Dual evaporator refrigeration system with zeotropic refrigerant mixture

Abstract

A refrigeration system is provided that uses dual evaporators and a zeotropic refrigerant mixture to provide more efficient cooling. The refrigeration system can be used in e.g., a refrigerator having a fresh food compartment and a frozen food compartment to provide separate cooling for each compartment. Multiple exemplary embodiments are described including embodiments utilizing a single compressor and a single condenser with dual evaporators.

What is claimed is: 
     
         1 . A refrigeration system, comprising:
 a zeotropic refrigerant for circulation within the refrigeration system;   a compressor for providing a pressurized flow of the refrigerant;   a condenser configured to receive and cool the flow of pressurized refrigerant, the condenser comprising a divider for separating the flow of pressurized refrigerant into a first refrigerant stream and a second refrigerant stream;   a first expansion device in receipt of the first refrigerant stream from the condenser and configured for reducing the pressure of the first refrigerant stream; and   a second expansion device in receipt of the second refrigerant stream from the condenser and configured for reducing the pressure of the second refrigerant stream;   a first evaporator configured to receive and evaporate at least a portion of the first refrigerant stream;   a junction that joins the first refrigerant stream from the first evaporator and the second refrigerant stream from the second expansion device into a combined refrigerant stream; and   a second evaporator configured to receive and evaporate at least a portion of the combined refrigerant stream and provide an inlet refrigerant flow to the compressor.   
     
     
         2 . A refrigeration system as in  claim 1 , wherein the first and second expansion devices are in thermal communication with the inlet refrigerant stream to the compressor so as to cool the first refrigerant stream and the second refrigerant stream. 
     
     
         3 . A refrigeration system as in  claim 2 , wherein the first expansion device and the second expansion device each comprise a capillary tube. 
     
     
         4 . A refrigeration system as in  claim 1 , wherein the pressure of the first refrigerant stream is substantially equal to the pressure of the second refrigerant stream. 
     
     
         5 . A refrigeration system as in  claim 1 , wherein the zeotropic refrigerant comprises two or more refrigerants selected from a group consisting of an R-134a refrigerant, an R-245fa refrigerant, an R-245ca refrigerant, an R-1234yf refrigerant, an R-600a refrigerant, pentane, butane, and propane. 
     
     
         6 . A refrigeration system, comprising:
 a zeotropic refrigerant for circulation within the refrigeration system;   a compressor for providing a pressurized flow of the refrigerant;   a condenser configured to receive and cool the flow of pressurized refrigerant, the condenser comprising a divider for separating the flow of pressurized refrigerant into a first refrigerant stream and a second refrigerant stream;   a first expansion device in receipt of the first refrigerant stream from the condenser and configured for reducing the pressure of the first refrigerant stream; and   a second expansion device in receipt of the second refrigerant stream from the condenser and configured for reducing the pressure of the second refrigerant stream;   a first evaporator;   a second evaporator configured to receive and evaporate at least a portion of the second refrigerant stream; and   a junction that joins the first refrigerant stream from the first expansion device and the second refrigerant stream from the second evaporator to provide a combined refrigerant stream to the first evaporator;   wherein the first evaporator is configured to receive and evaporate at least a portion of the combined refrigerant stream and provide an inlet refrigerant flow to the compressor.   
     
     
         7 . A refrigeration system as in  claim 6 , wherein the first and second expansion devices are in thermal communication with the inlet refrigerant stream to the compressor so as to cool the first refrigerant stream and the second refrigerant stream. 
     
     
         8 . A refrigeration system as in  claim 6 , wherein the first expansion device and the second expansion device each comprise a capillary tube. 
     
     
         9 . A refrigeration system as in  claim 6 , wherein the pressure of the first refrigerant stream is substantially equal to the pressure of the second refrigerant stream. 
     
     
         10 . A refrigeration system as in  claim 6 , wherein the zeotropic refrigerant comprises two or more refrigerants selected from a group consisting of an R-134a refrigerant, an R-245fa refrigerant, an R-245ca refrigerant, an R-1234yf refrigerant, an R-600a refrigerant, pentane, butane, and propane. 
     
     
         11 . A refrigeration system, comprising:
 a zeotropic refrigerant for circulation within the refrigeration system;   a compressor for providing a pressurized flow of the refrigerant;   a condenser configured to receive and cool the flow of pressurized refrigerant, the condenser comprising a divider for separating the flow of pressurized refrigerant into a first refrigerant stream and a second refrigerant stream;   a first expansion device in receipt of the first refrigerant stream from the condenser and configured for reducing the pressure of the first refrigerant stream; and   a second expansion device in receipt of the second refrigerant stream from the condenser and configured for reducing the pressure of the second refrigerant stream;   a first evaporator configured to receive and evaporate at least a portion of the first refrigerant stream;   a second evaporator configured to receive and evaporate at least a portion of the second refrigerant stream; and   a junction that combines the first refrigerant stream from the first evaporator with the second refrigerant stream from the second evaporator to provide an inlet refrigerant flow to compressor.   
     
     
         12 . A refrigeration system as in  claim 11 , wherein the first expansion device is in thermal communication with the inlet refrigerant flow to the compressor so as to cool the first refrigerant stream. 
     
     
         13 . A refrigeration system as in  claim 11 , wherein the second expansion device is in thermal communication with the inlet refrigerant stream to the compressor so as to cool the second refrigerant stream. 
     
     
         14 . A refrigeration system as in  claim 11 , wherein
 the second expansion device is in thermal communication with the inlet refrigerant stream to the compressor so as to cool the second refrigerant stream, and   the first expansion device is in thermal communication with the second refrigerant stream from the second expansion device so as to cool the first refrigerant stream.   
     
     
         15 . A refrigeration system as in  claim 11 , wherein the first expansion device and the second expansion device each comprise a capillary tube. 
     
     
         16 . A refrigeration system as in  claim 11 , wherein the pressure of the first refrigerant stream is substantially equal to the pressure of the second refrigerant stream. 
     
     
         17 . A refrigeration system as in  claim 11 , wherein the zeotropic refrigerant comprises two or more refrigerants selected from a group consisting of an R-134a refrigerant, an R-245fa refrigerant, an R-245ca refrigerant, an R-1234yf refrigerant, an R-600a refrigerant, pentane, butane, and propane.