Fuel cell system with load management

• US 7,390,587 B2
• Filed: 12/03/2004
• Issued: 06/24/2008
• Est. Priority Date: 03/29/2000
• Status: Expired due to Term

• Current Assignee: DCNS SA (Government of France)
• Original Assignee: IdaTech LLC (IdaTech Ltd.)
• Inventors: Edlund, David J., Dickman, Anthony J.
• Primary Examiner(s): Crepeau; Jonathan
• Assistant Examiner(s): HODGE, ROBERT W
• Application Number:
  US11/004,487
• Publication Number:
  US 20050084726A1
• Time in Patent Office: 1,299 Days
• Field of Search: 429/9, 429/13, 429/17, 429/23, 429/19, 429/21, 429/7, 320/101, 320/102, 731/47, 701/22, 423/652, 700/286
• US Class Current: 429/423
• CPC Class Codes: B60L 3/0023 Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
• CPC Class Codes: B60L 58/30 for monitoring or controlling fuel cells
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: B60L 58/34 by heating
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• 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 8/04365 of other components of a fuel cell or fuel cell stacks
• CPC Class Codes: H01M 8/04537 Electric variables
• CPC Class Codes: H01M 8/04589 of fuel cell stacks
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/04768 of the coolant
• CPC Class Codes: H01M 8/0494 of fuel cell stacks
• CPC Class Codes: H01M 8/04955 Shut-off or shut-down of fuel cells
• CPC Class Codes: H01M 8/0612 from carbon-containing material
• CPC Class Codes: H01M 8/249 comprising two or more groupings of fuel cells, e.g. modular assemblies
• CPC Class Codes: H02J 2310/40 The network being an on-board power network, i.e. within a vehicle
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A fuel cell system having partial and/or total redundancy of at least one operational component, such as a redundancy of fuel cell stacks and/or fuel processors. In some embodiments, the fuel cell system includes a plurality of fuel cell stacks adapted to deliver the same maximum rated power output as a comparative fuel cell system having only a single fuel cell stack. In some embodiments, the fuel cell system includes a plurality of fuel cell stacks adapted to deliver more than the maximum rated power output of the comparative fuel cell system. In some embodiments, the fuel cell system includes a plurality of fuel cell stacks having at least n+1 (or total) redundancy compared to a fuel cell system having only a single fuel cell stack. In some embodiments, the fuel cell system includes a control system and/or structure adapted to limit the applied load to the system.

Claims

1. A fuel cell system, comprising:

a fuel processing assembly adapted to produce a product hydrogen stream from a feedstock;

a fuel cell stack assembly adapted to receive at least a portion of the product hydrogen stream from the fuel processing assembly and to produce an electric current therefrom to at least partially satisfy an applied load having a magnitude, wherein the fuel cell stack assembly includes a plurality of fuel cell stacks that each have a maximum rated power output, wherein the fuel cell system is adapted to satisfy an applied load by supplying up to a maximum desired power output, wherein the fuel cell stack assembly has a total rated power output that is at least equal to the maximum desired power output, wherein each of the fuel cell stacks has a plurality of operational states that include at least a first operational state, in which the fuel cell stack receives at least a portion of the product hydrogen stream from the fuel processing assembly and produces an electric current therefrom, and a second operational state, in which the fuel cell stack is not producing an electric current, wherein each of the fuel cell stacks has a maximum rated power output, and further wherein each of the fuel cell stacks is adapted to selectively receive at least a portion of the product hydrogen stream and to produce an electric current therefrom; and

a control system with a controller adapted to selectively regulate the operational states of the plurality of fuel cell stacks, wherein the controller is adapted to regulate the operational states of the plurality of fuel cell stacks responsive at least in part to the magnitude of the applied load, and further wherein the controller is adapted to selectively configure at least one of the plurality of fuel cell stacks from the first operational state to the second operational state responsive to an applied load that is less than the maximum desired power output.

2. The fuel cell system of claim 1, wherein each of the fuel cell stacks is adapted to receive at least a portion of the product hydrogen stream and to produce an electric current therefrom regardless of the operational state of the other fuel cell stacks.

3. The fuel cell system of claim 1, wherein each of the fuel cell stacks is adapted to receive at least a portion of the product hydrogen stream and to produce an electric current therefrom independent of the operational state of the other fuel cell stacks.

4. The fuel cell system of claim 1, wherein the fuel cell stack assembly has a total rated power output that is greater than the maximum desired power output.

5. The fuel cell system of claim 4, wherein the total rated power output of the fuel cell stack assembly is greater than the maximum desired power output by at least the maximum rated power output of one of the plurality of fuel cell stacks.

6. The fuel cell system of claim 4, wherein the total rated power output of the fuel cell stack assembly is greater than the maximum desired power output by at least a sum of the maximum rated power outputs of at least two of the plurality of fuel cell stacks.

7. The fuel cell system of claim 4, wherein each of the fuel cell stacks has a maximum rated power output that is at least as great as the maximum desired power output.

8. The fuel cell system of claim 1, wherein the fuel cell stack assembly has a plurality of operational states that include at least a first operational state in which all of the fuel cell stacks are receiving at least a portion of the product hydrogen stream from the fuel processing assembly and producing an electric current therefrom, a second operational state, in which none of the fuel cell stacks are producing an electric current, and a third operational state, in which at least one of the plurality of fuel cell stacks is receiving at least a portion of the product hydrogen stream from the fuel processing assembly and producing an electric current therefrom, and at least one of the plurality of fuel cell stacks is not producing an electric current.

9. The fuel cell system of claim 8, wherein in the third operational state, the fuel cell stack assembly is adapted to produce an electric current sufficient to satisfy the applied load.

10. The fuel cell system of claim 8, wherein in the third operational state, the fuel cell stack assembly is adapted to produce an electric current sufficient to satisfy an applied load that corresponds to a maximum desired power output of the fuel cell stack assembly.

11. The fuel cell system of claim 8, wherein in the third operational state, the fuel cell stack assembly is adapted to produce an electric current sufficient to satisfy an applied load that exceeds a maximum desired power output of the fuel cell stack assembly.

12. The fuel cell system of claim 1, wherein the fuel cell system further includes means for limiting the magnitude of the applied load.

13. The fuel cell system of claim 1, wherein the fuel cell system further includes means for selectively delivering at least one of a portion of the product hydrogen stream, an air stream and a cooling fluid stream to the plurality of fuel cell stacks.

14. The fuel cell system of claim 1, wherein the fuel cell system further includes means for regulating the current produced by the fuel cell stack assembly.

15. The fuel cell system of claim 1, wherein the fuel cell system further includes a power management module adapted to receive the electric current produced by the fuel cell stack assembly and to produce an output current therefrom.

16. The fuel cell system of claim 15, wherein the power management module includes a DC-DC converter adapted to selectively regulate the voltage of the current.

17. The fuel cell system of claim 16, wherein the converter is adapted to receive the current from the fuel cell stack assembly and to regulate the current to produce a current having a predetermined voltage.

18. The fuel cell system of claim 16, wherein the converter is adapted to increase the voltage of the current.

19. The fuel cell system of claim 16, wherein the converter is adapted to decrease the voltage of the current.

20. The fuel cell system of claim 15, wherein the power management module includes at least one inverter adapted to convert the current produced by the fuel cell stack assembly to an AC current.

21. The fuel cell system of claim 15, wherein the power management module includes a battery assembly adapted to receive and selectively store at least a portion of the current produced by the fuel cell stack assembly.

22. The fuel cell system of claim 21, wherein the battery assembly includes at least one battery and at least one charger.

23. The fuel cell system of claim 1, wherein the controller is further adapted to regulate the operational states of the plurality of fuel cell stacks responsive at least in part to the flow rate of the product hydrogen stream.

24. The fuel cell system of claim 1, wherein the control system further includes a plurality of sensor assemblies associated with each of the fuel cell stacks, and further wherein the controller is further adapted to regulate the operational states of the plurality of fuel cell stacks responsive at least in part to inputs from the sensor assemblies.

25. The fuel cell system of claim 1, wherein the fuel cell system includes a plurality of contactors, wherein each of the fuel cell stacks is associated with one of the plurality of contactors, and further wherein each of the plurality of contactors includes a plurality of operational states that include at least a first operational state, in which the corresponding fuel cell stack is isolated from the applied load, and a second operational state, in which the corresponding fuel cell stack is not isolated from the applied load.

26. The fuel cell system of claim 25, wherein the controller is in communication with the plurality of contactors and adapted to selectively control the operational states of the contactors.

27. The fuel cell system of claim 1, wherein the fuel cell system includes a manifold assembly adapted to receive at least a portion of the product hydrogen stream and to selectively distribute the portion of the product hydrogen stream to the plurality of fuel cell stacks.

28. The fuel cell system of claim 27, wherein the controller is adapted to selectively regulate the operational states of the plurality of fuel cell stacks, and further wherein the controller communicates with the manifold assembly to selectively regulate the distribution of the product hydrogen stream between the plurality of fuel cell stacks.

29. The fuel cell system of claim 28, wherein the manifold assembly is further adapted to receive an air stream from an air delivery system and to selectively distribute the air stream to the plurality of fuel cell stacks, and further wherein the controller is adapted to selectively regulate the distribution of the air stream to the plurality of fuel cell stacks.

30. The fuel cell system of claim 27, wherein the manifold assembly is further adapted to receive an air stream from an air delivery system and to selectively distribute the air stream to the plurality of fuel cell stacks.

31. The fuel cell system of claim 30, wherein the controller is adapted to selectively regulate the distribution of the air stream by the manifold assembly to the plurality of fuel cell stacks.

32. The fuel cell system of claim 27, wherein the manifold assembly is further adapted to receive a cooling fluid stream from a cooling fluid delivery system and to selectively distribute the cooling fluid stream to the plurality of fuel cell stacks.

33. The fuel cell system of claim 32, wherein the controller is adapted to selectively regulate the distribution of the cooling fluid stream by the manifold assembly to the plurality of fuel cell stacks.

34. The fuel cell system of claim 1, wherein the fuel cell system further includes a manifold assembly adapted to receive an air stream from an air delivery system and to selectively distribute the air stream to the plurality of fuel cell stacks.

35. The fuel cell system of claim 34, wherein the manifold assembly is further adapted to only distribute the air stream to the fuel cell stacks that are in their first operational state.

36. The fuel cell system of claim 34, wherein the controller is in communication with the manifold assembly, and further wherein the controller is adapted to regulate the distribution of the air stream to the fuel cell stacks.

37. The fuel cell system of claim 1, wherein the fuel cell system further includes a manifold assembly adapted to receive a cooling fluid stream from a cooling fluid delivery system and to selectively distribute the cooling fluid stream to the plurality of fuel cell stacks.

38. The fuel cell system of claim 37, wherein the controller is in communication with the manifold assembly, and further wherein the controller is adapted to regulate the distribution of the cooling fluid stream to the fuel cell stacks.

39. The fuel cell system of claim 1, wherein the controller is further adapted to selectively limit the magnitude of the applied load.

40. The fuel cell system of claim 39, wherein the control system is adapted to regulate the magnitude of the applied load responsive at least in part to the sum of the maximum rated power outputs of the fuel cell stacks in the fuel cell stack assembly.

41. The fuel cell system of claim 39, wherein the control system is adapted to regulate the magnitude of the applied load responsive at least in part to the sum of the maximum rated power outputs of the fuel cell stacks that are in their first operational state.

42. The fuel cell system of claim 1, wherein the fuel cell system includes an energy-consuming device adapted to apply at least a portion of the applied load to the fuel cell stack assembly.

43. The fuel cell system of claim 42, wherein the energy-consuming device includes a plurality of devices that are each adapted to apply a portion of the applied load, wherein each of the plurality of devices has a plurality of operational states that include at least a first operational state, in which the device is applying a portion of the applied load, and a second operational state, in which the device is not applying a portion of the applied load.

44. The fuel cell system of claim 43, wherein each of the plurality of devices includes a switching module and further wherein the switching modules are adapted to communicate with each other to regulate the operational states of the devices.

45. The fuel cell system of claim 44, wherein each of the plurality of devices has a priority relative to the rest of the plurality of devices, and further wherein the switching modules are adapted to selectively control the operational states of the devices responsive at least in part to the priority of the devices.

46. The fuel cell system of claim 1, wherein each of the fuel cell stacks includes a plurality of fuel cells.

47. The fuel cell system of claim 1, wherein each of the fuel cell stacks includes a plurality of fuel cells connected between common end plates.

48. The fuel cell system of claim 1, wherein the system further includes an air delivery system adapted to deliver air streams to each of the fuel cell stacks.

49. The fuel cell system of claim 1, wherein the system further includes a cooling fluid delivery system adapted to deliver a cooling fluid stream to each of the fuel cell stacks.

50. The fuel cell system of claim 1, wherein each of the fuel cell stacks is in fluid communication with a cooling fluid delivery system adapted to deliver a cooling fluid stream to a respective one of the fuel cell stacks.

51. The fuel cell system of claim 1, wherein the fuel processing assembly includes at least one fuel processor.

52. The fuel cell system of claim 1, wherein the fuel processing assembly includes at least one steam reformer.

53. The fuel cell system of claim 1, wherein the controller is adapted to select which of the at least one of the plurality of fuel cell stacks is to be configured from the first operational state to the second operational state responsive at least in part to a predetermined sequence.

54. The fuel cell system of claim 1, wherein the controller is adapted to select which of the at least one of the plurality of fuel cell stacks is to be configured from the first operational state to the second operational state responsive at least in part to a rotationally selected sequence.

55. The fuel cell system of claim 1, wherein the controller is adapted to select when the at least one of the plurality of fuel cell stacks is to be configured from the first operational state to the second operational state responsive at least in part to a predetermined time sequence.