Method for initiating a fuel cell

• US 6,007,930 A
• Filed: 05/06/1998
• Issued: 12/28/1999
• Est. Priority Date: 05/06/1998
• Status: Expired due to Term

• Current Assignee: NuCellSys GmbH (Mercedes-Benz Group AG)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Sulek, Mark S., Adams, James A, Saloka, George Steve
• Primary Examiner(s): Bell, Bruce F.
• Assistant Examiner(s): Parsons, Thomas H
• Application Number:
  US09/073,309
• Time in Patent Office: 601 Days
• Field of Search: 429/13, 429/22, 429/23, 429/30
• US Class Current: 429/429
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04225 during start-up
• CPC Class Codes: H01M 8/04302 applied during start-up
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

The present invention provides a method for initiating a fuel cell power system by directly introducing a gas containing oxygen into the fuel cell stack 10. A gas storage source 28 provides oxidizer to the fuel cell 10 such that there is enough initial power to generate a load. The air compressor 24 is started electrically by a portion of the load, and begins to supply compressed air to the cathode 14. The fuel cell stack 10 thereby obtains a further quantity of oxidizer from the compressed air. The air system valve 32 then operates to transfer the fuel cell stack 10 from the gas storage source 28 to the air compressor 24.

Claims

1. A fuel cell power system comprising:

a fuel cell stack for continuously generating electric power to a load, said fuel cell having an anode, a cathode, and an electrolytic layer therebetween, in which a fuel containing hydrogen is supplied to said anode and a gas containing oxygen is supplied to said cathode to generate said electric power;

a gas storage source for supplying a stored gas to said cathode;

a compressor started electrically by a portion of said load, said compressor supplying compressed air to said cathode and to said gas storage source; and

a valve operable to select between said stored gas and said compressed air when said fuel cell stack is operable on oxygen supplied entirely from said air compressor.

2. A fuel cell power system according to claim 1, wherein said gas storage source contains pure oxygen.

3. A fuel cell power system according to claim 1, wherein said gas storage source contains oxygen rich air.

4. A fuel cell power system according to claim 1, wherein said gas storage source contains air.

5. A fuel cell power system according to claim 1, wherein said fuel cell stack is a proton exchange membrane.

6. A fuel cell power system according to claim 1, wherein said gas storage source is a pressure vessel.

7. A fuel cell power system according to claim 1, wherein said storage source is a plurality of pressure vessels.

8. A fuel cell power system according to claim 1, wherein said compressed air is filtered to oxygenate said compressed air prior to storage in said gas storage source.

9. A fuel cell power system according to claim 8, wherein said filter is a perfluorocopolymer.

10. A fuel cell power system according to claim 9, further comprising a motor controller to control said electric power provided to said air compressor.

11. A fuel cell power system according to claim 10, further comprising a system controller to monitor said electric power from said fuel cell stack and determines when said electric power is sufficient to start said air compressor.

12. A fuel cell power system according to claim 11, wherein said system controller monitors said electric power from said fuel cell stack and determines to shift from said gas storage source to said air compressor.

13. A fuel cell power system according to claim 12, wherein said valve is operable to supply any combination of from 0% to 100% stored gas from said gas storage source and from 0% to 100% of compressed air from said air compressor.

14. A method for starting a fuel cell power system, said method comprising the steps of:

supplying a fuel containing hydrogen to an anode of a fuel cell stack from a fuel source tank;

supplying a stored gas containing oxygen to a cathode of a fuel cell stack from a gas storage source;

said gas initiating said fuel cell and said fuel cell generating a level of electrical energy;

monitoring said level of electrical energy;

determining when said level of electrical energy exceeds a threshold level;

starting a compressor using said electrical energy when said threshold level is exceeded, and supplying compressed air from said air compressor to said fuel cell stack; and

withdrawing said supply of stored gas when a system controller determines said fuel cell stack is operable on oxygen supplied entirely from said compressed air.

15. The method according to claim 14 further comprising said air compressor replenishing said gas storage source.

16. The method according to claim 15, further comprising filtering said compressed air to oxygenate said compressed air prior to storage in said gas storage source.

17. The method according to claim 16, wherein said system controller monitors the percentage of said stored gas and the percentage of said compressed air supplied to said fuel cell stack.

18. The method according to claim 17, further comprising a computer calculating the percentage of said stored gas supplied to said fuel cell to sustain said threshold level electrical energy generated by said fuel cell stack.