SOLID OXIDE FUEL CELL SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a solid oxide fuel cell system which accurately detects deterioration of a cell stack due to gas sealability.SOLUTION: A solid oxide fuel cell system comprises: a reformer 4; a cell stack 6 for generating power by oxidation and reduction of reformed fuel gas and oxidation material; a fuel pump 28 for supplying raw fuel gas; an air blower 20 for supplying the oxidation material; and control means 60 for controlling the fuel pump 28 and the air blower. The fuel cell system also comprises: first voltage detection means 52 for detecting first open circuit voltage between first portions of the cell stack; and second voltage detection means 54 for detecting second open circuit voltage between second portions of the cell stack. The control means includes deterioration determination means, and the deterioration determination means determines a deterioration state of sealability reduction in the cell stack based on a voltage difference or a voltage ratio of the first and second open circuit voltages between the first and second portions.