High efficiency fuel cell system

• US 20070128478A1
• Filed: 12/06/2005
• Published: 06/07/2007
• Est. Priority Date: 12/06/2005
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company), Plug Power Inc.
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Ballantine, Arne, McElroy, James, Gasda, Michael
• Granted Patent: US 8,129,057 B2
• Time in Patent Office: Days
• US Class Current: 429/410
• CPC Class Codes: H01M 16/003 of fuel cells with other electrochemical devices, e.g. capacitors, electrolysers
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 8/04097 with recycling of the reactants H01M8/04119, H01M8/04104 take precedence
• CPC Class Codes: H01M 8/04171 using adsorbents, wicks or hydrophilic material
• CPC Class Codes: H01M 8/04179 by purging or increasing flow or pressure of reactants
• CPC Class Codes: H01M 8/04201 Reactant storage and supply, e.g. means for feeding, pipes
• CPC Class Codes: H01M 8/04291 Arrangements for managing water in solid electrolyte fuel cell systems H01M8/04119 takes precedence
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/04761 of fuel cell exhausts
• CPC Class Codes: H01M 8/04888 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/0681 Reactant purification by the use of electrochemical cells
• CPC Class Codes: H01M 8/249 comprising two or more groupings of fuel cells, e.g. modular assemblies
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A technique includes operating a fuel cell, which produces an effluent flow. The technique includes routing the effluent flow through an electrochemical pump to extract fuel from the effluent flow and providing the extracted fuel to the fuel cell.

Claims

1. A method comprising:

operating a fuel cell, the operation of the fuel cell producing an effluent flow;

routing the effluent flow through an electrochemical pump to extract fuel from the effluent flow; and

providing the extracted fuel to the fuel cell.

2. The method of claim 1, wherein the act of routing comprises routing the effluent flow through an electrochemical hydrogen pump.

3. The method of claim 2, wherein the act of routing the effluent flow through the hydrogen pump comprises:

providing the effluent flow to an anode chamber of another fuel cell; and

applying power to said another fuel cell to cause the fuel cell to produce hydrogen in a cathode chamber of said another fuel cell in response to the effluent flow.

4. The method of claim 2, wherein the act of routing the effluent flow through the hydrogen pump comprises:

providing the effluent flow to additional fuel cells arranged in cascaded stages.

5. The method of claim 4, wherein pursuant to the cascade arrangement a cathode chamber of one of said additional fuel cells is directly connected to an anode chamber of another one of said additional fuel cells.

6. The method of claim 4, further comprising:

providing a material to serve as a wick to collect water from one of the cascaded stages and route the water to another one of the cascaded stages.

7. The method of claim 6, further comprising:

placing the material in a recessed region formed inside said one of the cascaded stages.

8. The method of claim 4, further comprising:

providing a mechanism inside one of the cascaded stages to remove water from said one of the cascaded stages.

9. The method of claim 8, wherein the mechanism comprises one of a U-trap, a float valve and a solenoid valve.

10. The method of claim 4, further comprising:

regulating communication of exhaust from an anode chamber of one of the stages.

11. The method of claim 10, wherein the act of regulating comprises selectively opening and closing communication with the anode chamber based on a fuel cell voltage.

12. The method of claim 2, further comprising:

applying heat to the hydrogen pump to reduce water production inside the pump.

13. A system comprising:

a fuel cell stack comprising an anode intake plenum to receive a first fuel flow formed from a second fuel flow provided by a fuel flow source and a third fuel flow, the fuel cell stack adapted to generate an effluent flow in an anode exhaust plenum in response to the first fuel flow; and

an electrochemical pump adapted to purify the effluent flow to produce the third fuel flow.

14. The system of claim 13, wherein the electrochemical pump comprises an electrochemical hydrogen pump.

15. The system of claim 13, wherein the fuel flow source comprises a hydrogen source.

16. The system of claim 13, wherein the electrochemical pump is separate from the fuel cell stack.

17. The system of claim 13, wherein the electrochemical pump and the fuel cell stack are integrated together in a single flow plate stack.

18. The system of claim 17, wherein the single flow plate stack comprises first set of fuel cells to generate the effluent flow and a second set of fuel cells other than the first set of fuel cells to form the hydrogen pump.

19. The system of claim 18, wherein the first set of fuel cells produce electrical power, and the second set of fuel cells receive electrical power.

20. The system of claim 18, wherein the second set of fuel cells are arranged in cascade stages.

21. The system of claim 20, wherein at least two of the cascade stages have a different number of fuel cells.

22. The system of claim 20, wherein the cascade stages comprise:

a first cascade stage adapted to produce part of the third flow and a first exhaust flow in response to the effluent flow;

a second cascade stage adapted to produce part of the third flow and a second exhaust flow in response to the first exhaust flow; and

a third cascade stage adapted to produce part of the third flow in response to the second exhaust flow.

23. The system of claim 22, wherein the first cascade stage has a greater number of fuel cells than the second cascade stage, and the second cascade stage has a greater number of fuel cells than the third cascade stage.

24. The system of claim 22, further comprising:

a flow control device connected to the third cascade stage to regulate communication of a third exhaust flow from the third cascade stage in response to a voltage of a fuel cell of the third cascade stage.

25. The system of claim 22, wherein the third cascade stage comprises a single fuel cell.

26. The system of claim 20, further comprising:

a material to serve as a wick to collect water from one of the cascade stages and route the water to another one of the cascaded stages.

27. The system of claim 26, wherein the material is received in recessed region formed inside a flow plate.

28. The system of claim 20, further comprising:

a mechanism adapted to remove water from said one of the cascaded stages.

29. The system of claim 28, wherein the mechanism comprises one of a U-trap, a float valve and a solenoid valve.

30. The system of claim 13, further comprising:

a thermal element to apply heat to the electrochemical pump; and

a circuit to regulate the heat applied by the thermal element to at least minimize water production inside the pump.