Flexible system for hydrogen recirculation
AssigneeGeneral Motors Corporation
InventorRobert Schafer
Life of this patent
Estimating the term…
Abstract
A fuel cell system that routes anode effluent from one fuel cell stack to the anode side of another fuel cell stack to consume unused hydrogen in the production of electricity is disclosed. The routing of the anode effluent from one fuel cell stack to another is accomplished by providing flow paths that connect the anode sides of the various fuel cell stacks together. The flow paths contain valves that are operable to selectively block flow through the various flow paths as desired. Optionally, the flow paths can be operated free of any valves. Methods of operating such fuel cell systems are also disclosed.
Claims33
A method of operating a fuel cell system having a plurality of fuel cell stacks each operable to convert a hydrogen-containing anode reactant on an anode side of the fuel cell stack and an oxidant-containing cathode reactant on a cathode side of the fuel cell stack into electricity, a hydrogen-containing anode effluent on the anode side and an oxidant-containing cathode effluent on the cathode side, wherein the anode side of each fuel cell stack is connected to the anode side of a different fuel cell stack with a flow path, the method comprising:
- (a) supplying a hydrogen-containing anode reactant stream to an anode side of at least one fuel cell stack of the plurality of fuel cell stacks for reaction therein and production of a first anode effluent stream;
- (b) supplying said first anode effluent stream to the anode side of at least one of the other fuel cell stacks of the plurality of fuel cell stacks via the flow paths for reaction therein and production of a second anode effluent stream;
- and
- (c) switching which fuel cell stack(s) that receive said anode reactant stream.
A method of operating a fuel cell system having a plurality of fuel cell stacks each operable to convert a hydrogen-containing anode reactant on an anode side of the fuel cell stack and an oxidant-containing cathode reactant on a cathode side of the fuel cell stack into electricity, a hydrogen-containing anode effluent on the anode side and an oxidant-containing cathode effluent on the cathode side, the method comprising:
- (a) supplying a hydrogen-containing anode reactant stream to the anode sides of each fuel cell stack in a first segment of the system for reaction therein to produce at least one first segment anode effluent stream, wherein said first segment comprises one or more fuel cell stacks of the plurality of fuel cell stacks;
- (b) supplying said at least one first segment anode effluent stream to the anode sides of fuel cell stacks in a second segment of the system for reaction therein to produce at least one second segment anode effluent stream, wherein said second segment comprises other fuel cell stacks of the plurality of fuel cell stacks;
- and
- (c) changing a selection of said one or more fuel cell stacks that comprise said first segment.
A fuel cell system comprising:
- a plurality of fuel cell stacks each having an anode side with an inlet portion and an outlet portion and a cathode side with an inlet portion and an outlet portion, 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, and to produce a hydrogen-containing anode effluent and an oxidant-containing cathode effluent;
- a plurality of flow paths, each said flow path connecting said anode inlet portion of one of said fuel cell stacks to said anode outlet portion of a different one of said fuel cell stacks;
- and
- at least one vent valve, each said vent valve communicating with said anode outlet portion of at least one of said fuel cell stacks and operable to selectively vent said anode effluent.
Dependencies are inferred from the claim text.