Patent ID: 8277994

Claim:
A fuel cell system comprising: an anode gas flow path supplied with an anode gas; a cathode gas flow path supplied with a cathode gas; a fuel cell generating electricity by the anode gas being supplied to the anode gas flow path and the cathode gas being supplied to the cathode gas flow path; an anode gas supplying unit supplying the anode gas to the anode gas flow path; a blowdown valve ejecting fluid from inside the anode gas flow path towards an exterior; and a control unit which controls the anode gas supplying unit and the blowdown valve, supplies the anode gas from the anode gas supplying unit to the anode gas flow path, and performs a periodic fluid substitution by opening the blowdown valve periodically, wherein the blowdown valve comprises at least a first blowdown valve provided in the anode gas flow path and a second blowdown valve provided at a lower stream side of the first blowdown valve; and the control unit comprises a low temperature condition determination unit programmed to determine whether or not a low temperature condition is present after the fuel cell is activated, and when the low temperature condition determination unit determines that a low temperature condition is present, the control unit is programmed to perform fluid substitution within the anode gas flow path by increasing an amount of fluid ejected from the first blowdown valve or the second blowdown valve to be greater than an amount of fluid ejected during the periodic fluid substitution.