| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance detection accuracy of gas leak from a shut-off valve. <P>SOLUTION: When shifting to an idle running stop state, a controller 21 determines whether hydrogen gas leak from a shut-off valve 3c occurs or not based on change of hydrogen gas pressure on the downstream side of the shut-off valve 3c when pressure difference between the upstream side and the downstream side of the shut-off valve 3c is formed. By gas leak detection treatment like this, even when the shut-off valve 3c bites minute foreign matters not causing hydrogen gas leak, if no hydrogen gas leak from the shut-off valve arises, the pressure on the downstream side of the shut-off valve 3c reaches a target pressure value, and since the shut-off valve 3c is determined as a normal state, gas leak from the shut-off valve 3c can be detected in higher accuracy compared with the conventional gas leak detecting treatment detecting hydrogen gas leak from the shut-off valve 3c based on the closing position of a valve body. <P>COPYRIGHT: (C)2009,JPO&INPIT |
