Patent ID: 8034504

Claim:
A fuel cell system comprising: a fuel cell having an electrolyte electrode assembly which comprises an anode, a cathode and an electrolyte interposed between said anode and said cathode; a fuel gas supply unit for supplying a fuel gas to said fuel cell; an oxygen containing gas supply unit, which has a heat exchanger for heating an oxygen-containing gas, for supplying the oxygen containing gas heated by said heat exchanger to said fuel cell; an exhaust gas discharge unit configured to receive the fuel gas and the oxygen-containing gas discharged from said fuel cell after being used in a generating reaction, as a heating medium for heating the oxygen-containing gas to said heat exchanger; and a combustion gas supply unit, which has a combustor disposed out of a passageway of said exhaust gas discharge unit configured to generate a combustion gas by combusting a fuel with an oxygen-containing gas supplied thereto, for supplying said combustion gas, together with fuel gas and the oxygen-containing gas discharged from said fuel cell, to said heat exchanger, wherein said fuel gas supply unit has a reformer for reforming a raw fuel, which chiefly contains hydrocarbon, into the fuel gas, and wherein said combustion gas supply unit has a combustion gas supply passage for supplying the combustion gas to said reformer, wherein said exhaust gas discharge unit has an exhaust gas supply passage configured to receive the fuel gas from an anode exhaust passage and the oxygen-containing gas from a cathode exhaust passage discharged from said fuel cell, and said combustion gas supply unit has a combustion has supply passage configured to supply the combustion gas, said exhaust gas supply passage and said combustion gas supply passage being connected to each other by a passage junction and connected to said heat exchanger through said junction, wherein the exhaust gas supply passage is configured to receive an anode exhaust and a cathode exhaust gas exhausted from said fuel cell.