Apparatus And Method For Igniting A Gaseous Fuel In A Direct Injection Internal Combustion Engine

Patent metadata

Field	Value
Publication number	US-2016186673-A9
Application number	US-201414452728-A
Country	US
Kind code	A9
Filing date	Aug 6, 2014
Priority date	Feb 7, 2012
Publication date	Jun 30, 2016
Grant date	—

Abstract

An apparatus and method for igniting a gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprises steps of heating a space near a fuel injector nozzle; introducing a pilot amount of the gaseous fuel in the combustion chamber during a first stage injection event; controlling residency of the pilot amount in the space such that a temperature of the pilot amount increases to an auto-ignition temperature of the gaseous fuel whereby ignition occurs; introducing a main amount of the gaseous fuel during a second stage injection event after the first stage injection event; and using heat from combustion of the pilot amount to ignite the main amount.

First claim

What is claimed is:

1 . A method of igniting gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprising steps of:
introducing a pilot amount of gaseous fuel into said combustion chamber; igniting said pilot amount of gaseous fuel; introducing a main amount of gaseous fuel into said combustion chamber; using heat from combustion of said pilot amount of gaseous fuel to ignite said main amount of gaseous fuel; and controlling gaseous fuel flow into said combustion chamber between said main amount of gaseous fuel and said pilot amount of gaseous fuel by providing a ratio between a main cross-sectional area of a main injection passageway in a fuel injector nozzle and a pilot cross-sectional area of a pilot injection passageway in said fuel injector nozzle within a range of 4 to 49.

2 . The method of claim 1 , wherein said gaseous fuel is natural gas.

3 . The method of claim 1 , wherein said gaseous fuel is selected from the group consisting of methane, propane, ethane, biogas, landfill gas, hydrogen and mixtures of these fuels.

4 . The method of claim 1 , further comprising absorbing heat around said fuel injector nozzle to assist with combustion of said pilot amount and said main amount.

5 . The method of claim 1 , wherein said igniting said pilot amount is by one of:
heating a space around said fuel injector nozzle wherein said pilot amount auto-ignites; and spark igniting said pilot amount.

6 . The method of claim 1 , wherein said pilot amount is within a range of 2% to 20% of total gaseous fuel introduced.

7 . The method of claim 1 , wherein said pilot amount is within a range of 2% to 10% of total gaseous fuel introduced.

8 . The method of claim 1 , wherein said pilot amount is within a range of 2% to 8% of total gaseous fuel introduced.

9 . The method of claim 1 , wherein said pilot amount is introduced during a first stage injection event before said main amount is introduced.

10 . The method of claim 9 , wherein said main amount is introduced in a second stage injection event after said pilot amount ignites.

11 . The method of claim 9 , further comprising:
introducing a second pilot amount of said gaseous fuel before said first stage injection event; and igniting said second pilot amount with an external ignition source whereby combustion of said second pilot amount heats said combustion chamber.

12 . The method of claim 11 , wherein said external ignition source is a spark.

13 . The method of claim 1 , further comprising impacting a pilot fuel jet emanating from said pilot injection passageway into said combustion chamber against a diverting and retaining member wherein said pilot amount is diverted around said fuel injector nozzle.

14 . The method of claim 1 , further comprising co-injecting a second fuel such that ignitability of said gaseous fuel is improved.

15 . The method of claim 14 , wherein said second fuel is introduced into said combustion chamber separately from said gaseous fuel.

16 . The method of claim 14 , wherein said second fuel forms a mixture with said gaseous fuel, and said mixture is introduced into said combustion chamber.

17 . The method of claim 1 , wherein said ratio is within a range of 9 to 49.

18 . The method of claim 1 , wherein said ratio is within a range of 11.5 to 49.

19 . A method of igniting gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprising steps of:
introducing a main amount of gaseous fuel into said combustion chamber; introducing a pilot amount of gaseous fuel into said combustion chamber; igniting said pilot amount of gaseous fuel; using heat from combustion of said pilot amount of gaseous fuel to ignite said main amount of gaseous fuel; and controlling gaseous fuel flow into said combustion chamber between said main amount of gaseous fuel and said pilot amount of gaseous fuel by providing a ratio between a main cross-sectional area of a main injection passageway in a first fuel injector nozzle and a pilot cross-sectional area of a pilot injection passageway in said second fuel injector nozzle within a range of 4 to 49.

20 . The method of claim 19 , wherein said main amount is introduced into an intake manifold upstream from an intake valve of said combustion chamber.

21 . The method of claim 19 , wherein said ratio is within a range of 9 to 49.

22 . The method of claim 19 , wherein said ratio is within a range of 11.5 to 49.

23 . An apparatus for igniting gaseous fuel in a combustion chamber of an internal combustion engine comprising:
a fuel injector for directly introducing gaseous fuel into said combustion chamber; said fuel injector comprising a pilot injection passageway and a main injection passageway, said pilot injection passageway comprising a pilot cross-sectional area perpendicular to gaseous fuel flow therethrough, and said main injection passageway comprising a main cross-sectional area perpendicular to gaseous fuel flow therethrough, a ratio of said main cross-sectional area to said pilot cross-sectional area is within a range of 4 to 49; an ignition source; a controller operatively connected with said fuel injector and said ignition source and configured to:
actuate said fuel injector to introduce a pilot amount of gaseous fuel through said pilot injection passageway forming a pilot jet;
actuate said ignition source to ignite said pilot jet; and
actuate said fuel injector to introduce a main amount of gaseous fuel through said main injection passageway forming a main jet wherein said main jet ignites due to heat from combustion of said pilot jet.

24 . The apparatus of claim 23 , wherein the gaseous fuel is natural gas.

25 . The apparatus of claim 23 , wherein said gaseous fuel is selected from the group consisting of methane, propane, ethane, biogas, landfill gas, hydrogen and mixtures of these fuels.

26 . The apparatus of claim 23 , wherein said ratio is within a range of 9 to 49.

27 . The apparatus of claim 23 , wherein said ratio is within a range of 11.5 to 49.

28 . The apparatus of claim 23 , wherein said ignition source comprises a sparking mechanism.

29 . The apparatus of claim 23 , wherein said ignition source comprises a heating coil.

30 . The apparatus of claim 23 , wherein said ignition source comprises an induction heater.

31 . The apparatus of claim 23 , wherein said pilot amount is introduced during a first stage injection event and said main amount is introduced during a second stage injection event, and said controller is further configured to:
actuate said fuel injector to introduce a second pilot amount of gaseous fuel through said pilot injection passageway before said first stage injection event; and actuate a sparking mechanism to spark ignite said second pilot amount of said gaseous fuel; wherein heat from combustion of said second pilot amount assists with ignition of said pilot amount.

32 . The apparatus of claim 23 , further comprising a diverting and retaining member operable to divert flow of said pilot jet around said fuel injector.

33 . The apparatus of claim 23 , further comprising a second fuel injector for introducing a second fuel directly into said combustion chamber, said

Assignees

• Westport Power Inc

Inventors

• Huang Jian
• Munshi Sandeep
• Mctaggart-Cowan Gordon P
• Wager David R

Classifications

• F02D19/061 Primary

  by controlling fuel injectors · CPC title

• F02D19/0647

  the gaseous fuel being liquefied petroleum gas [LPG], liquefied natural gas [LNG], compressed natural gas [CNG] or dimethyl ether [DME] · CPC title

• F02B7/08

  Methods of operating · CPC title

• F02D19/0692

  Arrangement of multiple injectors per combustion chamber · CPC title

• F02D41/403

  with pilot injections · CPC title