| 摘要 |
A preferred stopping method for a SOFC system of the invention leads to an improvement in durability. The SOFC system houses a reformer (6) and a fuel cell stack (10) in a module case (2). Each cell (20) forming the fuel cell stack (10) is made of a porous material having a composition containing at least nickel metal, includes a cell support having a gas passage (22) through which the fuel gas from the reformer (6) flows from an lower end to an upper end on the inside thereof, and the cell (20) is formed by stacking a fuel electrode layer, a solid oxide electrolyte layer, and an air electrode layer on the cell support, and the excessive fuel gas is combusted at the upper end of the gas passage (22). Here, after the power generation stops, until the temperature of the maximum temperature portion (the upper end) of the fuel cell stack (10) falls below the minimum oxidation temperature of the nickel metal, the supply amount of the fuel gas to the fuel cell stack (10) is controlled in terms of a heat flow rate within a range of 0.1 to 0.5 times that during the system rated power generation. |
