Patent ID: 8101311

Claim:
A fuel cell system comprising: a power generation unit provided with a conduit for an oxidant gas containing at least oxygen; a casing for covering at least said power generation unit; a heat radiation unit including a plurality of radiating fins, the heat radiation unit connected to said power generation unit so as to radiate heat from said power generation unit; a separator included in the power generating unit, the separator including an upper-side portion including fuel conduits, a lower-side portion including oxidant gas channels, and a heat transfer portion formed on the lower-side portion and formed in an area corresponding to positions of the fuel conduits and the oxidant gas channels and extending beyond an outer edge of the upper-side portion so as to be formed on surfaces of the radiating fins of said heat radiation unit; a gas flow unit configured to suck said oxidant gas into a first intake port disposed on a first surface of said casing; a cooling unit configured to suck said oxidant gas into a second intake port disposed on the first surface of said casing and adjacent to said first intake port; a plurality of temperature detectors which detect a temperature of the power generation unit, the heat radiation unit, and the oxidant gas; and a humidity detector which detects a humidity of the oxidant gas, wherein an amount of moisture located inside the power generation unit and a temperature of the power generation unit are determined based on the temperatures detected by the plurality of temperature detectors and the humidity detected by the humidity detector, wherein when the amount of moisture located inside the power generation unit and/or the temperature of the power generation unit deviate from a stable zone of the power generation unit having a proper moisture content and appropriate temperature, the cooling unit is driven independently from said gas flow unit to return a state of the power generation unit to the stable zone, and wherein when the amount of moisture located inside the power generation unit is superfluous, the superfluous moisture is discharged with air by the gas flow unit.