FUEL CELL SYSTEM AND OPERATING METHOD THEREFOR

Fuel cell system (100) includes a fuel cell which generates power by using fuel, exhaust gas path (1) on which an exhaust gas flows, water circulation path (3) on which cooling water for cooling heat generated from the fuel cell circulates, and first heat exchanging apparatus (4) that is provided on exhaust gas path (1) and water circulation path (3), and performs heat exchange between the exhaust gas and the cooling water. Fuel cell system (100) further includes a tank which is provided for collecting condensed water generated by cooling the exhaust gas in first heat exchanging apparatus (4), radiator (6) that is provided on water circulation path (3) and dissipates heat of the cooling water, and circulation pump (7) that is provided on water circulation path (3) and causes the cooling water to be circulated. Fuel cell system (100) further includes control apparatus (8) which is configured to operate to switch between a first operation mode and a second operation mode. In the first operation mode, a temperature of the cooling water after passing through radiator (6) is controlled to be a first predetermined temperature by adjusting an amount of dissipated heat by the cooling water in radiator (6). In the second operation mode, the temperature of the cooling water is controlled to be a second predetermined temperature which is higher than the first predetermined temperature.