Refrigerator with enhanced efficiency

Abstract

The present invention relates to a refrigerator with a refrigerant circuit comprising a compressor, a condenser, an expansion device, a first evaporator downstream the expansion device, a second evaporator downstream the first evaporator, a heat exchanger to cause heat exchange between refrigerant downstream the condenser and upstream said first evaporator, on one side, and refrigerant downstream the second evaporator and upstream the compressor, on the other side.

The invention claimed is: 
     
         1 . A refrigerator with a refrigerant circuit comprising:
 a compressor;   a condenser;   an expansion device corresponding to a capillary tube;   a first evaporator downstream the expansion device;   a second evaporator downstream the first evaporator;   a first heat exchanger configured to cause heat exchange between refrigerant downstream the condenser and upstream the first evaporator, on a first side, and refrigerant downstream the second evaporator and upstream the compressor, on a second side; and   a second heat exchanger configured to cause heat exchange between refrigerant downstream the condenser and upstream the first evaporator, on the first side, and refrigerant downstream the first evaporator and upstream the second evaporator, on the second side, wherein the expansion device is configured to act as the first side of the first heat exchanger and the second heat exchanger.   
     
     
         2 . The refrigerator according to  claim 1 , wherein the refrigerant comprises a single compound. 
     
     
         3 . The refrigerator according to  claim 1 , wherein the first heat exchanger and the second heat exchanger are shaped as double-pipe exchangers formed by the capillary tube in a heat exchange relationship with the second side corresponding to a return line of the refrigerant circuit. 
     
     
         4 . The refrigerator according to  claim 3 , wherein the capillary tube is externally in contact the return line. 
     
     
         5 . The refrigerator according to  claim 1 , wherein the capillary tube has a total length greater than 3.5 m. 
     
     
         6 . The refrigerator according to  claim 5 , wherein the length of the second heat exchanger is greater than 0.7 m. 
     
     
         7 . The refrigerator according to  claim 1 , wherein the first heat exchanger and the second heat exchanger are formed by the capillary tube and by a return line in parallel one against the other. 
     
     
         8 . The refrigerator according to  claim 1 , wherein at least one of the first heat exchanger and the second heat exchanger is made by a return line defining the second side of the heat exchangers and by a the capillary tube wrapped around the return line. 
     
     
         9 . The refrigerator according to  claim 1 , wherein at least one of the first heat exchanger and the second heat exchanger is covered by an aluminum layer. 
     
     
         10 . The refrigerator according to  claim 1 , wherein the first evaporator and the second evaporator are static evaporators disposed in a freezer compartment and in a fridge compartment respectively. 
     
     
         11 . The refrigerator according to  claim 1 , wherein the second evaporator is a static evaporator disposed in a fridge compartment, and the first evaporator is a no-frost evaporator disposed in a freezer compartment. 
     
     
         12 . The refrigerator according to  claim 1 , wherein the refrigerant is n-butane. 
     
     
         13 . A refrigeration system 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;   a second heat exchanger, wherein the system forms a refrigerant circuit comprising:
 the first heat exchanger positioned upstream the second heat exchanger along the expansion device defining a first side and positioned downstream the second evaporator along a return line defining a second side; and 
 the second heat exchanger positioned upstream the first evaporator along the expansion device on the first side and positioned downstream the first evaporator along the return line on the second side. 
   
     
     
         14 . The system according to  claim 13 , wherein the at least a portion of the return line corresponds to a suction line. 
     
     
         15 . The system according to  claim 13 , wherein the expansion device corresponds to a capillary tube. 
     
     
         16 . The system according to  claim 14 , wherein the capillary tube is externally in contact with the return line. 
     
     
         17 . The system according to  claim 14 , wherein the capillary tube has a total length greater than 3.5 m. 
     
     
         18 . The system according to  claim 17 , wherein the length of the second heat exchanger is greater than 0.7 m. 
     
     
         19 . The system according to  claim 14 , wherein the first heat exchanger and the second heat exchanger are formed by the expansion device and by the return line in parallel one against the other. 
     
     
         20 . The system according to  claim 14 , wherein at least one of the first heat exchanger and the second heat exchanger is formed by a return line defining the second side of the at least one heat exchanger and by a the expansion device wrapped around the return line.