| 摘要 |
PROBLEM TO BE SOLVED: To provide a fuel cell system which precisely determines by simple means whether an exhaust drain valve is frozen.SOLUTION: The fuel cell system comprises a fuel cell 11, an exhaust drain valve 52 for water contents included in fuel gas after reaction, a fuel gas concentration detector 54 installed on the downstream of the exhaust drain valve, an outdoor air temperature sensor 17, a fuel cell coolant temperature sensor 36, and a control unit 90 which outputs a command to open or close the exhaust drain valve. The control unit includes: freeze determination means which, at startup of the fuel cell, estimates the initial temperature of the exhaust drain valve from the outdoor air temperature acquired by the outdoor temperature sensor 17 and the coolant temperature acquired by the coolant temperature sensor 36 and, when the estimated initial temperature is lower than a first threshold, determines that the exhaust drain valve is frozen; and defrost determination means which, when the exhaust drain valve is determined to be frozen and a change in the fuel gas concentration detected by the fuel gas concentration detector immediately after a command to open the exhaust drain valve was issued is larger than a second threshold, determines that the exhaust drain valve has been defrosted. |
