Laser-ignition combustor for gas turbine engine

Patent metadata

Field	Value
Publication number	US-9441546-B2
Application number	US-201313777238-A
Country	US
Kind code	B2
Filing date	Feb 26, 2013
Priority date	Feb 26, 2013
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

The combustor has a laser ignitor mounted to the casing, remotely from the liner of the combustion chamber. The laser ignitor has an igniter beam path for igniting the fuel and air mixture in the combustion chamber, the igniter beam path extending at least partially across the air plenum surrounding the liner and into the combustion chamber through a corresponding beam path aperture provided in the liner.

First claim

What is claimed is:

1. A combustor for a gas turbine engine, the combustor comprising:
a casing forming a pressure vessel and having an inlet for receiving compressed air;
a liner held inside the casing and delimiting a subchamber of the pressure vessel from a plenum extending between the liner and the casing, the liner having a plurality of apertures formed therethrough and allowing controlled fluid flow communication of the compressed air from the plenum into the subchamber, with at least one of the plurality of apertures being a dilution hole, and an outlet leading to a turbine stage of the gas turbine engine;
at least one fuel nozzle mounted to the liner, for injecting fuel into the subchamber, the liner having a combustion flow path extending from the fuel nozzle to the outlet;
at least one laser ignitor having a beam outlet, the at least one laser ignitor mounted to the casing remotely from the liner and wherein the beam outlet is positioned aft of the dilution hole in an axial direction, the at least one laser ignitor having an igniter beam path for igniting the fuel and air mixture in the subchamber, the igniter beam path extending at least partially across the plenum and into the subchamber through a corresponding one of the at least one dilution hole in the liner;
wherein the laser ignitor is on one side of the corresponding dilution hole and the laser beam path extends into the subchamber on another side of the corresponding dilution hole relative to the combustion flow path, the igniter beam path extending obliquely across the corresponding dilution hole relative to the combustion flow path.

2. The combustor of claim 1 wherein the laser igniter has a laser emitter and a focusing lens, the focusing lens being exposed to the compressed air circulating between the casing and the liner.

3. The combustor of claim 1 wherein the at least one laser igniter includes a pressure tight window made integral to the casing, and a laser emitter located externally from the window, the laser ignitor being configured for generating a laser beam across said window, and along said igniter beam path to reach the subchamber.

4. The combustor of claim 1 wherein the at least one laser igniter is positioned remotely from the compressed air inlet and the igniter beam path is oriented partially toward the compressed air inlet.

5. The combustor of claim 1 wherein the igniter beam path has a plurality of interspaced laser energy kernels, said laser energy kernels being located in the subchamber.

6. The combustor of claim 5 wherein the energy kernels are interspaced along the igniter beam path.

7. A gas turbine engine comprising:
a compressor section for compressing incoming air, a combustor having a casing forming a pressure vessel and having an inlet for receiving compressed air from the compressor section;
a liner held inside the casing and delimiting a subchamber of the pressure vessel from a plenum extending between the liner and the casing, the liner having a plurality of apertures formed therethrough and allowing controlled fluid flow communication of the compressed air from the plenum into the subchamber, with at least one of the plurality of apertures being a dilution hole, and an outlet;
at least one fuel nozzle mounted to the liner, for injecting fuel into the subchamber, the liner having a combustion flow path extending from the fuel nozzle to the outlet;
at least one laser ignitor having a beam outlet, the at least one laser ignitor mounted to the casing remotely from the liner and wherein the beam outlet is positioned aft of the dilution hole in an axial direction, the at least one laser ignitor having an igniter beam path for igniting the fuel and air mixture in the subchamber and generating a hot stream of combustion gasses through the outlet, the igniter beam path extending at least partially across the plenum and into the subchamber through a corresponding one of the at least one dilution holes in the liner;
wherein the laser ignitor is on one side of the corresponding dilution hole and the laser beam path extends into the subchamber on another side of the corresponding dilution hole relative to the combustion flow path, the igniter beam path extending obliquely across the corresponding dilution hole relative to the combustion flow path;
a turbine section for extracting energy from the hot stream of combustion gasses, the turbine section being in fluid flow communication with the outlet of the combustor.

8. The gas turbine engine of claim 7 wherein the laser igniter has a laser emitter and a focusing lens, the focusing lens being exposed to the compressed air circulating between the casing and the liner.

9. The gas turbine engine of claim 7 wherein the at least one laser igniter is positioned remotely from the compressed air inlet and the igniter beam path is oriented partially toward the compressed air inlet.

10. The gas turbine engine of claim 7 wherein the igniter beam path has a plurality of interspaced laser energy kernels, said laser energy kernels being located in the subchamber.

11. The gas turbine engine of claim 10 wherein the energy kernels are interspaced along the igniter beam path.

12. A combustion chamber for a gas turbine engine, the combustion chamber comprising:
a casing forming a pressure vessel and having an inlet for receiving compressed air;
a liner held inside the casing and delimiting a subchamber of the pressure vessel from a plenum extending between the liner and the casing, the liner having a plurality of apertures formed therethrough and allowing controlled fluid flow communication of the compressed air from the plenum into the subchamber, with at least one of the plurality of apertures being dilution hole, and an outlet leading to a turbine stage of the gas turbine engine;
at least one fuel nozzle mounted to the liner, for injecting fuel into the subchamber, the liner having a combustion flow path extending from the fuel nozzle to the outlet;
at least one laser ignitor window made integral to the casing,
at least one laser igniter emitter located externally from the laser ignitor window for generating an igniter laser beam along an igniter beam path, the laser igniter emitter having a beam outlet that is positioned aft of the dilution hole in an axial direction, the igniter beam path extending across a corresponding one of the at least one laser ignitor window, at least partially across the plenum, and into the subchamber through a corresponding one of the at least one dilution hole in the liner, the laser beam path having at least one focused energy kernel inside the subchamber for igniting the fuel and air mixture;
wherein the laser ignitor emitter is on one side of the corresponding dilution hole and the laser beam path extends into the subchamber on another side of the corresponding dilution hole relative to the combustion flow path, the igniter beam path extending obliquely across the corresponding dilution hole relative to the combustion flow path.

13. The combustor of claim 12 wherein the at least one laser emitter is positioned remotely from the compressed air inlet and the igniter beam path is oriented partially toward the compressed air inlet.

14. The combustion chamber of claim 12 wherein the igniter beam path has a plurality of laser energy kernels interspaced from one another along the igniter beam path, said laser energy kernels being located in the subchamber.

Assignees

• Pratt & Whitney Canada

Inventors

• Davenport Nigel
• Patel Bhawan
• Hawie Eduardo

Classifications

• F23R2900/00006

  Using laser for starting or improving the combustion process · CPC title

• F23R3/50

  Combustion chambers comprising an annular flame tube within an annular casing (toroidal combustion chambers F23R3/52) · CPC title

• F02C7/264 Primary

  Ignition · CPC title

• F23R3/002

  Wall structures (F23R3/02 and F23R3/007 take precedence) · CPC title

• F02P23/04

  Other physical ignition means, e.g. using laser rays · CPC title