【摘要】 建立三维稳态单流道质子交换膜燃料电池(PEMFC)模型,利用数值计算研究高温高压下加湿度对水传输及电池性能的影响,并与传统低温低压下的性能进行对比。在高温高压下,电池中的液态水含量处于较低水平,电池不易发生水淹,影响性能的主要因素为膜中水含量,因此阴、阳极100%加湿是性能最好的工况。降低阳极加湿度的影响不大;降低阴极加湿度时,膜中的水含量减小。增加电流密度,高温高压下膜中水含量的增速比低温低压下慢,阴极加湿度为20%的工况下,电流密度增到1. 4 A/cm~2时,膜中水含量仅达到4,为避免干膜,应提高阴极加湿度。相同工况时,高温高压下的净水传递系数均比低温低压下大。更多还原

【Abstract】 A three-dimensional single-channel proton exchange membrane fuel cell (PEMFC) model was developed,the effects of humidity on water transport and battery performance at high temperature and high pressure were studied by numerical calculation. The liquid water content was at a lower level at high temperature and high pressure,batteries were less likely to flood. The main factor effecting the performance was the water content in membrane,100% humidification in cathode and anode was the best working condition. Reducing humidity in anode had little effect,but decreasing humidity in cathode could reduce the water content in membrane. The water content in the membrane at high temperature and high pressure increased slower than that at low temperature and low pressure when current density increased. At the working condition of 20% humidification in cathode,the water content only reached 4 when the current density increased to 1. 4 A/cm~2. The humidity in cathode should be increased in order to avoid the dehydration of the membrane. The net water drag coefficient at high temperature and high pressure was larger than that at low temperature and low pressure.更多还原