Combustor heat shield for a gas turbine engine

Patent metadata

Field	Value
Publication number	US-9625152-B2
Application number	US-201414294473-A
Country	US
Kind code	B2
Filing date	Jun 3, 2014
Priority date	Jun 3, 2014
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A heat shield for a combustor of a gas turbine engine has a heat shield adapted to be mounted to a combustor wall with a back face of the heat shield in spaced-apart facing relationship with an inner surface of the combustor wall to define an air gap. Rails extend from the back face of the heat shield across the air gap. Grooves are defined in at least one of the rails. The rail grooves are in fluid flow communication with the air gap when the heat shield is mounted to the combustor wall.

First claim

What is claim is:

1. A heat shield for a combustor of a gas turbine engine, comprising a heat shield body adapted to be mounted to a combustor wall with a back face of the heat shield body in spaced-apart facing relationship with an inner surface of the combustor wall to define an air gap between the heat shield body and the combustor wall, rails extending from the back face of the heat shield body, and grooves defined in at least one of said rails, the grooves being in fluid flow communication with the air gap when the heat shield body is mounted to the combustor wall, wherein the rails include radially inner and radially outer rails extending between opposed side edges of the heat shield body and wherein at least two fuel nozzle openings are defined in the heat shield body between the inner and outer rails, wherein the rails further comprise a pair of mid rails projecting from the back face of the heat shield body, the mid rails extending radially between the radially inner and the radially outer rails and disposed between the at least two fuel nozzle openings, the mid rails and the inner and outer rails defining a mid-region passage, said mid-region passage having coolant air outlet openings defined in the inner and outer rails.

2. The heat shield defined in claim 1 , wherein at least one of the grooves is defined in each of said inner and outer rails.

3. The heat shield defined in claim 2 , wherein the grooves include first and second arrays of grooves distributed along the inner and outer rails.

4. The heat shield defined in claim 1 , wherein at least some of the grooves are positioned behind studs extending from the back face of the heat shield body.

5. The heat shield defined in claim 1 , wherein said at least one of said grooves is part of said coolant air outlet openings of the mid-region passage.

6. The heat shield defined in claim 5 , wherein the coolant air outlet openings further comprises holes defined in the inner and outer rails.

7. The heat shield defined in claim 6 , wherein the coolant air outlet openings of the mid-region passage further comprises openings defined in the mid rails.

8. The heat shield defined in claim 1 , wherein the mid-region passage has heat transfer augmentation features.

9. The heat shield defined in claim 8 , wherein the heat transfer augmentation features comprise different sizes of pin fins extending from the back face of the heat shield body.

10. The heat shield defined in claim 9 , wherein studs extend from the back face of the heat shield body, at least one of said studs being disposed in said mid-region passage, and wherein the pin fins disposed immediately in front of said at least one stud have a greater cross-section than the other pin fins provided in the mid-region passage.

11. The heat shield defined in claim 8 , wherein the heat transfer augmentation features comprise trip strips.

12. The heat shield defined in claim 8 , wherein the heat transfer augmentation features comprise dimples.

13. The heat shield defined in claim 1 , wherein said coolant air outlet openings are configured to discharge coolant air from the mid-region passage onto inner and outer lips projecting forwardly from a front face of the heat shield body.

14. The heat shield defined in claim 1 , wherein the mid-region passage has at least first and second air coolant inlets defined in respective ones of the mid rails.

15. The heat shield defined in claim 14 , wherein each of the at least first and second air coolant inlets includes a slot defined in a respective one of the mid-rails for receiving an anti-rotation tab of a floating collar.

16. The heat shield defined in claim 14 , wherein the first and second air coolant inlets respectively have a radially inner component and a radially outer component to provide for two radially opposite air coolant flows in the mid-region passage.

17. The heat shield defined in claim 1 , wherein the mid-region passage has an hourglass-like shape including a radially outwardly flaring section, a radially inwardly flaring section, and a central constricted section, the radially outwardly flaring section and the radially inwardly flaring section being individually feed via respective air coolant inlets defined in the mid-rails.

18. The heat shield defined in claim 1 , wherein each mid-rail extends along an arc of circle having a center coincident with a center of an adjacent one of the at least two fuel nozzle openings.

19. A method of cooling a combustor heat shield mounted in a combustor of a gas turbine engine, the method comprising: recuperating air leaking between a floating collar and a combustor dome portion, and directing the leakage air in a confined passage defined by a set of rails projecting from a back face of the combustor heat shield, wherein the set of rails comprises first and second mid rails extending between radially inner and radially outer rails, and wherein directing the leakage air in the confined passage comprises allowing the recuperated leakage air to leak through first and second anti-rotation slots respectively defined in said first and second mid rails for receiving corresponding anti-rotation tabs of associated floating collars.

20. A heat shield for a combustor of a gas turbine engine, comprising a heat shield body adapted to be mounted to a combustor wall with a back face of the heat shield body in spaced-apart facing relationship with an inner surface of the combustor wall to define an air gap between the heat shield body and the combustor wall, at least first and second fuel nozzle openings defined in said heat shield body, rails extending from the back face of the heat shield body across said air gap, the rails including radially inner and radially outer rails extending between opposed side edges of the heat shield body, and a pair of mid rails extending radially from the inner rail to the outer rail between the first and second fuel nozzle openings, the mid rails and the inner and outer rails defining a mid-region passage, said mid-region passage having coolant air outlet openings defined in the inner and outer rails.

21. The heat shield defined in claim 20 , wherein said mid-region passage has coolant air inlet openings defined in said mid rails.

Assignees

• Pratt & Whitney Canada

Inventors

• Papple Michael
• Sze Robert

Classifications

• F02C7/18

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

• F23R2900/03043

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

• F23R3/02

  characterised by the air-flow or gas-flow configuration (reverse- flow combustion chambers F23R3/54; cyclone or vortex type combustion chambers F23R3/58) · CPC title

• F23R3/10

  for primary air (F23R3/06, F23R3/045 take precedence) · CPC title

• F23R3/002 Primary

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