Two Stage Condensing and Metering Refrigeration System

Abstract

A refrigeration system is described having a main refrigeration system containing a main refrigerant and a separate, secondary refrigeration system containing a secondary refrigerant. In flow sequence in the main refrigerating system, an outlet of a main compressor is flow connected to a main condenser; the main condenser is flow connected to a pre-metering device; the pre-metering device is flow connected to an inlet to a cooling path within a secondary evaporator within the secondary refrigeration system; an outlet of the cooling path is flow connected to a main metering device; and the main metering device is flow connected to a main evaporator. The main evaporator is flow connected back to an inlet of the main compressor forming the complete circuit main refrigeration system. The secondary refrigeration system provides a separate mechanical refrigeration circuit with a secondary refrigerant but having the cooling path in the secondary evaporator such that the secondary evaporator cools the main refrigerant in the cooling path by vaporizing of the secondary refrigerant in the secondary evaporator.

The invention claimed is: 
     
         1 . A refrigeration system, comprising:
 a main refrigeration system including a main refrigerant, a main compressor, a main condenser, a pre-metering device, a main metering device, a main evaporator, and a secondary refrigeration system;   wherein an outlet of the main compressor is flow connected to the main condenser, the main condenser is flow connected to the pre-metering device, the pre-metering device is flow connected to the secondary refrigeration system, the secondary refrigeration system is flow connected to the main metering device, the main metering device is flow connected to the main evaporator, and the main evaporator is flow connected back to an inlet of the main compressor;   wherein, in flow sequence, the main refrigerant within the main refrigeration system is compressed by the main compressor, condensed by the main condenser, dropped in pressure by the pre-metering device, cooled by the secondary refrigeration system, dropped in pressure by the main metering device, vaporized by the main evaporator and returned to the main compressor.   
     
     
         2 . The system according to  claim 1 , wherein the secondary refrigeration system includes
 a secondary refrigerant, a secondary compressor, a secondary condenser, a secondary metering device, a secondary evaporator having a cooling path and evaporator path therein in heat transfer communication, the secondary compressor is flow connected to the secondary condenser, the secondary condenser is flow connected to the secondary metering device, the secondary metering device is flow connected to the evaporator path within the secondary evaporator, the evaporator path is flow connected to the secondary compressor;   wherein the pre-metering device of the main refrigeration system is flow connected to an inlet of the cooling path in the secondary evaporator of the secondary refrigeration system, wherein an outlet of the cooling path is flow connected to the main metering device of the main refrigeration system;   wherein, in flow sequence, the secondary refrigerant in the secondary refrigeration system is compressed by the secondary compressor, condensed by the secondary condenser, dropped in pressure by the secondary metering device, and vaporized by the evaporator path by heat transfer from the cooling path carrying the main refrigerant, and returned to the secondary compressor.   
     
     
         3 . A refrigeration system, comprising:
 a main refrigeration system including a main refrigerant, a main compressor, a main condenser, a pre-metering device, a main metering device, a main evaporator, and a secondary refrigeration system;   wherein an outlet of the main compressor is flow connected to the main condenser, the main condenser is flow connected to the pre-metering device, the pre-metering device is flow connected to the secondary refrigeration system, the secondary refrigeration system is flow connected to the main metering device, the main metering device is flow connected to the main evaporator, and the main evaporator is flow connected to an inlet of the main compressor;   wherein the secondary refrigeration system includes a secondary refrigerant, a secondary compressor, a secondary condenser, a secondary metering device, a secondary evaporator having cooling path and evaporator path in heat transfer communication, the secondary compressor is flow connected to the secondary condenser, the secondary condenser is flow connected to the secondary metering device, the secondary metering device is flow connected to the evaporator path within the secondary evaporator, the evaporator path is flow connected to the secondary compressor;   wherein the pre-metering device of the main refrigeration system is flow connected to an inlet of the cooling path in the secondary evaporator of the secondary refrigeration system, wherein an outlet of the cooling path is flow connected to the main metering device of the main refrigeration system;   wherein, in flow sequence, the main refrigerant within the main refrigeration system is compressed by the main compressor, condensed by the main condenser, dropped in pressure by the pre-metering device, cooled by the cooling path of the secondary evaporator of the secondary refrigeration system by heat transfer between the cooling path and the evaporator path in the secondary evaporator, dropped in pressure by the main metering device, vaporized by the main evaporator and returned to the main compressor;   wherein, in flow sequence, the secondary refrigerant in the secondary refrigeration system is compressed by the secondary compressor, condensed by the secondary condenser, dropped in pressure by the secondary metering device, and vaporized by the evaporator path by heat transfer from the cooling path carrying the main refrigerant, and returned to the secondary compressor.   
     
     
         4 . A method of refrigerating a media, comprising the steps of:
 In flow sequence, providing a main refrigerant in a gaseous state;   Compressing the main refrigerant to create a high pressure gaseous main refrigerant;   Condensing the high pressure gaseous main refrigerant into a high pressure liquid main refrigerant;   Dropping the pressure of the high pressure liquid main refrigerant to create a reduced pressure main refrigerant having a substantial liquid phase;   Cooling the reduced pressure main refrigerant;   Dropping the pressure of the reduced pressure cooled main refrigerant to create a further reduced pressure main refrigerant;   Vaporizing the further reduced pressure main refrigerant by transferring heat from the media to the further pressure reduced main refrigerant.   
     
     
         5 . The method according to  claim 4 , wherein the step of cooling the reduced pressure main refrigerant comprises the steps of:
 using a secondary refrigerant, vaporizing the secondary refrigerant by absorbing heat from the reduced pressure main refrigerant.   
     
     
         6 . The method according to  claim 5 , wherein the step of using a secondary refrigerant is further defined by the steps of:
 in flow sequence, providing the secondary refrigerant in a gaseous state;   compressing the secondary refrigerant to create a high pressure gaseous secondary refrigerant;   condensing the high pressure gaseous secondary refrigerant into a high pressure liquid secondary refrigerant;   dropping the pressure of the high pressure liquid secondary refrigerant to create a reduced pressure secondary refrigerant having a substantial liquid phase; and   vaporizing the reduced pressure secondary refrigerant by transferring heat from the reduced pressure main refrigerant.