Apparatus and method for controlling refrigerant temperature in a heat pump or refrigeration apparatus

Abstract

An apparatus includes: a compressor including a pair of ports in fluid communication with first and second heat exchangers and a reduced temperature refrigerant inlet for receiving reduced temperature refrigerant; and an expansion device coupled between the first and second heat exchangers for reducing a pressure of refrigerant flowing from one of the first and second heat exchangers to the other of the first and second heat exchangers; wherein the compressor, the first heat exchanger, the expansion device and the second heat exchanger are arranged in a loop to operate as a refrigeration or heat pump apparatus.

What is claimed is: 
     
         1 . An apparatus comprising:
 a compressor comprising a pair of ports in fluid communication with first and second heat exchangers and a reduced temperature refrigerant inlet for receiving reduced temperature refrigerant;   an expansion device coupled between the first and second heat exchangers for reducing a pressure of refrigerant flowing from one of the first and second heat exchangers to the other of the first and second heat exchangers;   wherein the compressor, the first heat exchanger, the expansion device and the second heat exchanger are arranged in a loop to operate as a refrigeration or heat pump apparatus.   
     
     
         2 . An apparatus as claimed in  claim 1 , comprising an expansion device in fluid communication with the reduced temperature refrigerant port for reducing a pressure of the reduced temperature refrigerant entering the compressor. 
     
     
         3 . An apparatus as claimed in  claim 1 , comprising a receiver coupled between the first heat exchanger and the expansion device when fluid flow is from the first heat exchanger and the second heat exchanger. 
     
     
         4 . An apparatus as claimed in  claim 1 , comprising a receiver coupled between the second heat exchanger and the expansion device when fluid flow is from the second heat exchanger and the first heat exchanger 
     
     
         5 . An apparatus as claimed in  claim 1 , wherein two expansion devices are coupled between the first and second heat exchangers and a receiver is coupled between the pair of expansion devices, one of the two expansion devices being operable as a check valve. 
     
     
         6 . An apparatus as claimed in  claim 5 , wherein the reduced temperature refrigerant port is in fluid communication with the receiver. 
     
     
         7 . An apparatus as claimed in  claim 1 , wherein a volume of refrigerant flowing through the apparatus is generally constant. 
     
     
         8 . An apparatus as claimed in  claim 1 , wherein the reduced temperature refrigerant is Trifluoroiodomethane. 
     
     
         9 . An apparatus as claimed in  claim 8 , wherein sesquiterpene is added to the refrigerant. 
     
     
         10 . An apparatus as claimed in  claim 1 , wherein the compressor is a scroll compressor and the reduced temperature refrigerant inlet is located in a flank of the scroll compressor. 
     
     
         11 . An apparatus as claimed in  claim 1 , wherein the compressor is driven by a variable speed motor. 
     
     
         12 . A method comprising:
 compressing a refrigerant during a compression step of a refrigeration cycle; and   injecting a reduced temperature refrigerant into a compressor part-way through the compression step.   
     
     
         13 . A method as claimed in  claim 12 , wherein the reduced temperature refrigerant is received from a receiver located between the condenser and evaporator. 
     
     
         14 . A method as claimed in  claim 12 , wherein the reduced temperature refrigerant is Trifluoroiodomethane. 
     
     
         15 . A method as claimed in  claim 12 , comprising measuring a temperature of the refrigerant at an outlet of the compressor and in response to the temperature being within a predetermined temperature range, injecting the reduced temperature refrigerant into a compressor part-way through the compression step.