Numerical analysis of static and dynamic heat transfer behaviors inside proton exchange membrane fuel cell

One dimension, two-phase transient proton exchange membrane fuel cell (PEMFC) thermal models, accounting for most relevant heat sources and energy transport terms, are presented. These thermal models fully consider the thermal contact resistance between gas diffusion backing (GDB) and bipolar plate, and the dependence of thermal conductivity (TC) and specific heat capacity (SHC) on liquid water, enabling the study of static and dynamic heat transfer behaviors under current loads and water conditions. In this paper, we first discussed current loads on temperature distribution, maximum temperature, transient response, and other thermal characters within the fuel cell. A noticeable temperature jump inside the cathode catalyst layer (CCL) is observed as the current step changes, induced by the different transients of heat generation and energy transport. Subsequently, the effects of water conditions are investigated. It is found that the liquid water dramatically affects the distribution and variation of temperature due to its high TC and SHC. Lastly, sensitivity analysis reveals that the TC of dry GDB contributes much to CCL's high temperature, which indicates that improving GDB TC is very important to avoid CCL overheating and explains the lower temperature gradient inside PEMFC under relatively wet conditions.