Gaseous fuel internal combustion engine and operating method therefor

Patent metadata

Field	Value
Publication number	US-10273891-B2
Application number	US-201615356116-A
Country	US
Kind code	B2
Filing date	Nov 18, 2016
Priority date	Nov 18, 2016
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

Operating a gaseous fuel engine includes injecting a pilot charge directly into a combustion chamber in an engine, and igniting one spray plume of the pilot charge. A flame front is propagated to other pilot spray plumes to produce an ignition flame for igniting later injected main charge spray plumes. Injection of the pilot and main charges is by way of the same fuel injection orifices.

First claim

What is claimed is:

1. A method of operating a gaseous fuel internal combustion engine comprising:
conveying gaseous fuel in a gaseous state to a fuel injector in the internal combustion engine;
injecting a total of one pilot charge of gaseous fuel from a plurality of fuel injection orifices of the fuel injector into a combustion chamber in the internal combustion engine to form a plurality of pilot spray plumes;
igniting one of the plurality of pilot spray plumes at a fixed ignition point within the combustion chamber;
propagating a flame front of the ignited pilot spray plume bidirectionally from the fixed ignition point to the other pilot spray plumes, such that an annular ignition flame is formed;
injecting a main charge of gaseous fuel from the plurality of fuel injection orifices into the combustion chamber to form a plurality of main spray plumes; and
igniting the plurality of main spray plumes within the combustion chamber by way of the annular ignition flame formed by the propagated flame front.

2. The method of claim 1 wherein the propagating further includes propagating the flame front such that the other pilot spray plumes are ignited, in advance of the igniting of the plurality of main spray plumes, from a total of one pilot spray plume ignited at the fixed ignition point.

3. The method of claim 2 wherein a center axis is defined by the plurality of fuel injection orifices and the annular ignition flame is centered on the center axis.

4. The method of claim 3 wherein the propagating of the flame front further includes propagating the flame front to form an ignition flame lying in plume paths of the plurality of main spray plumes.

5. The method of claim 1 further comprising lifting an outlet check within a fuel injector nozzle a first time to initiate the injection of the pilot charge, and lifting the outlet check a second time to initiate the injection of the main charge.

6. The method of claim 5 wherein the lifting of the outlet check a first time includes lifting the outlet check for a first time duration, and the lifting of the outlet check a second time includes lifting the outlet check for a second time duration that is longer than the first time duration, and further comprising closing the outlet check between the lifting of the outlet check a first time and the lifting of the outlet check a second time.

7. The method of claim 4 wherein a number of the fuel injection orifices is from 5 to 10 and an inter-orifice angle between adjacent ones of the plurality of fuel injection orifices is from 30 degrees to 90 degrees, and wherein a spray angle defined by the plurality of fuel injection orifices is from 90 degrees to 180 degrees.

8. The method of claim 1 wherein the igniting of the one of the pilot spray plumes at a fixed ignition point includes igniting the one of the pilot spray plumes at an electromagnetic discharge ignition point.

9. The method of claim 8 wherein the igniting of the one of the pilot spray plumes includes igniting the one of the pilot spray plumes at a spark gap defining the electromagnetic discharge ignition point and located on a circle that is intersected by plume paths from the plurality of fuel injection orifices.

10. A gaseous fuel internal combustion engine comprising:
a gaseous fuel supply;
a vaporizer;
a fuel pump structured to pressurize gaseous fuel supplied in a gaseous state from the vaporizer;
an engine housing including an engine block and an engine head assembly coupled with the engine block;
a piston positioned to reciprocate within the engine block, and the piston, the engine block, and the engine head assembly defining a combustion chamber;
an igniter supported within the engine head assembly and defining a fixed ignition point within the combustion chamber; and
a fuel injector supported within the engine head assembly and coupled with the gaseous fuel supply by way of the vaporizer and the fuel pump, the fuel injector including an injector body having a nozzle, and an outlet check movable within the injector body to open and close a plurality of injection orifices formed in the nozzle, the plurality of injection orifices defining a center axis and a plurality of plume paths directed radially outward from the center axis and axially downward toward the piston, and the plurality of injection orifices being from 5 to 10 in number and arranged for injection of both pilot and main charges of gaseous fuel;
a first one of the plume paths intersecting the fixed ignition point and the other plume paths being successively spaced from the fixed ignition point, such that a flame front formed by igniting a pilot spray plume injected along the first one of the plume paths is propagated to a plurality of other pilot spray plumes injected along the other plume paths to form an ignition flame positioned to ignite main spray plumes of a main charge of the gaseous fuel;
the fixed ignition point lying on a circle intersected by each of the plurality of plume paths, such that the ignition flame formed by propagation of the flame front has an annular form and extends circumferentially around the center axis;
the plurality of injection orifices defining a spray angle from 90 degrees to 180 degrees and an inter-orifice angle from 30 degrees to 90 degrees, and a distance from an outlet of the one of the plurality of injection orifices to the fixed ignition point being from 15 mm to 30 mm.

11. The engine of claim 10 wherein the fixed ignition point includes an electromagnetic discharge ignition point defined by the igniter.

12. The engine of claim 10 wherein the fuel injection orifices have a uniform spacing about the center axis and uniform spray angles such that the circle intersected by the plurality of plume paths lies in a plane oriented normal to the center axis.

13. The engine of claim 11 wherein the engine block forms a cylinder having a bore from 100 mm to 300 mm.

14. The engine of claim 10 wherein the engine block forms a plurality of cylinders, the piston is one of a plurality of pistons reciprocal one within each of the plurality of cylinders, and wherein the igniter includes a sparkplug that is one of a plurality of sparkplugs having a total number within the engine that is equal to a total number of the plurality of cylinders.

15. The method of claim 1 wherein the gaseous fuel internal combustion engine is operable in a load range, and wherein the injection of the main charge of gaseous fuel and the ignition of the plurality of main spray plumes occurs during operation of the gaseous fuel internal combustion engine in a full load portion of the load range.

16. A method of operating a gaseous fuel internal combustion engine comprising:
conveying a gaseous fuel in a gaseous state to a fuel injector in the internal combustion engine;
injecting a total of one pilot charge of the gaseous fuel from a plurality of fuel injection orifices of the fuel injector into a combustion chamber in the internal combustion engine;
producing a plurality of pilot spray plumes from the plurality of fuel injection orifices that begin to overlap one another at locations radially outward from the plurality of injection orifices;
igniting a total of one of the plurality of pilot spray plumes at a fixed ignition point within the combustion chamber;
propagating a flame front of the ignited pilot spray plume bidirectionally from the fixed ignition point to the other pilot spray plumes, such that an annular ignition flame is formed;
injecting a main charge of the gaseous fuel from the plurality of fuel injection orifices into the combustion chamber to form a

Assignees

• Caterpillar Inc

Inventors

• Martin Glen
• Ginter David
• Singh Jaswinder

Classifications

• F02P15/00

  Electric spark ignition having characteristics not provided for in, or of interest apart from, groups F02P1/00 - F02P13/00 {and combined with layout of ignition circuits (not combined F02B, F02C, F02G, F02K)} · CPC title

• F02P5/045

  combined with electronic control of other engine functions, e.g. fuel injection (in general F02D37/02) · CPC title

• F02D2041/389

  for injecting directly into the cylinder · CPC title

• F02M21/0245

  High pressure fuel supply systems; Rails; Pumps; Arrangement of valves · CPC title

• F02P5/04

  automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions (dependent on position of personal controls of engine F02P5/02) · CPC title