Parasitic load control system for exhaust temperature control

• US 7,523,606 B2
• Filed: 08/31/2005
• Issued: 04/28/2009
• Est. Priority Date: 08/31/2005
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Coldren, Dana R., Coleman, Gerald N., Strauser, Aaron D.
• Primary Examiner(s): Denion; Thomas E
• Assistant Examiner(s): TRAN, DIEM T
• Application Number:
  US11/214,955
• Publication Number:
  US 20070044453A1
• Time in Patent Office: 1,336 Days
• Field of Search: 602/86, 602/95, 602/97, 603/11, 602/74, 602/85, 603/00
• US Class Current: 60/300
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 13/0097 the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 2240/14 a fuel burner
• CPC Class Codes: F01N 3/0256 the fuel being ignited by electrical means
• CPC Class Codes: F01N 3/035 with catalytic reactors , e.g. catalysed diesel particulate filters
• CPC Class Codes: F01N 3/106 Auxiliary oxidation catalysts
• CPC Class Codes: F01N 3/2033 using a fuel burner or introducing fuel into exhaust duct
• CPC Class Codes: F01N 3/206 Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing agents F01N3/2066 takes precedence
• CPC Class Codes: F02D 2041/026 using an external load, e.g. by increasing generator load or by changing the gear ratio
• CPC Class Codes: F02D 41/029 the exhaust gas treating apparatus being a particulate filter
• CPC Class Codes: F02D 41/3836 Controlling the fuel pressure
• CPC Class Codes: F02M 45/02 with each cyclic delivery being separated into two or more parts
• CPC Class Codes: F02M 47/027 Electrically actuated valves draining the chamber to release the closing pressure
• CPC Class Codes: F02M 57/023 mechanical
• CPC Class Codes: F02M 59/366 Valves being actuated electrically
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A parasitic load control system is provided. The system may include an exhaust producing engine and a fuel pumping mechanism configured to pressurize fuel in a pressure chamber. The system may also include an injection valve configured to cause fuel pressure to build within the pressure chamber when in a first position and allow injection of fuel from the pressure chamber into one or more combustion chambers of the engine when in a second position. The system may further include a controller configured to independently regulate the pressure in the pressure chamber and the injection of fuel into the one or more combustion chambers, to increase a load on the fuel pumping mechanism, increasing parasitic load on the engine, thereby increasing a temperature of the exhaust produced by the engine.

Claims

1. A parasitic load control system, comprising:

an exhaust producing engine;

a fuel pumping mechanism configured to pressurize fuel in a pressure chamber;

an injection valve configured to cause fuel pressure to build within the pressure chamber when in a first position and allow injection of fuel from the pressure chamber into one or more combustion chambers of the engine when in a second position; and

a controller configured to independently regulate the pressure in the pressure chamber and the injection of fuel into the one or more combustion chambers, to increase a load on the fuel pumping mechanism, increasing parasitic load on the engine, thereby increasing a temperature of the exhaust produced by the engine.

2. The system of claim 1, wherein the system is configured to increase the load on the fuel pumping mechanism by creating pressure in the pressure chamber in excess of pressure used for the injection of fuel into the one or more combustion chambers.

3. The system of claim 1, wherein the system includes a hydraulically actuated fuel injector.

4. The system of claim 1, wherein the controller is further configured to operate the engine under increased parasitic load at substantially the same engine speed as when not under increased parasitic load and all other conditions are the same.

5. The system of claim 1, wherein the system is configured to increase the load on the fuel pumping mechanism by creating pressure in the pressure chamber more frequently than is used for the injection of fuel into the one or more combustion chambers.

6. The system of claim 5, wherein the system is also configured to increase the load on the fuel pumping mechanism by creating pressure in the pressure chamber in excess of pressure used for the injection of fuel into the one or more combustion chambers.

7. The system of claim 1, wherein the system includes a mechanically actuated fuel injector.

8. The system of claim 7, wherein the controller is configured to position the spill valve in the first position to build pressure and then the second position to relieve at least some of the pressure two or more times during an engine cycle.

9. The system of claim 1, further including:

a spill valve configured to;

cause fuel pressure to build within the pressure chamber when in a first position; and

allow fuel to drain from the pressure chamber when in a second position;

wherein the controller is further configured to;

position the spill valve in the first position and the injection valve in the first position to accumulate an amount of pressurized fuel within the pressure chamber; and

subsequently position the spill valve in the second position to drain off at least a portion of the pressurized fuel to a location separate from the one or more combustion chambers of the engine, thereby relieving at least some of the pressure in the pressure chamber.

10. The system of claim 9, wherein the controller is configured to position the spill valve in the first position to build pressure and then the second position to release the pressurized fuel two or more times during an engine cycle.

11. The system of claim 1, further including an after-treatment device configured to remove one or more constituents from the exhaust produced by the engine, wherein the system is configured such that the increasing of the temperature of the exhaust produced by the engine facilitates operation of the after-treatment device.

12. The system of claim 11, wherein the after-treatment device includes a catalytic material.

13. The system of claim 12, wherein the catalytic material includes an oxidation catalyst.

14. The system of claim 13, wherein the increasing of the temperature of the exhaust produced by the engine facilitates operation of the oxidation catalyst by increasing a temperature of the oxidation catalyst.

15. The system of claim 14, wherein the increasing of the temperature of the oxidation catalyst thereby enables fuel in the exhaust to be oxidized over the oxidation catalyst further increasing the temperature of the exhaust, thereby contributing to thermal regeneration of a particulate trap configured to remove one or more types of particulate matter from the exhaust, wherein thermal regeneration includes reducing an amount of particulate matter accumulated in the particulate trap.

16. The system of claim 12, wherein the after-treatment device includes a reduction catalyst.

17. The system of claim 16, wherein the after-treatment device is configured to provide selective catalytic reduction of one or more constituents in the exhaust.

18. The system of claim 11, wherein the system is further configured to raise the temperature of the exhaust in at least one additional manner including at least one of air inlet throttling, post-injection, increasing backpressure upstream from the after-treatment device, air inlet heating, operating an electrical heating element, and operating a burner assembly positioned upstream from the after-treatment device and configured to produce a flame and direct the exhaust in heat exchange relation to the flame.

19. A method of controlling parasitic load on an exhaust producing engine, comprising:

pressurizing fuel in a pressure chamber; and

independently regulating the pressure in the pressure chamber and the injection of fuel into one or more combustion chambers of the engine to increase a load on a fuel pumping mechanism, increasing parasitic load on the engine, thereby increasing a temperature of the exhaust produced by the engine.

20. The method of claim 19, wherein the increasing of the load on the fuel pumping mechanism is accomplished by creating pressure in the pressure chamber in excess of pressure used for the injection of fuel into the one or more combustion chambers.

21. The method of claim 19, further including hydraulically actuating the fuel pumping mechanism.

22. The method of claim 19, further including mechanically actuating the fuel pumping mechanism.

23. The method of claim 19, further including operating the engine under increased parasitic load at substantially the same engine speed as when not under increased parasitic load and all other conditions are the same.

24. The method of claim 19, wherein the increasing of the load on the fuel pumping mechanism is accomplished by creating pressure in the pressure chamber more frequently than is used for the injection of fuel into the one or more combustion chambers.

25. The method of claim 24, further including creating pressure in the pressure chamber in excess of pressure used for the injection of fuel into the one or more combustion chambers.

26. The method of claim 19, further including draining off at least a portion of the pressurized fuel to a location separate from the one or more combustion chambers of the engine, thereby relieving at least some of the pressure in the pressure chamber.

27. The method of claim 26, including building fuel pressure in the pressure chamber and relieving at least some of the pressure two or more times during an engine cycle.

28. The method of claim 19, further including facilitating operation of an after-treatment device configured to remove one or more constituents from the exhaust produced by the engine.

29. The method of claim 28, wherein the after-treatment device includes a catalytic material.

30. The method of claim 29, wherein operation of the after-treatment device includes an oxidation reaction over the catalytic material.

31. The method of claim 30, wherein the increasing of the temperature of the exhaust produced by the engine facilitates propagation of the oxidation reaction by increasing a temperature of the catalytic material.

32. The method of claim 31, wherein the increasing of the temperature of the catalytic material thereby enables fuel in the exhaust to be oxidized over the catalytic material further increasing the temperature of the exhaust, thereby contributing to thermal regeneration of a particulate trap configured to remove one or more types of particulate matter from the exhaust, wherein thermal regeneration includes reducing an amount of particulate matter accumulated in the particulate trap.

33. The method of claim 28, wherein operation of the after-treatment device includes a reduction reaction over the catalytic material.

34. The method of claim 33, further including providing selective catalytic reduction of one or more constituents in the exhaust.

35. The method of claim 28, further including raising the temperature of the exhaust using one or more additional methods besides the increasing of load on the fuel pumping mechanism, the one or more methods including at least one of air inlet throttling, post-injection, increasing backpressure upstream from the after-treatment device, air inlet heating, operating an electrical heating element, and operating a burner assembly positioned upstream from the after-treatment device and configured to produce a flame and direct the exhaust in heat exchange relation to the flame.

36. A machine, comprising:

a frame;

an exhaust producing engine coupled to the frame;

a fuel pumping mechanism configured to pressurize fuel in a pressure chamber

an injection valve configured to cause fuel pressure to build within the pressure chamber when in a first position and allow injection of fuel from the pressure chamber into one or more combustion chambers of the engine when in a second position; and

a controller configured to independently regulate the pressure in the pressure chamber and the injection of fuel into the one or more combustion chambers, to increase a load on the fuel pumping mechanism, increasing parasitic load on the engine, thereby increasing a temperature of the exhaust produced by the engine; and

a particulate trap configured to remove one or more types of particulate matter from the exhaust produced by the engine, wherein the increasing of the temperature of the exhaust produced by the engine contributes to thermal regeneration of the particulate trap, thereby reducing an amount of particulate matter accumulated in the particulate trap.

37. The machine of claim 36, wherein the system is configured to increase the load on the fuel pumping mechanism by creating pressure in the pressure chamber in excess of pressure used for the injection of fuel into the one or more combustion chambers.

38. The machine of claim 36, wherein the system includes a hydraulically actuated fuel injector.

39. The machine of claim 36, wherein the system includes a mechanically actuated fuel injector.

40. The machine of claim 36, wherein the after-treatment device includes an oxidation catalyst, the increasing of the temperature of the exhaust produced by the engine facilitating operation of the oxidation catalyst by increasing a temperature of the oxidation catalyst;

and

wherein the increasing of the temperature of the oxidation catalyst thereby enables fuel in the exhaust to be oxidized over the oxidation catalyst further increasing the temperature of the exhaust, thereby contributing to thermal regeneration of the particulate trap.

41. The machine of claim 36, wherein the system is configured to increase the load on the fuel pumping mechanism by creating pressure in the pressure chamber more frequently than is used for the injection of fuel into the one or more combustion chambers.

42. The machine of claim 41, wherein the system is also configured to increase the load on the fuel pumping mechanism by creating pressure in the pressure chamber in excess of pressure used for the injection of fuel into the one or more combustion chambers.

43. The machine of claim 36, further including:

a spill valve configured to;

cause fuel pressure to build within the pressure chamber when in a first position; and

allow fuel to drain from the pressure chamber when in a second position;

wherein the controller is further configured to;

position the spill valve in the first position and the injection valve in the first position to accumulate an amount of pressurized fuel within the pressure chamber; and

subsequently position the spill valve in the second position to drain off at least a portion of the pressurized fuel to a location separate from the one or more combustion chambers of the engine.

44. The machine of claim 43, wherein the controller is configured to position the spill valve in the first position to build pressure and then the second position to release the pressurized fuel two or more times during an engine cycle.