Bleed ejector

Patent metadata

Field	Value
Publication number	US-11092074-B2
Application number	US-201816202631-A
Country	US
Kind code	B2
Filing date	Nov 28, 2018
Priority date	Dec 13, 2017
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

A bleed valve system comprises a duct, featuring a central longitudinal axis and allowing a main flow of fluid to pass from a first environment at a first static pressure to a second environment at a second static pressure along a bleed direction, a valve comprising a valve member arranged within the duct between the first and second environments and movable to partially obstruct the duct and deviate the main flow of fluid to direct at least a part of it towards a portion of an internal wall of the duct; and an ejector, arranged within the duct, downstream of the valve member and offset from the central longitudinal axis in correspondence of said portion of the internal wall, adapted to supply an additional flow of fluid within the duct to accelerate the main flow of fluid and reduce the second static pressure.

First claim

I claim:

1. A bleed valve system comprising:
a duct, featuring a central longitudinal axis and allowing a main flow of fluid to pass from a first environment at a first static pressure to a second environment at a second static pressure along a bleed direction;
a valve comprising a valve member arranged within the duct between the first environment and the second environment and movable to partially obstruct the duct, wherein the valve member, when in an open position, divides the main flow of fluid in a first flow of fluid and a second flow of fluid, the first flow of fluid having a mass flow higher than the mass flow of the second flow of fluid; and
an ejector, arranged within the duct downstream of the valve member and offset from the central longitudinal axis at a longitudinal and circumferential portion of the internal wall corresponding to the location of a vena contracta created by the valve member for at least one rotation angle of the valve member greater 0 degrees and less than 70 degrees, wherein the ejector is configured to supply an additional flow of fluid within the duct to accelerate the first flow of fluid and reduce the second static pressure.

2. The bleed valve system according to claim 1 , wherein the ejector includes a nozzle arranged transversal to the central longitudinal axis.

3. The bleed valve system according to claim 2 , wherein the nozzle is arranged convergent to the central longitudinal axis of the duct along the bleed direction.

4. The bleed valve system according to claim 1 , wherein the ejector is arranged to accelerate the first flow of fluid.

5. The bleed valve system according to claim 4 , wherein the nozzle of the ejector is awash in the first flow of fluid.

6. The bleed valve system according to claim 1 , wherein the valve member includes a disc, a rotation angle being defined between a longitudinal plane of the disc and the central longitudinal axis of the duct, the disc being rotatable about an axis of rotation perpendicular to the central longitudinal axis for rotation angles between 0°, wherein the disc is arranged perpendicular to the central longitudinal axis and closes the duct, and 90°, wherein the disc is arranged parallel to the central longitudinal axis.

7. The bleed valve system according to claim 6 , wherein the disc, when in an open position, features a leading edge and a trailing edge, the leading edge being upstream of the trailing edge along the bleed direction, the internal wall of the duct featuring a first portion facing the leading edge of the disc and a second portion facing the trailing edge of the disc, the nozzle being arranged closer to the second portion than to the first portion of the internal wall of the duct.

8. The bleed valve system according to claim 1 , wherein the duct has a circular cross section and the valve member is a circular disc.

9. The bleed valve system according to claim 1 , wherein the valve is a butterfly valve or a ball valve.

10. A gas turbine engine comprising:
a compressor including a casing and a bleed port achieved therein;
a bypass duct comprising a bypass port; and
a bleed valve system according to claim 1 , wherein the duct of the bleed valve system is connected to the bleed port and the bypass port.

11. A method of expelling foreign object debris in a gas turbine engine comprising a compressor provided with a bleed port and a bypass duct provided with a bypass port, the method comprising:
providing a bleed valve system comprising:
a duct, featuring a central longitudinal axis and allowing a main flow of fluid to pass from a first environment at a first static pressure to a second environment at a second static pressure along a bleed direction;
a valve comprising a valve member arranged within the duct between the first environment and the second environment and movable to partially obstruct the duct, wherein the valve member, when in an open position, divides the main flow of fluid in a first flow of fluid and a second flow of fluid, the first flow of fluid having a mass flow higher than the mass flow of the second flow of fluid; and
an ejector, arranged within the duct downstream of the valve member and offset from the central longitudinal axis at a longitudinal and circumferential portion of the internal wall corresponding to the location of a vena contracta created by the valve member for at least one rotation angle of the valve member greater 0 degrees and less than 70 degrees, wherein the ejector is configured to supply an additional flow of fluid within the duct to accelerate the first flow of fluid and reduce the second static pressure;

connecting a first end of the duct of the bleed valve system to the bleed port and a second end of the duct of the bleed valve system to the bypass port;
deviating the main flow of fluid to direct the first flow of fluid towards the longitudinal and circumferential portion of the internal wall of the duct;
dividing the main flow of fluid in the first flow and a second flow of fluid, the first flow of fluid having a mass flow higher that the mass flow of the second flow of fluid;
detecting a pressure ratio between a first static pressure upstream of the valve and a second static pressure downstream of the valve; and
upon reaching a threshold value of the pressure ratio, supplying the additional flow of fluid through the ejector to accelerate the first flow of fluid and reduce the second static pressure.

12. The method according to claim 11 , wherein detecting a pressure ratio between a first static pressure upstream of the valve and a second static pressure downstream of the valve comprises detecting the pressure ratio between a first static pressure at the bleed port and a second static pressure at the bypass port.

13. The method according to claim 11 , wherein the valve member includes a disc, a rotation angle being defined between a longitudinal plane of the disc and the central longitudinal axis of the duct, the disc being rotatable about an axis of rotation perpendicular to the central longitudinal axis for rotation angles between 0°, wherein the disc is arranged perpendicular to the central longitudinal axis and closes the duct, and 90°, wherein the disc is arranged parallel to the central longitudinal axis, the method further comprising arranging the disc at a rotation angle between 1° and 75°.

14. The method according to claim 13 , further comprising arranging the disc at a rotation angle between 1° and 50°.

15. The method according to claim 14 , further comprising arranging the disc at a rotation angle between 1° and 25°.

16. The bleed valve system according to claim 1 , wherein the valve member causes the first flow to present a vena contracta downstream of a trailing edge of the valve member, and wherein the ejector is arranged within the duct to supply the additional flow of fluid to the first flow of fluid in the vena contracta.

17. The bleed valve system according to claim 1 , wherein the ejector comprises a nozzle, and wherein the nozzle is configured to rotate to maintain a constant angle of a longitudinal axis of nozzle relative to a plane of the valve member.

18. The bleed valve system according to claim 17 , wherein the constant angle is 90 degrees.

Assignees

• Rolls Royce Plc

Inventors

• Hussain Zahid M

Classifications

• F04D27/023 Primary

  Details or means for fluid extraction · CPC title

• F05D2270/3015

  differential pressure · CPC title

• F04D27/0292

  Stop safety or alarm devices, e.g. stop-and-go control; Disposition of check-valves · CPC title

• F02C7/05

  having provisions for obviating the penetration of damaging objects or particles · CPC title

• F04D27/0238

  Details or means for fluid reinjection · CPC title