THERMAL ENERGY STORAGE AND COOLING SYSTEM WITH MULTIPLE COOLING LOOPS UTILIZING A COMMON EVAPORATOR COIL

Info

Publication number: 20090133412
Type: Application
Filed: Nov 26, 2008
Publication Date: May 28, 2009
Applicant: Ice Energy, Inc. (Windsor, CO)
Inventors: Ramachandran Narayanamurthy (Loveland, CO), Brian Parsonnet (Fort Collins, CO), Donald Thomas Cook (Berthoud, CO)
Application Number: 12/324,369

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

Description

CROSS REFERENCE TO RELATED APPLICATION

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

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.

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

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.

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.

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.

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.

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

In the drawings,

FIG. 1 illustrates an embodiment of a thermal energy storage and cooling system with multiple condensing units utilizing a common evaporator coil.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Claims

1. 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 said first condensing unit; and, a thermal energy storage unit comprising a primary heat exchanger connected between said first expansion device and said first condensing unit that acts as a first evaporator and is located within a tank filled with a fluid, said primary heat exchanger that facilitates heat transfer from said first refrigerant from said first condenser to cool said fluid within said tank;

a second refrigerant loop containing additional said refrigerant comprising a load heat exchanger connected to said thermal energy storage unit that transfers cooling from said thermal energy storage unit to said load heat exchanger to a heat load;

a third refrigerant loop containing additional said refrigerant comprising: a second condensing unit comprising a second compressor and a second condenser; and, a second expansion device connected downstream of said second condensing unit, and said load heat exchanger connected between said second expansion device and said second condensing unit that transfers cooling capacity of said second condensing unit to said load heat exchanger to a heat load.

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 first expansion device and said second expansion device are 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. 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 said first condensing unit; and, a thermal energy storage unit comprising a primary heat exchanger connected between said first expansion device and said first condensing unit that acts as a first evaporator and is located within a tank filled with a fluid, said primary heat exchanger that facilitates heat transfer from said first refrigerant from said first condenser to cool said fluid within said tank;

a primary side of an isolating heat exchanger that draws cooling from said thermal energy storage unit and transfers cooling to a secondary side of said isolating heat exchanger;

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 said second condensing unit; and, a load heat exchanger connected between said second expansion device and said second condensing unit that transfers cooling capacity of said second refrigerant to said heat load in a first time period, said load heat exchanger that is connected to said secondary side of said isolating heat exchanger and that transfers cooling from said secondary side of said isolating heat exchanger to said heat load in a second time period.

8. The system of claim 7 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.

9. The system of claim 7 wherein said first expansion device and said second expansion device are chosen from the group consisting of a thermal expansion valve, an electronic expansion valve and a mixed-phase regulator.

10. The system of claim 7 wherein said fluid is a eutectic material.

11. The system of claim 7 wherein said fluid is water.

12. The system of claim 7 wherein said load heat exchanger is at least one mini-split evaporator.

13. The system of claim 7 wherein said first refrigerant is a different material from said second refrigerant.

14. The system of claim 7 wherein said first time period is concurrent with said second time period.

15. 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 said first condensing unit; and, a thermal energy storage unit comprising a primary heat exchanger connected between said first expansion device and said first condensing unit that acts as a first evaporator and is located within a tank filled with a fluid, said primary heat exchanger that facilitates heat transfer from said first refrigerant from said first condenser to cool said fluid within said tank;

a primary side of a sub-cooling heat exchanger that draws cooling from said thermal energy storage unit and transfers cooling to a secondary side of said sub-cooling heat exchanger;

a second refrigerant loop containing additional said refrigerant comprising: a second condensing unit comprising a second compressor and a second condenser; said second condensing unit that supplies said refrigerant to said secondary side of said sub-cooling heat exchanger where cooling is transferred from said secondary side of said sub-cooling heat exchanger to said additional said refrigerant thereby creating sub-cooled refrigerant; a second expansion device connected downstream of said secondary side of said sub-cooling heat exchanger; and, a load heat exchanger connected between said second expansion device and said second condensing unit that transfers cooling capacity of said sub-cooled refrigerant to said heat load in a first time period, said load heat exchanger that is connected to said thermal energy storage unit and that transfers cooling from said thermal energy storage unit to said heat load in a second time period.

16. The system of claim 15 wherein said first expansion device and said second expansion device are chosen from the group consisting of a thermal expansion valve, an electronic expansion valve and a mixed-phase regulator.

17. The system of claim 15 wherein said fluid is a eutectic material.

18. The system of claim 15 wherein said fluid is water.

19. The system of claim 15 wherein said load heat exchanger is at least one mini-split evaporator.

20. The system of claim 15 wherein said first time period is concurrent with said second time period.

21. 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 said first condensing unit; and, a thermal energy storage unit comprising a primary heat exchanger connected between said first expansion device and said first condensing unit that acts as a first evaporator and is located within a tank filled with a fluid, said primary heat exchanger that facilitates heat transfer from said first refrigerant from said first condenser to cool said fluid within said tank;

a primary side of an isolating heat exchanger that draws cooling from said thermal energy storage unit and transfers cooling to a secondary side of said isolating heat exchanger;

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 said second condensing unit; a primary side of a sub-cooling heat exchanger connected between said second expansion device and said second condenser; a secondary side of said sub-cooling heat exchanger that draws cooling from said secondary side of said isolating heat exchanger to sub-cool said second refrigerant in said primary side of said sub-cooling heat exchanger; and, a load heat exchanger that draws cooling from said primary side of said sub-cooling heat exchanger or said secondary side of said isolating heat exchanger and transfers cooling to a load.

22. The system of claim 21 wherein said first expansion device and said second expansion device are chosen from the group consisting of a thermal expansion valve, an electronic expansion valve and a mixed-phase regulator.

23. The system of claim 21 wherein said fluid is a eutectic material.

24. The system of claim 21 wherein said fluid is water.

25. The system of claim 21 wherein said load heat exchanger is at least one mini-split evaporator.

26. The system of claim 21 wherein said first refrigerant is a different material from said second refrigerant.

27. 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 said first condensing unit; and, a thermal energy storage unit comprising a primary heat exchanger connected between said first expansion device and said first condensing unit that acts as a first evaporator and is located within a tank filled with a fluid, said primary heat exchanger that facilitates heat transfer from said first refrigerant from said first condenser to cool said fluid within said 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 said second condensing unit; a primary side of a first isolating heat exchanger that draws cooling from said thermal energy storage unit and transfers cooling to a secondary side of said first isolating heat exchanger; a primary side of second a isolating heat exchanger connected between said second expansion device and said second condenser that transfers cooling to a secondary side of said second isolating heat exchanger; and,

a load heat exchanger receives cooling from a secondary side of said first isolating heat exchanger, or said secondary side of said second isolating heat exchanger, or a combination of said secondary side of said first isolating heat exchanger and said secondary side of said second isolating heat exchanger.

28. The system of claim 27 wherein said first expansion device and said second expansion device are chosen from the group consisting of a thermal expansion valve, an electronic expansion valve and a mixed-phase regulator.

29. The system of claim 27 wherein said fluid is a eutectic material.

30. The system of claim 27 wherein said fluid is water.

31. The system of claim 27 wherein said load heat exchanger is at least one mini-split evaporator.

32. The system of claim 27 wherein said first refrigerant is a different material from said second refrigerant.

33. 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 said 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 said fluid and forming ice within said tank during a first time period;

cooling said refrigerant in said primary heat exchanger with said ice and transferring said refrigerant to a load heat exchanger to provide load cooling;

returning said refrigerant to said primary heat exchanger; and,

re-cooling said refrigerant during a second time period;

compressing and condensing said refrigerant with a second air conditioner unit to create a second high-pressure refrigerant; and,

expanding said second high-pressure refrigerant in said load heat exchanger to provide load cooling during a third time period.

34. The method of claim 33 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 first air conditioner unit and said primary heat exchanger.

35. The method of claim 33 wherein said steps of said second time period are performed concurrent with said steps of said third time period.

36. A method of providing cooling with a refrigerant-based thermal energy storage and cooling system comprising the steps of:

compressing and condensing a first refrigerant to create a first high-pressure refrigerant;

providing cooling to a primary heat exchanger by expanding said first 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; and,

freezing a portion of said fluid to form ice within said tank during a first time period;

transferring cooling from said fluid and said ice to a primary side of an isolating heat exchanger;

transferring cooling from said primary side of said isolating heat exchanger to a second refrigerant on a secondary side of said isolating heat exchanger; and,

transferring cooling from cooled said second refrigerant to a load heat exchanger to provide load cooling during a second time period;

compressing and condensing said second refrigerant to create a second high-pressure refrigerant; and,

expanding said second high-pressure refrigerant in said load heat exchanger to provide load cooling during a third time period.

37. The method of claim 36 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 first air conditioner unit and said primary heat exchanger.

38. The method of claim 36 further comprising the step of:

managing volumes and phase of said second refrigerant with a refrigerant receiver, said refrigerant receiver in fluid communication with said second air conditioner unit and said isolating heat exchanger.

39. The method of claim 36 wherein said steps of said second time period are performed concurrent with said steps of said third time period.

40. 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 said first 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; and,

freezing a portion of said fluid to form ice within said tank during a first time period;

transferring cooling from said fluid and said ice to a load heat exchanger to provide load cooling in a second time period;

compressing and condensing said refrigerant with a second air conditioner unit to create a second high-pressure refrigerant;

transferring cooling from said fluid and said ice to a primary side of a sub-cooling heat exchanger;

transferring said second high-pressure refrigerant from said second air conditioner unit to a secondary side of said sub-cooling heat exchanger;

sub-cooling said second high-pressure refrigerant by transferring cooling from said primary side of said sub-cooling heat exchanger to said secondary side of said sub-cooling heat exchanger;

transferring sub-cooled said second high-pressure refrigerant from said secondary side of said isolating heat exchanger to a load heat exchanger;

expanding said sub-cooled said second high-pressure refrigerant in said load heat exchanger to provide load cooling; and,

returning said refrigerant to said second air conditioner unit during a third time period.

41. The method of claim 40 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 first air conditioner unit and said primary heat exchanger.

42. The method of claim 40 further comprising the step of:

managing volumes and phase of said second refrigerant with a refrigerant receiver, said refrigerant receiver in fluid communication with said second air conditioner unit and said sub-cooling heat exchanger.

43. The method of claim 40 wherein said steps of said second time period are performed concurrent with said steps of said third time period.

44. A method of providing cooling with a thermal energy storage and cooling system comprising the steps of:

compressing and condensing a first refrigerant with a first air conditioner unit to create a first high-pressure refrigerant;

providing cooling to a primary heat exchanger by expanding said first 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; and,

freezing a portion of said fluid to form ice within said tank during a first time period;

transferring cooling from said fluid and said ice to a primary side of a first isolating heat exchanger;

transferring cooling from said primary side of said first isolating heat exchanger to a secondary side of said first isolating heat exchanger; and,

transferring cooling from said secondary side of said first isolating heat exchanger to a load heat exchanger to provide load cooling in a second time period;

compressing and condensing a second refrigerant with a second air conditioner unit to create a second high-pressure refrigerant;

transferring cooling from said second high-pressure refrigerant to a primary side of a second isolating heat exchanger;

transferring cooling from said primary side of said second isolating heat exchanger to a secondary side of said second isolating heat exchanger; and,

transferring cooling from said secondary side of said second isolating heat exchanger to said load heat exchanger to provide load cooling in a third time period.

45. The method of claim 44 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 first air conditioner unit and said primary heat exchanger.

46. The method of claim 44 further comprising the step of:

managing volumes and phase of said second refrigerant with a refrigerant receiver, said refrigerant receiver in fluid communication with said second air conditioner unit and said second isolating heat exchanger.

47. The method of claim 44 wherein said steps of said second time period are performed concurrent with said steps of said third time period.

48. A method of providing cooling with a thermal energy storage and cooling system comprising the steps of:

compressing and condensing a first refrigerant with a first air conditioner unit to create a first high-pressure refrigerant;

providing cooling to a first primary heat exchanger by expanding said first high-pressure refrigerant in said first primary heat exchanger that is constrained within a first tank containing a first fluid capable of a phase change between liquid and solid; and,

freezing a portion of said first fluid to form first ice within said tank during a first time period;

transferring cooling from said first fluid and said first ice to a primary side of a first isolating heat exchanger;

transferring cooling from said primary side of said first isolating heat exchanger to a secondary side of said first isolating heat exchanger; and,

transferring cooling from said secondary side of said first isolating heat exchanger to a load heat exchanger to provide load cooling in a second time period;

compressing and condensing a second refrigerant with a second air conditioner unit to create a second high-pressure refrigerant;

providing cooling to a second primary heat exchanger by expanding said second high-pressure refrigerant in said second primary heat exchanger that is constrained within a second tank containing a second fluid capable of a phase change between liquid and solid; and,

freezing a portion of said second fluid to form second ice within said second tank during a third time period;

transferring cooling from said second fluid and said second ice to a primary side of a second isolating heat exchanger;

transferring cooling from said primary side of said second isolating heat exchanger to a secondary side of said second isolating heat exchanger; and,

transferring cooling from said secondary side of said second isolating heat exchanger to said load heat exchanger to provide load cooling in a fourth time period.

49. The method of claim 48 further comprising the step of:

managing volumes and phase of said first refrigerant with a first refrigerant management vessel, said first refrigerant management vessel in fluid communication with said first air conditioner unit and said first primary heat exchanger.

50. The method of claim 48 further comprising the step of:

managing volumes and phase of said second refrigerant with a second refrigerant management vessel, said second refrigerant management vessel in fluid communication with said second air conditioner unit and said second primary heat exchanger.

51. The method of claim 48 wherein said steps of said first time period are performed concurrent with said steps of said fourth time period.

52. The method of claim 48 wherein said steps of said second time period are performed concurrent with said steps of said third time period.

53. The method of claim 48 wherein said steps of said second time period are performed concurrent with said steps of said fourth time period.

54. A means for providing cooling with a thermal energy storage and cooling system comprising:

a first air conditioner means for compressing and condensing a first refrigerant to create a first high-pressure refrigerant;

a means for providing cooling to a primary heat exchanger by expanding said first 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; and,

a means for freezing a portion of said fluid to form ice within said tank during a first time period;

a means for transferring cooling from said first high-pressure refrigerant to a load heat exchanger to provide load cooling during a second time period;

a means for transferring cooling from said fluid and said ice to a load heat exchanger to provide load cooling during a third time period;

a second air conditioner means for compressing and condensing additional said refrigerant to create a second high-pressure refrigerant;

a means for transferring cooling from said second high-pressure refrigerant to said load heat exchanger to provide load cooling during a fourth time period.