Patent ID: 8900764

Claim:
A solid oxide fuel cell system for reacting fuel with an oxidation gas to generate electrical power responsive to a required power, comprising: a fuel cell module comprising multiple solid oxide fuel cell units; a reformer that supplies reformed fuel to the solid oxide fuel cell units; a fuel supply device that supplies the fuel to the reformer for reformation thereof; a water supply device that supplies water to the reformer; an oxidation gas supply device that supplies the oxidation gas to the solid oxide fuel cell units; and a controller programmed to execute, before transitioning to an output operation for outputting the electrical power from the solid oxide fuel cell system, a startup operation in which the solid oxide fuel cell units of the fuel cell module are raised to a temperature at which electricity can be outputted from the solid oxide fuel cell system, the startup operation comprising consecutively performed first and second steam reforming operations in which the controller is programmed to control the fuel supply device and the water supply device to begin a steam reforming reaction, the first steam reforming operation being performed prior to the second steam reforming operation, which is performed immediately prior to the output operation, wherein the controller is further programmed to determine, during the startup operation, a standby fuel supply rate according to power requirement monitored during the startup operation and control the fuel supply device to supply the fuel at the determined standby fuel supply rate during the second steam reforming operation, and further wherein the determined standby fuel supply rate is lower than a fuel supply rate effected during the first steam reforming operation.