Effect of inlet air temperature and relative humidity on performance of pem fuel cell

Abstract

Present paper investigates the influence of inlet air temperature and relative humidity on performance of a PEM Fuel Cell stack with maximum power of 175 W. In order to control the inlet air temperature, a cooling system was designed and implemented. Changing the inlet air temperature in the range between 15°C and 25°C, it was experimentally proved that the lower temperature results in better fuel cell performance. This dependence was found to be non-linear. Next step of the research was to take into account the air humidity and to analyze the cooling effect on membrane productivity. For this purpose, an air humidifier and a sensor were installed into the inlet channel. Experiments showed that the efficiency of the system is increasing with the growing relative humidity. CFD simulation of the reactants flow inside the FC stack was conducted, helping to analyze thermal regime, velocity distribution and migration of hydrogen ions through the membrane on a cathode side. Using experimental data, it was detected that temperature on cathode side exceeds operational limits already at 120W power load.