质子交换膜燃料电池停机策略的实验研究

Experimental Study on Shutdown Strategy of Proton Exchange Membrane Fuel Cells

质子交换膜燃料电池(PEMFC)停机过程中引起性能衰减的根本原因是阳极侧残留有氢气。为了满足快速消除电堆内残留的氢气,研究提出了利用空冷电堆的风扇对电堆放电和使用辅助负载对电堆中各个单电池单独放电的停机控制策略。通过实验研究对比了直接停机、利用辅助负载整体放电和利用辅助负载对各个单电池单独放电三种停机方式对PEMFC性能的影响。结果表明,利用辅助负载对各个单电池单独放电的停机策略不仅能缩短燃料电池停机后各个单电池维持在高电位的时间,同时也能防止PEMFC停机放电过程中单电池反极现象的发生,是一种十分有效的质子交换膜燃料电池停机策略。

The decrease of proton exchange membrane fuel cell performance during shutdown process is mainly due to the existence of residual hydrogen in the anode side. In order to quickly eliminate residual hydrogen, two shutdown control strategies （which discharge every single fuel cell using air-cooling stack fans and auxiliary load, respectively） were proposed in this paper. Effects of three shut-down strategies including direct shut-down, overall discharging shut-down and individually discharging shut-down using auxiliary load were studied on the performance of PEMFC. The results demonstrate that the strategy proposed can shorten the time for each cell remaining under high voltage and prevent the occurrence of single cell reverse polarity during shutdown, which proves the effectiveness of the proposed strategy.