Thermal energy storage and cooling system with isolated evaporator coil

Abstract

Disclosed is a method and device for a refrigerant-based thermal energy storage and cooling system with an isolated evaporator coil in a secondary cooling loop. The disclosed embodiments provide a refrigerant-based ice storage system with increased versatility, reliability, lower cost components, reduced power consumption and ease of installation.

1 . A refrigerant-based thermal energy storage and cooling system comprising:
 a refrigerant loop containing a refrigerant comprising:
 a condensing unit, said condensing unit comprising a compressor and a condenser; 
 an expansion device connected downstream of said condensing unit; and, 
 a primary heat exchanger connected between said expansion device and said condensing unit that is located within a tank filled with a fluid capable of a phase change between liquid and solid, said primary heat exchanger that performs as an evaporator and facilitates heat transfer from said refrigerant from said condenser to cool said fluid and to freeze at least a portion of said fluid within said tank in a first time period, and said primary heat exchanger that performs as a condenser and facilitates heat transfer from said fluid to cool said refrigerant in a second time period; 
   a cooling loop containing a heat transfer medium comprising:
 a load heat exchanger; 
 a first isolating heat exchanger that facilitates thermal contact between said refrigerant condensed within said primary heat exchanger and said heat transfer medium, said heat transfer medium that transfers cooling from said first isolating heat exchanger to said load heat exchanger in said second time period; and, 
 a second isolating heat exchanger that facilitates thermal contact between said refrigerant condensed within said condensing unit and said heat transfer medium, said heat transfer medium that transfers cooling from said second isolating heat exchanger to said load heat exchanger in a third time period. 
   
   
   
       2 . The system of  claim 1  further comprising:
 a refrigerant management vessel in fluid communication with, and located between said condensing unit and said primary heat exchanger comprising:
 an inlet connection that receives said refrigerant from said condensing unit and said primary heat exchanger; 
 a first outlet connection that supplies said refrigerant to said primary heat exchanger; and, 
 a second outlet connection that supplies said refrigerant to said condensing unit. 
   
   
   
       3 . The system of  claim 1  wherein said expansion device is chosen from the group consisting of a thermal expansion valve, an electronic expansion valve and a mixed-phase regulator. 
   
   
       4 . The system of  claim 1  wherein said fluid is a eutectic material. 
   
   
       5 . The system of  claim 1  wherein said fluid is water. 
   
   
       6 . The system of  claim 1  wherein said load heat exchanger is at least one mini-split evaporator. 
   
   
       7 . The system of  claim 1  wherein said second time period is concurrent with said third time period. 
   
   
       8 . The system of  claim 1  wherein said heat transfer medium is a coolant. 
   
   
       9 . The system of  claim 1  wherein said heat transfer medium is a refrigerant. 
   
   
       10 . The system of  claim 1  further comprising:
 a subcooling heat exchanger that facilitates thermal contact between said heat transfer medium upstream of said load heat exchanger and said refrigerant exiting said condenser to subcool said refrigerant.   
   
   
       11 . The system of  claim 1  further comprising:
 a bypass refrigeration loop that transfers cooling from said refrigerant leaving said expansion device to said load heat exchanger and returns warm expanded said refrigerant to said compressor.   
   
   
       12 . A refrigerant-based thermal energy storage and cooling system comprising:
 a refrigerant loop containing a refrigerant comprising:
 a condensing unit, said condensing unit comprising a compressor and a condenser; 
 an expansion device connected downstream of said condensing unit; and, 
 a primary heat exchanger connected between said expansion device and said condensing unit that is located within a tank filled with a fluid capable of a phase change between liquid and solid, said primary heat exchanger that performs as an evaporator and facilitates heat transfer from said refrigerant from said condenser to cool said fluid and to freeze at least a portion of said fluid within said tank in a first time period; 
   a cooling loop containing a heat transfer medium comprising:
 a load heat exchanger; 
 a first isolating heat exchanger that facilitates thermal contact between said fluid and said heat transfer medium, said heat transfer medium that transfers cooling from said first isolating heat exchanger to said load heat exchanger in said second time period; and, 
 a second isolating heat exchanger that facilitates thermal contact between said refrigerant condensed within said condensing unit and said heat transfer medium, said heat transfer medium that transfers cooling from said second isolating heat exchanger to said load heat exchanger in a third time period. 
   
   
   
       13 . The system of  claim 12  further comprising:
 a refrigerant management vessel in fluid communication with, and located between said condensing unit and said primary heat exchanger comprising:   an inlet connection that receives said refrigerant from said condensing unit and said primary heat exchanger;   a first outlet connection that supplies said refrigerant to said primary heat exchanger; and,   a second outlet connection that supplies said refrigerant to said condensing unit.   
   
   
       14 . The system of  claim 12  wherein said expansion device is chosen from the group consisting of a thermal expansion valve, an electronic expansion valve and a mixed-phase regulator. 
   
   
       15 . The system of  claim 12  wherein said fluid is a eutectic material. 
   
   
       16 . The system of  claim 12  wherein said fluid is water. 
   
   
       17 . The system of  claim 12  wherein said load heat exchanger is at least one mini-split evaporator. 
   
   
       18 . The system of  claim 12  wherein said second time period is concurrent with said third time period. 
   
   
       19 . The system of  claim 12  wherein said heat transfer medium is a coolant. 
   
   
       20 . The system of  claim 12  wherein said heat transfer medium is a refrigerant. 
   
   
       21 . The system of  claim 12  further comprising:
 a subcooling heat exchanger that facilitates thermal contact between said heat transfer medium upstream of said load heat exchanger and said refrigerant exiting said condenser to subcool said refrigerant.   
   
   
       22 . The system of  claim 12  further comprising:
 a bypass refrigeration loop that transfers cooling from said refrigerant leaving said expansion device to said load heat exchanger and returns warm expanded said refrigerant to said compressor.   
   
   
       23 . A refrigerant-based thermal energy storage and cooling system comprising:
 a refrigerant loop containing a refrigerant comprising:
 a condensing unit, said condensing unit comprising a compressor and a condenser; 
 an expansion device connected downstream of said condensing unit; and, 
 a primary heat exchanger connected between said expansion device and said condensing unit that is located within a tank filled with a fluid capable of a phase change between liquid and solid, said primary heat exchanger that performs as an evaporator and facilitates heat transfer from said refrigerant from said condenser to cool said fluid and to freeze at least a portion of said fluid within said tank in a first time period, and said primary heat exchanger that performs as a condenser and facilitates heat transfer from said fluid to cool said refrigerant in a second time period; 
   a cooling loop containing a heat transfer medium comprising:
 a load heat exchanger; 
 a first isolating heat exchanger that facilitates thermal contact between said fluid and said heat transfer medium, said heat transfer medium that transfers cooling from said first isolating heat exchanger to said load heat exchanger in said second time period; and, 
 a second isolating heat exchanger that facilitates thermal contact between said refrigerant cooled by said fluid within said tank and said heat transfer medium, said heat transfer medium that transfers cooling from said second isolating heat exchanger to said load heat exchanger in a third time period. 
   
   
   
       24 . The system of  claim 23  further comprising:
 a refrigerant management vessel in fluid communication with, and located between said condensing unit and said primary heat exchanger comprising:   an inlet connection that receives said refrigerant from said condensing unit and said primary heat exchanger;   a first outlet connection that supplies said refrigerant to said primary heat exchanger; and,   a second outlet connection that supplies said refrigerant to said condensing unit.   
   
   
       25 . The system of  claim 23  wherein said expansion device is chosen from the group consisting of a thermal expansion valve, an electronic expansion valve and a mixed-phase regulator. 
   
   
       26 . The system of  claim 23  wherein said fluid is a eutectic material. 
   
   
       27 . The system of  claim 23  wherein said fluid is water. 
   
   
       28 . The system of  claim 23  wherein said load heat exchanger is at least one mini-split evaporator. 
   
   
       29 . The system of  claim 23  wherein said second time period is concurrent with said third time period. 
   
   
       30 . The system of  claim 23  wherein said heat transfer medium is a coolant. 
   
   
       31 . The system of  claim 23  wherein said heat transfer medium is a refrigerant. 
   
   
       32 . The system of  claim 23  further comprising:
 a subcooling heat exchanger that facilitates thermal contact between said heat transfer medium upstream of said load heat exchanger and said refrigerant exiting said condenser to subcool said refrigerant.   
   
   
       33 . The system of  claim 23  further comprising:
 a bypass refrigeration loop that transfers cooling from said refrigerant leaving said expansion device to said load heat exchanger and returns warm expanded said refrigerant to said compressor.   
   
   
       34 . A method of providing cooling with a thermal energy storage and cooling system comprising:
 during a first time period:
 compressing and condensing a refrigerant with an air conditioner unit to create a high-pressure refrigerant; 
 expanding said high-pressure refrigerant to provide cooling in a primary heat exchanger, said primary heat exchanger that is constrained within a tank containing a fluid capable of a phase change between liquid and solid; and, 
 freezing a portion of said fluid and forming ice and cooled fluid within said tank; 
   during a second time period:
 transferring cooling from said fluid and said ice to said refrigerant within said primary heat exchanger; 
 transferring cooling from said refrigerant cooled within said primary heat exchanger to a heat transfer medium in a cooling loop with a first isolating heat exchanger; and, 
 transferring cooling from said heat transfer medium to a load heat exchanger within said cooling loop to provide load cooling; 
   during a third time period:
 transferring cooling from said refrigerant from said air conditioner unit to said heat transfer medium in said cooling loop with a second isolating heat exchanger; and, 
 transferring cooling from said heat transfer medium to said load heat exchanger within said cooling loop to provide load cooling. 
   
   
   
       35 . The method of  claim 34  further comprising the step of:
 managing volumes and phase of said refrigerant with a refrigerant management vessel, said refrigerant management vessel in fluid communication with said air conditioner unit and said primary heat exchanger.   
   
   
       36 . The method of  claim 34  wherein said steps of said second time period are performed concurrent with said steps of said third time period. 
   
   
       37 . The method of  claim 34  further comprising the step of:
 expanding said heat transfer medium upstream of said load heat exchanger and condensing said heat transfer medium in said first isolating heat exchanger or in said second isolating heat exchanger.   
   
   
       38 . The method of  claim 34  further comprising the step of:
 subcooling said refrigerant that exits said air conditioner unit with a subcooling heat exchanger in thermal communication with said heat transfer medium.   
   
   
       39 . The method of  claim 34  further comprising the steps of:
 during a fourth time period:
 bypassing said primary heat exchanger with said refrigerant leaving said expansion device; and, 
 transferring cooling from said refrigerant leaving said expansion device to said load heat exchanger to provide direct load cooling; 
 returning warm expanded said refrigerant to said air conditioner unit. 
   
   
   
       40 . A method of providing cooling with a thermal energy storage and cooling system comprising:
 during a first time period;
 compressing and condensing a refrigerant with an air conditioner unit to create a high-pressure refrigerant; 
 expanding said high-pressure refrigerant to provide cooling in a primary heat exchanger, said primary heat exchanger that is constrained within a tank containing a fluid capable of a phase change between liquid and solid; and, 
 freezing a portion of said fluid and forming ice and cooled fluid within said tank; 
   during a second time period:
 transferring cooling from said fluid to a heat transfer medium in a cooling loop with a first isolating heat exchanger; and, 
 transferring cooling from said heat transfer medium to a load heat exchanger within said cooling loop to provide load cooling; 
   during a third time period;
 transferring cooling from said refrigerant from said air conditioner unit to said heat transfer medium in said cooling loop with a second isolating heat exchanger; and, 
 transferring cooling from said heat transfer medium to said load heat exchanger within said cooling loop to provide load cooling. 
   
   
   
       41 . The method of  claim 40  further comprising the step of:
 managing volumes and phase of said refrigerant with a refrigerant management vessel, said refrigerant management vessel in fluid communication with said air conditioner unit and said primary heat exchanger.   
   
   
       42 . The method of  claim 40  wherein said steps of said second time period are performed concurrent with said steps of said third time period. 
   
   
       43 . The method of  claim 40  further comprising the step of:
 expanding said heat transfer medium upstream of said load heat exchanger and condensing said heat transfer medium in said first isolating heat exchanger or in said second isolating heat exchanger.   
   
   
       44 . The method of  claim 40  further comprising the step of:
 subcooling said refrigerant that exits said air conditioner unit with a subcooling heat exchanger in thermal communication with said heat transfer medium.   
   
   
       45 . The method of  claim 40  further comprising the steps of:
 during a fourth time period:
 bypassing said primary heat exchanger with said refrigerant leaving said expansion device; 
 transferring cooling from said refrigerant leaving said expansion device to said load heat exchanger to provide direct load cooling; and, 
 returning warm expanded said refrigerant to said air conditioner unit. 
   
   
   
       46 . A method of providing cooling with a thermal energy storage and cooling system comprising:
 during a first time period:
 compressing and condensing a refrigerant with an air conditioner unit to create a high-pressure refrigerant; 
 expanding said high-pressure refrigerant to provide cooling in a primary heat exchanger, said primary heat exchanger that is constrained within a tank containing a fluid capable of a phase change between liquid and solid; and, 
 freezing a portion of said fluid and forming ice and cooled fluid within said tank; 
 during a second time period: 
 transferring cooling from said fluid to a heat transfer medium in a cooling loop with a first isolating heat exchanger, and transferring cooling from said heat transfer medium to a load heat exchanger within said cooling loop to provide load cooling; 
   during a third time period:
 transferring cooling from said fluid and said ice to said refrigerant within said primary heat exchanger; 
 transferring cooling from said refrigerant cooled within said primary heat exchanger to said heat transfer medium in a cooling loop with a second isolating heat exchanger; and, 
 transferring cooling from said heat transfer medium to said load heat exchanger within said cooling loop to provide load cooling. 
   
   
   
       47 . The method of claim  56  further comprising the step of:
 managing volumes and phase of said refrigerant with a refrigerant management vessel, said refrigerant management vessel in fluid communication with said air conditioner unit and said primary heat exchanger.   
   
   
       48 . The method of claim  56  wherein said steps of said second time period are performed concurrent with said steps of said third time period. 
   
   
       49 . The method of claim  56  further comprising the step of:
 expanding said heat transfer medium upstream of said load heat exchanger and condensing said heat transfer medium in said first isolating heat exchanger or in said second isolating heat exchanger.   
   
   
       50 . The method of claim  56  further comprising the step of:
 subcooling said refrigerant that exits said air conditioner unit with a subcooling heat exchanger in thermal communication with said heat transfer medium.   
   
   
       51 . The method of claim  56  further comprising the steps of:
 during a fourth time period:
 bypassing said primary heat exchanger with said refrigerant leaving said expansion device; 
 transferring cooling from said refrigerant leaving said expansion device to said load heat exchanger to provide direct load cooling; and, 
 returning warm expanded said refrigerant to said air conditioner unit.