Two Spool Gas Generator with Improved Air Porting

• US 20150337738A1
• Filed: 05/10/2013
• Published: 11/26/2015
• Est. Priority Date: 01/10/2013
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Suciu, Gabriel L., Chandler, Jesse M., Lord, Wesley K.
• Granted Patent: US 10,309,310 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02C 3/13 having variable working fluid interconnections between turbines or compressors or stages of different rotors controlling flow ratio between different flows of multi-flow jet-propulsion plant, e.g. ducted fan F02K3/075
• CPC Class Codes: F02C 3/145 the combustion chamber being in the reverse flow-type
• CPC Class Codes: F02C 6/04 Gas-turbine plants providing heated or pressurised working fluid for other apparatus, e.g. without mechanical power output F02C6/18 takes precedence ; for a fluidised-bed combustor F02C3/205
• CPC Class Codes: F02C 6/08 the gas being bled from the gas-turbine compressor
• CPC Class Codes: F02C 7/185 Cooling means for reducing the temperature of the cooling air or gas
• CPC Class Codes: F02C 9/18 by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages F02C3/113 takes precedence
• CPC Class Codes: F02K 3/00 Plants including a gas turbine driving a compressor or a ducted fan
• CPC Class Codes: F02K 3/02 in which part of the working fluid by-passes the turbine and combustion chamber
• CPC Class Codes: F05D 2220/3217 for the first stage of a compressor or a low pressure compressor
• CPC Class Codes: F05D 2220/3218 for an intermediate stage of a compressor

Abstract

In a featured embodiment, a gas turbine engine has a first compressor rotor driven by a first turbine rotor, and a second compressor rotor driven by a second turbine rotor. The second compressor rotor is upstream of the first compressor rotor and the first turbine rotor is upstream of the second turbine rotor. An air mixing system taps air from a location upstream of the first compressor rotor for delivery to an environmental control system. The air mixing system receives air from a first air source and a second air source. The first air source includes air at a first pressure upstream of the first compressor rotor. The second air source includes air at a lower second pressure. At least one valve controls a mixture of air from the first and second sources to achieve a predetermined pressure for the environmental control system.

Claims

1. A gas turbine engine comprising:

a first compressor rotor driven by a first turbine rotor, and a second compressor rotor driven by a second turbine rotor, with said second compressor rotor being upstream of the first compressor rotor and said first turbine rotor being upstream of said second turbine rotor; and

an air mixing system for tapping air from a location upstream of said first compressor rotor and for delivery to an environmental control system, the air mixing system receiving air from a first air source and a second air source, the first air source including air at a first pressure upstream of said first compressor rotor, and the second air source including air at a lower second pressure, and at least one valve for controlling a mixture of air from said first and second sources to achieve a predetermined pressure for the environmental control system.

2. The gas turbine engine as set forth in claim 1, wherein said second compressor rotor having a first overall pressure ratio, and said first compressor rotor having a second overall pressure ratio, with a ratio of said first overall pressure ratio to said second overall pressure ratio being greater than or equal to about 2.0.

3. The gas turbine engine as set forth in claim 2, wherein said ratio of said first overall pressure ratio to said second overall pressure ratio is greater than or equal to about 3.0.

4. The gas turbine engine as set forth in claim 3, wherein said ratio of said first overall pressure ratio to said second overall pressure ratio is greater than or equal to about 3.5.

5. The gas turbine engine as set forth in claim 2, wherein said ratio of said first overall pressure ratio to said second overall pressure ratio being less than or equal to about 8.0.

6. The gas turbine engine as set forth in claim 1, wherein a propulsor turbine is positioned downstream of the second turbine rotor.

7. The gas turbine engine as set forth in claim 6, wherein the propulsor turbine drives a propeller.

8. The gas turbine engine as set forth in claim 6, wherein the propulsor turbine drives a fan at an upstream end of the engine.

9. The gas turbine engine as set forth in claim 8, wherein an axially outer position is defined by said fan, and said propulsor turbine being positioned between said fan and said first and second turbine rotors, and said first and second compressor rotors being positioned further into said engine relative to said first and second turbine rotors.

10. The gas turbine engine as set forth in claim 1, wherein said second air source is positioned to be upstream of said second compressor rotor.

11. The gas turbine engine as set forth in claim 10, wherein said second air source delivers air across a heat exchanger, and includes a particle separator for separating impurity.

12. The gas turbine engine as set forth in claim 1, wherein said second air source communicates through a conduit to a connection leading into said mixing box, and said second air source further selectively communicating with an outlet which is associated with said first compressor rotor.

13. The gas turbine engine as set forth in claim 12, wherein said second air source communicates from a single conduit through a port leading into a mixing box and, alternatively, flowing to said outlet at said first compressor rotor.

14. The gas turbine engine as set forth in claim 13, wherein said second air source communicating into a branch of two lines, with the first line including a valve control to control the amount of air reaching said mixing box, and a second valve on a second line leading to said outlet.

15. The gas turbine engine as set forth in claim 1, wherein said at least one valve is a pair of valves associated with the supply port from said first air source, and also on said second air source.

16. The gas turbine engine as set forth in claim 1, wherein said location upstream of said first compressor rotor is in an intermediate case intermediate said first and second compressor rotors.

17. A gas turbine engine comprising:

a first shaft connecting a first compressor rotor to be driven by a first turbine rotor, and a second shaft connecting a second compressor rotor to be driven by a second turbine rotor, with said second compressor rotor being upstream of the first compressor and said first turbine rotor being upstream of said second turbine rotor; and

an air mixing system for tapping air from a location upstream of said first compressor rotor and for delivery to an environmental control system, the air mixing system receiving air from a first air source and a second air source, the first air source including air at a first pressure upstream of said first compressor rotor, and the second air source including air at a lower second pressure, and at least one valve for controlling a mixture of air from said first and second sources to achieve a predetermined pressure for the environmental control system;

a propulsor turbine outwardly connected to drive one of a fan or propeller through a third shaft;

said first shaft surrounding said second shaft, but said first and second shafts not surrounding said third shaft;

said second compressor rotor having a first overall pressure ratio, and said first compressor rotor having a second overall pressure ratio, with a ratio of said first overall pressure ratio to said second overall pressure ratio being greater than or equal to about 2.0; and

said source of lower pressure air is positioned to be upstream of said second compressor rotor.

18. The gas turbine engine as set forth in claim 17, wherein said second air source communicates through a conduit to a connection leading into a mixing box, and said second air source further selectively communicating with an outlet which is associated with said first compressor rotor.

19. The gas turbine engine as set forth in claim 17, wherein said at least one valve is a pair of valves associated with a supply port for said first air source, and also on said supply of said lower pressure air.

20. The gas turbine engine as set forth in claim 17, wherein said first air source is in an intermediate case intermediate said first and second compressor rotors.