Gas turbine engine

Patent metadata

Field	Value
Publication number	US-2020291866-A1
Application number	US-201916401225-A
Country	US
Kind code	A1
Filing date	May 2, 2019
Priority date	May 31, 2018
Publication date	Sep 17, 2020
Grant date	—

Abstract

A gas turbine engine comprising: a compressor; a first turbine; and a first compressor bleed valve in fluid communication with the compressor and configured to release bleed air from the compressor; wherein the first compressor bleed valve is configured to release bleed air to a downstream location in the engine, the downstream location being downstream of the first turbine; wherein the first compressor bleed valve is configured to open wherein the first compressor bleed valve is configured to open to at least two positions, to thereby release a variable amount of bleed air from the compressor.

First claim

1 . A gas turbine engine comprising:
a compressor ( 15 ); a turbine ( 19 ); and a first compressor bleed valve ( 43 ) in fluid communication with the compressor and configured to release bleed air from the compressor;
wherein the first compressor bleed valve is configured to release bleed air to a downstream location ( 44 ) in the engine, the downstream location being downstream of the turbine;
wherein the first compressor bleed valve is configured to open to at least two positions, to thereby release a variable amount of bleed air from the compressor.

2 . The gas turbine engine according to claim 1 , wherein:
the engine comprises a second compressor bleed valve ( 45 ) in fluid communication with the compressor and configured to release bleed air from the compressor ( 15 ); and the second compressor bleed valve is located downstream of the first compressor bleed valve ( 43 ).

3 . The gas turbine engine according to claim 2 , wherein:
the compressor ( 15 ) is a multi-stage compressor; and the second compressor bleed valve is located at a higher stage of the compressor than the first compressor bleed valve.

4 . The gas turbine engine according to claim 1 , wherein the bleed air from the first compressor bleed valve ( 43 ) is directed to the downstream location by a first bleed duct ( 46 ).

5 . The gas turbine engine according to claim 1 , wherein the downstream location ( 44 ) is a tail bearing housing.

6 . The gas turbine engine according to claim 2 , wherein:
the engine comprises a bypass duct ( 22 ) configured to carry a bypass airflow (B); and the second compressor bleed valve ( 45 ) is configured to release bleed air into the bypass airflow through a second bleed duct ( 48 ).

7 . The gas turbine engine according to claim 6 , wherein a portion of the first bleed duct ( 46 ) passes through the second bleed duct ( 48 ), and the first and second bleed ducts are not in fluid communication with each other.

8 . The gas turbine engine according to claim 6 , wherein the bypass duct ( 22 ) comprises a deflector configured to deflect bleed air from the second compressor bleed valve ( 45 ) in order to promote mixing of the bleed air with the air in the bypass duct.

9 . The gas turbine engine according to claim 1 , wherein the turbine ( 1 is a low pressure turbine,
wherein the engine further comprises a high pressure turbine ( 17 ).

10 . The gas turbine engine according to claim 1 , wherein:
at least one of the valves comprises a multi-position bellcrank ( 71 ) and a flapper ( 74 ); and the bellcrank is configured to control the position of the flapper to control the opening amount of the at least one valve.

11 . The gas turbine engine according to claim 10 ; wherein the position of the multi-position bellcrank ( 71 ) is controlled by an actuator ( 73 ).

12 . The gas turbine engine according to claim 1 , wherein the first compressor bleed valve ( 43 ) is configured to move to an opening amount which is continuously variable between fully open and fully closed.

13 . The gas turbine engine according to claim 1 , wherein:
the opening amount of at least one of the valves is controlled by a difference in pressure of a control fluid across a control component ( 75 ) separate from the at least one valve and mechanically coupled to the at least one valve; and the difference in pressure across the control component is controlled by metered flow of a control fluid from a hydromechanical device.

14 . The gas turbine engine according to claim 1 , wherein:
the opening amount of at least one of the valves is controlled by a difference in pressure of a control fluid across a control component mounted to the at least one valve, the control fluid being supplied from a central source of pressurised control fluid; and the difference in pressure is controlled by a hydromechanical device.

15 . The gas turbine engine according to claim 13 , wherein the control fluid is a hydraulic fluid.

16 . The gas turbine engine according to claim 13 , wherein the control fluid is fuel.

17 . The gas turbine engine according to claim 1 , wherein the engine comprises:
a first turbine ( 17 ); a second turbine ( 19 ); a first compressor ( 14 ); and a second compressor ( 15 ); wherein the compressor with which the first compressor bleed valve ( 43 ) is in fluid communication is the second compressor ( 15 ); and the turbine downstream of which the downstream location ( 44 ) is located is the first turbine ( 17 ).

18 . The gas turbine engine according to claim 17 , further comprising a core shaft ( 26 ) connecting the first turbine ( 17 ) to the first compressor ( 14 );
wherein the first turbine ( 19 ), first compressor ( 14 ), second turbine ( 17 ), second compressor ( 15 ) and core shaft ( 26 ) are comprised in an engine core ( 11 ); wherein the engine further comprises: a fan ( 23 ) located upstream of the engine core, the fan comprising a plurality of fan blades; and a gearbox ( 30 ) that receives an input from the core shaft ( 26 ) and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft.

19 . The gas turbine engine according to claim 18 , wherein:
the core shaft is a first core shaft ( 26 ); the engine comprises a second core shaft ( 27 ) connecting the second turbine to the second compressor; and the second turbine, second compressor, and second core shaft are arranged to rotate at a higher rotational speed than the first core shaft.

Assignees

• Rolls Royce Plc

Inventors

• Peace Richard
• Goulds Robert

Classifications

• F05D2270/64

  Hydraulic actuators · CPC title

• F02K3/06

  with front fan · CPC title

• F02C6/08

  the gas being bled from the gas-turbine compressor · CPC title

• F02K3/02

  in which part of the working fluid by-passes the turbine and combustion chamber · CPC title

• F04D27/0215

  Arrangements therefor, e.g. bleed or by-pass valves · CPC title