High efficiency refrigeration system and cycle

A refrigeration system using a refrigerant cycled therethrough, said refrigeration system comprising:

• a two-stage vapor compressor comprising a first compression stage and a second compression stage, said second compression stage operating at a higher pressure than the first compression stage;
• a first high-pressure ejector in operative communication with the second compression stage of the vapor compressor, wherein the first ejector boosts the pressure of vapor-phase refrigerant received from the vapor compressor using a pressurized sub-cooled liquid mixed with said vapor-phase refrigerant, and further wherein said first ejector discharges a vapor stream having an elevated pressure that is greater than the pressure of either the input vapor-phase refrigerant received from the vapor compressor or the pressurized sub-cooled liquid;
• a condenser for converting the vapor stream discharged from the first ejector into a liquid-phase refrigerant;
• a heat exchanger for converting the liquid-phase refrigerant into a sub-cooled liquid-phase refrigerant;
• a centrifugal pump for pressurizing a first portion of the sub-cooled liquid-phase refrigerant discharged from the heat exchanger, wherein said pressurized sub-cooled liquid is provided to the first ejector for mixing with vapor-phase refrigerant therein;
• a second low-pressure ejector in operative communication with the first compression stage of the vapor compressor, wherein the second ejector boosts the pressure of vapor-phase refrigerant using a second portion of the sub-cooled liquid-phase refrigerant discharged from the heat exchanger mixed with said vapor-phase refrigerant, and further wherein the second ejector discharges a mixed refrigerant;
• a primary evaporator in operative communication with a discharge outlet of the second ejector for evaporating the mixed refrigerant discharged therefrom into a vapor-phase refrigerant;
• and
• a secondary evaporator that evaporates a portion of the second portion of the sub-cooled liquid-phase refrigerant discharged from the heat exchanger into a vapor-phase refrigerant that is provided to an input of the second ejector for mixing with the remainder of said second portion of the sub-cooled liquid-phase refrigerant therein;
• wherein the vapor-phase refrigerant discharged from the primary evaporator is provided to the first compression stage of the vapor compressor.

A refrigeration cycling method comprising:

• providing a mechanical vapor compressor having a low-pressure side and a high-pressure side;
• providing a first ejector in operative communication with the high-pressure side of the vapor compressor;
• mixing vapor-phase refrigerant discharged from the vapor compressor with a pressurized sub-cooled liquid in the first ejector so as to boost the pressure of the vapor-phase refrigerant to an elevated pressure that is greater than the pressure of either the input vapor-phase refrigerant received from the vapor compressor or the pressurized sub-cooled liquid;
• converting the vapor stream discharged from the first ejector into a sub-cooled liquid-phase refrigerant;
• providing a second ejector in operative communication with the low-pressure side of the vapor compressor;
• mixing vapor-phase refrigerant with the sub-cooled liquid-phase refrigerant in the second ejector to provide a mixed vapor-phase refrigerant having an elevated pressure;
• evaporating the mixed-phase refrigerant into a vapor-phase refrigerant that is provided through the heat exchanger to the mechanical vapor compressor;
• superheating the vapor-phase refrigerant;
• and
• providing the superheated vapor-phase refrigerant to the low-pressure side of the vapor compressor.