| 摘要 |
PURPOSE:To prevent the characteristics such as the electrolyte holding force and gas pressure resistance of a matrix membrane from being deteriorated by feeding the wet gas to lower the electrolyte density when an operation is stopped in an electrolyte fixed type fuel cell. CONSTITUTION:Feed valves 17, 20 of a fuel gas system and oxidizer gas system are closed, the inlet and outlet valves 24, 25 of an N2 gas humidistat and a valve 26 are opened, the N2 gas is fed with its humidity being controlled at a fixed level by a humidistat 23, and the water is absorbed by phosphoric acid so as to lower the density to 75wt%. Around the density of 75wt%, the cryohydrate point of phosphoric acid is about -20 deg.C, and at this temperature the phosphoric acid being held on the matrix membrane and reaction boundary of the electrode catalyst layer is prevented from being crystallized and deposited. |
