Refrigerators with a non-azeotropic mixtures of hydrocarbons refrigerants

Abstract

A refrigerant circuit using a non-azeotropic mixture of hydrocarbons refrigerants comprises a compressor, a condenser, an expansion device, a first evaporator downstream the expansion device, a second evaporator downstream the first evaporator, a first heat exchanger to cause heat exchange between refrigerant downstream the condenser and upstream the first evaporator, on one side, and refrigerant downstream the first evaporator and upstream the second evaporator, on the other side, and a second heat exchanger to cause heat exchange between refrigerant downstream the condenser and upstream the first heat exchanger, on one side, and refrigerant downstream the second evaporator and upstream the compressor, on the other side, the expansion device having a capillary tube as part of both heat exchangers as a side of exchangers, the capillary tube being parallel to and in contact with a tube of the circuit or it is wrapped around such tube.

What is claimed is: 
     
         1 . A refrigerant circuit using a non-azeotropic mixture of refrigerants, the circuit comprising:
 a compressor;   a condenser;   an expansion device;   a first evaporator downstream the expansion device;   a second evaporator downstream the first evaporator;   a first heat exchanger to cause heat exchange between refrigerant downstream the condenser and upstream the first evaporator on a first side, and refrigerant downstream the first evaporator and upstream the second evaporator on a second side; and   a second heat exchanger to cause heat exchange between refrigerant downstream the condenser and upstream the first heat exchanger on a first side, and refrigerant downstream the second evaporator and upstream the compressor on a second side,   wherein the expansion device comprises a capillary tube adapted to act as the first side of both heat exchangers.   
     
     
         2 . A refrigerant circuit as defined in  claim 1 , wherein the first and second heat exchangers are each shaped as a double-pipe exchanger formed by the capillary tube in a heat exchange relationship with portions of respective circuit tubes of the first and second heat exchangers. 
     
     
         3 . A refrigerant circuit as defined in  claim 2 , wherein the capillary tube is externally in contact with the portions of the circuit tubes. 
     
     
         4 . A refrigerant circuit as defined in  claim 3 , wherein the capillary tube is at least partially wrapped around the portions of the respective circuit tubes of the first and second heat exchangers. 
     
     
         5 . A refrigerant circuit as defined in  claim 3 , wherein the first and second heat exchangers are each covered by an aluminum layer. 
     
     
         6 . A refrigerant circuit as defined in  claim 2 , wherein the capillary tube has a total length between 2 meters (m) and 5 m. 
     
     
         7 . A refrigerant circuit as defined in  claim 2 , wherein the capillary tube has an internal diameter comprised between 0.6 millimeters (mm) and 0.8 mm. 
     
     
         8 . A refrigerant circuit as defined in  claim 2 , wherein the length of the first heat exchanger is between 0.5 meters (m) and 1 m. 
     
     
         9 . A refrigerant circuit as defined in  claim 2 , wherein the length of the second heat exchanger is between 1.5 meters (m) and 3 m. 
     
     
         10 . A refrigerant circuit as defined in  claim 2 , wherein the first and second heat exchangers are each covered by an aluminum layer. 
     
     
         11 . A refrigerant circuit as defined in  claim 1 , wherein the first and second heat exchangers are each covered by an aluminum layer. 
     
     
         12 . A refrigerant circuit as defined in  claim 1 , wherein the first and second evaporators comprise static evaporators placed in a freezing compartment and in a refrigerating compartment, respectively. 
     
     
         13 . A refrigerant circuit as defined in  claim 1 , wherein the second evaporator comprises a static evaporator placed in a refrigerating compartment, and the first evaporator comprises a no-frost evaporator placed in a freezing compartment. 
     
     
         14 . A refrigerant circuit as defined in  claim 1 , wherein the refrigerant comprises a mixture of propane and butane of 20 to 80% by mass in liquid phase.