Effect of ambient air conditions on PEM fuel cell performance

Abstract

This paper focuses on the influence of inlet air temperature and relative humidity on the performance of a proton exchange membrane fuel cell (FC) stack with maximum power of 175 W. To control the inlet air temperature, a cooling system was designed and integrated with the fuel cell stack. It was experimentally proven that the lower temperature results in better fuel cell performance. This dependence was found to be non-linear in the range of 15–25 °C. To take into account air humidity and analyze its effects on FC efficiency, an air humidifier was installed at the air inlet. Experiments showed that the increased relative humidity positively affected FC efficiency. Computational fluid dynamics (CFD) simulation of the reactant flow inside the FC stack was conducted, helping to analyze thermal regime, velocity distribution, and migration of hydrogen ions through the membrane on the cathode side. The temperature on the cathode side exceeded operational limits already at 120 W power load. CFD simulation results support the need for an additional cooling system for experimental setup.