Centrifugal compressor with recirculation passage

Patent metadata

Field	Value
Publication number	US-11499561-B2
Application number	US-202117482526-A
Country	US
Kind code	B2
Filing date	Sep 23, 2021
Priority date	Feb 9, 2018
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

An example centrifugal compressor includes a housing that defines an inlet chamber and includes first and second openings that define a recirculation passage in fluid communication with the inlet chamber. An impeller is disposed within the housing and is rotatable about a longitudinal axis to draw fluid into the inlet chamber. The first and second openings are at different axial locations along the longitudinal axis. A plurality of inlet guide vanes are rotatable and situated in the inlet chamber. The centrifugal compressor includes a ring and a controller for moving the ring along the longitudinal axis between a first position and a second position when rotating the inlet guide vanes. The ring obstructs at least one of the first and second openings more in the second position than in the first position.

First claim

What is claimed is:

1. A centrifugal compressor comprising:
a housing defining an inlet chamber and comprising first and second openings that define a recirculation passage in fluid communication with the inlet chamber;
an impeller within the housing and rotatable about a longitudinal axis to draw fluid into the inlet chamber, the first and second openings at different axial locations along the longitudinal axis;
a plurality of inlet guide vanes that are rotatable and situated in the inlet chamber;
a first ring that includes a cam member;
a second ring that includes a cam surface, wherein the second ring is separate from the first ring, and rotation of the second ring about the longitudinal axis translates the cam member along the cam surface and provides axial movement of the first ring; and
a controller configured to rotate the second ring and thereby move the first ring along the longitudinal axis between a first position and a second position when rotating the inlet guide vanes, wherein the first ring obstructs at least one of the first and second openings more in the second position than in the first position.

2. The centrifugal compressor of claim 1 , comprising:
an actuator;
wherein the controller is configured to utilize the actuator to rotate the second ring about the longitudinal axis.

3. The centrifugal compressor of claim 2 , comprising:
an actuator rod that couples the actuator to the second ring and is non-parallel to the longitudinal axis, wherein the actuator rotates the second ring through movement of the actuator rod.

4. The centrifugal compressor of claim 1 , wherein the first ring is configured to move towards the first position to decrease obstruction of the second opening, and the first ring is configured to move towards the second position to increase obstruction of the second opening.

5. The centrifugal compressor of claim 4 , wherein the inlet guide vanes are configured to rotate to reduce fluid flow to the impeller as the first ring moves towards the first position, and the inlet guide vanes are configured to rotate to increase fluid flow to the impeller as the first ring moves towards the second position.

6. The centrifugal compressor of claim 1 , wherein the plurality of inlet guide vanes are located axially between the first and second openings.

7. The centrifugal compressor of claim 1 , wherein the first ring is disposed within the inlet chamber.

8. The centrifugal compressor of claim 1 , wherein the first ring is disposed radially outward of the inlet chamber.

9. The centrifugal compressor of claim 1 , wherein the first opening is an inlet to the inlet chamber, and the second opening is an outlet of the inlet chamber.

10. The centrifugal compressor of claim 1 , wherein the entire first ring is axially between the first and second openings in the first position, and the first ring covers the entire second opening along a wall of a ported shroud that surrounds an impeller of the centrifugal compressor in the second position.

11. The centrifugal compressor of claim 1 , wherein the controller is configured to move the first ring between the first position and the second position based on a pressure level of the centrifugal compressor.

12. The centrifugal compressor of claim 11 , wherein the controller is configured to:
move the first ring towards the first position to decrease obstruction to the second opening based on a first detected pressure difference between an inlet and an outlet of the centrifugal compressor; and
move the first ring towards the second position to increase obstruction to the second opening based on a second detected pressure difference between the inlet and the outlet of the centrifugal compressor that is higher than the first detected pressure difference.

13. The centrifugal compressor of claim 11 , comprising:
at least one pressure sensor configured to measure a pressure associated with the compressor housing;
wherein the controller is configured to detect the pressure level of the centrifugal compressor based on a refrigerant pressure measurement from the at least one pressure sensor.

14. The centrifugal compressor of claim 1 , wherein the centrifugal compressor is part of a refrigeration circuit, and the fluid drawn into the inlet chamber by the impeller is refrigerant.

15. A method of operating a centrifugal compressor comprising:
rotating an impeller about a longitudinal axis within a compressor housing to draw fluid into an inlet chamber, the compressor housing having first and second openings that define a recirculation passage in fluid communication with the inlet chamber;
recirculating fluid from the inlet chamber through the recirculation passage and back into the inlet chamber;
rotating a plurality of inlet guide vanes disposed within the inlet chamber; and
moving a first ring along the longitudinal axis between a first position and a second position during said rotating, wherein the first ring obstructs at least one of the first and second openings more in the second position than in the first position;
said moving the first ring comprising rotating a second ring that is separate from the first ring and includes a cam surface about the longitudinal axis, wherein rotation of the second ring about the longitudinal axis translates a cam member of the first ring along the cam surface and provides axial movement of the first ring.

16. The method of claim 15 , wherein rotating the second ring comprises:
rotating an actuator rod that is non-parallel to the longitudinal axis and is mechanically coupled to the second ring.

17. The method of claim 15 , wherein said moving the first ring is performed based on a pressure level of the centrifugal compressor.

18. The method of claim 17 , wherein said moving the first ring comprises:
moving the first ring towards the first position to decrease obstruction to the second opening based on a first detected pressure difference between an inlet and an outlet of the centrifugal compressor; and
moving the first ring towards the second position to increase obstruction to the second opening based on a second detected pressure difference between the inlet and the outlet of the centrifugal compressor that is higher than the first detected pressure difference.

19. The method of claim 15 , wherein:
movement of the first ring towards the first position decreases obstruction of the second opening; and
movement of the first ring towards the second position increases obstruction of the second opening.

20. The method of claim 19 , wherein said rotating the plurality of inlet guide vanes disposed within the inlet chamber comprises:
rotating the inlet guide vanes to reduce fluid flow to the impeller as the first ring moves towards the first position, and
rotating the inlet guide vanes to increase fluid flow to the impeller as the first ring moves towards the second position.

Assignees

• Carrier Corp

Inventors

• Sishtla Vishnu M
• Cousins William T

Classifications

• F04D29/284

  for compressors · CPC title

• F04D29/685

  Inducing localised fluid recirculation in the stator-rotor interface · CPC title

• F04D29/4213

  suction ports · CPC title

• F04D27/0246

  by varying geometry within the pumps, e.g. by adjusting vanes · CPC title

• F04D27/009

  by bleeding, by passing or recycling fluid · CPC title