氢空PEMFC发动机的几个须关注的问题

针对一个2.5kW氢空质子交换膜燃料电池(PEMFC)堆,研究了不同负载下电堆侧面的温度分布、不同温度下电堆极化曲线、以及不同电流时单电池电压的变化。实验表明,PEMFC发动机设计中以下几个问题应该予以关注(1)电堆温度分布具有明显非均匀性,中心温度一般比边缘高,减小温度不均匀性对于充分发挥电堆性能具有重要意义;(2)低温下电堆性能比高温低很多,并且低温大电流时电堆难以稳定,这增加了发动机低温启动难度;(3)单电池一致性的提高,可以提高电堆性能,减小辅助系统功率和体积。

Several important aspects of H2-air PEMFC engine

The polarization curves at different temperatures, the voltage fluctuation among single cells and the local temperature on the side face of a 2.5 kW proton exchange membrane fuel cell (PEMFC) stack were studied. The experimental results show that several aspects should be paid attention to during the development of the H2-Air PEMFC engine. Firstly, the local temperature is not uniform across the entire PEMFC stack. The temperature at the central area of the side face is often higher than the outer part by several percent degrees, which lowers the capability of the stack. Secondly, the performance of the stack at lower temperature is worse than that of at higher temperature, and the stack cannot work steadily at lower temperature but larger current. It is difficult to start the engine at low temperature. Thirdly, the increase of consistency among cells can improve the performance of the stack, and reduce the power and size of the auxiliary systems of the engine.