Claims
- 1. A fuel injector for vaporizing and metering a liquid fuel to an internal combustion engine, comprising:
(a) at least one capillary flow passage, said at least one capillary flow passage having an inlet end and at least one outlet end; (b) a heat source arranged along said at least one capillary flow passage, said heat source operable to heat the liquid fuel in said at least one capillary flow passage to a level sufficient to change at least a portion thereof from the liquid state to a vapor state and deliver a stream of substantially vaporized fuel from said outlet end of said at least one capillary flow passage; and (c) a valve for metering fuel to the internal combustion engine, said valve located proximate to said outlet end of said at least one capillary flow passage, said valve including a low mass member for substantially occluding the stream of fuel to the internal combustion engine;
wherein said low mass member for substantially occluding the stream of fuel to the internal combustion engine is formed of a material having low mass and/or a low coefficient of thermal conductivity.
- 2. The fuel injector of claim 1, wherein said low mass member of said valve for metering fuel to the internal combustion engine is a plug member for substantially occluding the stream of fuel from said outlet end of said at least one capillary flow passage.
- 3. The fuel injector of claim 2, wherein said low mass plug member of said valve for metering fuel to the internal combustion engine is axially aligned with said at least one capillary flow passage.
- 4. The fuel injector of claim 2, wherein said low mass plug member of said valve for metering fuel to the internal combustion engine is tangentially alignable with said outlet end of said at least one capillary flow passage.
- 5. The fuel injector of claim 2, wherein said low mass plug member of said valve for metering fuel to the internal combustion engine is a hollow sleeve member for substantially occluding the stream of fuel from said outlet end of said at least one capillary flow passage.
- 6. The fuel injector of claim 5, wherein said low mass hollow sleeve member of said valve for metering fuel to the internal combustion engine is axially aligned with said at least one capillary flow passage.
- 7. The fuel injector of claim 6, wherein said low mass hollow sleeve member of said valve for metering fuel to the internal combustion engine has an internal cross sectional area effective for positioning said hollow sleeve member over said at least one capillary flow passage enabling the stream of fuel from said outlet end of said at least one capillary flow passage to be substantially occluded.
- 8. The fuel injector of claim 1, wherein said low mass member of said valve for metering fuel to the internal combustion engine is a spherical plug member.
- 9. The fuel injector of claim 8, wherein said at least one capillary flow passage is positionable to enable said outlet end to contact an outer surface of said low mass spherical plug member and occlude the stream of fuel from said outlet end of said at least one capillary flow passage.
- 10. The fuel injector of claim 1, further comprising:
(d) means for cleaning deposits formed during operation of the apparatus.
- 11. The fuel injector of claim 10, wherein said means for cleaning deposits includes said heat source and an oxidizer control valve for placing said at least one capillary flow passage in fluid communication with an oxidizer, said heat source also being operable to heat the oxidizer in said at least one capillary flow passage to a level sufficient to oxidize deposits formed during the heating of the liquid fuel, wherein said oxidizer control valve for placing said at least one capillary flow passage in fluid communication with an oxidizer is operable to alternate between the introduction of liquid fuel and the introduction of oxidizer into said capillary flow passage and enable in-situ cleaning of said capillary flow passage when the oxidizer is introduced into said at least one capillary flow passage.
- 12. The fuel injector of claim 11, wherein the oxidizer comprises air, exhaust gas, steam and mixtures thereof.
- 13. The fuel injector of claim 10, wherein said means for cleaning deposits includes a solvent control valve for placing said at least one capillary flow passage in fluid communication with a solvent, said solvent control valve disposed at one end of said at least one capillary flow passage, and wherein said solvent control valve for placing said at least one capillary flow passage in fluid communication with a solvent is operable to alternate between the introduction of liquid fuel and the introduction of solvent into said capillary flow passage and enable in-situ cleaning of said capillary flow passage when the solvent is introduced into said at least one capillary flow passage.
- 14. The fuel injector of claim 13, wherein the solvent comprises liquid fuel from the liquid fuel source and wherein the heat source is phased-out during cleaning of said capillary flow passage.
- 15. The fuel injector of claim 10, wherein the means for cleaning deposits employs a solvent comprising liquid fuel from the liquid fuel source and wherein the heat source is phased-out during cleaning of said capillary flow passage.
- 16. The fuel injector of claim 1, further comprising a nozzle to atomize a portion of the liquid fuel.
- 17. The fuel injector of claim 1, further including a solenoid to actuate said valve for metering fuel to the internal combustion engine.
- 18. The fuel injector of claim 1, wherein said at least one capillary flow passage is a helical passage.
- 19. The fuel injector of claim 1, further comprising a non-capillary liquid fuel flow passage, said non-capillary liquid fuel flow passage having an inlet end and an outlet end, said inlet end in fluid communication with the liquid fuel supply.
- 20. The fuel injector of claim 19, further comprising a first fluid control valve for placing said inlet end of said capillary liquid fuel flow passage in fluid communication with a liquid fuel supply and a second fluid control valve for placing said inlet end of said non-capillary liquid fuel flow passage in fluid communication with the liquid fuel supply, and wherein both said fluid control valves for placing said inlet end of said at least one capillary flow passage in fluid communication with the liquid fuel supply and said valve for placing said inlet end of said non-capillary liquid fuel flow passage in fluid communication with the liquid fuel supply share a valve body controllable to direct fuel to said at least one capillary flow passage and said liquid fuel flow passage.
- 21. The fuel injector of claim 1, wherein said heat source includes a resistance heater.
- 22. A fuel system for use in an internal combustion engine, comprising
(a) a plurality of fuel injectors, each injector including (i) at least one capillary flow passage said at least one capillary flow passage having an inlet end and an outlet end; (ii) a heat source arranged along the at least one capillary flow passage, said heat source operable to heat the liquid fuel in said at least one capillary flow passage to a level sufficient to change at least a portion thereof from the liquid state to a vapor state and deliver a stream of substantially vaporized fuel from said outlet end of said at least one capillary flow passage; and (iii) a valve for metering fuel to the internal combustion engine, said valve located proximate to said outlet end of said at least one capillary flow passage, said valve including a low mass member for substantially occluding the stream of fuel to the internal combustion engine;
wherein said low mass member for substantially occluding the stream of fuel to the internal combustion engine is formed of a material having low mass and/or a coefficient of thermal conductivity; (b) a liquid fuel supply system in fluid communication with said plurality of fuel injectors; and (c) a controller to control the supply of fuel to said plurality of fuel injectors.
- 23. The fuel system of claim 22, wherein said low mass member of said valve for metering fuel to the internal combustion engine is a plug member for substantially occluding the stream of fuel from said outlet end of said at least one capillary flow passage.
- 24. The fuel system of claim 23, wherein said low mass plug member of said valve for metering fuel to the internal combustion engine is axially aligned with said at least one capillary flow passage.
- 25. The fuel system of claim 23, wherein said low mass plug member of said valve for metering fuel to the internal combustion engine is tangentially alignable with said outlet end of said at least one capillary flow passage.
- 26. The fuel system of claim 23, wherein said low mass member of said valve for metering fuel to the internal combustion engine is a hollow sleeve member for substantially occluding the stream of fuel from said outlet end of said at least one capillary flow passage.
- 27. The fuel system of claim 26, wherein said low mass hollow sleeve member of said valve for metering fuel to the internal combustion engine is axially aligned with said at least one capillary flow passage.
- 28. The fuel system of claim 27, wherein said low mass hollow sleeve member of said valve for metering fuel to the internal combustion engine has an internal cross sectional area effective for positioning said hollow sleeve member over said at least one capillary flow passage enabling the stream of fuel from said outlet end of said at least one capillary flow passage to be substantially occluded.
- 29. The fuel system of claim 22, wherein said low mass member of said valve for metering fuel to the internal combustion engine is a spherical plug member.
- 30. The fuel system of claim 29, wherein said at least one capillary flow passage is positionable to enable said outlet end to contact an outer surface of said low mass spherical plug member and occlude the stream of fuel from said outlet end of said at least one capillary flow passage.
- 31. The fuel system of claim 22, further comprising means for cleaning deposits formed during operation of the apparatus.
- 32. The fuel system of claim 31, wherein said means for cleaning deposits includes said heat source and an oxidizer control valve for placing said at least one capillary flow passage in fluid communication with an oxidizer, said heat source also being operable to heat the oxidizer in said at least one capillary flow passage to a level sufficient to oxidize deposits formed during the heating of the liquid fuel, wherein said oxidizer control valve for placing said at least one capillary flow passage in fluid communication with an oxidizer is operable to alternate between the introduction of liquid fuel and the introduction of oxidizer into said capillary flow passage and enable in-situ cleaning of said capillary flow passage when the oxidizer is introduced into said at least one capillary flow passage.
- 33. The fuel system of claim 32, wherein the oxidizer comprises air, exhaust gas, steam and mixtures thereof.
- 34. The fuel system of claim 31, wherein said means for cleaning deposits includes a solvent control valve for placing said at least one capillary flow passage in fluid communication with a solvent, said solvent control valve disposed at one end of said at least one capillary flow passage, and wherein said solvent control valve for placing said at least one capillary flow passage in fluid communication with a solvent is operable to alternate between the introduction of liquid fuel and the introduction of solvent into said capillary flow passage and enable in-situ cleaning of said capillary flow passage when the solvent is introduced into said at least one capillary flow passage.
- 35. The fuel system of claim 34, wherein the solvent comprises liquid fuel from the liquid fuel source and wherein the heat source is phased-out during cleaning of said capillary flow passage.
- 36. The fuel system of claim 31, wherein the means for cleaning deposits employs a solvent comprising liquid fuel from the liquid fuel source and wherein the heat source is phased-out during cleaning of said capillary flow passage.
- 37. The fuel system of claim 22, further comprising at least one additional liquid fuel injector for the delivery of liquid fuel.
- 38. The fuel system of claim 37, wherein said controller controls fuel delivery to said at least one capillary flow passage of said plurality of fuel injectors and to said at least one liquid fuel injector.
- 39. The fuel system of claim 22, wherein said valves for metering fuel are solenoid operated.
- 40. The fuel system of claim 37, further comprising at least one liquid fuel injector control valve in fluid communication with said at least one liquid fuel injector to direct fluid flow to said at least one liquid fuel injector.
- 41. The fuel system of claim 40, further comprising at least one solenoid operated by said controller to actuate said at least one liquid fuel injector valve.
- 42. The fuel system of claim 22, further comprising a fluid control valve, wherein said controller and said fluid control valve cooperate to deliver liquid fuel to said at least one capillary flow passage during start-up and warm-up of the internal combustion engine.
- 43. The fuel system of claim 22, wherein each said fuel injector further comprises a liquid fuel flow passage.
- 44. The fuel system of claim 43, wherein said controller is operable to control fuel delivery to said at least one capillary flow passage and said liquid fuel flow passage of each said fuel injector.
- 45. The fuel system of claim 22, wherein under cold starting conditions said at least one capillary flow passage delivers vaporized fuel, which condenses in air at ambient temperature to form an aerosol.
- 46. The fuel system of claim 22, further comprising at least one sensor operably connected to said controller, wherein said controller determines metering valve position and temperature of said heat source in response to at least one sensed condition.
- 47. The fuel system of claim 22, wherein said at least one capillary flow passage is a helical passage.
- 48. The fuel system of claim 22, wherein said heat source includes a resistance heater.
- 49. A method of delivering fuel to an internal combustion engine, comprising the steps of:
(a) supplying liquid fuel to at least one capillary flow passage of a fuel injector; (b) causing a stream of substantially vaporized fuel to pass through an outlet of the at least one capillary flow passage by heating the liquid fuel in the at least one capillary flow passage; and (c) metering the vaporized fuel to a combustion chamber of the internal combustion engine through a valve located proximate to the outlet end of the at least one capillary flow passage, the valve including a low mass member for substantially occluding the stream of fuel to the internal combustion engine;
wherein the low mass member for substantially occluding the stream of fuel to the internal combustion engine is formed of a material having low mass and/or a coefficient of thermal conductivity.
- 50. The method of claim 49, wherein said delivery of vaporized fuel to the combustion chamber of the internal combustion engine is limited to start-up and warm-up of the internal combustion engine.
- 51. The method of claim 50, wherein a stream of vaporized fuel is delivered to each combustion chamber of the internal combustion engine.
- 52. The method of claim 49, wherein a stream of vaporized fuel is delivered to each combustion chamber of the internal combustion engine.
- 53. The method of claim 50, further comprising delivering liquid fuel to the combustion chamber of the internal combustion engine when the internal combustion engine is at a fully warmed condition.
- 54. The method of claim 53, wherein a liquid fuel injector is operated to deliver liquid fuel to the at least one combustion chamber of the internal combustion engine.
- 55. The method of claim 49, further comprising the step of selecting fuel delivery from either the at least one capillary flow passage or the liquid fuel injector.
- 56. The method of claim 49, further comprising cleaning periodically the at least one capillary flow passage.
- 57. The method of claim 56, wherein said periodic cleaning comprises (i) halting liquid fuel flow to the at least one capillary flow passage, (ii) supplying an oxidizer to the at least one capillary flow passage and (iii) heating the at least one capillary flow passage whereby deposits formed in the at least one capillary flow passage are oxidized.
- 58. The method of claim 57, further comprising selectively supplying fuel and oxidizer to the at least one capillary flow passage, wherein the supply selection is achieved by a valve mechanism operated by a controller.
- 59. The method of claim 58, wherein the oxidizer includes pressurized air, exhaust gas, steam and mixtures thereof.
- 60. The method of claim 56, wherein said periodic cleaning comprises (i) phasing-out said heating of the at least one capillary flow passage, (ii) supplying a solvent to the at least one capillary flow passage, whereby deposits formed in the at least one capillary flow passage are removed.
- 61. The method of claim 60, wherein the solvent includes liquid fuel from the liquid fuel source.
- 62. The method of claim 49, wherein the stream of vaporized fuel mixes with air and forms an aerosol in the combustion chamber prior to start up of combustion, the method including forming the aerosol with a particle size distribution, a fraction of which is 25 μm or less prior to igniting the vaporized fuel to initiate combustion.
RELATED APPLICATIONS
[0001] This patent application is a continuation-in-part of application Ser. No. 10/143,250, filed on May 10, 2002, directed to a Fuel Injector for an Internal Combustion Engine, which is hereby incorporated by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60367121 |
Mar 2002 |
US |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
10143250 |
May 2002 |
US |
Child |
10342267 |
Jan 2003 |
US |