セパレーター厚みが高温運転PEFC単セル内の水分移動特性と温度面分布に及ぼす影響

抄録

According to the NEDO road map 2017, the high temperature condition over 90 °C is the target operation temperatures of PEFC systems for stationary and vehicle application from 2020 to 2025. Power generation experiments were conducted for a single cell of PEFC at 80 °C, 90 °C, and 100 °C using three different thicknesses of separator. The flow rate/relative humidity of inflow gas was varied. The temperature distribution on the separator back at anode and cathode was measured by a thermograph. The water rate difference between the outlet and the inlet at the anode and the cathode was also measured using a dew point meter. As a result, under the low relative humidity condition at cathode, the amount of electro-osmosis water was larger than that of back diffusion water, resulting in the water transfer from the anode to the cathode. In case of the separator thickness of 2.0 mm, it is confirmed that the temperature rises at the positions I and Q which are the corners of separator. The vapor remains at the positions I and Q and the concentration of vapor increases, resulting that it is condensed generating the heat. In addition, it is confirmed that the temperature decreases at the position L and near the outlet. The liquid water produced at the positions I and Q moves to the position L and near the outlet, which causes the gas diffusion inhibition, resulting in the temperature drop.