FUEL BATTERY SYSTEM AND ITS OPERATING METHOD

摘要

A fuel battery system exhibiting an adequately ensured proton conductivity and an adequately ensured energy conversion efficiency, adaptable to a start-and-stop operation mode, including a polymer electrolytic membrane effectively prevented from degrading, and having an excellent durability is provided. Its operating method is also provided. The fuel battery system (100) comprises a fuel battery (11), a fuel gas supply unit (16) and an oxidizing agent gas supply unit (17), a temperature control unit (19) for controlling the temperature of the fuel battery, and a humidifier (18) for humidifying the oxidizing agent gas. The system further comprises a control unit (20) for making a control so as to keep the dew point of the fuel gas above the temperature of the fuel battery, keep the dew point of the oxidizing agent gas below the temperature of the fuel battery, and at least equalize the temperature of the fuel battery to the dew point of the oxidizing agent gas before the fuel battery is electrically disconnected from the load.