氢气循环条件下燃料电池中氮气和水传输特性研究

Analysis of nitrogen and water transport in proton exchange membrane fuel cell under hydrogen recirculation

质子交换膜燃料电池系统在氢气循环的运行过程中,阴极侧空气中的氮气和水会穿过质子交换膜渗透到阳极并逐渐积累,降低阳极的氢气浓度,影响燃料电池系统的发电性能。通过研究电堆结构参数和运行参数对氮气和水从阴极渗透到阳极的传输过程,发现氮气的渗透主要受膜厚度、膜湿度和气体压力的影响,而水的渗透除了膜厚影响以外,还受电流的大小的影响。这些结果为氢气循环条件下燃料电池系统稳定运行和制定合理的尾气排放策略提供理论依据和设计参数。

During the operation of proton exchange membrane fuel cell(PEMFC)systems,nitrogen and water in the air at the cathode side penetrate through proton exchange membranes into anode and accumulate gradually,which reduces hydrogen concentration in anode and affects power generation performance of PEMFC systems.This study finds that the permeation of nitrogen is mainly affected by proton exchange membrane(PEM)thickness,PEM humidity and gas pressure.In addition to PEM thickness,water penetration is also affected by current.These results provide theoretical basis and designing parameters for stable operation of PEMFC systems under hydrogen cycle conditions,and they can also be used for building reasonable exhaust emission strategies.