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.