外界供给参数对PEMFC输出性能及水热平衡的影响

为了改善质子交换膜燃料电池(PEMFC)内部的水热平衡,从而进一步改善PEMFC的输出性能,文章建立了PEMFC的三维模型,通过改变PEMFC的外界供给参数(进气速度、加湿率以及冷却水流速),应用COMSOL模拟仿真得到了PEMFC的极化曲线和功率曲线、流道和气体扩散层(GDL)的水浓度分布情况,以及冷却水流速对PEMFC温度的影响。研究结果表明:随着进气速度和加湿率的逐渐增加,PEMFC的输出性能均逐渐提升,但是,过高的加湿率可能导致电极水淹;随着冷却水流速的增加,PEMFC温度加速下降,膜内温度分布变得更均匀。

Effects of external supply parameters on the output performance and hydrothermal balance of PEMFC

In order to improve the output performance of proton exchange membrane fuel cell(PEMFC)and maintain the balance of water and heat,a three-dimensional model of PEMFC was established.By changing the supply parameters(inlet velocity,humidification ratio and flow rate of cooling water),COMSOL was used to simulate the polarization and power density curves,the water distribution in flow channel and gas diffusion layer(GDL),including the influence of cooling water on the temperature were presented,respectively.The results show that with the increase of inlet velocity and humidification ratio,the output performance of PEMFC is gradually improved,but excessive humidification may lead to electrode flooding.Increasing flow rate of cooling water,the temperature of PEMFC decreases rapidly,and the temperature distribution in the membrane becomes more uniform.