Claims
- 1. An electrochemical fuel cell system adapted for maintaining the efficient production of electrical power of a fuel cell, said system comprising:
a fuel supply containing a hydrogen rich fuel for delivery to said fuel cell; a fuel supply conduit connecting said fuel supply and said fuel cell for delivering a fuel stream of said hydrogen rich fuel to said fuel cell; an impurity sensor carried by said fuel supply conduit for detecting impurities in said fuel stream prior to said impurities entering said fuel cell; a pressure adjusting mechanism in communication with said impurity sensor being operatively associated with said fuel cell for changing the pressure of said fuel cell; and, said pressure adjusting mechanism raising the pressure of the fuel cell from a normal operating pressure to an elevated operating pressure when said impurity sensor detects impurities in said fuel stream; whereby, the detrimental effect of impurities in the fuel stream on the normal operation of the fuel cell is reduced.
- 2. The system of claim 1 wherein said impurity sensor signals said pressure adjusting mechanism to raise the pressure of said fuel cell from said normal operating pressure to said elevated operating pressure when said impurity sensor detects a rise in the level of impurities in said fuel stream above a predetermined level.
- 3. The system of claim 2 wherein said impurity sensor signals said pressure adjusting mechanism to cease raising the pressure of said fuel cell and return the fuel cell to said normal operating pressure when said impurity sensor detects a drop in the level of impurities in said fuel stream below said predetermined level.
- 4. The system of claim 1 including a control unit in electronic communication with said impurity sensor and said pressure adjusting mechanism.
- 5. The system of claim 4 wherein said control unit signals said pressure adjusting mechanism to raise the pressure of said fuel cell to said elevated operating pressure when a rise in the level of impurities is detected above a predetermined level.
- 6. The system of claim 5 wherein said control unit signals said pressure adjusting mechanism to cease raising the pressure of said fuel cell and return said fuel cell to said normal operating pressure when the level of impurities drops below said predetermined level.
- 7. The system of claim 6 wherein said pressure adjusting mechanism includes a backpressure regulator; a gas output control valve connected to said fuel cell operatively associated with said backpressure regulator; said backpressure regulator in electronic communication with said control unit for monitoring the operating pressure of said fuel cell and activating said gas output control valve to restrict or increase the flow of gas through said fuel cell to raise and lowering the operating pressure of said fuel cell as necessary.
- 8. The system of claim 1 wherein said pressure adjusting mechanism includes a gas output control valve operatively associated with said fuel cell; said gas output control valve closing to restrict the flow of gas out of said fuel cell to raise the operating pressure of the fuel cell, and said gas output control valve opening to allow the flow of gas out of said fuel cell to maintain said normal operating pressure.
- 9. The system of claim 1 wherein said pressure adjusting mechanism includes a fuel pump operatively associated with said fuel stream; said fuel pump increasing the rate of delivery of said fuel stream to said fuel cell to raise the operating pressure of said fuel cell, and said fuel pump reducing the rate of delivery of said fuel stream to said fuel cell to lower the operating pressure of said fuel cell.
- 10. The system of claim 1 including a voltage sensor for detecting a rise or drop in the voltage of said fuel cell from a predetermined voltage level.
- 11. The system of claim 10 wherein said voltage sensor is operatively associated with said pressure adjusting mechanism to increase the pressure of said fuel cell to said elevated operating pressure when a drop in voltage is detected below said predetermined voltage level to remove impurities from said fuel cell.
- 12. The system of claim 11 wherein said voltage sensor is operatively associated with said pressure adjusting mechanism to cease raising the temperature of said fuel cell and return said fuel cell to said normal operating pressure when said voltage sensor detects a return in voltage to said predetermined voltage level.
- 13. The system of claim 1 wherein said pressure adjusting mechanism is activated to raise the pressure of said fuel cell to said elevated operating pressure for a predetermined period of time upon detection of an impurity in said fuel stream; and said pressure adjusting mechanism being deactivated after said predetermined period of time to return said fuel cell to said normal operating pressure.
- 14. A system for maintaining the efficiency of an electrochemical fuel cell of the type having a fuel supply for delivering a hydrogen rich stream of fuel through a fuel supply conduit to a fuel cell stack, said system comprising:
an impurity sensor for detecting impurities in said fuel supply upstream of said fuel cell stack; a pressure adjusting mechanism operatively associated with said fuel cell stack for changing the pressure of said fuel cell stack; and, a control unit operatively associated with said impurity sensor and said pressure adjusting mechanism for raising the pressure of said fuel cell stack when impurities are detected in said fuel supply; whereby, the detrimental effect of impurities in the fuel stream on the normal operation of the fuel cell is reduced.
- 15. The system of claim 14 wherein said control unit monitors the level of impurities detected by said impurity sensor and signals said pressure adjusting mechanism to raise the pressure of said fuel cell stack to said elevated operating pressure when a rise in the level of impurities is detected above a predetermined level.
- 16. The system of claim 15 wherein said control unit signals said pressure adjusting mechanism to cease raising the pressure of said fuel cell stack and return said fuel cell stack to said normal operating pressure when the level of impurities monitored by said control unit and detected by said impurity sensor drops below said predetermined level.
- 17. The system of claim 16 wherein said pressure adjusting mechanism includes a backpressure regulator; a gas output control valve connected to said fuel cell stack operatively associated with said backpressure regulator; said backpressure regulator in electronic communication with said control unit for monitoring the operating pressure of said fuel cell stack and activating said gas output control valve to restrict or increase the flow of gas through said fuel cell stack to raise and lowering the operating pressure of said fuel cell stack as necessary.
- 18. The system of claim 14 wherein said pressure adjusting mechanism includes a gas output control valve operatively associated with said fuel cell stack; said gas output control valve closing to restrict the flow of gas out of said fuel cell stack to raise the operating pressure of the fuel cell stack, and said gas output control valve opening to allow the flow of gas out of said fuel cell stack to maintain said normal operating pressure.
- 19. The system of claim 14 wherein said pressure adjusting mechanism includes a fuel pump operatively associated with said fuel stream; said fuel pump increasing the rate of delivery of said fuel stream to said fuel cell stack to raise the operating pressure of said fuel cell stack, and said fuel pump reducing the rate of delivery of said fuel stream to said fuel cell stack to lower the operating pressure of said fuel cell stack.
- 20. The system of claim 14 including a voltage sensor for detecting a rise or drop in the voltage of said fuel cell stack from a predetermined voltage level.
- 21. The system of claim 20 wherein said voltage sensor is operatively associated with said pressure adjusting mechanism to increase the pressure of said fuel cell stack to said elevated operating pressure when a drop in voltage is detected below said predetermined voltage level to remove impurities from said fuel cell stack.
- 22. The system of claim 21 wherein said voltage sensor is operatively associated with said pressure adjusting mechanism to cease raising the temperature of said fuel cell stack and return said fuel cell stack to said normal operating pressure when said voltage sensor detects a return in voltage to said predetermined voltage level.
- 23. The system of claim 14 wherein said pressure adjusting mechanism is activated to raise the pressure of said fuel cell stack to said elevated operating pressure for a predetermined period of time upon detection of an impurity in said fuel stream; and said pressure adjusting mechanism being deactivated after said predetermined period of time to return said fuel cell stack to said normal operating pressure.
- 24. A method of improving the efficiency of an electrochemical fuel cell system of the type having a fuel supply for delivering a hydrogen rich stream of fuel through a fuel supply conduit to a fuel cell stack, said method comprising the steps of:
detecting the presence of impurities in said stream of fuel passing through said fuel supply conduit; and, actuating a pressure adjusting mechanism to raise the pressure of said fuel cell stack to an elevated operating pressure upon detecting impurities in said stream of fuel.
- 25. The method of claim 24 including the step of detecting a drop in the level of impurities below a predetermined level in said stream of fuel passing through said fuel supply conduit.
- 26. The method of claim 25 including the step of actuating said pressure adjusting mechanism to lower the pressure of said fuel cell stack to a normal operating pressure.
- 27. The method of claim 24 including the step of increasing the rate of delivery of said fuel to raise the operating pressure of said fuel cell stack.
- 28. The method of claim 24 including the step of closing a gas output control valve included in said pressure adjusting mechanism to raise the operating pressure of said fuel cell stack when impurities are detected in said stream of fuel.
- 29. The method of claim 28 including the step of opening said gas output control valve to lower the operating pressure of said fuel cell stack when impurities are no longer detected.
- 30. The method of claim 28 including the step of opening said gas output control valve after a predetermined period of time expires and said impurities drop below a predetermined level to reduce the pressure of said fuel cell stack to said normal operating pressure.
- 31. The method of claim 24 including the step of detecting a drop in voltage of said fuel cell stack from a predetermined voltage level.
- 32. The method of claim 31 including the step of actuating said pressure adjusting mechanism to raise the pressure of said fuel cell stack to said elevated operating pressure upon detecting a drop in voltage below said predetermined voltage level.
- 33. The method of claim 32 including the step of actuating said pressure adjusting mechanism to lower the pressure of said fuel cell stack to said normal operating pressure when said voltage sensor detects a return in voltage to said predetermined voltage level.
- 34. A method of improving the efficiency of an electrochemical fuel cell system of the type having a fuel supply for delivering a hydrogen rich stream of fuel through a fuel supply conduit to a fuel cell stack, said method comprising the steps of:
receiving a signal representing the presence of impurities in said stream of fuel passing through said fuel supply conduit prior to said impurities entering said fuel cell stack; and, sending a signal to a pressure adjusting mechanism for raising the pressure of said fuel cell stack from a normal operating pressure to an elevated operating pressure.
- 35. The method of claim 34 including the step of receiving a signal representing a decrease in the level of impurities in said stream of fuel.
- 36. The method of claim 34 including the step of sending a signal to said pressure adjusting mechanism to lower the pressure of said fuel cell stack to said normal operating pressure.
- 37. The method of claim 34 including the step of sending a signal to said pressure adjusting mechanism to increase the rate of delivery of said fuel to raise the operating pressure of said fuel cell stack.
- 38. The method of claim 34 including the step of sending a signal to a gas output control valve included in said pressure adjusting mechanism to close and raise the operating pressure of said fuel cell stack.
- 39. The method of claim 38 including the step of sending a signal to said gas output control valve included in said pressure adjusting mechanism to open and lower the operating pressure of said fuel cell stack.
- 40. The method of claim 38 including the step of sending a signal to said gas output control valve to open after a predetermined period of time expires once said impurities drop below a predetermine level to reduce the pressure of said fuel cell stack to said normal operating pressure.
- 41. The method of claim 34 including the step of receiving a signal representing a drop in voltage of said fuel cell stack from a predetermined voltage level.
- 42. The method of claim 41 including the step of sending a signal to said pressure adjusting mechanism to raise the pressure of said fuel cell stack to said elevated operating pressure upon a drop in voltage below said predetermined voltage level.
- 43. The method of claim 42 including the step of sending a signal to said pressure adjusting mechanism to lower the pressure of said fuel cell stack to said normal operating pressure upon a return in voltage to said predetermined voltage level.
Parent Case Info
[0001] Applicant claims priority of provisional application Nos. 60/362,693 and 60/363,200.
Provisional Applications (2)
|
Number |
Date |
Country |
|
60362693 |
Mar 2002 |
US |
|
60363200 |
Mar 2002 |
US |