System and method of mechanical compression refrigeration based on two-phase ejector

Abstract

The present invention discloses the use of two-phase ejector(s) activated by pressurized refrigerant, said two-phase ejector(s) are strategically located in the cycle of the refrigeration system so as to provide part of the compression effect required for the refrigeration load, thereby relieving the conventional mechanical compressor from part of its duty, hence increasing the overall cycle efficiency of the refrigeration system.

1 . A refrigeration system, comprising:
 a metering device for controlling flow of a refrigerant,   an evaporator,   means for supplying the refrigerant from the metering device into the evaporator wherein the refrigerant evaporates into vapor,   a two-phase ejector comprising means defining a liquid chamber having a liquid inlet, means defining a vapor chamber having a vapor inlet, and an outlet discharging a two-phase vapor-liquid refrigerant stream,   means for supplying the vapor from the evaporator into the vapor inlet of the two-phase ejector,   a flash tank compound separator,   means for supplying the refrigerant from the two-phase ejector into the flash tank compound separator wherein the refrigerant separates into two phases,   a compressor,   means for supplying the refrigerant from the flash tank compound separator into the compressor wherein the refrigerant compresses,   a condenser,   means for supplying the refrigerant from the compressor into the condenser wherein the refrigerant condenses,   a receiver,   means for supplying the refrigerant from the condenser to the receiver,   means for supplying the refrigerant from the receiver to the liquid inlet of the two-phase ejector,   means for supplying the refrigerant from the receiver to the metering device and then into the evaporator to start another cycle through the system,   means for supplying the refrigerant from the flash tank compound separator into a pump where the pressure of the refrigerant is regulated,   means for supplying the refrigerant from the pump into the receiver,   wherein the two-phase ejector then draws vapor from the evaporator lifting its pressure to an intermediate level when activated a mixture of condensate from the condenser and subcooled refrigerant fed by the pump, and   wherein the pressure of the liquid inlet of the two-phase ejector is controlled by the pump in accordance with the operating conditions of the compressor.   
     
     
         2 . A refrigeration system, comprising:
 a metering device for controlling flow of a refrigerant,   an evaporator,   means for supplying the refrigerant from the metering device into the evaporator wherein the refrigerant evaporates into vapor,   a two-phase ejector comprising means defining a liquid chamber having a liquid inlet, means defining a vapor chamber having a vapor inlet, and an outlet discharging a two-phase vapor-liquid refrigerant stream,   means for supplying the vapor from the evaporator into the vapor inlet of the two-phase ejector,   a flash tank compound separator,   means for supplying the refrigerant from the two-phase ejector into the flash tank compound separator wherein the refrigerant separates into two phases,   a compressor,   means for supplying the refrigerant from the flash tank compound separator into the compressor wherein the refrigerant compresses,   a condenser,   means for supplying the refrigerant from the compressor into the condenser wherein the refrigerant condenses,   a heat exchanger,   means for supplying the refrigerant from the condenser to the heat exchanger,   means for supplying the refrigerant from the heat exchanger to the liquid inlet of the two-phase ejector,   means for supplying the refrigerant from the heat exchanger to the metering device where the pressure and temperature of the refrigerant decrease and then into the evaporator to start another cycle through the system,   wherein the heat exchanger simultaneously increases condensate subcooling at the inlet of metering device and decreases motive liquid subcooling at the liquid inlet of two-phase ejector,   means for supplying the refrigerant from the flash tank compound separator into a pump where the pressure of the refrigerant is regulated,   means for supplying the refrigerant from the pump into the heat exchanger,   wherein the two-phase ejector then draws vapor from the evaporator lifting its pressure to an intermediate level when activated a mixture of condensate from the condenser and subcooled refrigerant fed by the pump, and   wherein the pressure of the liquid inlet of the two-phase ejector is controlled by the pump in accordance with the operating conditions of the compressor.   
     
     
         3 . A refrigeration system, comprising:
 a metering device for controlling flow of a refrigerant,   an evaporator,   means for supplying the refrigerant from the metering device into the evaporator wherein the refrigerant evaporates into vapor,   a two-phase ejector comprising means defining a liquid chamber having a liquid inlet, means defining a vapor chamber having a vapor inlet, and an outlet discharging a two-phase vapor-liquid refrigerant stream,   means for supplying the vapor from the evaporator into the vapor inlet of the two-phase ejector,   a flash tank compound separator,   means for supplying the refrigerant from the two-phase ejector into the flash tank compound separator wherein the refrigerant separates into two phases,   a compressor,   means for supplying the refrigerant from the flash tank compound separator into the compressor wherein the refrigerant compresses,   a condenser,   means for supplying the refrigerant from the compressor into the condenser wherein the refrigerant condenses,   a mixing junction,   means for supplying the refrigerant from the condenser to the mixing junction,   means for supplying the refrigerant from the mixing junction to the liquid inlet of the two-phase ejector,   means for supplying the refrigerant from the flash tank compound separator to the metering device where the pressure and temperature of the refrigerant decrease and then into the evaporator to start another cycle through the system,   means for supplying the refrigerant from the flash tank compound separator into a pump,   means for supplying the refrigerant from the pump into the mixing junction,   wherein the two-phase ejector then draws vapor from the evaporator lifting its pressure to an intermediate level when activated a mixture of condensate from the condenser and subcooled refrigerant fed by the pump, and   wherein the pressure of the liquid inlet of the two-phase ejector is controlled by the pump in accordance with the operating conditions of the compressor.   
     
     
         4 . A refrigeration system, comprising:
 a metering device for controlling flow of a refrigerant,   an evaporator,   means for supplying the refrigerant from the metering device into the evaporator wherein the refrigerant evaporates into vapor,   a two-phase ejector comprising means defining a liquid chamber having a liquid inlet, means defining a vapor chamber having a vapor inlet, and an outlet discharging a two-phase vapor-liquid refrigerant stream,   means for supplying the vapor from the evaporator into the vapor inlet of the two-phase ejector,   a flash tank compound separator,   means for supplying the refrigerant from the two-phase ejector into the flash tank compound separator wherein the refrigerant separates into two phases,   a compressor,   means for supplying the refrigerant from the flash tank compound separator into the compressor wherein the refrigerant compresses,   a condenser,   means for supplying the refrigerant from the compressor into the condenser wherein the refrigerant condenses,   a heat exchanger,   means for supplying the refrigerant from the condenser to the heat exchanger,   means for supplying the refrigerant from the compressor to the heat exchanger,   a first valve for controlling the supply of the refrigerant from the compressor to the condenser and a second valve for controlling the supply of the refrigerant from the compressor to the heat exchanger;   wherein by controlling and adjusting the first and/or the second valve, the heat exchanger transfers part of condensation heat of the compressed vapor to subcooled compressed liquid circulated by pump to the two-phase ejector,   means for supplying the refrigerant from the heat exchanger to the liquid inlet of the two-phase ejector,   means for supplying the refrigerant from the heat exchanger to the metering device where the pressure and temperature of the refrigerant decrease and then into the evaporator to start another cycle through the system,   wherein the heat exchanger simultaneously increases condensate subcooling at the inlet of metering device and decreases motive liquid subcooling at the liquid inlet of two-phase ejector,   means for supplying the refrigerant from the flash tank compound separator into a pump where the pressure of the refrigerant is regulated,   means for supplying the refrigerant from the pump into the heat exchanger,   wherein the two-phase ejector then draws vapor from the evaporator lifting its pressure to an intermediate level when activated a mixture of condensate from the condenser and subcooled refrigerant fed by the pump, and   wherein the pressure of the liquid inlet of the two-phase ejector is controlled by the pump in accordance with the operating conditions of the compressor.   
     
     
         5 . A refrigeration system, comprising:
 a metering device for controlling flow of a refrigerant,   an evaporator,   means for supplying the refrigerant from the metering device into the evaporator wherein the refrigerant evaporates into vapor,   a two-phase ejector comprising means defining a liquid chamber having a liquid inlet, means defining a vapor chamber having a vapor inlet, and an outlet discharging a two-phase vapor-liquid refrigerant stream,   means for supplying the vapor from the evaporator into the vapor inlet of the two-phase ejector,   a flash tank compound separator,   means for supplying the refrigerant from the two-phase ejector into the flash tank compound separator wherein the refrigerant separates into two phases,   a compressor,   means for supplying the refrigerant from the flash tank compound separator into the compressor wherein the refrigerant compresses,   a condenser,   means for supplying the refrigerant from the compressor into the condenser wherein the refrigerant condenses,   a direct contact condenser,   means for supplying the refrigerant from the condenser to the direct contact condenser,   means for supplying the refrigerant from the compressor to the direct contact condenser,   a first valve for controlling the supply of the refrigerant from the compressor to the condenser and a second valve for controlling the supply of the refrigerant from the compressor to the direct contact condenser;   wherein by controlling and adjusting the first and/or the second valve, the direct contact condenser transfers part of condensation heat of the compressed vapor to subcooled compressed liquid circulated by pump to the two-phase ejector,   means for supplying the refrigerant from the direct contact condenser to the liquid inlet of the two-phase ejector,   means for supplying the refrigerant from the flash tank compound separator to the metering device where the pressure and temperature of the refrigerant decrease and then into the evaporator to start another cycle through the system,   means for supplying the refrigerant from the flash tank compound separator into a pump where the pressure of the refrigerant is regulated,   means for supplying the refrigerant from the pump into the direct contact condenser,   wherein the two-phase ejector then draws vapor from the evaporator lifting its pressure to an intermediate level when activated a mixture of condensate from the condenser and subcooled refrigerant fed by the pump, and   wherein the pressure of the liquid inlet of the two-phase ejector is controlled by the pump in accordance with the operating conditions of the compressor.   
     
     
         6 . The refrigeration system according to any one of  claims 1  to  5 , wherein the metering device is a thermal expansion valve, or a capillary tube. 
     
     
         7 . The refrigeration system according to any one of  claims 1  to  6 , wherein the refrigerant is carbon dioxide.