Black start method and apparatus for a fuel cell power plant, and fuel cell power plant with black start capability

• US 20040180243A1
• Filed: 03/12/2003
• Published: 09/16/2004
• Est. Priority Date: 03/12/2003
• Status: Active Grant

• Current Assignee: BDF IP Holdings Ltd. (Siemens AG)
• Original Assignee: Ballard Power Systems Corporation (Siemens AG)
• Inventors: Pearson, Martin T.
• Granted Patent: US 7,011,902 B2
• Time in Patent Office: Days
• US Class Current: 429/13
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 8/0258 characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04223 during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells
• CPC Class Codes: H01M 8/04225 during start-up
• CPC Class Codes: H01M 8/04302 applied during start-up
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/0488 of fuel cell stacks
• CPC Class Codes: H01M 8/0491 of fuel cell stacks
• CPC Class Codes: H01M 8/2483 characterised by internal manifolds
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A black start operation employs the accumulation of power resulting from a reaction of fuel and ambient oxidant passively seeped or diffused into a fuel cell stack to bootstrap the fuel cell system operation.

Claims

1. A method of operating a fuel cell system comprising a fuel cell stack, a reactant supply system to selectively supply a reactant to the fuel cell stack, an oxidant supply system to selectively supply an oxidant to the fuel cell stack, and an electrical storage device electrically coupled to the fuel cell stack, the method comprising:

operating the reactant supply system to supply the reactant to the fuel cell stack;

reacting the reactant and ambient air in the fuel cell stack to produce power;

accumulating the power in the electrical storage device; and

operating the oxidant supply system to supply the oxidant to the fuel cell stack after sufficient power has been accumulated in the electrical storage device to power at least the oxidant supply system.

2. The method of claim 1 wherein operating the reactant supply system to supply the reactant to the fuel cell stack comprises manually opening a valve between a reactant supply reservoir and the fuel cell stack.

3. The method of claim 1 wherein accumulating the power in the electrical storage device comprises accumulating power in a number of electrically coupled super-capacitors.

4. The method of claim 1, further comprising:

limiting a rate of the accumulating of power in the electrical storage device.

5. The method of claim 1, further comprising:

boost converting the power before accumulating the power in the electrical storage device.

6. The method of claim 1, further comprising:

supplying a low voltage from the fuel cell stack to operate a switch mode charging circuit electrically coupled between the fuel cell stack and the electrical storage device.

7. The method of claim 1, further comprising:

manually operating an anode purge valve before operating the oxidant supply system.

8. The method of claim 1, further comprising:

supplying a low voltage from the fuel cell stack to operate an anode purge valve before operating the oxidant supply system.

9. The method of claim 1 wherein operating the oxidant supply system to supply an oxidant to the fuel cell stack comprises powering at least one of a compressor, a blower and a fan to actively supply air to the fuel cell stack.

10. A method of operating a fuel cell system to power a number of internal and external loads, the method comprising:

manually opening a reactant supply valve to supply a reactant from a reactant supply to a fuel cell stack;

producing power from a reaction of the reactant and oxidant passively diffused into the fuel cell stack;

accumulating the power produced from the reaction of the reactant and the oxidant passively diffused into the fuel cell stack in an electrical storage device; and

supplying power from the electrical storage device to at least a first internal load after sufficient power has been accumulated in the electrical storage device to power at least the first internal load and before supplying power to the external load.

11. The method of claim 10 wherein the first internal load is an oxidant supply system and supplying power from the electrical storage device to at least a first internal load comprises supplying power from the electrical storage device to at least one component of the oxidant supply system to actively supply oxidant to the fuel cell stack.

12. The method of claim 10, further comprising:

supplying power from the electrical storage device to at least a second internal load after sufficient power has been accumulated in the electrical storage device to power at least the first and the second internal loads and before supplying power to the external load.

13. The method of claim 10, further comprising:

supplying at least a portion of the power produced from the reaction of the reactant and oxidant passively diffused into the fuel cell stack to a power charging circuit electrically coupled between the fuel cell stack and the electrical storage device.

14. The method of claim 10, further comprising:

limiting a rate of accumulating the power in the electrical storage device.

15. The method of claim 10, further comprising:

boost converting the power produced from the reaction of the reactant and the oxidant air passively diffused into the fuel cell stack before accumulating the power in the electrical storage device.

16. The method of claim 10, further comprising:

supplying a low voltage from the fuel cell stack to operate a switch mode charging circuit electrically coupleable between the fuel cell stack and the electrical storage device.

17. The method of claim 10, wherein the first internal load is an oxidant supply system, and further comprising:

supplying a low voltage from the fuel cell stack to an anode purge valve before supplying power from the electrical storage device to the oxidant supply system.

18. The method of claim 10, further comprising:

manually operating an anode purge valve before operating the oxidant supply system.

19. The method of claim 10, further comprising:

supplying power produced from the reaction of the reactant and oxidant actively supplied to the fuel cell stack to at least a first one of the external loads, after supplying power from the electrical storage device to the first internal load.

20. A fuel cell system, comprising:

a fuel cell stack;

a reactant supply system coupled to supply a flow of reactant to the fuel cell stack;

an oxidant supply system coupled to supply a flow of oxidant to the fuel cell stack; and

an electrical storage device electrically coupleable to the fuel cell stack to accumulate power produced from a reaction of the reactant and ambient air passively diffused into the fuel cell stack and further electrically coupled to supply the accumulated power to at least the oxidant supply system after sufficient power has been accumulated in the electrical storage device to power at least the oxidant supply system.

21. The fuel cell system of claim 20 wherein the reactant supply system comprises at least one reactant supply valve that is manually actuatable to selectively control the flow of reactant to the fuel cell stack.

22. The fuel cell system of claim 20 wherein the reactant supply system comprises a first flow path and a first reactant supply valve that is electrically actuatable to selectively control the flow of reactant to the fuel cell stack via the first flow path, and a second flow path and a second reactant supply valve that is manually actuatable to selectively control the flow of reactant to the fuel cell stack via the second flow path that bypasses the first reactant supply valve.

23. The fuel cell system of claim 20, further comprising:

at least one reactant supply reservoir coupled to the reactant supply system.

24. The fuel cell system of claim 20, further comprising:

a flyback converter electrically coupled between the fuel cell stack and the electrical storage device.

25. The fuel cell system of claim 20, further comprising:

a boost converter electrically coupled between the fuel cell stack and the electrical storage device.

26. The fuel cell system of claim 20, further comprising:

a switch mode current limiting source electrically coupled between the fuel cell stack and the electrical storage device.

27. The fuel cell system of claim 20 wherein the electrical storage device comprises a number of super capacitors.

28. The fuel cell system of claim 20, further comprising:

an anode purge valve manually operable to selectively purge an anode of the fuel cell stack.

29. A fuel cell system to supply power to internal and external loads, the fuel cell system comprising:

a fuel cell stack;

a reactant supply system comprising at least a first reactant supply valve that is manually actuatable to supply a flow of reactant to the fuel cell stack;

an oxidant supply system selectively having at least one element selectively operable to actively supply a flow of oxidant to the fuel cell stack; and

an electrical storage device electrically coupleable to the fuel cell stack to accumulate power produced from a reaction of the reactant and oxidant passively diffused into the fuel cell stack and further electrically coupled to supply power to at least a first internal load before supplying power from the fuel cell stack to the external load.

30. The fuel cell system of claim 29 wherein the at least one element of the oxidant supply system is electrically coupled to the electrical storage device as the first internal load.

31. The fuel cell system of claim 29, further comprising:

a charging circuit electrically coupled between the fuel cell stack and the electrical storage device.

32. The fuel cell system of claim 29, further comprising:

a boost converter electrically coupled between the fuel cell stack and the electrical storage device.

33. The fuel cell system of claim 29, further comprising:

a switch mode charging circuit electrically coupled between the fuel cell stack and the electrical storage device, the switch mode charging circuit comprising an oscillation circuit electrically coupled to the fuel cell stack as a second internal load to receive a portion of the power produced from the reaction of the reactant and oxidant passively diffused into the fuel cell stack.

34. The fuel cell system of claim 29, further comprising:

a manually operable anode purge valve.

35. The fuel cell system of claim 29 wherein the at least one element of the oxidant supply system is electrically coupled to the electrical storage device as the first internal load, and further comprising:

a microprocessor operationally coupled to control at least a portion of the fuel cell system operation and electrically coupled to the electrical storage device as a second internal load.

36. A fuel cell system, comprising:

a fuel cell stack;

a reactant supply system selectively operable to supply a reactant to the fuel cell stack;

an oxidant supply system selectively operable to actively supply a flow of oxidant to the fuel cell stack; and

means for accumulating power produced by a reaction of the reactant and ambient oxidant in the fuel cell stack, and for powering the oxidant supply system to actively supply the flow of oxidant after sufficient power has been accumulated.

37. The fuel cell system of claim 36 wherein the means for accumulating power comprises a switch mode current limiting circuit.

38. The fuel cell system of claim 36 wherein the means for accumulating power comprises a boost converter.

39. A fuel cell system, comprising:

a fuel cell stack;

a reactant supply system selectively operable to supply a reactant to the fuel cell stack;

an oxidant supply system selectively operable to actively supply a flow of oxidant to the fuel cell stack; and

means for accumulating power produced by a reaction of the reactant and oxidant passively diffused into the fuel cell stack, and for powering the oxidant supply system to actively supply the flow of oxidant after sufficient power has been accumulated.

40. The fuel cell system of claim 39 wherein the means for accumulating power comprises means for voltage controlling and current limiting the power produced by the reaction of the reactant and oxidant passively diffused into the fuel cell stack.