Patent ID: 8592093

Claim:
A solid oxide fuel cell system for generating electrical power by reacting fuel gas and air, comprising: a fuel cell assembly disposed in a power generating chamber inside a fuel cell module and comprising a plurality of solid oxide fuel cells; a reformer that steam-reforming the fuel gas and supplies the fuel gas to the fuel cell assembly; a fuel gas supply device that supplies the fuel gas to the reformer; a water supply device that produces pure water and supplies the pure water to the reformer; a reforming air supply device that supplies reforming air to the reformer; a power generating air supply device that supplies power generating air to the fuel cell assembly; an ignition device that ignites the fuel gas which has reached the upper portion of the fuel cell assembly from the reformer; a temperature detection device that detects a temperature indicative of combustion of the fuel gas, which is one of a temperature of exhaust gas, a temperature of the fuel cell assembly and a temperature of the reformer; and a control device programed to control the fuel gas supply device, the water supply device, the reforming air supply device, the power generating air supply device, the ignition device, and the temperature detection device to conduct a combustion operation in which the fuel gas is ignited by the ignition device and combusted with the reforming air during a startup of the solid oxide fuel cell device, and then to supply the fuel gas and water into the reformer to conduct a steam reforming reaction (SR) operation, thereby starting generation of electricity by the solid oxide fuel cell device, wherein a plurality of predetermined temperature drop rates are defined, respectively, for a plurality of temperature ranges such that a predetermined temperature drop rate becomes higher as a temperature range becomes lower, and wherein the control device is programed to detect a flameout when the control device detects an occurrence of one or more of at least one operation condition of the solid oxide fuel cell device, wherein the at least one operation condition comprises a first operation condition in which the temperature detected by the temperature detection device drops at a rate greater than the predetermined temperature drop rate defined for a temperature range within which the temperature detected by the temperature detection device falls.