SOLID OXIDE FUEL CELL SYSTEM, AND SYSTEM STOPPING METHOD UPON FAILURE OF REFORMING CATALYST TEMPERATURE SENSOR

摘要

PROBLEM TO BE SOLVED: To ensure normal stop of a system upon failure of a reforming catalyst temperature sensor for detecting the reforming catalyst temperature of a reformer.SOLUTION: Upon failure of a reforming catalyst temperature sensor, the system is stopped by controlling the state of a reformer and a fuel cell stack according to a predetermined procedure, as the cell temperature lowers, while detecting the cell temperature by means of the cell temperature sensor, in place of the reforming catalyst temperature. More specifically, the system is stopped via a reforming stop process (S32, S33) for continuing supply of raw fuel and reforming water to the reformer until the cell temperature lowers to reach a first predetermined temperature T1, and a cathode air cooling process (S35, S36) for continuing supply of air for cathode to the fuel cell stack until the cell temperature lowers furthermore to reach a second predetermined temperature T2.