Abstract
For improving performance of the stationary Polymer Electrolyte Fuel Cell (PEFC) system, the cell operating temperature up to 90°C will be preferred in Japan during the period from 2020 to 2030. To understand the operation of the PEFC system under relatively high temperature conditions, detail heat and mass transfer analysis is required. The main focus of this study is to analyze the PEFC performance under operational conditions, such as initial operational temperature of cell (Tini), relative humidity of supply gas, and the cathode gas type, temperature distribution in a cell of PEFC (using Nafion membrane) under relatively higher operating temperature conditions. The in-plane temperature distributions on backside of gas separator of cell under power generation were measured using thermograph and it was observed that the in-plane temperature distribution at the anode was more uniform than that at the cathode under the O2 supply condition, irrespective of Tini, relative humidity of supply gases except Tini of 100°C. As to Tini of 100°C, the in-plane temperature distribution at the anode was broader since the back diffusion of water from the cathode to the anode was helped compared to the other Tini. The temperature at the cathode was raised through the gas channel toward the outlet of cell for the relative humidity of supply gases of 100 %RH at Tini of 90°C, while the temperature increase was relatively smaller at Tini of 80°C. The in-plane temperature distribution at the anode under the air supply condition was broader compared to not only that at the cathode, but also that at the anode under the O2 supply condition. It is necessary to manage the water concentration (liquid water accumulation in gas channel and gas diffusion layer (GDL) as well as relative humidity in PEM and catalyst layer) and required O2 supply in order to obtain a good power generation performance of PEFC under relatively higher temperature operating conditions than usual.
