Vapor compression refrigeration system having ejector

Abstract

Piping, which connects between a radiator and an ejector, is covered with a thermal insulator to thermally insulate a refrigerant passage defined in the piping. Thus, it is possible to limit a reduction in enthalpy of refrigerant, which could be induced by cooling of high temperature refrigerant by low temperature atmosphere to lose the enthalpy before depressurization of the high temperature refrigerant through the ejector. As a result, it is possible to limit a reduction in a theoretical value of recoverable energy at the time of depressurization and expansion of the refrigerant.

What is claimed is:  
     
         1 . A vapor compression refrigeration system that transfers heat from a low temperature side to a high temperature side, wherein the temperature of the high temperature side is higher than that of the low temperature side, the vapor compression refrigeration system comprising: 
 a compressor that compresses refrigerant;    a radiator that cools high pressure refrigerant discharged from the compressor;    an evaporator that evaporates refrigerant;    an ejector that depressurizes and expands high pressure refrigerant supplied from the radiator to draw evaporated vapor phase refrigerant evaporated in the evaporator, such that the ejector converts expansion energy of refrigerant to pressure energy to increase intake pressure of the compressor; and    a refrigerant passage means for fluidly connecting between the radiator and the ejector, wherein the refrigerant passage means is substantially, thermally insulated from a surrounding atmosphere that surrounds the refrigerant passage means.    
     
     
         2 . A vapor compression refrigeration system according to  claim 1 , wherein the refrigerant passage means includes piping that is covered with a thermal insulator.  
     
     
         3 . A vapor compression refrigeration system according to  claim 1 , further comprising a heat exchanger that exchanges heat between refrigerant, which is discharged from the radiator, and refrigerant to be supplied to the compressor, wherein the heat exchanger is inserted in the refrigerant passage means and is substantially, thermally insulated together with the refrigerant passage means from the surrounding atmosphere.  
     
     
         4 . A vapor compression refrigeration system according to  claim 1 , wherein the refrigerant includes chlorofluorocarbon.  
     
     
         5 . A vapor compression refrigeration system according to  claim 1 , wherein the refrigerant includes carbon dioxide.  
     
     
         6 . A vapor compression refrigeration system according to  claim 1 , wherein the refrigerant includes hydrocarbon.  
     
     
         7 . A vapor compression refrigeration system according to  claim 1 , wherein the pressure of the high pressure refrigerant discharged from the compressor is equal to or greater than a critical pressure of the refrigerant.  
     
     
         8 . A vapor compression refrigeration system according to  claim 1 , wherein the vapor compression refrigeration system is disposed in an environment where the temperature of the surrounding atmosphere is normally substantially kept equal to or less than zero degrees Celsius during operation of the vapor compression refrigeration system.