| 摘要 |
PROBLEM TO BE SOLVED: To enable operation of a fuel cell at higher temperature while securing efficient operation of the fuel cell in a fuel cell system.SOLUTION: In the fuel cell system 10, used gas exhausted from an anode-side gas outlet 54 of a fuel cell stack 14 is made to return to a circulation flow passage 60 by increasing its humidity, or moisture of the used gas is made to return to the circulation flow passage 60 as it is without separation, and a dew point-adjusting part 70 to adjust the dew point θ of gas supplied to an anode-side gas inlet 52 is installed at a vapor-liquid separator 58. In a control device 80, a threshold temperature Tof a cooling water for the fuel cell preliminarily set when operated in high temperature operation conditions set close to the upper limit of efficient operation conditions of the fuel cell stack 14, a cooling water temperature Tdetected by a cooling water thermometer 36 are compared, and operation of the dew point adjustment part 70 is controlled according to a difference between the threshold temperature Tand the cooling water temperature T. |
