Auxiliary fuel cell system

• US 7,250,231 B2
• Filed: 06/09/2003
• Issued: 07/31/2007
• Est. Priority Date: 06/09/2003
• Status: Active Grant

• Current Assignee: DCNS SA (Government of France)
• Original Assignee: IdaTech LLC (IdaTech Ltd.)
• Inventors: Edlund, David J.
• Primary Examiner(s): Maples; John S.
• Application Number:
  US10/458,140
• Publication Number:
  US 20040247961A1
• Time in Patent Office: 1,513 Days
• Field of Search: 429/23, 429/22, 429/13
• US Class Current: 429/429
• CPC Class Codes: H01M 16/003 of fuel cells with other electrochemical devices, e.g. capacitors, electrolysers
• CPC Class Codes: H01M 8/04014 Heat exchange using gaseous fluids; Heat exchange by combustion of reactants
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04626 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04686 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/0494 of fuel cell stacks
• CPC Class Codes: H01M 8/04947 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

Auxiliary fuel cell system that provides backup power to a primary power source, and energy-consuming systems that are otherwise associated with at least one primary power source and at least one auxiliary fuel cell system. The auxiliary fuel cell system includes at least one fuel cell stack that is adapted to produce an electric current from a fuel and an oxidant, such as from hydrogen and oxygen gases. The auxiliary fuel cell system further includes a source of fuel, such as a source of hydrogen gas, and this source may include a fuel processor that is adapted to produce the hydrogen gas or other fuel. The energy-consuming system is adapted to selectively draw an electric current from a primary power source or an auxiliary fuel cell system. A source selection system selectively establishes electrical communications between an energy-consuming system and the primary power source or the auxiliary fuel cell system.

Claims

1. An auxiliary fuel cell system configured to backup a primary power source adapted to supply power to an energy-consuming system, the primary power source being in electrical communication with the energy-consuming system via at least a first power linkage, the first power linkage being configured to be enabled and disabled regardless of whether the primary power source is producing electric current, the auxiliary fuel cell system comprising:

a fuel source;

an oxidant source;

a fuel cell stack configured to conditionally produce an electric current from fuel received from the fuel source and oxidant received from the oxidant source according to the operating state of the primary power source, wherein the fuel cell stack produces electric current when the primary power source is in an interrupted operating state, and the fuel cell stack does not produce electric current when the primary power source is in a power delivery operating state, wherein the primary power source includes at least one of a utility grid, a wind-powered energy source, a solar-powered energy source, a water-powered energy source, and a nuclear-powered energy source, wherein the auxiliary fuel cell system is in electrical communication with the energy-consuming system via at least a second power linkage, the second power linkage being configured to be enabled and disabled regardless of whether the auxiliary fuel cell system is producing electric current; and

a source-selection subsystem that selectively enables and disables at least the first and second power linkages to selectively regulate, based at least in part upon determination of the operating state of the primary power source, which of the auxiliary fuel cell system and the primary power source is currently configured to provide power to satisfy an applied load from the energy-consuming system, wherein the source-selection subsystem is configured to implement a break-then-make connection to prevent backfeed between the primary power source and the auxiliary fuel cell system.

2. The system of claim 1, wherein the auxiliary fuel cell system further comprises a communication subsystem adapted to selectively send or receive signals.

3. The system of claim 2, wherein the communication subsystem is adapted to transmit notification signals responsive to at least one of detecting that the primary power source is in an interrupted operating state and the enabling of a power linkage between the energy-consuming system and the auxiliary fuel cell system.

4. The system of claim 2, wherein the communication subsystem is adapted to enable a power linkage between the energy-consuming system and the auxiliary fuel cell system responsive to receiving a signal indicative of the primary power source transitioning to an interrupted operating state.

5. The system of claim 2, wherein the communication subsystem is adapted to disable a power linkage between the energy-consuming system and the auxiliary fuel cell system responsive to receiving a signal indicative of the primary power source returning to a power delivery operating state.

6. The system of claim 1, wherein the source-selection subsystem further comprises a power monitor adapted to detect an operating state of a primary power source, wherein responsive to the detection that the primary power source is in an interrupted operating state in which the primary power source is not currently configured to provide power to satisfy the applied load from the energy-consuming system, the auxiliary fuel cell system is adapted to provide power to the energy-consuming system from the fuel cell stack.

7. The system of claim 6, wherein upon detection that the primary power source has returned to a power producing operating state in which the primary power source is currently configured to provide power to the energy-consuming system, the source-selection subsystem is adapted to selectively disable the power linkage between the auxiliary fuel cell system and the energy-consuming system.

8. The system of claim 7, wherein upon disabling of the power linkage with the energy-consuming system, the auxiliary fuel cell system is adapted to automatically shut down.

9. The system of claim 7, further comprising an energy storage subsystem adapted to receive at least a portion of the electric current from the fuel cell stack.

10. The system of claim 9, wherein upon disabling of the power linkage with the energy-consuming system, the auxiliary fuel cell system is adapted to recharge the energy storage subsystem.

11. The system of claim 7, wherein upon disabling of the power linkage with the energy-consuming system, the auxiliary fuel cell system is adapted to transition to an idle operating state.

12. The system of claim 1, wherein the source-selection subsystem includes feedback prevention structure adapted to prevent power from at least one of the primary power source and the fuel cell stack of the auxiliary fuel cell system from being applied to the other of the primary power source and the fuel cell stack of the auxiliary fuel cell system.

13. The system of claim 1, wherein the source-selection subsystem is adapted to selectively disable the power linkage between the primary power source and the energy-consuming system prior to enabling the power linkage between the auxiliary fuel cell system and the energy-consuming system.

14. The system of claim 1, wherein the fuel comprises hydrogen gas and the fuel source includes a storage device containing hydrogen gas.

15. The system of claim 1, wherein the fuel comprises hydrogen gas and the fuel source comprises a fuel processor adapted to produce hydrogen gas.

16. The system of claim 15, wherein the fuel processor is adapted to produce the fuel by steam reforming water and a carbon-containing feedstock.

17. The system of claim 1, wherein the primary power source includes a utility grid.

18. The system of claim 1, wherein the primary power source includes at least one of a wind-powered energy source, a water-powered energy source, and a water-powered energy source.