Compressor Protection Against Liquid Slug

Abstract

A liquid slug protector device for air conditioning and heat pump systems can include a housing having an inlet port, an outlet port, an abutment surface, and a cavity. The device can include a piston disposed in the cavity. The piston can have a primary channel. The device can include a secondary channel. A first refrigerant flow path extending between the inlet port and the outlet port can include the primary channel. A second refrigerant flow path extending between the inlet port and the outlet port can include the secondary channel. The second refrigerant flow path can be closed when the piston abuts against the abutment surface.

What is claimed is: 
     
         1 . A liquid slug protector device comprising:
 a housing comprising:
 an inlet port and an outlet port; 
 an abutment surface upstream from the outlet port; and 
 a cavity at least partially disposed between the inlet port and the abutment surface; and 
   a piston disposed in the cavity, the piston comprising a primary channel and a secondary channel, wherein:
 the piston is configured to move between a first position and a second position, the piston being spaced apart from the abutment surface when the piston is in the first position, and the piston abutting the abutment surface when the piston is in the second position, 
 a first refrigerant flow path extending between the inlet port and the outlet port includes the primary channel, 
 when the piston is in the first position, a second refrigerant flow path from the inlet port to the outlet port includes the secondary channel, and 
 when the piston is in the second position, the second refrigerant flow path is closed. 
   
     
     
         2 . The liquid slug protector device of  claim 1 , wherein the first refrigerant flow path is open when the piston is in the first position and when the piston is in the second position. 
     
     
         3 . The liquid slug protector device of  claim 1 , wherein the piston is moveable between the first and second positions depending on pressure exerted on the piston by a refrigerant in the cavity. 
     
     
         4 . The liquid slug protector device of  claim 1 , wherein the abutment surface comprises an O-ring gasket. 
     
     
         5 . The liquid slug protector device of  claim 1  further comprising a spring positioned in the cavity. 
     
     
         6 . The liquid slug protector device of  claim 5 , wherein the spring is located between the piston and the abutment surface, and the piston is configured to compress the spring toward the abutment surface when the piston is moving from the first position to the second position. 
     
     
         7 . The liquid slug protector device of  claim 5 , wherein the spring is positioned annularly around a shaft portion of the piston. 
     
     
         8 . The liquid slug protector device of  claim 1 , wherein the secondary channel has a plurality of sidewalls, at least one of the plurality of sidewalls being a sidewall of the piston and at least one other of the plurality of sidewalls being a sidewall of the cavity. 
     
     
         9 . The liquid slug protector device of  claim 1 , wherein the primary channel has a diameter that is less than a diameter of the inlet port. 
     
     
         10 . The liquid slug protector device of  claim 1  further comprising an outflow channel located between the abutment surface and the outlet port. 
     
     
         11 . The liquid slug protector device of  claim 10 , wherein the primary channel has a diameter that is less than a diameter of the outflow channel and a diameter of the outlet port. 
     
     
         12 . A liquid slug protector device comprising:
 a housing comprising:
 an inlet port and an outlet port; 
 an abutment surface upstream from the outlet port; and 
 a cavity at least partially disposed between the inlet port and the abutment surface; and 
   a piston disposed in the cavity, the piston comprising a primary channel extending therethrough and a plurality of protrusions arranged at a periphery of the piston, each adjacent pair of the plurality of protrusions forming a secondary channel therebetween such that the liquid slug protector device comprises one or more secondary channels,   wherein:
 the piston is configured to move between a first position and a second position, the piston being spaced apart from the abutment surface when the piston is in the first position, and the piston abutting the abutment surface when the piston is in the second position, 
 a first refrigerant flow path extending between the inlet port and the outlet port includes the primary channel, 
 when the piston is in the first position, one or more second refrigerant flow paths extending between the inlet port and the outlet port includes a corresponding one of the one or more secondary channels, and 
 when the piston is in the second position, the second refrigerant flow path is closed. 
   
     
     
         13 . The liquid slug protector device of  claim 12 , wherein the primary channel has a diameter that is less than a diameter of the inlet port. 
     
     
         14 . The liquid slug protector device of  claim 12 , wherein the first refrigerant flow path is open when the piston is in the first position and when the piston is in the second position. 
     
     
         15 . The liquid slug protector device of  claim 12 , wherein the piston is moveable between the first and second positions depending on pressure exerted on the piston by a refrigerant in the cavity. 
     
     
         16 . The liquid slug protector device of  claim 12  further comprising a spring positioned in the cavity. 
     
     
         17 . A system comprising:
 a compressor; and   a liquid slug protector device that is fluidly couples to the compressor, the liquid slug protector device comprising:
 an inlet port and an outlet port; 
 an abutment surface upstream from the outlet port; and 
 a cavity at least partially disposed between the inlet port and the abutment surface; and 
   a piston disposed in the cavity, the piston comprising a primary channel and a secondary channel,   wherein:
 the piston is configured to move between a first position and a second position, the piston being spaced apart from the abutment surface when the piston is in the first position, and the piston abutting the abutment surface when the piston is in the second position, 
 a first refrigerant flow path extending between the inlet port and the outlet port includes the primary channel, 
 when the piston is in the first position, a second refrigerant flow path from the inlet port to the outlet port includes the secondary channel, and 
 when the piston is in the second position, the second refrigerant flow path is closed. 
   
     
     
         18 . The system of  claim 17 , wherein the primary channel has a diameter that is less than a diameter of the inlet port. 
     
     
         19 . The system of  claim 17 , wherein the first refrigerant flow path is open when the piston is in the first position and when the piston is in the second position. 
     
     
         20 . The system of  claim 17 , wherein the piston is moveable between the first and second positions depending on pressure exerted on the piston by a refrigerant in the cavity.