Patent ID: 7427451

Claim:
A fuel cell system having: a fuel cell generating power as a result of chemical reactions between supplied gases, wherein a coolant flows in the fuel cell and undergoes a temperature increase as a result of absorbing waste heat produced by power generation in the fuel cell; a water tank; a humidifying device for humidifying at least one supplied gas by using water from the water tank; and a coolant temperature regulation device for regulating a temperature of the coolant flowing inside the fuel cell so as to control the temperature of the fuel cell; the fuel cell system comprising: a defrosting device for melting ice in the water tank by applying heat of the coolant to the water tank, wherein the defrosting device is disposed in the water tank and comprises a heat exchanger allowing heat exchange between the coolant from the fuel cell and the ice in the water tank; a heater for heating the coolant discharged from the defrosting device; a coolant recirculation passage for allowing a recirculation of the coolant through the defrosting device, the heater and the fuel cell; a flow generator for generating a flow of the coolant heated by the heater from the heater to the defrosting device via the fuel cell; and a controller for controlling a startup operation of the fuel cell system, the controller having the function of controlling the flow generator to generate a flow of coolant from the fuel cell to the defrosting device so as to melt ice in the water tank while the startup operation of the fuel cell system.