Patent ID: 7001682

Claim:
In fuel cell system for generating electric power by combination of oxygen with hydrogen-containing fuel, the system having a combustor for burning a mixture of anode tail gas, spent cathode air, and fresh air, a system for controlling combustion temperature in the combustor, comprising: a) temperature measuring means within said combustor; b) first conduit means for providing said spent cathode air to said combustor, said first conduit means including a three-way valve for controllably diverting a portion of said spent cathode air from entering said combustor; c) second conduit means for providing fresh air to said combustor, said second conduit means including a control valve for controllably varying the amount of air flowing to said combustor; and d) control means for monitoring said combustion temperature via said temperature measuring means and for responding when said combustor temperature is out of a predetermined operating range, said control means being operationally connected to said three-way valve to provide less spent cathode air to said combustor when said operating temperature is below a lower limit of said range, and being further operationally connected to said control valve to provide more fresh air to said combustor when said operating temperature is above an upper limit of said range.