结构可以有效改善电池内氧分布和水分布的均匀性,其最高功率密度最大可以提升13.58%,但在流道内会产生较大的压降。当流道进出口高度一定时,通过增加阶梯数量可以减小PEMFC阴极流道内的压降,最大可降低24.9%。

关键词: 车辆工程；质子交换膜燃料电池；阶梯流道；数值模拟；燃料电池性能