Fuel injector systems for torch igniters

Patent metadata

Field	Value
Publication number	US-11209164-B1
Application number	US-202017127250-A
Country	US
Kind code	B1
Filing date	Dec 18, 2020
Priority date	Dec 18, 2020
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A fuel injector system for a torch igniter includes an injector body centered on an axis, a receiving aperture formed in a cap of the torch igniter, an injector aperture, an air channel, a fuel channel, and a purge passage formed in a housing of the torch igniter and fluidly connected to a cooling air source. The injector body includes an axial wall at a first axial end of the injector body, an outer wall connected to the axial wall and extending along the axis transverse to the first wall, and an inner portion connected to the axial wall and extending along the axis transverse to the axial wall. An outer surface of the inner portion is spaced a distance from an inner surface of the outer wall, forming an insulating space between the outer wall and the inner portion.

First claim

The invention claimed is:

1. A fuel injector system for a torch igniter, the fuel injector system comprising:
an injector body centered on an axis, wherein the injector body includes:
an axial wall at a first axial end of the injector body;
an outer wall connected to the axial wall and extending along the axis transverse to the axial wall; and
an inner portion connected to the axial wall and extending along the axis transverse to the axial wall, wherein an outer surface of the inner portion is spaced a distance from an inner surface of the outer wall, forming an insulating space between the outer wall and the inner portion;

a receiving aperture formed in a cap of the torch igniter that receives the inner portion of the injector body at a second axial end of the injector body, the second axial end opposite the first axial end;
an injector aperture formed within the inner portion of the injector body and directly fluidly connected to an interior volume of the torch igniter;
an air inlet configured to intake a flow of air at the axial wall;
a fuel inlet configured to intake a flow of fuel at the axial wall;
an air channel disposed within the inner portion and configured to channel the air from the air inlet to the injector aperture, wherein the air channel is centered on and extends along the axis;
a fuel channel disposed within the inner portion and configured to channel the fuel from the fuel inlet to the injector aperture, wherein the fuel channel is centered on the axis and extends helically about the air channel along the axis;
a purge passage formed in a housing of the torch igniter and fluidly connected to a cooling air source, wherein the purge passage is configured to impinge cooling air from the cooling air source onto an exterior surface of the outer wall near the receiving aperture.

2. The fuel injector system of claim 1 , wherein the air channel extends linearly through the inner portion.

3. The fuel injector system of claim 1 , wherein the outer wall is annular, the inner portion is cylindrical, and the insulating space between the outer wall and inner portion is annular.

4. The fuel injector system of claim 1 , wherein the air channel includes an air swirler that imparts a swirl to the air relative to the axis.

5. The fuel injector system of claim 1 , wherein the injector aperture is configured to impinge the fuel from the fuel channel and the air from the air channel onto a surface igniter at least partially disposed within the interior volume of the torch igniter.

6. The fuel injector system of claim 1 , further comprising a mixing cavity formed within the inner portion of the injector body, wherein the mixing cavity connects the air channel and the fuel channel to the injector aperture.

7. The fuel injector system of claim 6 , wherein the fuel is liquid fuel and the mixing cavity is configured to atomize the liquid fuel with the air from the air channel.

8. The fuel injector system of claim 1 , wherein a helical diameter of the fuel channel decreases as the fuel channel extends from the fuel inlet to the injector aperture.

9. The fuel injector system of claim 1 , wherein a helical pitch of the fuel channel increases as the fuel channel extends from the fuel inlet to the injector aperture.

10. The fuel injector system of claim 1 , wherein the fuel injector system is formed monolithically.

11. The fuel injector system of claim 1 , wherein the injector body comprises a metallic material.

12. The fuel injector system of claim 1 , wherein the housing of the torch igniter forms a receiving cavity that receives the outer wall of the injector body.

13. The fuel injector system of claim 12 , wherein the outer wall of the injector body is spaced a second distance from an inner surface of the receiving cavity near the purge passage.

14. The fuel injector system of claim 13 , wherein the outer wall of the injector body and the inner surface of the receiving cavity form a cooling air channel configured to channel the cooling air from the purge passage to the receiving aperture.

15. The fuel injector system of claim 14 , wherein a fluid pressure within the cooling air channel is higher than a fluid pressure adjacent to the receiving aperture within the interior volume of the torch igniter.

16. The fuel injector system of claim 1 , wherein the fuel from the fuel inlet is at a lower temperature than an operating temperature of the injector body, and the fuel channel is configured to conduct heat from the injector body to the fuel flowing through the fuel channel.

17. The fuel injector system of claim 1 , wherein the cooling air from the cooling air source is at a higher temperature than an operating temperature of the inner portion of the injector body.

18. The fuel injector system of claim 1 , wherein a first operating temperature of the outer wall of the injector body is greater than a second operating temperature of the inner portion of the injector body.

19. A torch igniter for use in a combustor section of a gas turbine engine, the torch igniter comprising:
a combustion chamber oriented about an axis, the combustion chamber having axially upstream and downstream ends defining a flow direction through the combustion chamber, along the axis;
a cap defining the axially upstream end of the combustion chamber and oriented about the axis;
a tip defining the axially downstream end of the combustion chamber;
a housing extending from the cap to the tip and defining a radial extent of the combustion chamber;
an outlet passage defined by the housing within the tip, wherein the outlet passage is fluidly connected to the combustion chamber;
a glow plug capable of being resistively heated, wherein an innermost end of the glow plug extends through the cap into the combustion chamber; and
a fuel injector system comprising:
an injector body centered on the axis, wherein the injector body includes:
an axial wall at a first axial end of the injector body;
an outer wall connected to the axial wall and extending along the axis transverse to the axial wall; and
an inner portion connected to the axial wall and extending along the axis transverse to the axial wall, wherein an outer surface of the inner portion is spaced a distance from an inner surface of the outer wall, forming an insulating space between the outer wall and the inner portion;

a receiving aperture formed in the cap of the torch igniter that receives the inner portion of the injector body at a second axial end of the injector body, the second axial end opposite the first axial end;
an injector aperture formed within the inner portion of the injector body and directly fluidly connected to an interior volume of the torch igniter;
an air inlet configured to intake a flow of air at the axial wall;
a fuel inlet configured to intake a flow of fuel at the axial wall;
an air channel disposed within the inner portion and configured to channel the air from the air inlet to the injector aperture, wherein the air channel is centered on and extends along the axis;
a fuel channel disposed within the inner portion and configured to channel the fuel from the fuel inlet to the injector aperture, wherein the fuel channel is centered on the axis and extends helically about the air channel along the axis; and
a purge passage formed in the housing of the torch igniter and fluidly connected to a cooling air source, wherein the purge passage is configured to impinge cooling air from the cooling air source onto an exterior surface of the outer wall near the receiving aperture;

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Assignees

• Delavan Inc

Inventors

• Ryon Jason
• Prociw Lev Alexander

Classifications

• F02C7/264

  Ignition · CPC title

• F23R3/343

  Pilot flames, i.e. fuel nozzles or injectors using only a very small proportion of the total fuel to insure continuous combustion (ignition in gas-turbine plants F02C7/264; pilot flame igniters F23Q9/00) · CPC title

• F23R3/283 Primary

  Attaching or cooling of fuel injecting means including supports for fuel injectors, stems, or lances · CPC title

• F23R3/005

  Combined with pressure or heat exchangers · CPC title

• F05D2260/20

  Heat transfer, e.g. cooling · CPC title