Abstract:
Disclosed is a method and device for a refrigerant-based a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil. The disclosed embodiments provide a refrigerant-based ice storage system with increased reliability, lower cost components, and reduced power consumption and ease of installation.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based upon and claims the benefit of U.S. provisional application No. 60/990,685, entitled “Thermal Energy Storage and Cooling System with Multiple Cooling Loops Utilizing a Common Evaporator Coil”, filed Nov. 28, 2007, the entire disclosure of which is hereby specifically incorporated by reference for all that it discloses and teaches. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    With the increasing demands on peak demand power consumption, ice storage has been utilized to shift air conditioning power loads to off-peak times and rates. A need exists not only for load shifting from peak to off-peak periods, but also for increases in air conditioning unit capacity and efficiency. Current air conditioning units having energy storage systems have had limited success due to several deficiencies, including reliance on water chillers that are practical only in large commercial buildings and have difficulty achieving high-efficiency. In order to commercialize advantages of thermal energy storage in large and small commercial buildings, thermal energy storage systems must have minimal manufacturing costs, maintain maximum efficiency under varying operating conditions, have minimal implementation and operation impact and be suitable for multiple refrigeration or air conditioning applications. 
         [0003]    Systems for providing thermal stored energy have been previously contemplated in U.S. Pat. No. 4,735,064, U.S. Pat. No. 5,225,526, both issued to Harry Fischer, U.S. Pat. No. 5,647,225 issued to Fischer et al., U.S. Pat. No. 7,162,878 issued to issued to Narayanamurthy et al., U.S. patent application Ser. No. 11/112,861 filed Apr. 22, 2005 by Narayanamurthy et al., U.S. patent application Ser. No. 11/138,762 filed May 25, 2005 by Narayanamurthy et al., U.S. patent application Ser. No. 11/208,074 filed Aug. 18, 2005 by Narayanamurthy et al., U.S. patent application Ser. No. 11/284,533 filed Nov. 21, 2005 by Narayanamurthy et al., U.S. patent application Ser. No. 11/610,982 filed Dec. 14, 2006 by Narayanamurthy, and U.S. patent application Ser. No. 11/837,356 filed Aug. 10, 2007 by Narayanamurthy et al. All of these patents utilize ice storage to shift air conditioning loads from peak to off-peak electric rates to provide economic justification and are hereby incorporated by reference herein for all they teach and disclose. 
       SUMMARY OF THE INVENTION 
       [0004]    An embodiment of the present invention may therefore comprise a refrigerant-based thermal energy storage and cooling system comprising: a first refrigerant loop containing a refrigerant comprising: a first condensing unit comprising a first compressor and a first condenser; a first expansion device connected downstream of the first condensing unit; and, a thermal energy storage unit comprising a primary heat exchanger connected between the first expansion device and the first condensing unit that acts as a first evaporator and is located within a tank filled with a fluid, the primary heat exchanger that facilitates heat transfer from the first refrigerant from the first condenser to cool the fluid within the tank; a second refrigerant loop containing additional refrigerant comprising a load heat exchanger connected to the thermal energy storage unit that transfers cooling from the thermal energy storage unit to the load heat exchanger to a heat load; a third refrigerant loop containing additional refrigerant comprising: a second condensing unit comprising a second compressor and a second condenser; and, a second expansion device connected downstream of the second condensing unit, and the load heat exchanger connected between the second expansion device and the second condensing unit that transfers cooling capacity of the second condensing unit to the load heat exchanger to a heat load. 
         [0005]    An embodiment of the present invention may also comprise a refrigerant-based thermal energy storage and cooling system comprising: a first refrigerant loop containing a refrigerant comprising: a first condensing unit comprising a first compressor and a first condenser; a first expansion device connected downstream of the first condensing unit; and, a thermal energy storage unit comprising a primary heat exchanger connected between the first expansion device and the first condensing unit that acts as a first evaporator and is located within a tank filled with a fluid, the primary heat exchanger that facilitates heat transfer from the first refrigerant from the first condenser to cool the fluid within the tank; a primary side of a sub-cooling heat exchanger that draws cooling from the thermal energy storage unit and transfers cooling to a secondary side of the sub-cooling heat exchanger; a second refrigerant loop containing additional refrigerant comprising: a second condensing unit comprising a second compressor and a second condenser; the second condensing unit that supplies the refrigerant to the secondary side of the sub-cooling heat exchanger where cooling is transferred from the secondary side of the sub-cooling heat exchanger to the additional refrigerant thereby creating sub-cooled refrigerant; a second expansion device connected downstream of the secondary side of the sub-cooling heat exchanger; and, a load heat exchanger connected between the second expansion device and the second condensing unit that transfers cooling capacity of the sub-cooled refrigerant to the heat load in a first time period, the load heat exchanger that is connected to the thermal energy storage unit and that transfers cooling from the thermal energy storage unit to the heat load in a second time period. 
         [0006]    An embodiment of the present invention may also comprise a refrigerant-based thermal energy storage and cooling system comprising: a first refrigerant loop containing a first refrigerant comprising: a first condensing unit comprising a first compressor and a first condenser; a first expansion device connected downstream of the first condensing unit; and, a thermal energy storage unit comprising a primary heat exchanger connected between the first expansion device and the first condensing unit that acts as a first evaporator and is located within a tank filled with a fluid, the primary heat exchanger that facilitates heat transfer from the first refrigerant from the first condenser to cool the fluid within the tank; a second refrigerant loop containing a second refrigerant comprising: a second condensing unit comprising a second compressor and a second condenser; a second expansion device connected downstream of the second condensing unit; a primary side of a first isolating heat exchanger that draws cooling from the thermal energy storage unit and transfers cooling to a secondary side of the first isolating heat exchanger; a primary side of second a isolating heat exchanger connected between the second expansion device and the second condenser that transfers cooling to a secondary side of the second isolating heat exchanger; and, a load heat exchanger receives cooling from a secondary side of the first isolating heat exchanger, or the secondary side of the second isolating heat exchanger, or a combination of the secondary side of the first isolating heat exchanger and the secondary side of the second isolating heat exchanger. 
         [0007]    An embodiment of the present invention may also comprise a method of providing cooling with a refrigerant-based thermal energy storage and cooling system comprising the steps of: compressing and condensing a refrigerant with a first air conditioner unit to create a first high-pressure refrigerant; expanding the first high-pressure refrigerant to provide cooling to a 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 the fluid and forming ice within the tank during a first time period; cooling the refrigerant in the primary heat exchanger with the ice and transferring the refrigerant to a load heat exchanger to provide load cooling; returning the refrigerant to the primary heat exchanger; and, re-cooling the refrigerant during a second time period; compressing and condensing the refrigerant with a second air conditioner unit to create a second high-pressure refrigerant; and, expanding the second high-pressure refrigerant in the load heat exchanger to provide load cooling during a third time period. 
         [0008]    An embodiment of the present invention may also comprise a method of providing cooling with a thermal energy storage and cooling system comprising the steps of: compressing and condensing a refrigerant with a first air conditioner unit to create a first high-pressure refrigerant; providing cooling to a primary heat exchanger by expanding the first high-pressure refrigerant in the 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 the fluid to form ice within the tank during a first time period; transferring cooling from the fluid and the ice to a load heat exchanger to provide load cooling in a second time period; compressing and condensing the refrigerant with a second air conditioner unit to create a second high-pressure refrigerant; transferring cooling from the fluid and the ice to a primary side of a sub-cooling heat exchanger; transferring the second high-pressure refrigerant from the second air conditioner unit to a secondary side of the sub-cooling heat exchanger; sub-cooling the second high-pressure refrigerant by transferring cooling from the primary side of the sub-cooling heat exchanger to the secondary side of the sub-cooling heat exchanger; transferring sub-cooled the second high-pressure refrigerant from the secondary side of the isolating heat exchanger to a load heat exchanger; expanding the sub-cooled the second high-pressure refrigerant in the load heat exchanger to provide load cooling; and, returning the refrigerant to the second air conditioner unit during a third time period. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    In the drawings, 
           [0010]      FIG. 1  illustrates an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil. 
           [0011]      FIG. 2  illustrates an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil with an isolated primary refrigerant loop. 
           [0012]      FIG. 3  illustrates a configuration of another embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil. 
           [0013]      FIG. 4  illustrates a configuration of an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil with an isolated primary refrigerant loop. 
           [0014]      FIG. 5  illustrates an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil with a sub-cooled secondary refrigerant loop. 
           [0015]      FIG. 6  illustrates a configuration of an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil with an isolated primary refrigerant loop and a sub-cooled secondary refrigerant loop. 
           [0016]      FIG. 7  illustrates a configuration of an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil with isolated primary and secondary refrigerant loops. 
           [0017]      FIG. 8  illustrates another configuration of an embodiment of multiple thermal energy storage and cooling systems with multiple condensing units utilizing a common evaporator coil with isolated primary and secondary refrigerant loops. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    While this invention is susceptible to embodiment in many different forms, it is shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not to be limited to the specific embodiments described. 
         [0019]      FIG. 1  illustrates an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil. This embodiment may function with or without an accumulator vessel or URMV (universal refrigerant management vessel), and is depicted in  FIG. 1  with the vessel. As illustrated in  FIG. 1 , a first air conditioner unit #1  102  utilizes a compressor  110  to compress cold, low pressure refrigerant gas to hot, high-pressure gas. Next, a condenser  111  removes much of the heat in the gas and discharges the heat to the atmosphere. The refrigerant leaves the condenser  111  as a warm, high-pressure liquid refrigerant delivered through a high-pressure liquid supply line  112  to an expansion device  130  and to an accumulator vessel or URMV  146  acting as a collector and phase separator of multi-phase refrigerant. This expansion device  130  may be a conventional or non-conventional thermal expansion valve, a mixed-phase regulator and surge vessel (reservoir) or the like. Liquid refrigerant is then transferred from the URMV  146  to the thermal energy storage unit  106 . A primary heat exchanger  160  within an insulated tank  140  expands refrigerant that is fed from a lower header assembly  156  through the freezing/discharge coils  142 , to the upper header assembly  154 . Low-pressure vapor phase and liquid refrigerant is then returned to the URMV  146  and compressor  110  via low pressure return line  118  completing the refrigeration loop. 
         [0020]    As illustrated in  FIG. 1 , the thermal energy storage unit  106  comprises an insulated tank  140  that houses the primary heat exchanger  160  surrounded by a liquid phase change material  152  and/or solid phase change material  153  (fluid/ice depending on the current system mode). The primary heat exchanger  160  further comprises a lower header assembly  156  connected to an upper header assembly  154  with a series of freezing and discharge coils  142  to make a fluid/vapor loop within the insulated tank  140 . The upper and lower header assemblies  154  and  156  communicate externally of the thermal energy storage unit  106  with inlet and outlet connections. 
         [0021]    The embodiment illustrated in  FIG. 1  utilizes the air conditioner unit #1  102  as the principal cooling source for the thermal energy storage unit  106 . This portion of the disclosed embodiment functions in two principal modes of operation, ice-make (charging) and ice-melt (cooling) mode. 
         [0022]    In ice-make mode, compressed high-pressure refrigerant leaves the air conditioner unit #1  102  through high-pressure liquid supply line  112  and is fed through an expansion device  130  and URMV  146  to cool the thermal energy storage unit  106  where it enters the primary heat exchanger  160  through the lower header assembly  156  and is then distributed through the freezing coils  142  which act as an evaporator. Cooling is transmitted from the freezing coils  142  to the surrounding liquid phase change material  152  that is confined within the insulated tank  140  and may produce a block of solid phase change material  153  (ice) surrounding the freezing coils  142  and storing thermal energy in the process. Warm liquid and vapor phase refrigerant leaves the freezing coils  142  through the upper header assembly  154  and exits the thermal energy storage unit  106  returning to the URMV  146  and then to the air conditioner unit #1  102  through the low pressure return line  118  and is fed to the compressor  110  and re-condensed into liquid by condenser  111 . 
         [0023]    In ice-melt mode, cool liquid refrigerant leaves the lower portion of the insulated tank  140  via lower header assembly  156  and is propelled by a thermosiphon or optional pump  120  through a check valve (CV-2)  166  to a load heat exchanger  122  where cooling is transferred to a load (i.e., with the aid of an air handler not shown). Warm vapor or liquid/vapor mixture leaves load heat exchanger  122  where the liquid is returned through another check valve (CV-  1 )  164  to the upper header assembly  154  of the thermal energy storage unit  106  and draws cooling from the solid phase change material  153  and or liquid phase change material  152  surrounding the coils. The check valve (CV-1)  164  may contain a capillary by-pass  165  to assist in refrigerant charge balancing and pressure equalization in the return line to the primary heat exchanger  160 . 
         [0024]    Additional cooling is provided within the embodiment of  FIG. 1  by a second air conditioner unit #2  103  that utilizes an additional compressor  114  to compress cold, low pressure refrigerant gas to hot, high-pressure gas. Next, a condenser  116  removes much of the heat in the gas and discharges the heat to the atmosphere. The refrigerant leaves the condenser  116  as a warm, high-pressure liquid refrigerant delivered through a high-pressure liquid line  113 . Liquid refrigerant is then transferred to the load heat exchanger  122  through a check valve CV-3  168  to an expansion valve  170 . This expansion device  170  can be either a conventional thermal expansion device (TXV), an electronic expansion device (EEV) or a like pressure regulating device. 
         [0025]    When cooling is being supplied from the thermal energy storage unit  106 , the check valve  168  CV-3 acts to prevent backflow through the expansion valve  170 . Upon leaving the expansion valve  170 , refrigerant flows to the load heat exchanger  122  where cooling is transferred to a cooling load. Warm vapor or liquid/vapor mixture leaves load heat exchanger  122  and is fed through suction line  119  past a solenoid valve (SV-1)  180  back to air conditioner #2  103  and is fed to the compressor  114  and re-condensed into liquid by condenser  116 . The function of the (SV-1)  180  is to prevent backflow through the suction line  119  when the thermal energy storage unit  106  is operating. 
         [0026]    Upon leaving the load heat exchanger  122 , the temperature of the refrigerant is sensed with a temperature sensor  172  that is in communication with expansion valve  170 . The temperature of the refrigerant at this sensing point acts as a feedback and regulation mechanism in combination with the expansion valve  170 . If the temperature sensor  172  senses that the refrigerant temperature is too high then the expansion valve  170  will respond by producing an increased rate of expansion of the compressed refrigerant. Conversely, if the temperature sensor  172  senses that the refrigerant temperature is too low, then the expansion valve  170  will respond by producing a reduced rate of expansion of the compressed refrigerant. In this way, the amount of cooling transmitted to the cooling load is regulated. The embodiment illustrated in  FIG. 1  additionally shows an optional pressure equalization line  174  that acts to balance the pressure in the refrigerant loop which includes air conditioner #2  103  and load heat exchanger  122 . 
         [0027]    The additional loops with (SV-2) and capillary bypass are intended for refrigerant balancing in various modes. When air conditioner #2  103  is providing cooling, often the pressure in suction line  119  is lower than in upper header  154 . Hence, (CV-1)  164  serves to prevent backflow of a large quantity of refrigerant to compressor  114 . Capillary bypass  165  serves to equalize the suction line pressure between  119  and  154  during ice make to ensure that all refrigerant is not drained from air conditioner #2  103 . In the same way, (SV-2)  182  is activated by a low pressure signal on the suction line  119  to transfer larger amounts of refrigerant from the thermal energy storage unit  106  to the air conditioner #2  103  when it is providing cooling to the load heat exchanger  122 . 
         [0028]    The additional cooling provided by the second air conditioner unit #2  103  can replace, augment, or supplement space cooling driving either of the ice make or ice melt modes that are driven by the first air conditioner unit #1  102 . For example, the system may be in ice-make mode with the first air conditioner unit #1  102  transferring cooling to the thermal energy storage unit  106 , wile the second air conditioner unit #2  103  is either off, or with the second air conditioner unit #2  103  providing cooling to the thermal energy storage unit  106  or the load heat exchanger  122 . Additionally, the system may be in ice-melt mode with the first air conditioner unit #1  102  off, and with cooling being provided to the load heat exchanger  122  from the thermal energy storage unit  106 . In this situation the second air conditioner unit #2  103  is either off, or the second air conditioner unit #2  103  may provide additional direct cooling to the load heat exchanger  122  thereby augmenting the amount of cooling that is being provided by the thermal energy storage unit  106 . Finally, the system may be in ice-make/direct cooling mode with the first air conditioner unit #1  102  in ice-make mode by transferring cooling to the thermal energy storage unit  106  while the second air conditioner unit #2  103  is providing direct (direct expansion [DX]) cooling to the load heat exchanger  122 . In this way, a wide variety of cooling responses can be delivered by a single system in order to meet various cooling, environmental, and economic variables. 
         [0029]    This variability may be further extended by specific sizing of the compressor and condenser components within the system. By having one large and one small air conditioner unit, precise loads can be matched by a combination of modes to provide greater efficiency to the cooling of the system. Additionally, the two air conditioner units can be packaged, for example, as a conventional single roof-top unit with each of the units within the single housing providing the first air conditioner unit #1  102  and the second air conditioner unit #2  103 . 
         [0030]      FIG. 2  illustrates an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil with an isolated primary refrigerant loop. As with the embodiment of  FIG. 1 , this embodiment may function with or without an accumulator vessel or URMV (universal refrigerant management vessel), and is depicted in  FIG. 2  with the vessel in place. As illustrated in  FIG. 2 , a first air conditioner unit #1  102  utilizes a compressor  110  to compress cold, low pressure refrigerant gas to hot, high-pressure gas. Next, a condenser  111  removes much of the heat in the gas and discharges the heat to the atmosphere. The refrigerant leaves the condenser  111  as a warm, high-pressure liquid refrigerant delivered through a high-pressure liquid supply line  112  to an expansion device  130  and to an accumulator vessel or URMV  146  acting as a collector and phase separator of multi-phase refrigerant. This expansion device  130  may be a conventional or non-conventional thermal expansion valve, a mixed-phase regulator and surge vessel (reservoir) or the like. Liquid refrigerant is then transferred from the URMV  146  to the thermal energy storage unit  106 . A primary heat exchanger  160  within an insulated tank  140  expands refrigerant that is fed from a lower header assembly  156  through the freezing/discharge coils  142 , to the upper header assembly  154 . Low-pressure vapor phase and liquid refrigerant is then returned to the URMV  146  and compressor  110  via low pressure return line  118  completing the refrigeration loop. 
         [0031]    As was illustrated in  FIG. 1 , the thermal energy storage unit  106  of  FIG. 2  comprises an insulated tank  140  that houses the primary heat exchanger  160  surrounded by a liquid phase change material  152  and/or solid phase change material  153  (fluid/ice depending on the current system mode). The primary heat exchanger  160  further comprises a lower header assembly  156  connected to an upper header assembly  154  with a series of freezing and discharge coils  142  to make a fluid/vapor loop within the insulated tank  140 . The upper and lower header assemblies  154  and  156  communicate externally of the thermal energy storage unit  106  with inlet and outlet connections. 
         [0032]    The embodiment illustrated in  FIG. 2  utilizes the air conditioner unit #1  102  as the principal cooling source for the thermal energy storage unit  106 . This portion of the disclosed embodiment functions in two principal modes of operation, ice-make (charging) and ice-melt (cooling) mode. 
         [0033]    In ice-make mode, compressed high-pressure refrigerant leaves the air conditioner unit #1  102  through high-pressure liquid supply line  112  and is fed through an expansion device  130  and URMV  146  to cool the thermal energy storage unit  106  where it enters the primary heat exchanger  160  through the lower header assembly  156  and is then distributed through the freezing coils  142  which act as an evaporator. Cooling is transmitted from the freezing coils  142  to the surrounding liquid phase change material  152  that is confined within the insulated tank  140  and may produce a block of solid phase change material  153  (ice) surrounding the freezing coils  142  and storing thermal energy in the process. Warm liquid and vapor phase refrigerant leaves the freezing coils  142  through the upper header assembly  154  and exits the thermal energy storage unit  106  returning to the URMV  146  and then to the air conditioner unit #1  102  through the low pressure return line  118  and is fed to the compressor  110  and re-condensed into liquid by condenser  111 . 
         [0034]    In ice-melt mode, cool liquid refrigerant leaves the lower portion of the insulated tank  140  via lower header assembly  156  and is propelled by a thermosiphon or optional pump  121  to a primary side of an isolating heat exchanger  162  where cooling is transferred to the secondary side of this isolating heat exchanger  162  and to a secondary refrigerant loop. Warmed refrigerant is then returned from the primary side of the isolating heat exchanger  162  back to the thermal energy storage unit  106  where it is cooled again. Refrigerant that is cooled by the primary refrigerant loop is propelled in the secondary refrigerant loop by a thermosiphon or optional pump  120  through a check valve (CV-2)  166  to a load heat exchanger  122  where cooling is transferred to a load (i.e., with the aid of an air handler not shown). 
         [0035]    Warm vapor or liquid/vapor mixture leaves load heat exchanger  122  where it is returned through another check valve (CV-1)  164  to the secondary side of this isolating heat exchanger  162  where it is again cooled by the primary side of this isolating heat exchanger  162  being fed by the thermal energy storage unit  106  which draws cooling from the solid phase change material  153  and or liquid phase change material  152  surrounding the coils. The check valve (CV-1)  164  may contain a capillary by-pass  165  to assist in refrigerant charge balancing and pressure equalization in the return line to the isolating heat exchanger  162 . Additionally, this refrigerant may contain a refrigerant receiver  190  within the loop to act as a surge vessel and reservoir for maintaining proper levels of refrigerant within this loop. 
         [0036]    In a similar manner to the embodiment of  FIG. 1 , additional cooling may be provided within the embodiment of  FIG. 2  by a second air conditioner unit #2  103  that utilizes an additional compressor  114  to compress cold, low pressure refrigerant gas to hot, high-pressure gas. Next, a condenser  116  removes much of the heat in the gas and discharges the heat to the atmosphere. The refrigerant leaves the condenser  116  as a warm, high-pressure liquid refrigerant delivered through a high-pressure liquid line  113  to the load heat exchanger  122  through a check valve CV-3  168  to an expansion device  170 . This expansion device  170  may be a conventional or non-conventional thermal expansion valve (TXV), an electronic expansion device (EEV), a mixed-phase regulator and surge vessel (reservoir) or the like. 
         [0037]    When cooling is being supplied from the thermal energy storage unit  106  the check valve  168  CV-3 acts to prevent backflow through the expansion valve  170 . Upon leaving the expansion valve  170 , refrigerant flows to the load heat exchanger  122  where cooling is transferred to a cooling load. Warm vapor or liquid/vapor mixture refrigerant leaves the load heat exchanger  122  and is fed through suction line  119  back to air conditioner #2  103  and is fed to the compressor  114  and re-condensed into liquid by condenser  116 . The function of valve (SV-1)  180  is to prevent backflow through the suction line  119  when the thermal energy storage unit  106  is operating. 
         [0038]    Upon leaving the load heat exchanger  122 , the temperature of the refrigerant is sensed with a temperature sensor  172  that is in communication with expansion valve  170 . The temperature of the refrigerant at this sensing point acts as a feedback and regulation mechanism in combination with the expansion valve  170 . As with  FIG. 1 , the additional loops with (SV-2) and capillary bypass are intended for refrigerant balancing in various modes. 
         [0039]    The additional cooling provided by the second air conditioner unit #2  103  can replace or augment cooling of the ice melt mode that are driven by the first air conditioner unit #1  102 . For example, the system may be in ice-melt mode with the first air conditioner unit #1  102  off, and with cooling being provided to the load heat exchanger  122  from the thermal energy storage unit  106  via isolation heat exchanger  162 . In this situation the second air conditioner unit #2  103  is either off, or the second air conditioner unit #2  103 , may provide additional direct (DX) cooling to the load heat exchanger  122  thereby augmenting the amount of cooling that is being provided by the thermal energy storage unit  106 . Additionally, the system may be in ice-make/direct cooling mode with the first air conditioner unit #1  102  in ice-make mode by transferring cooling to the thermal energy storage unit  106  wile the second air conditioner unit #2  103  is providing direct cooling to the load heat exchanger  122 . In this way, a wide variety of cooling responses can be delivered by a single system in order to meet various cooling, environmental, and economic variables. 
         [0040]    The isolation heat exchanger  162  provides additional control and refrigerant management to the overall system by reducing the line volumes and path length variability that can be seen in the embodiment of  FIG. 1 . Additionally, since the primary and secondary refrigerant loops are isolated from one another, different refrigerants may be used within each loop of the system. For example, one type of highly efficient refrigerant that may have properties that would discourage use within a dwelling (such as propane) may be utilized within the primary refrigerant loop that is isolated by the isolating heat exchanger  162 , while a more suitable refrigerant (such as R-22 or R-410A) can be used for the secondary refrigerant loop that may enter the dwelling. This allows greater versatility and efficiency of the system while maintaining safety, environmental, and application issues to be addressed. 
         [0041]    Additionally, the isolating heat exchanger  162  may also provide a junction point between the primary refrigerant loop that may be located outside a structure, while the secondary refrigerant loop is located within the structure. It is also noted that the embodiment illustrated in  FIG. 2  shows the system without the pressure equalization line  174  that is shown in  FIG. 1 . In any of the disclosed embodiments, the pressure equalization line  174  shown in  FIG. 1  may be used as an optional feature. 
         [0042]    The embodiment illustrated in  FIG. 3  shows a thermal energy storage unit  106  that operates using an independent refrigerant loop that transfers the cooling between the air conditioner unit #1  102  and the thermal energy storage unit  106 . This embodiment may function with or without an accumulator vessel or URMV (universal refrigerant management vessel), and is depicted in  FIG. 3  with the vessel. In this example, acting as a collector and phase separator of multi-phase refrigerant, the accumulator or universal refrigerant management vessel (URMV)  146 , is in fluid communication with both the thermal energy storage unit  106  and the air conditioner unit  102 . 
         [0043]    This embodiment functions in five principal modes of operation: ice-make (charging), ice-melt (cooling), ice-melt/boost (high capacity cooling), ice-make/boost (high capacity charging) and bypass mode. Ice-make mode in the primary refrigerant loop utilizing air conditioner unit #1  102  is identical to that of  FIG. 1 . 
         [0044]    In ice-melt only (cooling) mode, the primary refrigerant loop driven by air conditioner unit #1  102  can continue to cool, can be shut down, or can be disengaged (valves not shown). Cool liquid refrigerant is drawn from the thermal energy storage unit  106  and is transported by thermosiphon or pumped by a liquid pump  120  through a 3-way valve  188  to the load heat exchanger  122  where cooling is transferred to a load. The warm mixture of liquid and vapor phase refrigerant leaves the load heat exchanger  122  where the mixture is returned to the thermal energy storage unit  106  now acting as a condenser, through a 3-way valve  186 . Vapor phase refrigerant is cooled and condensed by drawing cooling from the cold fluid or ice where it becomes again available for load cooling. 
         [0045]    In ice-melt/boost (high capacity cooling) mode, the primary refrigerant loop driven by air conditioner unit #1  102  can again continue to cool, can be shut down, or can be disengaged (valves not shown). In addition to the cooling provided by ice-melt from the thermal energy storage unit  106 , air conditioner unit #2  103  may operate to additionally boost the cooling provided to the load heat exchanger  122 . When in operation, air conditioner unit #2  103  utilizes a compressor  114  to compress cold, low pressure refrigerant gas to hot, high-pressure gas. Next, a condenser  116  removes much of the heat in the gas and discharges the heat to the atmosphere. The refrigerant leaves the condenser  116  as a warm, high-pressure liquid refrigerant delivered through a high-pressure liquid line  113  through an optional refrigerant receiver  190  and solenoid valve (SV-1)  180  to an expansion valve  170 . Like expansion device  130 , this second expansion device  131  may be a conventional or non-conventional thermal expansion valve, a mixed-phase regulator and surge vessel (reservoir) or the like. 
         [0046]    Refrigerant is metered and regulated by expansion valve  170  and transferred to a 3-way valve  188 . Upon leaving the 3-way valve  188 , refrigerant flows to the load heat exchanger  122  where cooling is transferred to a cooling load. Warm vapor or liquid/vapor mixture refrigerant leaves the load heat exchanger  122  where the temperature of the refrigerant is sensed with a temperature sensor  172  that is in communication with expansion valve  170 . The temperature of the refrigerant at this sensing point acts as a feedback and regulation mechanism in combination with the expansion valve  170  thereby controlling the amount of cooling transmitted to the cooling load. 
         [0047]    The refrigerant is then controlled by 3-way valve (3WV-1)  186  that directs the refrigerant to either the suction line  119 , back to air conditioner #2  103  where it is fed to the compressor  114  and re-condensed into liquid by condenser  116 , and/or to the thermal energy storage unit  106 . Valve  165  is placed on a separate charge equalization line between the two outlet lines of 3-way valve (3WV-1)  186  to enable refrigerant to migrate from the thermal energy storage unit  106  to air conditioner #2  103  and vice versa. Since the thermal energy storage unit  106  is usually the coldest location in the system, the refrigerant will likely migrate to the thermal energy storage unit during idle periods and will need to be returned to the air conditioning unit #2  103  during its operation. 
         [0048]    With both the thermal energy storage unit  106  and air conditioner unit #2  103  operating in conjunction, a very high cooling capacity is realized within the system. This boost mode may be accomplished with shared refrigerant lines as depicted in  FIG. 3 , or with a separate set of refrigerant lines (not shown) where the thermal energy storage unit  106  and air conditioner unit #2  103  may be independently plumbed into and out of the load heat exchanger  122 . This type of embodiment would also be favorable to a load heat exchanger that contains multiple cooling coils or a mini-split evaporator. 
         [0049]    In ice-make/boost (high capacity charging) mode, air conditioner unit #2  103  supplies refrigerant that is metered and regulated by expansion valve  170  (temperature sensor  172  deactivated) and transferred to the 3-way valve  188 . Upon leaving the 3-way valve  188 , refrigerant flows to the thermal energy storage unit  106  (bypassing pump  120 ) where it enters the primary heat exchanger  160  through the lower header assembly  156  and is then distributed through the freezing coils  142  which act as an evaporator. Cooling is transmitted from the freezing coils  142  to the surrounding liquid phase change material  152  that is confined within the insulated tank  140  and may produce a block of solid phase change material  153  (ice) surrounding the freezing coils  142  and storing thermal energy in the process. Warm liquid and vapor phase refrigerant leaves the freezing coils  142  through the upper header assembly  154  and exits the thermal energy storage unit  106  and proceeds to 3-way valve (3WV-1)  186  that returns the refrigerant to air conditioner unit #2  103  through suction line  119 . In this mode, both air conditioner units may act to rapidly deliver cooling to the thermal energy storage unit  106  and produce thermal energy storage within a short time. 
         [0050]    Additionally, the system may also be run in bypass mode where air conditioner unit #2  103  may operate without the assistance of either the thermal energy storage unit  106  or air conditioner unit #1  102  to supply conventional air conditioning to the load heat exchanger  122 . 
         [0051]      FIG. 4  illustrates an embodiment (similar to that detailed in  FIG. 3 ) of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil with an isolated primary refrigerant loop. As with the embodiment of  FIG. 3 , this embodiment may function with or without an accumulator vessel or URMV (universal refrigerant management vessel), and is depicted in  FIG. 4  with the vessel in place. This embodiment also functions in four principal modes of operation: ice-make (charging), ice-melt (cooling), ice-melt/boost (high capacity cooling), and bypass mode. Ice-make mode in the primary refrigerant loop utilizing air conditioner unit #1  102  is identical to that of  FIG. 1 . 
         [0052]    In ice-melt only (cooling) mode, the primary refrigerant loop driven by air conditioner unit #1  102  can continue to cool, can be shut down, or can be disengaged (valves not shown). Cool liquid refrigerant is drawn from the thermal energy storage unit  106  and is transported by thermosiphon or optionally pumped by a liquid pump  121  to a primary side of an isolating heat exchanger  162  where cooling is transferred to the secondary side of the isolating heat exchanger  162 . Warm refrigerant is then returned to the thermal energy storage unit  106  where it is cooled by the solid phase change material  153  and/or the liquid phase change material  152  that are in thermal contact with the primary heat exchanger  160 . 
         [0053]    Refrigerant within the secondary side of the isolating heat exchanger  162  is cooled by the primary side and flows by thermosiphon or optional pump  120  through a 3-way valve  188  to load heat exchanger  122  where cooling is transferred from the refrigerant to a load. The warm mixture of liquid and vapor phase refrigerant leaves the load heat exchanger  122  where the mixture is returned to the secondary side of the isolating heat exchanger  162  now acting as a condenser, through a 3-way valve  186 . Vapor phase refrigerant is cooled and condensed by drawing cooling from the primary side of the isolating heat exchanger  162  where it becomes again available for load cooling. 
         [0054]    In ice-melt/boost (high capacity cooling) mode, the primary refrigerant loop driven by air conditioner unit #1  102  can again continue to cool, can be shut down, or can be disengaged (valves not shown). In addition to the cooling provided by ice-melt from the thermal energy storage unit  106 , air conditioner unit #2  103  may operate to additionally boost the cooling provided to the load heat exchanger  122 . When in operation, air conditioner unit #2  103  utilizes a compressor  114  to compress cold, low pressure refrigerant gas to hot, high-pressure gas. Next, a condenser  116  removes much of the heat in the gas and discharges the heat to the atmosphere. The refrigerant leaves the condenser  116  as a warm, high-pressure liquid refrigerant delivered through a high-pressure liquid line  113  through an optional refrigerant receiver  190  and solenoid valve (SV-1)  180  to an expansion valve  170 . Like expansion device  130 , this second expansion device  131  may be a conventional or non-conventional thermal expansion valve, a mixed-phase regulator, and surge vessel (reservoir) or the like. 
         [0055]    Refrigerant is metered and regulated by expansion valve  170  and transferred to a 3-way valve  188 . Upon leaving the 3-way valve  188 , refrigerant flows to the load heat exchanger  122  where cooling is transferred to a cooling load. Warm vapor or liquid/vapor mixture refrigerant leaves the load heat exchanger  122  where the temperature of the refrigerant is sensed with a temperature sensor  172  that is in communication with expansion valve  170 . The temperature of the refrigerant at this sensing point acts as a feedback and regulation mechanism in combination with the expansion valve  170  thereby controlling the amount of cooling transmitted to the cooling load. 
         [0056]    The refrigerant is then controlled by 3-way valve  186  that directs the refrigerant to enter the suction line  119 , back to air conditioner #2  103  where it is fed to the compressor  114  and re-condensed into liquid by condenser  116 . 
         [0057]    With both the thermal energy storage unit  106  and air conditioner unit #2  103  operating in conjunction, a very high cooling capacity is realized within the system. This boost mode may be accomplished with shared refrigerant lines as depicted in  FIG. 4 , or with a separate set of refrigerant lines (not shown) where the thermal energy storage unit  106  and air conditioner unit #2  103  may be independently pumped into and out of the load heat exchanger  122 . This type of embodiment would also be favorable to a load heat exchanger that contains multiple cooling coils or a mini-split evaporator. 
         [0058]    Additionally, the system may also be run in bypass mode where air conditioner unit #2  103  may operate without the assistance of either the thermal energy storage unit  106  (via the isolating heat exchanger  162 ) or air conditioner unit #1  102  to supply conventional air conditioning to the load heat exchanger  122 . 
         [0059]    As with the embodiments described in  FIGS. 2 and 3 , the isolation heat exchanger  162  provides additional control and refrigerant management to the overall system by reducing the line volumes and path length variability that can be seen in the embodiment of  FIG. 4 . Additionally, since the primary and secondary refrigerant loops are isolated from one another, different refrigerants maybe used within each loop of the system. 
         [0060]      FIG. 5  illustrates an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil with a sub-cooled secondary refrigerant loop. As with the embodiment of  FIG. 4 , this embodiment may function with or without an accumulator vessel or URMV (universal refrigerant management vessel) on the primary refrigerant loop, and is depicted in  FIG. 5  with the vessel in place. This embodiment functions in five principal modes of operation: ice-make (charging), ice-melt (cooling), ice-melt/boost (high capacity cooling), ice-melt/sub-cool (high capacity cooling) mode and bypass mode. Ice-make mode in the primary refrigerant loop utilizing air conditioner unit #1  102  is identical to that of  FIG. 1 . 
         [0061]    In ice-melt only (cooling) mode, the cooling loop utilizing the thermal storage unit  106  is similar to that of  FIG. 3 . In this mode, the primary refrigerant loop driven by air conditioner unit #1  102  can continue to cool, can be shut down, or can be disengaged (valves not shown). Cool liquid refrigerant is drawn from the thermal energy storage unit  106  and is transported by thermosiphon or pumped by an optional liquid pump  120  through two 3-way valves  189  and  188  to the load heat exchanger  122  where cooling is transferred to a load. The warm mixture of liquid and vapor phase refrigerant leaves the load heat exchanger  122  where the mixture is returned to the thermal energy storage unit  106  now acting as a condenser, through a third 3-way valve  186 . Vapor phase refrigerant is cooled and condensed by drawing cooling from the cold fluid or ice where it becomes again available for load cooling. 
         [0062]    In ice-melt/boost (high capacity cooling) mode, the primary refrigerant loop driven by air conditioner unit #1  102  can again continue to cool, can be shut down, or can be disengaged (valves not shown). In addition to the cooling provided by ice-melt from the thermal energy storage unit  106 , air conditioner unit #2  103  may operate to additionally boost the cooling provided to the load heat exchanger  122 . When in operation, air conditioner unit #2  103  utilizes a compressor  114  to compress cold, low pressure refrigerant gas to hot, high-pressure gas. Next, condenser  116  removes much of the heat in the gas and discharges the heat to the atmosphere. The refrigerant leaves the condenser  116  as a warm, high-pressure liquid refrigerant delivered through a high-pressure liquid line  113  through an optional refrigerant receiver  190  and solenoid valve (SV-1)  180  through a secondary side of a sub-cooling heat exchanger  163  and then to an expansion device  131 . Like expansion device  130 , this second expansion device  131  may be a conventional or non-conventional thermal expansion valve, a mixed-phase regulator and surge vessel (reservoir) or the like. 
         [0063]    Refrigerant is metered and regulated by expansion device  13  land transferred to a 3-way valve  188 . Upon leaving the 3-way valve  188 , refrigerant flows to the load heat exchanger  122  where cooling is transferred to a cooling load. Warm vapor or liquid/vapor mixture refrigerant leaves the load heat exchanger  122  and is then controlled by 3-way valve  186  that directs the refrigerant to the suction line  119 , back to air conditioner #2  103  where it is fed to the compressor  114  and re-condensed into liquid by condenser  116 . 
         [0064]    In ice-melt/sub-cool (high capacity cooling) mode, the primary refrigerant loop driven by air conditioner unit #1  102  can again continue to cool, can be shut down, or can be disengaged (valves not shown). In this embodiment, the cooling provided by ice-melt from the thermal energy storage unit  106  is used to sub-cool the refrigerant that leaves air conditioner #2  103  thereby increasing the cooling capacity of the refrigerant and in effect increasing the cooling capacity of air conditioner #2  103 . 
         [0065]    In this mode, cool liquid refrigerant leaves the lower portion of the insulated tank  140  via lower header assembly  156  and is propelled by a thermosiphon or optional pump  120  through a 3-way valve (3WV-3)  189  to a primary side of a sub-cooling heat exchanger  163  where cooling is transferred to the secondary side of the heat exchanger. The secondary side of a sub-cooling heat exchanger  163  is a refrigerant that has been compressed and condensed by air conditioner #2  103  and fed through liquid line  113  through and optional refrigerant receiver  190  and check valve (SV-1)  180 . Once cooling is transferred from the thermal energy storage unit  106  to the refrigerant produced by air conditioner unit #2  103 , the sub-cooled refrigerant is fed to the expansion device  131 . 
         [0066]    Sub-cooled refrigerant is metered and regulated by expansion device  131  and transferred to a 3-way valve  188 . Upon leaving the 3-way valve  188 , refrigerant flows to the load heat exchanger  122  where cooling is transferred to a cooling load. Warm vapor or liquid/vapor mixture refrigerant leaves the load heat exchanger  122  and is then controlled by 3-way valve  186  that directs the refrigerant to the suction line  119 , back to air conditioner #2  103  where it is fed to the compressor  114  and re-condensed into liquid by condenser  116 . Subcooling increases the capacity of the refrigeration loop without increasing the size of the compressor. It can also be accomplished without sharing the refrigeration loops. 
         [0067]      FIG. 6  illustrates an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil with an isolated secondary refrigerant loop. As with the embodiment of  FIG. 5 , this embodiment may function with or without an accumulator vessel or URMV (universal refrigerant management vessel) on the primary refrigerant loop, and is depicted in  FIG. 6  with the vessel in place. This embodiment functions in five principal modes of operation: ice-make (charging), ice-melt (cooling), ice-melt/boost (high capacity cooling), ice-melt/sub-cool (high capacity cooling) mode and bypass mode. Ice-make mode in the primary refrigerant loop utilizing air conditioner unit #1  102  is identical to that of  FIG. 1 . 
         [0068]    In ice-melt mode, cool liquid refrigerant leaves the lower portion of the insulated tank  140  via lower header assembly  156  and is propelled by a thermosiphon or optional pump  121  to a primary side of an isolating heat exchanger  162  where cooling is transferred to the secondary side of this isolating heat exchanger  162  and to a secondary refrigerant loop. Warmed refrigerant is then returned from the primary side of the isolating heat exchanger  162  back to the thermal energy storage unit  106  where it is cooled again. Refrigerant that is cooled by the primary side of the isolating heat exchanger  162  loop is propelled in the secondary refrigerant loop by a thermosiphon or optional pump  120  through a 3-way valve (3WV-3)  189  and then through another 3-way valve (3WV-2)  188  to a load heat exchanger  122  where cooling is transferred to a load. 
         [0069]    Warm vapor or liquid/vapor mixture leaves load heat exchanger  122  where it is returned through a 3-way valve (3WV-1)  186  back to the secondary side of this isolating heat exchanger  162  where it is again cooled by the primary side of this isolating heat exchanger  162  being fed by the thermal energy storage unit  106  which draws cooling from the solid phase change material  153  and/or liquid phase change material  152  surrounding the coils. 
         [0070]    In ice-melt/boost (high capacity cooling) mode, the primary refrigerant loop driven by air conditioner unit #1  102  can again continue to cool, can be shut down, or can be disengaged (valves not shown). In addition to the cooling provided by ice-melt from the thermal energy storage unit  106 , air conditioner unit #2  103  may operate to additionally boost the cooling provided to the load heat exchanger  122 . When in operation, air conditioner unit #2  103  produces refrigerant that leaves the condenser  116  as a warm, high-pressure liquid delivered through a high-pressure liquid line  113  through an optional refrigerant receiver  190  and solenoid valve (SV-1)  180  through a secondary side of a sub-cooling heat exchanger  163  and then to an expansion device  131 . 
         [0071]    Refrigerant is metered and regulated by expansion device  13  land transferred to a 3-way valve  188 . Upon leaving the 3-way valve  188 , refrigerant flows to the load heat exchanger  122  where cooling is transferred to a cooling load. Warm vapor or liquid/vapor mixture refrigerant leaves the load heat exchanger  122  and is then controlled by 3-way valve  186  that directs the refrigerant to the suction line  119 , back to air conditioner #2  103  where it is fed to the compressor  114  and re-condensed into liquid by condenser  116 . 
         [0072]    In ice-melt/sub-cool (high capacity cooling) mode, the primary refrigerant loop driven by air conditioner unit #1  102  can again continue to cool, can be shut down, or can be disengaged. In this embodiment, the cooling provided by ice-melt from the thermal energy storage unit  106  is used to sub-cool the refrigerant that leaves air conditioner #2  103  via an isolating heat exchanger  162 , thereby increasing the cooling capacity of the refrigerant and in effect increasing the cooling capacity of air conditioner #2  103 . 
         [0073]    In this mode, cool liquid refrigerant leaves the lower portion of the insulated tank  140  via lower header assembly  156  and is propelled by a thermosiphon or optional pump  121  to a primary side of an isolating heat exchanger  162  where cooling is transferred to the secondary side of this isolating heat exchanger  162  and to a secondary refrigerant loop. Warmed refrigerant is then returned from the primary side of the isolating heat exchanger  162  back to the thermal energy storage unit  106  where it is cooled again. Refrigerant that is cooled by the primary side of the isolating heat exchanger  162  loop is propelled in the secondary refrigerant loop by a thermosiphon or optional pump  120  through a 3-way valve (3WV-3)  189  to a primary side of a sub-cooling heat exchanger  163  where cooling is transferred to the secondary side of the heat exchanger. The secondary side of a sub-cooling heat exchanger  163  is a refrigerant that has been compressed and condensed by air conditioner #2  103  and fed through liquid line  113  through and optional refrigerant receiver  190  and check valve (SV-1)  180 . Once cooling is transferred from the thermal energy storage unit  106  and the refrigerant is produced by air conditioner unit #2  103 , the sub-cooled refrigerant is fed to the expansion device  131 . 
         [0074]    Sub-cooled refrigerant is metered and regulated by expansion device  131  and transferred to a 3-way valve  188 . Upon leaving the 3-way valve  188 , refrigerant flows to the load heat exchanger  122  where cooling is transferred to a cooling load. Warm vapor or liquid/vapor mixture refrigerant leaves the load heat exchanger  122  and is then controlled by 3-way valve  186  that directs the refrigerant to the suction line  119 , back to air conditioner #2  103  where it is fed to the compressor  114  and re-condensed into liquid by condenser  116 . 
         [0075]      FIG. 7  illustrates an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil with an isolated secondary refrigerant loop and an isolated sub-cooled second air conditioner loop. As with the embodiment of  FIG. 6 , this embodiment may function with or without an accumulator vessel or URMV (universal refrigerant management vessel) on the primary refrigerant loop, and is depicted in  FIG. 7  with the vessel in place. This embodiment functions in four principal modes of operation: ice-make (charging), ice-melt (cooling), ice-melt/boost (high capacity cooling), and bypass mode. Ice-make mode in the primary refrigerant loop utilizing air conditioner unit #1  102  is identical to that of  FIG. 1 . 
         [0076]    In ice-melt mode, cool liquid refrigerant leaves the lower portion of the insulated tank  140  via lower header assembly  156  and is propelled by a thermosiphon or optional pump  121  to a primary side of an isolating heat exchanger  162  where cooling is transferred to the secondary side of this isolating heat exchanger  162  and to a secondary refrigerant loop. Warmed refrigerant is then returned from the primary side of the isolating heat exchanger  162  back to the thermal energy storage unit  106  where it is cooled again. Refrigerant that is cooled by the primary side of the isolating heat exchanger  162  loop is propelled in the secondary refrigerant loop by a thermosiphon or optional pump  120  through a solenoid valve (SV-2)  182  and to a load heat exchanger  122  where cooling is transferred to a load. 
         [0077]    Warm vapor or liquid/vapor mixture leaves load heat exchanger  122  where it is returned to the secondary side of this isolating heat exchanger  162  where it is again cooled by the primary side of this isolating heat exchanger  162  being fed by the thermal energy storage unit  106  which draws cooling from the solid phase change material  153  and/or liquid phase change material  152  surrounding the coils. 
         [0078]    In ice-melt/boost (high capacity cooling) mode, the primary refrigerant loop driven by air conditioner unit #1  102  can again continue to cool, can be shut down, or can be disengaged (valves not shown). In addition to the cooling provided by ice-melt from the thermal energy storage unit  106 , air conditioner unit #2  103  may operate to additionally boost the cooling provided to the load heat exchanger  122 . When in operation, air conditioner unit #2  103  produces refrigerant that leaves the condenser  116  as a warm, high-pressure liquid delivered through a high-pressure liquid line  113  through an optional refrigerant receiver  190  and solenoid valve (SV-1)  180  to an expansion device  131  and then through a primary side of an isolating heat exchanger  165 . 
         [0079]    Refrigerant is metered and regulated by the expansion device  131  and transfers cooling from the primary side of the isolating heat exchanger  165  to the secondary side. Refrigerant flowing on the secondary side of the isolating heat exchanger  165  is driven by thermosiphon or optional pump  120  to the load heat exchanger  122  where cooling is transferred to a cooling load. Warm vapor or liquid/vapor mixture refrigerant leaves the load heat exchanger  122  and returns through another solenoid valve (SV-3)  184  back to the isolating heat exchanger  165  where it is cooled again by the primary side of the heat exchanger being fed cooling from air conditioner #2  130 . 
         [0080]      FIG. 8  illustrates an embodiment of multiple thermal energy storage and cooling systems with two air conditioner loops and two thermal energy storage units utilizing multiple evaporator coil paths that include an isolated evaporator coil. As with previous embodiments, this embodiment may function with or without an accumulator vessel or URMV (universal refrigerant management vessel) on the primary refrigerant loop on either refrigerant management and distribution system  104 ,  105 , and is depicted in  FIG. 8  with the vessel in place for each. This embodiment functions in four principal modes of operation, ice-make (1 or 2 AC units charging), ice-melt (1 or 2 AC units cooling), ice-make/ice-melt (1 AC unit charging, 1 AC unit cooling). Ice-make mode in the primary refrigerant loop utilizing air conditioner unit #1  102  and/or air conditioner unit #2  103  is identical to that of  FIG. 1 . 
         [0081]    In ice-melt mode, one or both thermal energy storage units  106 / 107  may be utilized for cooling. In this embodiment, cool liquid refrigerant or coolant leaves the lower portion of the insulated tank  140  via lower header assembly  156  and is propelled by a thermosiphon or optional pump  121 / 122  to a primary side of an isolating heat exchanger  162 / 163  where cooling is transferred to the secondary side of this isolating heat exchanger  162 / 163  and to a secondary loop. Warmed refrigerant or coolant is then returned from the primary side of the isolating heat exchanger  162 / 163  back to the thermal energy storage unit  106  and/or  107  where it is cooled again. Refrigerant or coolant that is cooled by the primary side of the isolating heat exchanger  162 / 163  loop is propelled in the secondary cooling loop by a thermosiphon or optional pump  120  to a load heat exchanger  122  where cooling is transferred to a load. 
         [0082]    Warm refrigerant or coolant leaves load heat exchanger  122  where it is returned to the secondary side of the first isolating heat exchanger  162  where it is again cooled by the primary side of this first isolating heat exchanger  162  being fed by the thermal energy storage unit  106  which draws cooling from the solid phase change material  153  and or liquid phase change material  152  surrounding the coils. The refrigerant or coolant leaves the first isolating heat exchanger  163  and travels to the secondary side of the second isolating heat exchanger  163  where it is again cooled by the primary side of this second isolating heat exchanger  163  being fed by the thermal energy storage unit  107  which draws cooling from the solid phase change material  153  and or liquid phase change material  152  surrounding the coils. 
         [0083]    In ice-make/ice-melt mode, one AC unit is charging a thermal energy storage unit while the other AC unit can either charge a second thermal energy storage unit or can be shut down. For example, air conditioner unit #1  102  may be forming ice within thermal energy storage unit #1  106 . Cooling is transferred from the thermal energy storage unit #1  106  to the first isolating heat exchanger  162  which transfers cooling to the cooling loop on the secondary side and then to the load heat exchanger  122 . During this period, air conditioner unit #2  103  may be dormant or utilizing air conditioner unit #1  102  to charge the second thermal energy storage unit  107 . Thus in this embodiment, as with all the disclosed embodiments, the time periods for charging and discharging the thermal energy storage units and the air conditioning units is independent of sequence and coincidence. Various “time periods” even though referred to as a “first time period” or a “second time period” may be concurrent or reversed in actual order that they are performed. 
         [0084]    The foregoing description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art.