Variable geometry diffuser ring

Abstract

A compressor includes an impeller, a diffuser passage having a diffuser vane therein, and a variable geometry diffuser ring positioned between the impeller and the diffuser vane with respect to a flow of a refrigerant through the compressor. The compressor also includes an actuator configured to move the variable geometry diffuser ring in a direction transverse to the flow of the refrigerant, and between a plurality of ring positions including a fully retracted ring position in which the variable geometry diffuser ring does not block the flow of the refrigerant, and at least one protruded ring position in which the variable geometry diffuser ring adjusts an angle of the flow of the refrigerant upstream of the diffuser vane.

1 . A compressor, comprising:
 an impeller;   a diffuser passage comprising a diffuser vane therein;   a variable geometry diffuser ring positioned between the impeller and the diffuser vane with respect to a flow of a refrigerant through the compressor; and   an actuator configured to move the variable geometry diffuser ring in a direction transverse to the flow of the refrigerant, and between a plurality of ring positions including a fully retracted ring position in which the variable geometry diffuser ring does not block the flow of the refrigerant, and at least one protruded ring position in which the variable geometry diffuser ring adjusts an angle of the flow of the refrigerant upstream of the diffuser vane.   
     
     
         2 . The compressor of  claim 1 , comprising a controller configured to instruct the actuator to move the variable geometry diffuser ring between the plurality of positions based at least in part on an operating capacity of the compressor, a temperature of the refrigerant, or both. 
     
     
         3 . The compressor of  claim 1 , comprising a controller configured to instruct the actuator to move the variable geometry diffuser ring between the plurality of ring positions based at least in part on an incidence angle of a leading edge of the diffuser vane. 
     
     
         4 . The compressor of  claim 3 , wherein the controller is configured to instruct the actuator to move the variable geometry diffuser ring such that the angle of the flow of the refrigerant proximate to the diffuser vane corresponds to the incidence angle of the leading edge of the diffuser vane. 
     
     
         5 . The compressor of  claim 1 , wherein the actuator is a motor-driven actuator. 
     
     
         6 . The compressor of  claim 1 , wherein the diffuser vane is stationary. 
     
     
         7 . The compressor of  claim 1 , wherein the variable geometry diffuser ring comprises a rectangular cross-sectional shape. 
     
     
         8 . The compressor of  claim 1 , wherein the variable geometry diffuser ring comprises at least a portion having a triangular cross-sectional shape, a curvilinear cross-sectional shape, or an L-shaped cross-sectional shape. 
     
     
         9 . The compressor of  claim 1 , comprising a collector positioned downstream from the diffuser passage and configured to receive the refrigerant after the refrigerant is pressurized by the diffuser vane. 
     
     
         10 . The compressor of  claim 1 , wherein the variable geometry diffuser ring is positioned within the diffuser passage. 
     
     
         11 . A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, comprising:
 a compressor comprising a diffuser vane, and having a variable geometry diffuser ring positioned upstream of the diffuser vane with respect to a flow of a refrigerant therethrough; and   a controller configured to control a position of the variable geometry diffuser ring based at least in part on an operating capacity of the compressor and at least in part on an incidence angle of a leading edge of the diffuser vane.   
     
     
         12 . The system of  claim 11 , wherein the diffuser vane is stationary. 
     
     
         13 . The system of  claim 11 , comprising an actuator coupled to the variable geometry diffuser ring, wherein the controller is configured to control the position of the variable geometry diffuser ring by instructing the actuator to move the variable geometry diffuser ring to the position. 
     
     
         14 . The system of  claim 13 , wherein the actuator is a motor-driven actuator. 
     
     
         15 . The system of  claim 11 , wherein the controller is configured to control the variable geometry diffuser ring to move the variable geometry diffuser ring to at least one protruding position that corresponds to the compressor operating at less than full capacity, wherein the variable geometry diffuser ring is disposed in the diffuser passage in the at least one protruding position, wherein the controller is configured to control the variable geometry diffuser ring to move the variable geometry diffuser ring to a fully retracted position of the variable geometry diffuser ring that corresponds to the compressor operating at full capacity, and wherein the variable geometry diffuser ring is not disposed in the diffuser passage in the fully retracted position. 
     
     
         16 . The system of  claim 11 , wherein the variable geometry diffuser ring comprises a rectangular cross-sectional shape. 
     
     
         17 . The system of  claim 11 , comprising a collector positioned downstream from the diffuser passage and configured to receive the refrigerant after the refrigerant is pressurized by the diffuser vane. 
     
     
         18 . A method of operating a compressor, comprising:
 detecting a temperature of a refrigerant;   determining, via a controller, an operating capacity of the compressor based at least in part on the temperature of the refrigerant; and   controlling a position of a variable geometry diffuser ring based at least in part on the operating capacity of the compressor and at least in part on an incidence angle of a leading edge of a diffuser vane of the compressor.   
     
     
         19 . The method of  claim 18 , comprising actuating, via an actuator, the variable geometry diffuser ring from a previous position to the position based on a change in the operating capacity of the compressor. 
     
     
         20 . The method of  claim 18 , comprising determining that the operating capacity of the compressor is fully capacity, and instructing the position of the variable geometry diffuser ring such that the variable geometry diffuser ring is fully retracted from a flow path of the refrigerant.