Thermal energy storage and cooling system with isolated external melt cooling

Abstract

Disclosed are a method and device for a refrigerant-based thermal energy storage and cooling system with isolated external melt cooling. The disclosed embodiments provide a refrigerant-based ice storage system with increased reliability, lower cost components, and reduced power consumption compared to a single phase system such as a glycol system.

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 that acts as an evaporator and is located within a tank filled with a fluid capable of a phase change between liquid and solid, said primary heat exchanger that 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; a cooling loop containing said fluid from said tank comprising: 
 a load heat exchanger connected to said tank that transfers cooling capacity of said fluid to a heat load; and, 
 a pump that distributes said fluid from said tank to said load heat exchanger and returns said fluid to said tank. 
   
   
   
       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 refrigerant from said condensing unit and said primary heat exchanger; 
 a first outlet connection that supplies refrigerant to said primary heat exchanger; and, 
 a second outlet connection that supplies refrigerant to said condensing unit. 
   
   
   
       3 . The system of  claim 1  wherein said expansion device is a thermal expansion valve. 
   
   
       4 . The system of  claim 1  wherein said expansion device is a mixed-phase regulator. 
   
   
       5 . The system of  claim 1  wherein said fluid is a eutectic material. 
   
   
       6 . The system of  claim 1  wherein said fluid is water. 
   
   
       7 . The system of  claim 1  wherein said first refrigerant is a different material from said second refrigerant. 
   
   
       8 . The system of  claim 1  wherein said load heat exchanger is at least one mini-split evaporator. 
   
   
       9 . A refrigerant-based thermal energy storage and cooling system comprising:
 a first refrigerant loop containing a first refrigerant comprising:   a condensing unit, said condensing unit comprising a compressor and a first condenser;   an expansion device connected downstream of said condensing unit; and,   a first evaporator on a primary side of an isolating heat exchanger located downstream of said expansion device;   a second refrigerant loop containing a second refrigerant comprising:   a second condenser on a secondary side of said isolating heat exchanger;   a tank filled with a fluid capable of a phase change between liquid and solid and containing a primary heat exchanger therein, said primary heat exchanger in fluid communication with said second condenser and that utilizes said second refrigerant from said second condenser to cool said fluid and to freeze at least a portion of said fluid within said tank;   a load heat exchanger connected in fluid communication with said fluid in said tank that transfers cooling capacity of said fluid to a heat load; and,   a pump for distributing said fluid from said tank to said to said load heat exchanger.   
   
   
       10 . The system of claim of  claim 9  further comprising:
 a refrigerant management vessel connected to receive said second refrigerant from said isolating heat exchanger and supply said second refrigerant to said primary heat exchanger, and to receive said second refrigerant from said primary heat exchanger and supply said second refrigerant to said isolating heat exchanger.   
   
   
       11 . The system of  claim 9  wherein said expansion device is a thermal expansion valve. 
   
   
       12 . The system of  claim 9  wherein said expansion device is a mixed-phase regulator. 
   
   
       13 . The system of  claim 9  wherein said fluid is a eutectic material. 
   
   
       14 . The system of  claim 9  wherein said fluid is water. 
   
   
       15 . The system of  claim 9  wherein said first refrigerant is a different material from said second refrigerant. 
   
   
       16 . The system of  claim 9  wherein said load heat exchanger is at least one mini-split evaporator. 
   
   
       17 . The system of  claim 9  further comprising:
 a by-pass refrigerant loop that allows said first refrigerant to by-pass said primary heat exchanger and provide cooling directly to said fluid downstream of said tank and transfer cooling to said heat load.   
   
   
       18 . A refrigerant-based thermal energy storage and cooling system comprising:
 a first refrigerant loop containing a first 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 that acts as an evaporator and is located within a tank filled with a fluid capable of a phase change between liquid and solid, said primary heat exchanger that facilitates heat transfer from said first refrigerant from said condenser to cool said fluid and to freeze at least a portion of said fluid within said tank; 
   a cooling loop containing said fluid from said tank comprising:
 an intermediate heat exchanger connected to said tank that transfers cooling capacity of said fluid to a primary side of said intermediate heat exchanger; 
 a pump that distributes said fluid from said tank to said intermediate (load) heat exchanger and returns said fluid to said tank; 
   a second refrigerant loop containing a second refrigerant comprising:
 a load heat exchanger connected in fluid communication with a secondary side of said intermediate heat exchanger that transfers cooling capacity of said second refrigerant to a heat load; and, 
 a refrigerant pump for distributing said second refrigerant from said intermediate heat exchanger to said load heat exchanger and back to said intermediate heat exchanger. 
   
   
   
       19 . The system of  claim 18  wherein said expansion device is a thermal expansion valve. 
   
   
       20 . The system of  claim 18  wherein said expansion device is a mixed-phase regulator. 
   
   
       21 . The system of  claim 18  wherein said fluid is a eutectic material. 
   
   
       22 . The system of  claim 18  wherein said fluid is water. 
   
   
       23 . The system of  claim 18  wherein said first refrigerant is a different material from said second refrigerant. 
   
   
       24 . The system of  claim 18  wherein said load heat exchanger is at least one mini-split evaporator. 
   
   
       25 . The system of  claim 18  wherein said second refrigerant remains liquid. 
   
   
       26 . The system of  claim 18  further comprising:
 a refrigerant management vessel connected to receive said second refrigerant from said isolating heat exchanger and supply said second refrigerant to said primary heat exchanger, and to receive said second refrigerant from said primary heat exchanger and supply said second refrigerant to said isolating heat exchanger:   
   
   
       27 . The system of  claim 18  further comprising:
 a by-pass refrigerant loop that allows said first refrigerant to by-pass said primary heat exchanger and provide cooling directly to said fluid downstream of said tank and transfer cooling to said intermediate heat exchanger.   
   
   
       28 . A method of providing cooling with a refrigerant-based thermal energy storage and cooling system comprising the steps of:
 providing cooling to a primary heat exchanger by evaporating a high-pressure refrigerant in said primary heat exchanger that is constrained within a tank containing a fluid capable of a phase change between liquid and solid;   freezing a portion of said fluid and form ice within said tank;   delivering a liquid portion of said fluid to a load heat exchanger;   transferring cooling from said liquid portion of said fluid to said load heat exchanger to provide load cooling;   returning said liquid portion of said fluid to said tank; and,   cooling said liquid portion of said fluid with said ice within said tank.   
   
   
       29 . The method of  claim 28  further comprising the step of:
 managing volumes and phase of said first refrigerant with a refrigerant management vessel, said refrigerant management vessel in fluid communication with said primary heat exchanger and said condenser.   
   
   
       30 . A method of providing cooling with a refrigerant-based thermal energy storage and cooling system comprising the steps of:
 providing cooling to a first evaporator on a primary side of an isolating heat exchanger by evaporating a high-pressure refrigerant in said first evaporator;   transferring cooling from said primary side of said isolating heat exchanger to a second refrigerant loop containing a second refrigerant through a secondary side of said isolating heat exchanger;   providing cooling with said second refrigerant loop to a primary heat exchanger that is constrained within a tank containing a fluid capable of a phase change between liquid and solid;   freezing a portion of said fluid and form ice within said tank;   delivering a liquid portion of said fluid to a load heat exchanger;   transferring cooling from said liquid portion of said fluid to said load heat exchanger to provide load cooling;   returning said liquid portion of said fluid to said tank; and,   cooling said liquid portion of said fluid with said ice within said tank.   
   
   
       31 . The method of  claim 30  further comprising the step of:
 managing volumes and phase of said second refrigerant with a refrigerant management vessel, said refrigerant management vessel in fluid communication with said isolating heat exchanger and said primary heat exchanger.   
   
   
       32 . The method of  claim 30  further comprising the step of:
 by-passing said primary heat exchanger with said primary refrigerant; delivering said primary refrigerant to said to said fluid downstream of said tank; and,   transferring cooling to said intermediate heat exchanger.   
   
   
       33 . A method of providing cooling with a refrigerant-based thermal energy storage and cooling system comprising the steps of:
 providing cooling to a primary heat exchanger by evaporating a high-pressure refrigerant in said primary heat exchanger that is constrained within a tank containing a fluid capable of a phase change between liquid and solid;   freezing a portion of said fluid and form ice within said tank;   delivering a liquid portion of said fluid to a primary side of an intermediate heat exchanger;   transferring cooling from said primary side of said intermediate heat exchanger to a second refrigerant loop containing a second refrigerant through a secondary side of said intermediate heat exchanger;   returning said liquid portion of said fluid to said tank;   cooling said liquid portion of said fluid with said ice within said tank;   delivering said second refrigerant to a load heat exchanger;   transferring cooling from said second refrigerant to a load heat exchanger to provide load cooling;   returning said second refrigerant to said secondary side of said intermediate heat exchanger; and,   cooling said second refrigerant with said primary side of said intermediate heat exchanger.   
   
   
       34 . The method of  claim 33  further comprising the step of:
 managing volumes and phase of said first refrigerant with a refrigerant management vessel, said refrigerant management vessel in fluid communication with said primary heat exchanger and said condenser.   
   
   
       35 . The method of  claim 33  further comprising the step of:
 isolating said primary heat exchanger from said condensing unit with an isolating heat exchanger that transfers heat to and from said primary heat exchanger and said condensing unit.   
   
   
       36 . The method of  claim 33  further comprising the step of:
 maintaining said second refrigerant in liquid phase throughout said second refrigerant loop.