抄録
To know the movement of water in Polymer Electrolyte Fuel Cell (PEFC) is important for deciding the optimum shape of the cell and the optimum operating condition. And it is well known that PEFC shows the best performance under moderate relative humidity condition. However, the experimental measurement is difficult because of the flow through the complex geometry of diffusion layer. Therefore, in order to know the movement of water in PEFC, microscopic analysis was performed by lattice gas automata (LGA) method. The influence of gas diffusion prevention by water was investigated. In addition, the relationship between reaction time and reaction quantity for PEFC with dry membrane was investigated. A reaction quantity, which had increased due to membrane getting more wet by generation water, decreased due to gas diffusion prevention by water, and after a while, it settled into steady state. According to the channel configuration, a distribution of water was observed in the diffusion layer and a distribution of oxygen and hydrogen reaction quantity was affected. Moreover, since the influence of gas diffusion prevention by water in the cathode side was more extremely than that in anode side, it was shown that concentration overpotential of cathode side affects a cell performance greatly.
