Auxiliary Torch Ingnition

Patent metadata

Field	Value
Publication number	US-10704469-B2
Application number	US-201715643736-A
Country	US
Kind code	B2
Filing date	Jul 7, 2017
Priority date	Jul 7, 2017
Publication date	Jul 7, 2020
Grant date	Jul 7, 2020

Abstract

A torch igniter includes an auxiliary fuel injector; an ignition source; and an igniter body carrying the auxiliary fuel injector and the ignition source. The igniter body includes an auxiliary combustion chamber having a side wall extending axially from a first end wall to a second end wall, the side wall defining an interior cavity between the first and second end walls. The igniter body further includes a premixing cup residing within the interior cavity including a cylindrical wall radially surrounding the auxiliary fuel injector and an auxiliary air inlet, the cylindrical wall of the premixing cup protruding axially outward relative to the first end wall of the auxiliary combustion chamber through a portion of the interior cavity to delineate a premixing zone radially inward of the cylindrical wall and a recirculation zone radially outward of the cylindrical wall.

First claim

What is claimed is:

1. A gas turbine combustor assembly, comprising:
a primary combustion chamber in fluid communication with a primary fuel injector and a primary air inlet; and
a torch ignitor coupled to the primary combustion chamber, the torch igniter comprising:
an auxiliary fuel injector;
an ignition source; and
an igniter body carrying the auxiliary fuel injector and the ignition source, the igniter body comprising:
an auxiliary combustion chamber having a side wall extending axially from a first end wall to a second end wall, the side wall defining an interior cavity between the first and second end walls; and
a premixing cup residing within the interior cavity comprising a cylindrical wall radially surrounding the auxiliary fuel injector and an auxiliary air inlet, the cylindrical wall of the premixing cup protruding axially outward relative to the first end wall of the auxiliary combustion chamber through a portion of the interior cavity to delineate a premixing zone radially inward of the cylindrical wall and a recirculation zone radially outward of the cylindrical wall,

wherein the recirculation zone is a space defined by the first end wall of the auxiliary combustion chamber, the side wall of the auxiliary combustion chamber, and the cylindrical wall of the premixing cup, the space of the recirculation zone configured to draw fuel/air mixture expelled downstream from the premixing cup back upstream toward the first end wall, and
wherein the ignition source resides on the side wall of the auxiliary combustion chamber and at least a portion of the ignition source protrudes radially into the space of the recirculation zone.

2. The combustor assembly of claim 1 , wherein the torch igniter further comprises:
an auxiliary fuel source in fluid communication with a nozzle orifice of the auxiliary fuel injector, the auxiliary fuel source configured to provide a pressurized flow of fuel for injection into the auxiliary combustion chamber by the auxiliary fuel injector; and a bypass line configured to return at least a portion of the pressurized flow of fuel to a main engine fuel manifold.

3. The combustor assembly of claim 1 , wherein the auxiliary combustion chamber is substantially cylindrical in shape, with the side wall having a circular cross-section of constant diameter, and the first and second end walls being substantially planar.

4. The combustor assembly of claim 1 , wherein the second end wall defines a fluid outlet leading to an outlet tube in fluid communication with the primary combustion chamber; and
wherein the igniter body further comprises an outer shell surrounding at least a portion of the auxiliary combustion chamber, the outer shell comprising a fluid inlet coaxially aligned with the outlet tube.

5. The combustor assembly of claim 4 , wherein the igniter body comprises a fluid annulus formed between an inner surface of the shell and an outer surface of the auxiliary combustion chamber, the annulus directing fluid from the fluid inlet across the outer surface of the auxiliary combustion chamber towards the first end wall.

6. The combustor assembly of claim 1 , wherein the second end wall of the auxiliary combustion chamber defines a fluid outlet leading to an outlet tube in fluid communication with the primary combustion chamber, at least a portion of the outlet tube comprising a distributed pattern of dilution apertures, with each of the dilution apertures configured to direct fluid in cross-flow with heated gas exiting the auxiliary combustion chamber through the outlet tube.

7. The combustor assembly of claim 1 , wherein the igniter body further comprises a fluid swirler residing at an entrance to the premixing cup.

8. The combustor assembly of claim 7 , wherein the fluid swirler comprises an axial fluid swirler comprising a circumferential pattern of swirl opening surrounding an outlet of the auxiliary fuel injector.

9. The combustor assembly of claim 1 , wherein the torch igniter further comprises a shielding device configured to at least partially shield the ignition source from fluid flow through the auxiliary combustion chamber.

10. The combustor assembly of claim 9 , wherein the shielding device is coupled to an inner surface of the auxiliary combustion chamber proximate the ignition source, and comprises a curved, convex surface projecting towards the premixing cup.

11. The combustor assembly of claim 1 , wherein at least a portion of the side wall of the auxiliary combustion chamber comprises a distributed pattern of cooling apertures, with each of the cooling apertures obliquely canted relative to an inner surface of the side wall so as to cause fluid entering an interior cavity of the auxiliary combustion chamber through the cooling apertures to form a fluid film along the inner surface.

12. A method of operating a gas turbine combustor assembly, the method comprising:
receiving auxiliary flows of fuel and air in a premixing cup of an igniter body of the gas turbine combustor assembly;
at least partially mixing the auxiliary fuel and air flows in a premixing zone of the premixing cup, and discharging the auxiliary fuel/air mixture downstream into an auxiliary combustion chamber of the igniter body;
drawing at least a portion of the discharged auxiliary fuel/air mixture back upstream toward a front end wall of the auxiliary combustion chamber into a recirculation zone between the premixing cup and a side wall of the auxiliary combustion chamber, wherein the recirculation zone is an annular space defined by the front wall of the auxiliary combustion chamber, the side wall of the auxiliary combustion chamber, and a cylindrical wall of the premixing cup;
igniting at least a portion of the auxiliary fuel/air mixture within the recirculation zone to form an auxiliary flow of heated fluid; and
igniting a primary air/fuel mixture in a primary combustion chamber of the gas turbine combustor assembly with the auxiliary flow of heated fluid from the auxiliary combustion chamber of the igniter body.

13. The method of claim 12 , wherein receiving the auxiliary flow of fuel comprises directing a pressurized flow of fuel from an auxiliary fuel source to a nozzle orifice of an auxiliary fuel injector in fluid communication with the premixing cup, bypassing the nozzle orifice with at least a portion of the pressurized flow of fuel, and directing the bypassed portion of the pressurized flow of fuel to a main engine fuel manifold.

14. The method of claim 12 , wherein receiving the auxiliary flow of air comprises directing the auxiliary flow of air through a fluid inlet, and wherein the method further comprises:
directing the auxiliary flow of heated fluid through a fluid outlet tube coaxially aligned with the fluid inlet as the auxiliary flow of air is directed through the fluid inlet.

15. The method of claim 14 , further comprising:
diluting the auxiliary flow of heated fluid by directing a portion of the auxiliary flow of air in cross-flow with the auxiliary flow of heated fluid through a pattern of dilution apertures of the outlet tube.

16. The method of claim 12 , further comprising:
cooling a portion of the auxiliary combustion chamber by forming a cooling fluid film along an inner surface of the auxiliary combustion chamber.

17. The method of claim 16 , wherein forming the cooling fluid film comprises directing a portion of the auxiliary flow of air through a distributed pattern of obliquely canted cooling apertures of the auxiliary combustion chamber.

18. The method of claim 12 , wherein at least partially mixing t

Assignees

• Woodward Inc

Inventors

• Dam Bidhan
• Mccormack Jimroy
• Lee Fei Philip
• Riordan Conor
• Oonk Logan
• Pederson Erik
• Stratton Michael

Classifications

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title

• F05D2260/202

  by film cooling · CPC title

• F23R3/14

  by using swirl vanes · CPC title

• F23R3/286

  having fuel-air premixing devices (F23R3/30 takes precedence) · CPC title

• F23C2900/03005

  Burners with an internal combustion chamber, e.g. for obtaining an increased heat release, a high speed jet flame or being used for starting the combustion · CPC title