Igniter for gas turbine engine

Patent metadata

Field	Value
Publication number	US-11268486-B2
Application number	US-201916369661-A
Country	US
Kind code	B2
Filing date	Mar 29, 2019
Priority date	Sep 12, 2018
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

There is disclosed an igniter for a gas turbine engine including: a base, a glow plug heater rod, the glow plug heater rod extending from the base along an axis and terminating in a rod end, a sleeve extending circumferentially around the glow plug heater rod along at least a portion of a length of the glow plug heater rod, the sleeve having an inner surface spaced from the glow plug heater rod to provide a gap between the inner surface and the glow plug heater rod, the gap extending radially relative to said axis.

First claim

The invention claimed is:

1. A method of operating an igniter of a gas turbine engine, the igniter extending through an igniter aperture of a combustor liner enclosing a combustion chamber, a collar being secured to the combustor liner and extending from the combustor liner, the method comprising:
receiving a mixture of air and fuel to be ignited in a flow circulation area around a heating section of a glow plug heater rod of the igniter, the glow plug heater rod extending along an axis and terminating in a rod end, the flow circulation area being annular, extending circumferentially around the glow plug heater rod and radially between the glow plug heater rod and a sleeve relative to the axis, and communicating with the combustion chamber, the sleeve having an inner surface continuously extending around the flow circulation area to block fluid communication between the flow circulation area and an environment outside the flow circulation area through the sleeve in a radial direction relative to the axis, the sleeve extending through the collar;
preventing compressed air from flowing in the combustion chamber via the igniter aperture with a substantially cylindrical outer surface of the sleeve being in abutment against an inner surface of the collar;
igniting the mixture of air and fuel with the heating section of the glow plug heater rod; and
impeding fluid circulation of the ignited mixture of the air and the fuel from flowing between the sleeve and the glow plug heater rod towards a base of the igniter.

2. A gas turbine engine comprising:
a casing;
a combustor liner within the casing and spaced apart therefrom, the combustor liner delimiting a combustion chamber and defining an igniter aperture, the igniter aperture bounded by a peripheral face;
a collar secured to the combustor liner and extending from the combustor liner;
an igniter, the igniter having a base connected to the casing and a glow plug heater rod, the glow plug heater rod extending from the base along an axis and terminating in a rod end, a sleeve extending circumferentially around the glow plug heater rod along at least a portion of a length of the glow plug heater rod, the sleeve having an inner surface spaced from the glow plug heater rod to provide a gap between the inner surface and the glow plug heater rod, the gap being annular, extending radially and circumferentially relative to the axis, and being opened to the combustion chamber,
wherein a substantially cylindrical outer surface of the sleeve is in abutment against an inner surface of the collar to limit a flow of compressed air from a compressor of the gas turbine engine from entering the combustion chamber.

3. The gas turbine engine of claim 2 , wherein the sleeve is connected to the base and protrudes along the axis from the base towards the rod end.

4. The gas turbine engine of claim 2 , wherein the sleeve and the gap extend around a full circumference of the glow plug heater rod and axially relative to the axis from the casing to the combustor liner.

5. The gas turbine engine of claim 2 , wherein the sleeve has a portion connected to the glow plug heater rod between the gap and the base.

6. A gas turbine engine comprising:
a casing;
a combustor liner within the casing and spaced apart therefrom, the combustor liner delimiting a combustion chamber, the combustor liner defining an igniter aperture;
a collar secured to the combustor liner and extending from the combustor liner, the collar extending about a whole circumference of the igniter aperture; and
an igniter having a base connected to the casing, a glow plug heater rod, the glow plug heater rod extending from the base along an axis and terminating in a rod end, a sleeve extending circumferentially around a full circumference of the glow plug heater rod along at least a portion of a length of the glow plug heater rod, the sleeve extending through the collar and through the igniter aperture, a portion of an outer surface of the sleeve being in abutment against an inner surface of the collar to limit a flow of compressed air from a compressor of the gas turbine engine from entering the combustion chamber via the igniter aperture, the portion of the outer surface of the sleeve that is in abutment against the inner surface of the collar being substantially cylindrical, the sleeve having an inner surface spaced from the glow plug heater rod to provide a gap between the inner surface of the sleeve and the glow plug heater rod, the gap being annular and extending radially and circumferentially relative to the axis, the inner surface of the sleeve continuously extending around the gap to block fluid communication between the gap and an environment outside the gap through the sleeve in a radial direction relative to the axis, the gap fluidly communicating with the combustion chamber.

7. The gas turbine engine of claim 6 , wherein the glow plug heater rod has a metal to ceramic junction between the base and the rod end, the sleeve extending circumferentially around the glow plug heater rod along at least a portion of a length extending between the metal to ceramic junction and the rod end.

8. The gas turbine engine of claim 6 , wherein the gap forms a constriction at a position located axially between the rod end and the base.

9. The gas turbine engine of claim 8 , wherein the glow plug heater rod has a heating section axially extending along the axis between axially opposite ends of a heater contained within the glow plug heater rod, at least a portion of the heating section axially protruding from the constriction.

10. The gas turbine engine of claim 6 , wherein the gap is fluidly connected to a fluid flow circulation area located around the rod end.

11. The gas turbine engine of claim 6 , wherein the gap defines a constricted area and an expanded area delimiting a fluid flow circulation area around the rod end, the constricted area being located axially between the rod end and the base, a cross-sectional area of the constricted area taken along a plane normal to the axis being less than that of the expanded area.

12. The gas turbine engine of claim 6 , wherein the sleeve is structurally connected to the base and protrudes along the axis from the base towards the rod end.

13. The gas turbine engine of claim 6 , wherein the sleeve has a portion connected to the glow plug heater rod between the rod end and the base.

14. The gas turbine engine of claim 6 , wherein the glow plug heater rod has a heating section axially extending along the axis between axially opposite ends of a heater contained within the glow plug heater rod, the sleeve extending circumferentially around the glow plug heater rod axially along at least the heater section of the glow plug heater rod.

15. The gas turbine engine of claim 6 , wherein the base includes a body of a glow plug, the glow plug including the glow plug heater rod and further including at least a casing portion of an adaptor, the casing portion of the adaptor connected to the body of the glow plug around the body of the glow plug.

16. The gas turbine engine of claim 15 , wherein the sleeve forms part of the casing portion of the adaptor.

17. The gas turbine engine of claim 15 , wherein the adaptor further comprises a liner portion configured to be matingly connected to a combustor liner of the gas turbine engine, the sleeve forming part of the liner portion.

18. The gas turbine engine of claim 6 , wherein a portion of an outer surface of the base is threaded for engaging a correspondingly threaded aperture of a casing of the gas turbine engine.

Assignees

• Pratt & Whitney Canada

Inventors

• Freer Richard
• Mccaldon Kian
• Hu Tin-Cheung John
• Bousquet Michel
• Fortin André

Classifications

• F02C7/266

  Electric (sparking plugs H01T) · CPC title

• F23R2900/00015

  Trapped vortex combustion chambers · 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

• F23R3/18

  Flame stabilising means, e.g. flame holders for after-burners of jet-propulsion plants · CPC title

• F02C7/264

  Ignition · CPC title