COOLING DEVICE OF FUEL CELL

PROBLEM TO BE SOLVED: To prevent an supercooled cooling medium from being supplied to a fuel cell by controlling the temperature of the cooling medium of the fuel cell even when the temperature of the cooling medium returned from a cooling medium tank is excessively lowered, in a fuel cell system having the cooling medium tank and the like as a cooling medium system. SOLUTION: This cooling device of a fuel cell is equipped with circulation passages P1 and P2 for circulating the cooling medium from the exit of the fuel cell 1 to the entrance of the fuel cell 1 through a cooling heat exchanger 2 for cooling the cooling medium heated by cooling of the fuel cell 1. The cooling device is provided with: a bypass passage Pb for bypassing a radiator 4 to short the circulation passages P1 and P2; a thermostat 4 installed on the entrance side of the fuel cell 1 in the circulation passages P1 and P2 for switching over the circulation passages P1 and P2 to the bypass passage Pb and vice versa depending on the temperature of the cooling medium; and a tank 3 capable of storing a part of the cooling medium in the circulation passages P1 and P2. The thermostat 4 is provided with a pipe for connecting a thermostat temperature sensing part to the tank 3, and the cooling medium stored in the tank 3 is returned to the circulation passages through a pipe P4 connected to the tank 3. COPYRIGHT: (C)2005,JPO&NCIPI