Torch igniter cooling system

Patent metadata

Field	Value
Publication number	US-11982237-B2
Application number	US-202217983691-A
Country	US
Kind code	B2
Filing date	Nov 9, 2022
Priority date	Nov 4, 2020
Publication date	May 14, 2024
Grant date	May 14, 2024

Abstract

An embodiment of a torch igniter for a combustor of a gas turbine engine comprises a combustion chamber oriented about an axis, a cap defining an axially upstream end of the combustion chamber and oriented about the axis, a tip defining an axially downstream end of the combustion chamber, a structural wall coaxial with and surrounding the igniter wall, an outlet passage defined by the igniter wall within the tip, and a cooling system. The cooling system comprises an air inlet formed within the structural wall, a first flow path disposed between the structural wall and the igniter wall, and an aperture extending through the igniter wall transverse to the flow direction. The aperture directly fluidly connects the first flow path to the combustion chamber.

First claim

The invention claimed is:

1. A torch igniter for a combustor of a gas turbine engine, the torch igniter comprising:
a combustion chamber oriented about an axis, the combustion chamber having an axially upstream end and an axially downstream end together defining a flow direction through the combustion chamber, along the axis;
a cap defining the axially upstream end of the combustion chamber and situated on the axis, wherein the cap is configured to receive a fuel injector and a glow plug;
a tip defining the axially downstream end of the combustion chamber;
an igniter wall extending from the cap to the tip and defining a radial extent of the combustion chamber;
a structural wall coaxial with and surrounding the igniter wall;
an outlet passage defined by the igniter wall within the tip, wherein the outlet passage fluidly connects the combustion chamber to the combustor of the gas turbine engine;
a cooling system comprising:
an air inlet formed within the structural wall and configured to intake a flow of air from a compressed air source;
a first flow path disposed between the structural wall and the igniter wall and extending from the air inlet to the cap, wherein the first flow path is configured to receive a first portion of the air taken in by the air inlet;
an aperture extending transverse to the flow direction through the igniter wall, wherein the aperture directly fluidly connects the first flow path to the combustion chamber; and
a quench hole disposed at a downstream location within the combustion chamber;
wherein:
the quench hole directly fluidly connects the first flow path to a quenching zone;
the quenching zone is co-spatial with the outlet passage;

an annular divider centered on the axis and disposed at the axially downstream end of the combustion chamber at a position upstream of the quench hole, wherein the annular divider is configured to define an upstream end of the quenching zone; and
a mixing nozzle attached to and extending away from a downstream face of the annular divider,
wherein the mixing nozzle is configured to mix combustion gases formed in the combustion chamber with the air from the quench hole;
wherein a downstream end of the mixing nozzle comprises:
a plurality of protrusions distributed symmetrically about the axis; and
a plurality of indentations distributed symmetrically about the axis; and

wherein a first diameter between diametrically-opposed protrusions is greater than a second diameter between diametrically opposed indentations.

2. The torch igniter of claim 1 , wherein the quench hole fluidly connects the first flow path to the outlet passage and is configured to divert a portion of the air flowing through the first flow path to the outlet passage to cool the combustion gases flowing through the outlet passage.

3. The torch igniter of claim 1 , wherein the mixing nozzle is attached to and extends away from a center of the annular divider.

4. The torch igniter of claim 1 , wherein the mixing nozzle is annular.

5. The torch igniter of claim 1 , wherein an upstream end of the mixing nozzle is annular.

6. The torch igniter of claim 1 , wherein:
the igniter wall is annular, a radius of the combustion chamber is greater than a radius of the outlet passage, forming an elbow region in the combustion chamber adjacent to the tip; and
the quench hole is disposed in the elbow region.

7. The torch igniter of claim 1 , wherein:
the igniter wall is annular, a radius of the combustion chamber is greater than a radius of the outlet passage, and further comprising an elbow region in the combustion chamber adjacent to the tip; and
the first flow path extends axially along the tip, radially through the elbow region, and axially along the combustion chamber.

8. The torch igniter of claim 1 , wherein the first flow path comprises:
a first section surrounding the combustion chamber; and
a second section disposed within the cap.

9. The torch igniter of claim 8 , wherein the second section is configured to first flow the air toward an axially upstream end of the cap and then to turn the flow of air at the axially upstream end of the cap to flow toward a downstream end of the torch igniter.

10. The torch igniter of claim 1 , further comprising a second flow path disposed between the structural wall and the igniter wall and extending from the air inlet to a downstream end of the torch igniter, wherein the second flow path is configured to receive a second portion of air flow taken in by the air inlet.

11. The torch igniter of claim 10 , wherein the tip is attached to the combustor, the outlet passage is fluidly connected to an interior volume of the combustor, the air inlet is positioned outside of the combustor in a high-pressure case of the gas turbine engine, and the air taken in by the air inlet is compressed air.

12. The torch igniter of claim 11 , the cooling system further comprising:
a tip hole in an exterior of the tip that directly fluidly connects the second flow path to the interior volume of the combustor, such that the air flowing through the second flow path is able to flow into the combustor.

13. The torch igniter of claim 10 , wherein at least one of the first flow path and the second flow path has a helical shape.

14. The torch igniter of claim 1 , wherein the air inlet is disposed adjacent to the tip of the torch igniter.

15. The torch igniter of claim 1 , further comprising fins extending radially outward from the igniter wall to the structural wall that split the first flow path into a plurality of flow paths, wherein the fins are configured to conduct heat from the igniter wall.

16. The torch igniter of claim 1 , and further comprising the glow plug, wherein:
an innermost end of the glow plug extends into the combustion chamber and an outermost end of the glow plug extends away from and is disposed outside of the combustion chamber; and
the aperture is disposed at a position upstream of the innermost end of the glow plug.

17. The torch igniter of claim 16 , and further comprising a metering hole disposed in the igniter wall at a position downstream of the innermost end of the glow plug that directly fluidly connects the first flow path to the combustion chamber at a position in the flow path before the aperture, wherein the metering hole is configured to divert a portion of the air flowing toward the aperture into the combustion chamber before it reaches the aperture.

Assignees

• Collins Engine Nozzles Inc

Inventors

• Ryon Jason
• Prociw Lev Alexander

Classifications

• F02C7/264 Primary

  Ignition · CPC title

• F02C7/18

  the medium being gaseous, e.g. air {(F02C7/125 takes precedence)} · CPC title

• F23R3/06

  Arrangement of apertures along the flame tube · CPC title

• F23R2900/00009

  Using plasma torches for igniting, stabilizing, or improving the combustion process · CPC title

• F23R2900/03043

  Convection cooled combustion chamber walls with means for guiding the cooling air flow · CPC title