Abstract
The passive type PEFC cannot operate stably longer than several hours even with the hydrogen circulating system, which uses the pressure difference of 5-15 kPa generated by repetition of opening and closing of the hydrogen supply valve. In this paper, water transport in the hydrogen circulation system was investigated using the transparent acrylic modul. The results showed that the output voltage fluctuation increased as the amount of circulating hydrogen decreased. This is probably because the generated water accumulated inside the system when the amount of hydrogen circulating flow decreased. The hydrogen supply channels inside the system were visualized and it was found that water plugging and backflow of water were clearly observed near the exit of the channels.
