FUEL CELL SYSTEM

PROBLEM TO BE SOLVED: To provide a fuel cell system which enables keeping temperature of water to be substantially constant, in a water tank of the fuel cell system by preheating water being supplied to the water tank, using exhaust heat generated in the fuel cell system. SOLUTION: Electric power is generated, by supplying an anode of a fuel cell 5 reformed gas being mainly constituted of hydrogen, which is made from raw fuel gas (domestic fuel gas, etc.), using a fuel reforming device A comprising, desulfurization equipment 1, reforming equipment 2, a carbon monoxide transformer 3 and carbon monoxide eliminating equipment, and by supplying a cathode of the fuel cell 5 humidified air made by bubbling air in a water tank 6. A first preheating circuit 9, through which ion exchange water from a demineralized water device 7 flows to the water tank 6 via a cell-exhausting air heat exchanger 8, is disposed. The ion exchange water is preheated to an appropriate temperature, by exchanging heat between air from the cathode flowing into the cell exhausting air heat exchanger 8 before the bubbling and the ion exchange water of the normal temperature. COPYRIGHT: (C)2003,JPO