Fuel cell systems
View Patent ↗A method of operating a fuel cell system having a fuel cell stack and a plurality of fuel cells associated with the fuel cell stack. The method includes monitoring an operating parameter associated with the fuel cell stack, and adjusting a temperature of the fuel cell stack based on the operating parameter.
1. A method of operating a fuel cell system comprising a fuel cell stack and a plurality of fuel cells associated with the fuel cell stack, the method comprising:
monitoring voltages of a set of fuel cells; and
restricting coolant flow through the fuel cell stack when one or more of the monitored voltages decreases from a predetermined voltage range,
wherein:
the fuel cell system further comprises a first end plate associated with a first end of the fuel cell stack, and
the method further comprises heating the first end plate.
2. The method of claim 1 , further comprising unrestricting coolant flow through the fuel cell stack.
3. The method of claim 2 , wherein restricting and unrestricting coolant flow are performed as a function of time.
4. The method of claim 2 , wherein restricting and unrestricting coolant flow are performed to cause the voltages of a set of fuel cells to be a predetermined level.
5. The method of claim 4 , wherein the predetermined level is within about 15% of the voltages of a set of fuel cells under normal operation of the fuel cell system.
6. The method of claim 1 , wherein heating the first end plate comprises heating a first heating element different than the first end plate.
7. The method of claim 6 , wherein the first heating element is adjacent to the first end plate.
8. The method of claim 6 , wherein the first heating element is disposed between the first end plate and the fuel cell stack.
9. The method of claim 1 , further comprising:
flowing a fluid through a flow channel defined by the first end plate.
10. The method of claim 9 , wherein the fluid is heated.
11. The method of claim 1 , further comprising:
heating the first end plate with a heating element disposed on the first end plate.
12. The method of claim 1 , wherein the heating is performed electrically.
13. The method of claim 1 , further comprising:
heating a second end plate associated with the fuel cell stack.
14. The method of claim 13 , wherein heating the second end plate comprises heating a second heating element different than the second end plate.
15. The method of claim 14 , wherein the second heating element is adjacent to the second end plate.
16. The method of claim 14 , wherein the second heating element is between the second end plate and the fuel cell stack.
17. The method of claim 1 , wherein the method is performed as a feedback loop.
18. A method of operating a fuel cell system comprising a fuel cell stack and a plurality of fuel cells associated with the fuel cell stack, the method comprising:
monitoring voltages of a set of fuel cells; and
restricting coolant flow through the fuel cell stack when one or more of the monitored voltages decreases from a predetermined voltage range.
19. The method of claim 18 , wherein the set of fuel cells includes all the fuel cells associated with the fuel cell stack.
20. The method of claim 18 , wherein restricting coolant flow is performed when one or more of the monitored voltages deviate by more than about 10% from an operating voltage under normal operation of the fuel cell system.
21. The method of claim 18 , further comprising unrestricting coolant flow through the fuel cell stack.
22. The method of claim 21 , wherein unrestricting coolant flow is performed when the monitored voltages are in the predetermined voltage range.
23. The method of claim 21 , wherein unrestricting coolant flow is performed after a predetermined time of restricting coolant flow.
24. The method of claim 18 , wherein the fuel cell stack further comprises a first end plate associated with the fuel cell stack, the method further comprising:
monitoring an operating parameter of the fuel cell system; and
adjusting a temperature of the first end plate based on the operating parameter.
25. The method of claim 24 , wherein adjusting the temperature comprises heating a first heatable element.
26. The method of claim 24 , wherein adjusting the temperature comprises flowing a fluid through the first end plate.
27. The method of claim 24 , further comprising:
adjusting a temperature of a second end plate associated with the fuel cell stack based on the operating parameter.
28. The method of claim 24 , wherein the operating parameter is a power output of the fuel cell system.
29. The method of claim 24 , wherein the operating parameter is a temperature of the fuel cell stack.
30. The method of claim 25 , wherein the operating parameter is a temperature of the first heatable element.
31. The method of claim 25 , wherein the heatable element is adapted to heat an outer periphery of the fuel cell stack.
32. The method of claim 18 , wherein the method is performed as a feedback loop.