Patent ID: 6899969

Claim:
A fuel cell system comprising: a fuel cell that generates electricity by an electrochemical reaction; a cooling medium channel which is formed in the fuel cell and through which a cooling medium passes; a pump which moves the cooling medium through the cooling medium channel; a temperature sensor positioned to detect a temperature reflecting an internal temperature of the fuel cell; a control pardon which stops the pump when the temperature detected by the temperature sensor is equal to or lower than a first predetermined temperature, wherein the control portion drives the pump to adjust a flow rate of the cooling medium according to the temperature detected by the temperature sensor if the temperature exceeds the first predetermined temperature; and wherein the control portion controls the pump such that when the temperature detected by the temperature sensor is higher than the first predetermined temperature and is equal to or lower than a second predetermined temperature which is higher than the first predetermined temperature, a degree of increase in flow rate is kept lower compared with the degree of increase in flow rate according to a rise in temperature when the detected temperature is higher than the second predetermined temperature.