摘要 |
A gas-supply passage (6) via which anode gas is supplied to a fuel cell unit (2) and a gas-discharge passage (12) via which anode gas is discharged from the fuel cell unit (2) are connected via a communication passage (30). Circulation pump (32) switches the communication state of the communication passage between a closed state and an opened state. Circulation pump (32) causes a gas flow from the gas-discharge passage to the gas-supply passage when the communication passage (30) is in the opened state. The communication passage (30) is normally closed, and it is opened when a predetermined condition related to the operation state of the fuel cell unit (2) is satisfied. |