| 摘要 |
PROBLEM TO BE SOLVED: To prevent a gas from inversely flowing in a recycle circuit, and make a recycle flow rate larger by using a pipe which has a larger pipe size of the recycle circuit. SOLUTION: This has the recycle circuit 4 of an off-gas, which is laid of pipes between an off-gas exit of a fuel cell 1 and a suction port of an ejector 3, a recycle line valve 12 to open and close the recycle circuit 4, a pressure sensor 11 to detect a nearby pressure of the suction port of the ejector 3, a gas purge line 7 to be branched from the off-gas exit of the recycle circuit 4 and the recycle line valve 12 and to open in atmospheric air side, and a gas purge line valve 13 to open and close the gas purge line 7. When the detected value of the pressure sensor 11 does not exceed a prescribed value, the recycle line valve 12 is closed, and reverse flowing of the fuel gas to the recycle circuit is prevented by opening the gas purge line valve 13. |
