Method of low pressure bleed

Patent metadata

Field	Value
Publication number	US-9650967-B2
Application number	US-201514713041-A
Country	US
Kind code	B2
Filing date	May 15, 2015
Priority date	Jan 14, 2011
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

A method for decreasing a throttle setting at which a gas turbine-powered aircraft must switch from low-pressure bleed air to a high-pressure bleed air. The method includes flowing low-pressure bleed air from a compressor at a first pressure. A first portion of the low-pressure bleed air is directed to an air-to-air heat exchanger and cooled in the air-to-air heat exchanger. The first portion of the low-pressure bleed air is flowed from the air-to air heat exchanger into a cooled bleed air line. A second portion of the low-pressure bleed air is directed to a low-pressure bypass line. The second portion of the low-pressure bleed air is flowed from the low-pressure bypass line into the cooled bleed air line upstream of an environmental control system.

First claim

The invention claimed is:

1. A method for decreasing a throttle setting at which a gas turbine-powered aircraft must switch from low-pressure bleed air to a high-pressure bleed air, the method comprising:
flowing low-pressure bleed air from a compressor at a first pressure;
directing a first portion of the low-pressure bleed air to an air-to-air heat exchanger;
cooling the first portion of the low-pressure bleed air in the air-to-air heat exchanger;
flowing the first portion of the low-pressure bleed air from the air-to air heat exchanger into a cooled bleed air line;
directing a second portion of the low-pressure bleed air to a low-pressure bypass line; and
flowing the second portion of the low-pressure bleed air from the low-pressure bypass line into the cooled bleed air line upstream of all components of an environmental control system.

2. The method of claim 1 , further comprising:
flowing high-pressure bleed air from a compressor at a second pressure, wherein the second pressure is greater than the first pressure;
preventing the flow of the first portion of low-pressure bleed air to the air-to-air heat exchanger by flowing the high-pressure bleed air;
preventing the flow of the second portion of low-pressure bleed air to the cooled bleed air line by flowing the high-pressure bleed air;
directing the high-pressure bleed air to the air-to-air heat exchanger;
cooling the high-pressure bleed air in the air-to-air heat exchanger; and
flowing the high-pressure bleed air from the air-to air heat exchanger into the cooled bleed air line.

3. The method of claim 2 , wherein preventing the flow of the first portion of low-pressure bleed air to the air-to-air heat exchanger by flowing the high-pressure bleed air and preventing the flow of the second portion of low-pressure bleed air to the cooled bleed air line by flowing the high-pressure bleed air further comprises:
flowing the first portion of the low-pressure bleed air to the air-to-air heat exchanger through a check valve; and
flowing the second portion of the low-pressure bleed air through a check valve.

4. The method of claim 1 , further comprising:
balancing the flow of the second portion of low-pressure bleed air through the low-pressure bypass line with the flow of the first portion of low-pressure bleed air through the air-to-air heat exchanger.

5. The method of claim 4 , wherein balancing the second portion of low-pressure bleed air through the low-pressure bypass line with the flow of the first portion of low-pressure bleed air through the air-to-air heat exchanger further comprises:
flowing the second portion of low-pressure bleed air through an orifice disposed within the low-pressure bypass line.

6. The method of claim 1 , further comprising:
providing fan bleed air to the air-to-air heat exchanger, the fan bleed air acting as cooling air.

7. The method of claim 6 , further comprising:
controlling the flow of fan bleed air to the air-to-air heat exchanger with a fan bleed valve.

8. The method of claim 1 , further comprising:
sensing a pressure of the bleed air in the cooled bleed air line downstream of the point of connection between the low-pressure bypass line and the cooled bleed air line with a pressure sensor.

9. The method of claim 1 , further comprising:
sensing a temperature of the bleed air in the cooled bleed air line downstream of the point of connection between the low-pressure bypass line and the cooled bleed air line with a temperature sensor.

10. A method of flowing air to an environmental control system, the method comprising:
flowing a first fluid at a first pressure through a first line;
flowing a first portion of first fluid to a second line;
directing the first portion of first fluid to a heat exchanger;
cooling the first portion of first fluid in the heat exchanger;
flowing the first portion of first fluid from the heat exchanger into a third line;
flowing a second portion of first fluid around the heat exchanger through the first line; and
flowing the second portion of first fluid from the first line into the third line at a location upstream of all components of the environmental control system.

11. The method of claim 10 , further comprising:
flowing a second fluid at a second pressure through the second line, wherein the second pressure is greater than the first pressure;
directing the second fluid to the heat exchanger;
cooling the second fluid in the heat exchanger; and
flowing the second fluid into the third line and to the environmental control system.

12. The method of claim 11 , further comprising:
preventing the flow of the first portion of first fluid to the second line; and
preventing the flow of the second portion of first fluid to the third line.

13. The method of claim 12 , wherein preventing the flow of the first portion of the first fluid to the second line and preventing the flow of the second portion of first fluid to the third line further comprises:
flowing the first portion of first fluid through a check valve disposed upstream of the second line; and
flowing the second portion of first fluid through a check valve disposed within the first line.

14. The method of claim 10 , further comprising:
balancing the flow of the first portion of first fluid through the second line with the flow of the second portion of first fluid through the first line.

15. The method of claim 14 , wherein balancing the flow of the first portion of first fluid through the second line with the flow of the second portion of first fluid through the first line further comprises:
flowing the second portion of first fluid through an orifice disposed within the first line.

16. The method of claim 10 , further comprising:
providing air to the heat exchanger, the air acting as cooling air.

17. The method of claim 16 , wherein providing air to the heat exchanger further comprises:
providing bleed air from a fan to the heat exchanger, the bleed air acting as cooling air.

18. The method of claim 17 , further comprising:
controlling the flow of bleed air to the heat exchanger with a valve.

19. The method of claim 10 , further comprising:
sensing a temperature of the fluid in the third line downstream of the point of connection between the first line and the third line with a temperature sensor.

20. The method of claim 10 , further comprising:
sensing a pressure of the fluid in the third line downstream of the point of connection between the first line and the third line with a pressure sensor.

Assignees

• Hamilton Sundstrand Corp
• Hamiilton Sundstrand Corp

Inventors

• Defrancesco Gregory L

Classifications

• F02C7/185

  Cooling means for reducing the temperature of the cooling air or gas · CPC title

• B64D13/08 Primary

  the air being heated or cooled · CPC title

• Y02T50/56

  Cross-Sectional Technologies · mapped topic

• B64D2013/0618

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

• F02C9/18 Primary

  by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)} · CPC title