操作参数对PEM燃料电池中水迁移的影响

质子膜内水分和阴极多孔电极中液态水含量是PEM燃料电池正常运行的控制因素。本文给出了一个用于研究PEM燃料电池内水迁移的稳态、等温、两相流模型。模型耦合了连续方程、动量守恒方程和物质守恒方程,以及水在质子膜中传递方程。运用试验结果验证了模型的有效性。分析模拟结果表明,增大系统操作压力、升高电池操作温度和降低加湿温度将会使质子膜中水的净迁移通量增大;增大操作压力、降低操作温度和升高加湿温度会增加阴极CTL与GDL界面上液态水含量。

EFFECTS OF OPERATING PARAMETERS ON WATER TRANSPORT IN PEM FUEL CELLS

Water content in the membrane and liquid water content in the porous cathode have significant effects on the performance of PEM fuel cells. A steady state isothermal two-phase flow model is presented in this paper to study water transport in PEM fuel cells. This model couples the conservation of mass, momentum and species equations as well as water transport equation in the membrane. Simulation results indicate that the polarization curves agree well with experimental data, and that higher operating pressure and temperature of a PEM fuel cell as well as lower humidification temperature of reactants lead to the increase of net water transport flux across the membrane; higher operating pressure, higher humidification temperature and lower operating temperature result in the increase of liquid water content at the interface of CTL and GDL.