METHOD AND DEVICE FOR STOPPING SOLID-OXIDE FUEL CELL SYSTEM

摘要

The present invention provides a suitable method for stopping an SOFC system whereby durability of said system is improved. In an SOFC system, a reformer (6) and a fuel cell stack (10) are stored within a module case (2). The cells (20) constituting the fuel cell stack (10) are formed from a porous substance having a composition containing at least a nickel metal, and contain a cell support body having in the interior thereof a gas flow path (22) through which fuel gas from the reformer (6) flows from the bottom edge to the top edge. A fuel electrode layer, a solid-oxide electrolyte layer, and an air electrode layer are laminated on the cell support body, and excess fuel gas is burned at the top edge of the gas flow path (22). After power generation is stopped, the amount of fuel gas supplied to the fuel cell stack (10) is controlled to a range of 0.1 to 0.5 times the amount during system rated power generation in terms of heat flow rate until the temperature of the maximum temperature part (top edge) of the fuel cell stack (10) drops below the minimum oxidation temperature of nickel metal.