Single skin combustor with heat transfer enhancement

Patent metadata

Field	Value
Publication number	US-10260751-B2
Application number	US-201514867377-A
Country	US
Kind code	B2
Filing date	Sep 28, 2015
Priority date	Sep 28, 2015
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

A combustor for a gas turbine engine comprises a single skin liner defining a combustion chamber. The single skin liner has an inner surface facing the combustion chamber and an outer surface exposed to a coolant flow discharged in a plenum extending from the outer surface of the single skin liner to the engine casing. Cooling holes extend through the single skin liner. Cooling protuberances, such as fins or pin fins, project integrally from the outer surface of the single skin liner into the plenum, the cooling fins being interspersed between the cooling holes.

First claim

The invention claimed is:

1. A single skin combustor for a gas turbine engine having an engine casing, the single skin combustor comprising: a single skin liner defining a combustion chamber having a primary zone, a secondary zone and a dilution zone, the single skin liner having an inner surface exposed to the combustion chamber and an outer surface exposed to air in a plenum circumscribed by the engine casing, the outer surface of the single skin liner being an outermost surface of the single skin combustor, cooling holes extending through the single skin liner, and cooling protrusions projecting integrally from the outer surface of the single skin liner, wherein at least some of the cooling protrusions have a non-concave upstream face relative to a flow direction of the air in the plenum, and wherein at least some of the cooling protrusions are interspersed between the cooling holes in the primary zone of the combustion chamber, the cooling holes having inlet openings on the outer surface of the single skin liner, the inlet openings being offset from the cooling protrusions, wherein a higher density of cooling protrusions is provided in the primary zone of the combustor than in the secondary zone thereof.

2. The single skin combustor defined in claim 1 , wherein the cooling protrusions are an extension of a base metal of the single skin liner.

3. The single skin combustor defined in claim 1 , wherein each cooling protrusion comprises successive layers of sequentially deposit material on a sheet metal base.

4. The single skin combustor defined in claim 1 , wherein the cooling protrusions comprise individually free standing fins.

5. The single skin combustor defined in claim 1 , wherein the cooling protrusions are of non-uniform height.

6. The single skin combustor defined in claim 1 , wherein at least some of the cooling protrusions are disposed immediately downstream of corresponding neighboring cooling holes.

7. The single skin combustor defined in claim 1 , wherein at least some of the cooling protrusions and the cooling holes have similar inclination angles.

8. The single skin combustor defined in claim 1 , wherein the cooling protrusions are selected from a group consisting of: fins, pin fins, dimples and truss-shaped fins.

9. A method of cooling a single skin liner of a combustor of a gas turbine engine having an engine casing defining a plenum around the single skin liner, the combustor having a primary zone, a secondary zone and a dilution zone, the method comprising: 1) providing a first usage of cooling air in the plenum by causing the cooling air to flow through cooling protuberances extending from an outer surface of a combustion chamber circumscribed by the single skin liner, the cooling protuberances projecting into the plenum around the combustion chamber, wherein a higher density of cooling protuberances is provided in the primary zone of the combustor than in the secondary zone thereof, 2) providing a second usage of the cooling air by flowing the cooling air through cooling holes defined in the single skin liner, and 3) providing a third usage of the cooling air by using the cooling air exiting the cooling holes to form a film of cooling air over an inner surface of the single skin liner.

10. The method defined in claim 9 , wherein the cooling air is compressor bleed air, and wherein the method comprises: discharging the compressor bleed air in the plenum, the compressor bleed air being free to flow in various directions within the plenum.

11. The method of claim 9 , comprising locally building up pressure in front of the cooling holes.

12. The method of claim 11 , wherein locally building up pressure comprises positioning the cooling protuberances directly behind the cooling holes.

13. A gas turbine engine comprising a gas generator case, a combustor disposed within the gas generator case, the combustor comprising a single skin liner circumscribing a combustion chamber, the combustion chamber having a primary zone, a secondary zone and a dilution zone, the single skin liner and the gas generator case defining therebetween a plenum, the single skin liner having an outer surface exposed to cooling air in the plenum and an inner surface exposed to combustion gases in the combustion chamber, cooling holes defined in the single skin liner, the cooling holes fluidly linking the plenum to the combustion chamber, and cooling protuberances integrally projecting from the outer surface of the single skin liner into the plenum, wherein a higher density of cooling protuberances is provided in the primary zone of the combustor than in the secondary zone thereof, the cooling holes having inlet openings on the outer surface of the single skin liner, the inlet openings being offset from the cooling protuberances.

14. The gas turbine engine defined in claim 13 , wherein the cooling protuberances comprise individually free standing fins projecting from a perforated sheet metal substrate.

15. The gas turbine engine defined in claim 14 , wherein the individually free standing fins are interspersed between the cooling holes, and wherein a density of fins varies over the outer surface of the single skin liner.

Assignees

• Pratt & Whitney Canada

Inventors

• Hu Tin-Cheung John
• Lao Si-Man Amy
• Sreekanth Sri
• Papple Michael

Classifications

• F23R3/005 Primary

  Combined with pressure or heat exchangers · CPC title

• F23R3/06

  Arrangement of apertures along the flame tube · CPC title

• F23R3/04 Primary

  Air inlet arrangements · CPC title

• F23R2900/03045

  Convection cooled combustion chamber walls provided with turbolators or means for creating turbulences to increase cooling · CPC title

• F23R3/002

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