Patent ID: 7087333

Claim:
A fuel cell system comprising: a plurality of fuel cell stacks each having an anode side with an inlet and an outlet and a cathode side with an inlet and an outlet, each fuel cell stack being operable to convert a hydrogen-containing anode reactant feed stream and an oxidant-containing cathode reactant feed stream into electricity, a hydrogen-containing anode effluent and an oxidant-containing cathode effluent; a plurality of flow paths, each connecting said anode outlet of one of said fuel cell stacks to said anode inlet of a different one of said fuel cell stacks; a check valve in at least one of said flow paths, said check valve allowing flow in an associated flow path in a single direction corresponding to flowing from said anode outlet of said one of said fuel cell stacks to said anode inlet of said different one of said fuel cell stacks, said check valve being the only active flow control valve in an associated flow path during nominal operation of said fuel cell stack; and at least one vent valve, said vent valve communicating with at least one of said flow paths, said vent valve operable to selectively vent anode effluent from said associated flow path.