| 摘要 |
PROBLEM TO BE SOLVED: To provide a fuel cell system which can store hot water in a hot water storage tank even under difficult conditions to store the hot water in the hot water storage tank because of the small amount of power generation and the small amount of circulation of heat recovery water.SOLUTION: When the state that the temperature detected by a low temperature sensor 206 is equal to or lower than a first low predetermined temperature lower than the stop temperature requiring the stop of power generation of a fuel cell 101 and a circulation pump 103 is continued for a predetermined period of time, in situations that the temperature detected by a high temperature sensor 108 is lower than the target temperature of the hot water storage tank 104, and equal to or lower than a first high predetermined temperature higher than the stop temperature, the state that the temperature detected by the low temperature sensor 206 is higher than the first low predetermined temperature, and equal to or higher than a second low predetermined temperature not more than the stop temperature is continued for the predetermined period of time, or a passage switching vale 204 is switched so that the hot water from a heat exchanger 102 flows from the passage switching valve 204 through the branched heat recovery piping 205 and flows out to the lower part of the hot water storage tank 104 until the temperature detected by the high temperature sensor 108 exceeds the first high predetermined temperature. |
