Refrigeration system having dual compressors and either a single evaporator or dual evaporators

Abstract

A refrigeration system having either a single evaporator or dual evaporators where a flash chamber is used with first and second compressor stages. The flash chamber separates the refrigerant mixture from a high-stage capillary into liquid and gas, where the liquid is directed to a low-stage capillary and the gas is directed back to the first compressor. Additionally, the flash chamber may also be used for intercooling the gas going from the second compressor to the first compressor. For dual evaporator systems, this system is especially good for compartments where a first compartment requires a very low evaporator temperature and a second compartment requires a controllable evaporator temperature.

What is claimed is: 
     
         1 . A refrigeration system comprising:
 a first compressor;   a second compressor;   a condenser for receiving a refrigerant gas from at least one of the first compressor and the second compressor and condensing the refrigerant gas to a refrigerant liquid;   a high-stage first capillary for receiving the refrigerant liquid from the condenser;   a flash chamber for receiving a mixture of the refrigerant gas and the refrigerant liquid, wherein the flash chamber separates the refrigerant gas from the refrigerant liquid and provides the refrigerant gas to the second compressor;   a low-stage second capillary for receiving the refrigerant liquid from the flash chamber; and   an evaporator for receiving the refrigerant liquid from the second capillary and evaporating the liquid to form the refrigerant gas that is supplied to the first compressor.   
     
     
         2 . The refrigeration system of  claim 1 , wherein the first compressor supplies the refrigerant gas to the second compressor, the condenser receives the refrigerant gas from the second compressor, and the flash chamber receives the mixture of the refrigerant gas and the refrigerant liquid from the high-stage capillary. 
     
     
         3 . The refrigeration system of  claim 2 , wherein the flash chamber intercools the refrigerant gas supplied from the first compressor to the second compressor. 
     
     
         4 . The refrigeration system of  claim 1 , further comprising a second evaporator for receiving the refrigerant liquid from the high-stage capillary, wherein the condenser receives the refrigerant gas from both the first compressor and the second compressor, and the flash chamber receives the mixture of the refrigerant gas and the refrigerant liquid from the second evaporator. 
     
     
         5 . The refrigeration system of  claim 1 , wherein the first compressor comprises a high-stage compressor. 
     
     
         6 . The refrigeration system of  claim 1 , wherein the second compressor comprises a low-stage compressor. 
     
     
         7 . The refrigeration system of  claim 1 , further comprising a drier located between the condenser and the high-stage capillary, wherein the drier receives the refrigerant liquid from the condenser. 
     
     
         8 . The refrigeration system of  claim 1 , further comprising a first capillary located between the flash chamber and the high-stage capillary and a second capillary located between the low-stage capillary and the evaporator. 
     
     
         9 . A refrigeration system comprising:
 a high-stage compressor;   a low-stage compressor;   a condenser for receiving a refrigerant gas from at least one of the high-stage compressor and the low-stage compressor and condensing the refrigerant gas to a refrigerant liquid;   a first heat exchanger for receiving the refrigerant liquid from the condenser;   a flash chamber for receiving a mixture of the refrigerant gas and the refrigerant liquid from the first heat exchanger, wherein the flash chamber separates the refrigerant gas from the refrigerant liquid and provides the refrigerant gas to the low-stage compressor;   a second heat exchanger for receiving the refrigerant liquid from the flash chamber; and   an evaporator for receiving the refrigerant liquid from the second heat exchanger and evaporating the refrigerant liquid to form the refrigerant gas that is supplied to the high-stage compressor.   
     
     
         10 . The refrigeration system of  claim 9 , wherein the high-stage compressor supplies the refrigerant gas to the low-stage compressor, the condenser receives the refrigerant gas from the low-stage compressor, and the flash chamber receives the mixture of the refrigerant gas and the refrigerant liquid from the first heat exchanger. 
     
     
         11 . The refrigeration system of  claim 10 , wherein the flash chamber intercools the refrigerant gas supplied from the low-stage compressor to the high-stage compressor. 
     
     
         12 . The refrigeration system of  claim 9 , further comprising a second evaporator for receiving the refrigerant liquid from the first heat exchanger, wherein the condenser receives the refrigerant gas from both the high-stage compressor and the low-stage compressor and the flash chamber receives the mixture of the refrigerant gas and the refrigerant liquid from the second evaporator. 
     
     
         13 . The refrigeration system of  claim 9 , further comprising a drier located between the condenser and the first heat exchanger, wherein the drier receives the refrigerant liquid from the condenser. 
     
     
         14 . A refrigeration system comprising:
 a first compressor;   a second compressor;   a condenser for receiving refrigerant gas from at least one of the first compressor and the second compressor and condensing the refrigerant gas to a refrigerant liquid;   a high-stage first capillary for receiving the refrigerant liquid from the condenser;   a first evaporator for receiving the refrigerant liquid from the high-stage capillary;   a flash chamber for receiving a mixture of the refrigerant gas and the refrigerant liquid from the first evaporator, wherein the flash chamber separates the refrigerant gas from the refrigerant liquid and provides the refrigerant gas to the second compressor;   a low-stage second capillary for receiving the refrigerant liquid from the flash chamber; and   a second evaporator for receiving the refrigerant liquid from the low-stage capillary and evaporating the refrigerant liquid to form the refrigerant gas that is supplied to the first compressor.   
     
     
         15 . The refrigeration system of  claim 14 , wherein the condenser receives the refrigerant gas from both the first compressor and the second compressor and condenses the refrigerant gas to the refrigerant liquid. 
     
     
         16 . The refrigeration system of  claim 14 , wherein the first compressor comprises a mid-stage compressor. 
     
     
         17 . The refrigeration system of  claim 14 , wherein the second compressor comprises a low-stage compressor. 
     
     
         18 . The refrigeration system of  claim 14 , further comprising a drier located between the high-stage first capillary and the condenser, wherein the drier receives the refrigerant liquid from the condenser. 
     
     
         19 . The refrigeration system of  claim 14 , further comprising a third capillary located between the high-stage first capillary and the first evaporator, wherein the third capillary receives the refrigerant liquid from the high-stage first capillary. 
     
     
         20 . The refrigeration system of  claim 14 , further comprising a fourth capillary located between the low-stage second capillary and the second evaporator, wherein the fourth capillary receives the refrigerant liquid from the low-stage second capillary.