Numerical investigation of water and temperature distributions in a proton exchange membrane electrolysis cell

A three-dimensional, non-isothermal, two-phase model for a PEM water electrolysis cell (PEMEC) is established in this study. An effective connection between two-phase transport and performance in the PEMECs is built through coupling the liquid water saturation and temperature in the charge conservation equation. The distributions of liquid water and temperature with different operating (voltage, temperature, inlet velocity) and physical (contact angle, and porosity of anode gas diffusion layer) parameters are examined and discussed in detail. The results show that the water and temperature distributions, which are affected by the operating and physical parameters, have a combined effect on the cell performance. The effects of various parameters on the PEMEC are of interaction and restricted mutually. As the voltage increases, the priority factor caused by the change of inlet water velocity changes from the liquid water saturation increase to the temperature drop in the anode catalyst layer. While the priority influence factor caused by the contact angle and porosity of anode gas diffusion layer is the liquid water saturation. Decreasing the contact angle or/and increasing the porosity can improve the PEMEC performance especially at the high voltage. The results can provide a better understanding of the effect of heat and mass transfer and the foundation for optimization design.