Patent ID: 7736777

Claim:
A fuel cell system for receiving input fuel gas and input oxidant gas comprising: a fuel processing assembly for at least humidifying the input fuel gas; a fuel cell having an anode configured to receive the humidified input fuel gas and a cathode configured to receive the input oxidant gas; an anode oxidizing assembly coupling the output of the anode of said fuel cell to the input of said cathode of said fuel cell during normal operation, shutdown and restart of the fuel cell system and further configured to receive at least one of said input oxidant gas and exhaust gas from said cathode; and a control assembly responding to shut down of said fuel cell during which at least the input fuel gas ceases to be received by said fuel cell system, said control assembly, when said fuel cell system is shut down: controlling said fuel cell system so as to enable a purging gas to be able to flow through said fuel processing assembly to remove humidified fuel gas from said fuel processing assembly, to enable a purging gas to be able to flow through said anode of said fuel cell, and to enable a predetermined flow of one of input oxidant gas and exhaust gas from said cathode to said anode oxidizing assembly.