Bleed flow extraction system for a gas turbine engine

Patent metadata

Field	Value
Publication number	US-2018009536-A1
Application number	US-201615206663-A
Country	US
Kind code	A1
Filing date	Jul 11, 2016
Priority date	Jul 11, 2016
Publication date	Jan 11, 2018
Grant date	—

Abstract

An air cycle machine for extracting bleed air from a gas turbine engine of an aircraft is provided. The air cycle machine extracts a stream of low pressure bleed air and a stream of high pressure bleed air from a compressor section of the gas turbine engine. The air cycle machine includes a compressor that receives the stream of low pressure bleed air and a turbine that receives the stream of high pressure bleed air. The stream of high pressure bleed air is expanded as it drives the turbine, and the stream of low pressure bleed air is compressed by the compressor. The resulting streams of bleed air are substantially the same pressure, such that they may be merged using a junction into a combined bleed air stream having a temperature and pressure suitable for use by a variety of aircraft accessory systems, such as an environmental control system. The air cycle machine may further power or be powered from an electrical storage device or generator on the fan.

First claim

What is claimed is:

1 . A gas turbine engine assembly for an aircraft, the gas turbine engine assembly comprising:
a core engine comprising a compressor section, the compressor section defining a low pressure bleed port for extracting a first stream of bleed air and a high pressure bleed port for extracting a second stream of bleed air; and an air cycle machine configured for providing bleed air to an accessory system of the aircraft, the air cycle machine comprising:
a turbine in fluid communication with the high pressure bleed port for receiving the second stream of bleed air, the turbine expanding the second stream of bleed air such that the second stream of bleed air rotates the turbine;
a compressor in fluid communication with the low pressure bleed port for receiving the first stream of bleed air, the compressor being mechanically coupled to the turbine by a shaft such that the turbine drives the compressor and increases a pressure of the first stream of bleed air; and
a junction in fluid communication with both the turbine and the compressor, the junction being configured to combine the first stream of bleed air from the compressor and the second stream of bleed air from the turbine into a combined bleed air stream to be supplied to the accessory system.

2 . The gas turbine engine assembly of claim 1 , wherein the air cycle machine further comprises:
a bypass bleed line configured for placing the low pressure bleed port in fluid communication with the junction; and a bypass valve operably coupled to the bypass bleed line, the bypass valve configured to control the flow of the first stream of bleed air through the bypass bleed line to the junction.

3 . The gas turbine engine assembly of claim 2 , wherein the air cycle machine further comprises a high pressure regulating valve operably coupled to the high pressure bleed port, the high pressure regulating valve configured for controlling the flow of the second stream of bleed air to the turbine of the air cycle machine.

4 . The gas turbine engine assembly of claim 3 , wherein the bypass valve and the high pressure regulating valve operate independently of each other to adjust a respective flow rate of the first stream of bleed air and the second stream of bleed air.

5 . The gas turbine engine assembly of claim 1 , wherein a temperature of the combined bleed air stream is lower than a temperature of the second stream of bleed air exiting the high pressure bleed port but of sufficiently high pressure to meet system requirements.

6 . The gas turbine engine assembly of claim 1 , wherein a mass flow rate of the combined bleed air stream is approximately 2 times greater than the mass flow rate of a single air stream bleed system.

7 . The gas turbine engine assembly of claim 1 , wherein an electrical motor-generator is mechanically coupled to the shaft of the air cycle machine, the electrical motor-generator configured for either extracting rotational energy from the shaft of the air cycle machine to generate electrical power or supplying a motive force input to the shaft of the air cycle machine.

8 . The gas turbine engine assembly of claim 7 , further comprising a power storage device, the power storage device being electrically connected to the electrical motor-generator and configured to selectively receive and transmit an electrical power to the electrical motor-generator.

9 . The gas turbine engine assembly of claim 1 , wherein the accessory system is an environmental control system.

10 . The gas turbine engine assembly of claim 1 , wherein the junction is selected from a group consisting of an ejector and a mixing manifold.

11 . The gas turbine engine assembly of claim 1 , wherein the core engine further comprises a fan, the fan being mechanically coupled an electrical motor-generator such that in descent conditions, the fan may drive the electrical motor-generator to generate electrical power.

12 . An air cycle machine for extracting bleed air from a gas turbine engine of an aircraft, the gas turbine engine comprising a compressor section, the compressor section defining a low pressure bleed port for extracting a first stream of bleed air and a high pressure bleed port for extracting a second stream of bleed air, the air cycle machine comprising:
a compressor in fluid communication with the low pressure bleed port for receiving a first stream of bleed air and compressing the first stream of bleed air; a turbine in fluid communication with the high pressure bleed port for receiving a second stream of bleed air and expanding the second stream of bleed air to rotate the turbine; a shaft mechanically coupling the turbine to the compressor, such that rotation of the turbine drives the compressor; and a junction in fluid communication with both the compressor and the turbine, the junction being configured to combine the first stream of bleed air from the compressor and the second stream of bleed air from the turbine into a combined bleed air stream to be supplied to an accessory system of the aircraft.

13 . The air cycle machine of claim 12 , wherein the air cycle machine further comprises:
a bypass bleed line configured for placing the low pressure bleed port in fluid communication with the junction; and a bypass valve operably coupled to the bypass bleed line, the bypass valve configured to control the flow of the first stream of bleed air through the bypass bleed line to the junction.

14 . The air cycle machine of claim 13 , wherein the air cycle machine further comprises a high pressure regulating valve operably coupled to the high pressure bleed port, the high pressure regulating valve configured for controlling the flow of the second stream of bleed air to the turbine of the air cycle machine.

15 . The air cycle machine of claim 14 , wherein the bypass valve and the high pressure regulating valve operate independently of each other to adjust a respective flow rate of the first stream of bleed air and the second stream of bleed air.

16 . The air cycle machine of claim 12 , wherein a temperature of the combined bleed air stream is lower than a temperature of the second stream of bleed air exiting the high pressure bleed port but of sufficiently high pressure to meet system requirements.

17 . The air cycle machine of claim 12 , wherein a mass flow rate of the combined bleed air stream is approximately 2 times greater than the mass flow rate of a single air stream bleed system.

18 . The air cycle machine of claim 12 , further comprising:
an electrical motor-generator, the electrical motor-generator being mechanically coupled to the shaft of the air cycle machine and being configured for either extracting rotational energy from the shaft of the air cycle machine to generate electrical power or supplying a motive force input to the shaft of the air cycle machine; and a power storage device, the power storage device being electrically connected to the electrical motor-generator and configured to selectively receive and transmit an electrical power to the electrical motor-generator.

19 . The air cycle machine of claim 12 , wherein the accessory system is an environmental control system.

20 . The air cycle machine of claim 12 , wherein the junction is selected from a group consisting of an ejector and a mixing manifold.

Assignees

• Gen Electric

Inventors

• Christopherson Charles Kammer
• Miller Brandon Wayne

Classifications

• F05D2220/76

  an electrical generator · CPC title

• F02C6/08

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

• B64D13/02

  the air being pressurised · CPC title

• B64D2013/0618

  with arrangements for reducing or managing bleed air, using another air source, e.g. ram air · CPC title

• B64D2013/0648

  with energy recovery means, e.g. using turbines · CPC title