# US 2023/0056774 A1 · Sub-cooling a refrigerant in an air conditioning system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0056774 A1 - Document ID: US20230056774A1 - Status: Published application - Kind: A1 - Application number: 17/819,553 - Filed: 2022-08-12 - Published: 2023-02-23 - Earliest claimed: 2021-08-17 - Assignees: SolariSine Innovations, LLC - Applicants: SolariSine Innovations, LLC - Inventors: Kevin Spaeth - Web page: https://patentgrep.com/patent/US20230056774A1 ## CPC - F25B 40/02: Subcoolers - F25B 39/04: Condensers - F25B 41/20: Disposition of valves, e.g. of on-off valves or flow control valves (expansion valves F25B41/31) - F25B 49/02: for compression type machines, plants or systems - F25B 49/027: {Condenser control arrangements} - F25B 2339/044: Condensers with an integrated receiver - F25B 2400/16: Receivers - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract An air conditioning system includes a compressor configured to compress a refrigerant in a vapor phase; a condenser that receives the compressed vapor phase and is configured to change the compressed vapor phase to a liquid phase; an expansion device that receives the liquid phase of the refrigerant and is configured to expand the liquid phase of the refrigerant from a first pressure to a second pressure lower than the first pressure; an evaporator that receives the liquid phase of the refrigerant at the second pressure and is configured to transfer heat from an airflow circulated through the evaporator to the liquid phase of the refrigerant and change water vapor in the airflow into a liquid condensate; and a heat exchanger that receives at least a portion of the liquid phase of the refrigerant and is immersed in the liquid condensate to sub-cool the liquid phase of the refrigerant. ## Claims ### Claim 1 An air conditioning system, comprising: at least one compressor configured to compress a refrigerant in a vapor phase; a condenser fluidly coupled to the at least one compressor to receive the compressed vapor phase of the refrigerant and configured to change the compressed vapor phase of the refrigerant to a liquid phase of the refrigerant by transferring heat from the compressed vapor phase of the refrigerant to a cooling fluid; an expansion device fluidly coupled to the condenser with a liquid line to receive the liquid phase of the refrigerant and configured to expand the liquid phase of the refrigerant from a first pressure to a second pressure lower than the first pressure; an evaporator fluidly coupled to the expansion device to receive the liquid phase of the refrigerant at the second pressure and configured to transfer heat from an airflow circulated through the evaporator to the liquid phase of the refrigerant at the second pressure to change at least a portion of the liquid phase of the refrigerant at the second pressure to the vapor phase of the refrigerant and change at least a portion of water vapor in the airflow into a liquid condensate; and a heat exchanger fluidly coupled to the liquid line to receive at least a portion of the liquid phase of the refrigerant from the condenser upstream of the expansion device, the heat exchanger at least partially immersed in the liquid condensate captured in a condensate receiver from the evaporator and configured to sub-cool the portion of the liquid phase of the refrigerant based on a transfer of heat from the portion of the liquid phase of the refrigerant to the liquid condensate. ### Claim 2 (depends on 1) The system of claim 1, wherein the heat exchanger is integral with and part of the liquid line. ### Claim 3 (depends on 2) The system of claim 2, wherein the heat exchanger comprises a plurality of loops that are immersed in the liquid condensate captured in the condensate receiver from the evaporator. ### Claim 4 (depends on 3) The system of claim 3, wherein the evaporator comprises a cooling coil that comprises a plurality of tubing rows, and the plurality of loops comprise a subset of the plurality of tubing rows. ### Claim 5 (depends on 1) The system of claim 1, wherein the heat exchanger comprises a shell-and-tube heat exchanger at least partially immersed in the liquid condensate captured in the condensate receiver from the evaporator. ### Claim 6 (depends on 5) The system of claim 5, wherein the shell-and-tube heat exchanger comprises: a condensate inlet fluidly coupled to the liquid condensate in the condensate receiver; a condensate outlet fluidly coupled to an outlet of the condensate receiver; a liquid refrigerant inlet fluidly coupled to the condenser through the liquid line; and a liquid refrigerant outlet fluidly coupled to the expansion device through the liquid line. ### Claim 7 (depends on 5) The system of claim 5, further comprising a pump positioned to circulate liquid condensate to the shell-and-tube heat exchanger and through the condensate inlet. ### Claim 8 (depends on 5) The system of claim 5, wherein the shell-and-tube heat exchanger comprises a heat exchange surface configured to transfer heat from the liquid phase of the refrigerant to the liquid condensate. ### Claim 9 (depends on 1) The system of claim 1, wherein the heat exchanger comprises a liquid refrigerant inlet directly fluidly coupled to an outlet the condenser and a liquid refrigerant outlet directly coupled to an inlet of the expansion device. ### Claim 10 (depends on 9) The system of claim 9, further comprising a valve positioned in the liquid line between the liquid refrigerant inlet and the liquid refrigerant outlet. ### Claim 11 (depends on 10) The system of claim 10, wherein the valve comprises a solenoid valve. ### Claim 12 (depends on 1) The system of claim 1, wherein the refrigerant comprises a non-natural refrigerant. ### Claim 13 (depends on 12) The system of claim 12, wherein the non-natural refrigerant comprises at least one hydrofluorocarbon (HFC) refrigerant. ### Claim 14 (depends on 13) The system of claim 13, wherein the at least one HFC refrigerant comprises a blend of two or more HFC refrigerants. ### Claim 15 (depends on 13) The system of claim 13, wherein the at least one HFC refrigerant comprises at least one of HFC-134a, HFC-404a, HFC-410a, or HFC-407c. ### Claim 16 (depends on 1) The system of claim 1, wherein the cooling fluid comprises a cooling airflow circulated through the condenser by at least one fan to transfer heat from the vapor phase of the refrigerant to the cooling airflow. ### Claim 17 (depends on 1) The system of claim 1, wherein the heat exchanger comprises a liquid-to-liquid heat exchanger, the system further comprising a liquid-to-air heat exchanger positioned to receive at least a portion of the airflow that exits the evaporator and the portion of the liquid phase of the refrigerant from the condenser upstream of the liquid-to-liquid heat exchanger, the liquid-to-air heat exchanger configured to transfer heat from the portion of the liquid phase of the refrigerant to the portion of the airflow that exits the evaporator. ### Claim 18 (depends on 17) The system of claim 17, wherein the liquid-to-air heat exchanger comprises a first liquid-to-air heat exchanger, the system further comprising a second liquid-to-air heat exchanger positioned to receive at least a portion of the airflow that enters the evaporator and the portion of the liquid phase of the refrigerant from the first liquid-to-air heat exchanger upstream of the liquid-to-liquid heat exchanger, the second liquid-to-air heat exchanger configured to transfer additional heat from the portion of the liquid phase of the refrigerant to the portion of the airflow that enters the evaporator. ### Claim 19 (depends on 1) The system of claim 1, wherein the heat exchanger comprises a liquid-to-liquid heat exchanger, the system further comprising a liquid-to-air heat exchanger positioned to receive at least a portion of the airflow that enters the evaporator and the portion of the liquid phase of the refrigerant from the condenser upstream of the liquid-to-liquid heat exchanger, the liquid-to-air heat exchanger configured to transfer heat from the portion of the liquid phase of the refrigerant to the portion of the airflow that enters the evaporator. ### Claim 20 A method for sub-cooling a refrigerant in an air conditioning system, comprising: compressing a refrigerant in a vapor phase with at least one compressor; circulating the compressed vapor phase of the refrigerant from the at least one compressor to a condenser; changing the compressed vapor phase of the refrigerant to a liquid phase of the refrigerant in the condenser by transferring heat from the compressed vapor phase of the refrigerant to a cooling fluid; circulating at least a portion of the liquid phase of the refrigerant from the condenser through a liquid line to a heat exchanger that is at least partially immersed in a liquid condensate captured in a condensate receiver of an evaporator; sub-cooling the portion of the liquid phase of the refrigerant in the heat exchanger; circulating the sub-cooled portion of the liquid phase to an expansion device through the liquid line; expanding the liquid phase of the refrigerant from a first pressure to a second pressure lower than the first pressure in the expansion device; circulating the liquid phase of the refrigerant at the second pressure to the evaporator; and transferring heat from an airflow circulated through the evaporator to the liquid phase of the refrigerant at the second pressure to change at least a portion of the liquid phase of the refrigerant at the second pressure to the vapor phase of the refrigerant and change at least a portion of water vapor in the airflow into the liquid condensate. ### Claim 21 (depends on 20) The method of claim 20, wherein the heat exchanger is integral with and part of the liquid line. ### Claim 22 (depends on 21) The method of claim 21, further comprising circulating the portion of the liquid phase through a plurality of loops of the heat exchanger that are immersed in the liquid condensate captured in the condensate receiver from the evaporator. ### Claim 23 (depends on 21) The method of claim 21, wherein the evaporator comprises a cooling coil that comprises a plurality of tubing rows, and the plurality of loops comprise a subset of the plurality of tubing rows. ### Claim 24 (depends on 20) The method of claim 20, further comprising circulating the portion of the liquid phase through a shell-and-tube heat exchanger at least partially immersed in the liquid condensate captured in the condensate receiver from the evaporator. ### Claim 25 (depends on 24) The method of claim 24, further comprising: circulating liquid condensate from the condensate receiver through the shell-and-tube heat exchanger; transferring heat from the portion of the liquid phase of the refrigerant to the liquid condensate in the shell-and-tube heat exchanger to sub-cool the portion of the liquid phase of the refrigerant and heat the liquid condensate; circulating the sub-cooled portion of the liquid phase of the refrigerant through the liquid line to the expansion device from the shell-and-tube heat exchanger; and circulating the heated liquid condensate to a drain of the condensate receiver. ### Claim 26 (depends on 25) The method of claim 25, wherein circulating liquid condensate from the condensate receiver through the shell-and-tube heat exchanger comprises circulating liquid condensate from the condensate receiver through the shell-and-tube heat exchanger with a pump in or adjacent the condensate receiver. ### Claim 27 (depends on 20) The method of claim 20, further comprising circulating another portion of the liquid phase of the refrigerant through a valve positioned in the liquid line between the condenser and the expansion valve. ### Claim 28 (depends on 27) The method of claim 27, wherein the valve comprises a solenoid valve. ### Claim 29 (depends on 20) The method of claim 20, wherein the refrigerant comprises a non-natural refrigerant. ### Claim 30 (depends on 29) The method of claim 29, wherein the non-natural refrigerant comprises at least one hydrofluorocarbon (HFC) refrigerant. ### Claim 31 (depends on 30) The method of claim 30, wherein the at least one HFC refrigerant comprises a blend of two or more HFC refrigerants. ### Claim 32 (depends on 30) The method of claim 30, wherein the at least one HFC refrigerant comprises at least one of HFC-134a, HFC-404a, HFC-410a, or HFC-407c. ### Claim 33 (depends on 20) The method of claim 20, wherein the cooling fluid comprises a cooling airflow, the method further comprising circulating the cooling airflow through the condenser by at least one fan to transfer heat from the vapor phase of the refrigerant to the cooling airflow. ### Claim 34 (depends on 20) The method of claim 20, wherein the heat exchanger comprises a liquid-to-liquid heat exchanger, the method further comprising: circulating the portion of the liquid phase of the refrigerant from the condenser to a liquid-to-air heat exchanger prior to circulating the portion of the liquid phase of the refrigerant to the liquid-to-liquid heat exchanger; circulating at least a portion of the airflow that exits the evaporator through the liquid-to-air heat exchanger; transferring heat from the portion of the liquid phase of the refrigerant to the portion of the airflow that exits the evaporator in the liquid-to-air heat exchanger; and circulating the cooled portion of the liquid phase of the refrigerant from the liquid-to-air heat exchanger to the liquid-to-liquid heat exchanger. ### Claim 35 (depends on 34) The method of claim 34, wherein the liquid-to-air heat exchanger comprises a first liquid-to-air heat exchanger, the method further comprising: circulating the cooled portion of the liquid phase of the refrigerant from the first liquid-to-air heat exchanger to a second liquid-to-air heat exchanger prior to circulating the portion of the liquid phase of the refrigerant to the liquid-to-liquid heat exchanger; circulating at least a portion of the airflow that enters the evaporator through the second liquid-to-air heat exchanger; transferring heat from the cooled portion of the liquid phase of the refrigerant to the portion of the airflow that enters the evaporator in the second liquid-to-air heat exchanger; and circulating the further cooled portion of the liquid phase of the refrigerant from the second liquid-to-air heat exchanger to the liquid-to-liquid heat exchanger. ### Claim 36 (depends on 20) The method of claim 20, wherein the heat exchanger comprises a liquid-to-liquid heat exchanger, the method further comprising: circulating at least a portion of the liquid phase of the refrigerant from the condenser to a liquid-to-air heat exchanger prior to circulating the portion of the liquid phase of the refrigerant to the liquid-to-liquid heat exchanger; circulating at least a portion of the airflow that enters the evaporator through the liquid-to-air heat exchanger; transferring heat from the portion of the liquid phase of the refrigerant to the portion of the airflow that enters the evaporator in the liquid-to-air heat exchanger; and circulating the cooled portion of the liquid phase of the refrigerant from the liquid-to-air heat exchanger to the liquid-to-liquid heat exchanger.