Modular Thermal Energy Storage System

Abstract

A thermal management system having integrated thermal energy storage is described herein. The thermal energy storage is advantageously provided in a modular structure including a lead thermal energy storage module and one or more extension thermal energy storage modules. The lead thermal energy storage module is advantageously designed to connect, in a modular manner, with an arbitrary number of the extension thermal energy storage modules to expand the total thermal energy storage capacity of the modular thermal energy storage. Each thermal energy storage module provides nominal thermal energy storage capacity to the thermal management system such that any desired heating or cooling capacity can be provided.

Claims

1. A thermal management system comprising: a thermal energy transport fluid loop through which thermal energy transport fluid circulates; a first thermal energy storage module having a first fluid connector, a second fluid connector, a third fluid connector, and a fourth fluid connector, the first fluid connector and the second fluid connector being connected to the thermal energy transport fluid loop such that the thermal energy transport fluid flows into the first fluid connector and out of the second fluid connector, the first fluid connector being connected to the third fluid connector such that the thermal energy transport fluid flows from the first fluid connector to the third fluid connector, the fourth fluid connector being connected to the second fluid connector such that the thermal energy transport fluid flows from the fourth fluid connector to the second fluid connector; and at least one second thermal energy storage module connected between the third fluid connector and the fourth fluid connector of the first thermal energy storage module such that the thermal energy transport fluid flows through the at least one second thermal energy storage module.

2. The thermal management system according to claim 1, the first thermal energy storage module further comprising: a first thermal storage medium; and a first heat exchanger connected such that the thermal energy transport fluid flows through the first heat exchanger, wherein the first heat exchanger is arranged with respect to the first thermal storage medium so as to exchange thermal energy between the thermal energy transport fluid and the first thermal storage medium.

3. The thermal management system according to claim 2, wherein the first heat exchanger is connected between the first fluid connector and the third fluid connector.

4. The thermal management system according to claim 2, wherein the first heat exchanger is connected between the second fluid connector and the fourth fluid connector.

5. The thermal management system according to claim 2, wherein: the first heat exchanger is connected between the first fluid connector and the second fluid connector; the first fluid connector is connected to the third fluid connector; and the second fluid connector is connected to the fourth fluid connector.

6. The thermal management system according to claim 1, the first thermal energy storage module further comprising: a first compressor connected between the first fluid connector and the third fluid connector; and a first expander connected between the second fluid connector and the fourth fluid connector.

7. The thermal management system according to claim 1, wherein the at least one second thermal energy storage module is a plurality of second thermal energy storage modules connected between the fourth fluid connector and the third fluid connector of the first thermal energy storage module.

8. The thermal management system according to claim 7, wherein the plurality of second thermal energy storage modules are connected in series with one another between the fourth fluid connector and the third fluid connector of the first thermal energy storage module.

9. The thermal management system according to claim 7, wherein the plurality of second thermal energy storage modules are connected in parallel with one another between the fourth fluid connector and the third fluid connector of the first thermal energy storage module.

10. The thermal management system according to claim 7, wherein each second thermal energy storage module in the plurality of second thermal energy storage modules has a respective fifth fluid connector and a respective sixth fluid connector.

11. The thermal management system according to claim 10, each second thermal energy storage module in the plurality of second thermal energy storage modules further comprising: a respective second thermal storage medium; and a respective second heat exchanger connected between the respective fifth fluid connector and the respective sixth fluid connector such that the thermal energy transport fluid flows through the respective second heat exchanger, wherein the respective second heat exchanger is arranged with respect to the respective second thermal storage medium so as to exchange thermal energy between the thermal energy transport fluid and the respective second thermal storage medium.

12. The thermal management system according to claim 10, wherein: the respective fifth fluid connector of each of the plurality of second thermal energy storage modules is connected to one of (i) the third fluid connector of the first thermal energy storage module or (ii) the respective sixth fluid connector of another of the plurality of second thermal energy storage modules; and the respective sixth fluid connector of each of the plurality of second thermal energy storage modules is connected to one of (i) the fourth fluid connector of the first thermal energy storage module or (ii) the respective fifth fluid connector of another of the plurality of second thermal energy storage modules.

13. The thermal management system according to claim 7 further comprising: a fluid pump connected at least one of (i) between the third fluid connector of the first thermal energy storage module and the plurality of second thermal energy storage modules, (ii) between the plurality of second thermal energy storage modules and the fourth fluid connector of the first thermal energy storage module, and (iii) between two second thermal energy storage modules of the plurality of second thermal energy storage modules.

14. The thermal management system according to claim 1, wherein the at least one second thermal energy storage module is connected to the fourth fluid connector and the third fluid connector of the first thermal energy storage module via at least one of brazing, welding, or soldering.

15. The thermal management system according to claim 1, wherein the at least one second thermal energy storage module is connected to the fourth fluid connector and the third fluid connector of the first thermal energy storage module via a connecting device configured to connect piping in an impermanent manner.

16. The thermal management system according to claim 1 further comprising: a plurality of switchable valves configured to connect the first fluid connector and the second fluid connector of the first thermal energy storage module to the thermal energy transport fluid loop, the plurality of switchable valves being operable in (i) a first state to bypass the first thermal energy storage module from the thermal energy transport fluid loop and (ii) at least one second state to connect the first thermal energy storage module in the thermal energy transport fluid loop such that the thermal energy transport fluid circulates through the first thermal energy storage module and the at least one second thermal energy storage module.

17. The thermal management system according to claim 1, further comprising: a third heat exchanger arranged within a first environment; and a fourth heat exchanger arranged within a second environment, wherein the thermal energy transport fluid loop connects the third heat exchanger with the fourth heat exchanger in a closed loop.

18. The thermal management system according to claim 1 further comprising: a second compressor arranged in the thermal energy transport fluid loop; and a second expander arranged in the thermal energy transport fluid loop.

19. A modular thermal energy storage system comprising: a first thermal energy storage module having a first fluid connector, a second fluid connector, a third fluid connector, and a fourth fluid connector, the first fluid connector and the second fluid connector being configured to connect with a thermal energy transport fluid loop of a thermal management system such that thermal energy transport fluid in the thermal energy transport fluid loop flows into the first fluid connector and out of the second fluid connector, the first fluid connector being connected to the third fluid connector such that the thermal energy transport fluid flows from the first fluid connector to the third fluid connector, the fourth fluid connector being connected to the second fluid connector such that the thermal energy transport fluid flows from the fourth fluid connector to the second fluid connector; and at least one second thermal energy storage module connected between the third fluid connector and the fourth fluid connector of the first thermal energy storage module such that the thermal energy transport fluid flows through the at least one second thermal energy storage module.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The foregoing aspects and other features of the system are explained in the following description, taken in connection with the accompanying drawings.

[0008] FIG. 1 shows exemplary components of a heat pump system for a building having integrated thermal energy storage.

[0009] FIG. 2 shows exemplary components of a modular thermal energy storage for integration into a heat pump system.

[0010] FIG. 3A shows a first exemplary configuration of the lead thermal energy storage (TES) module in which the TES heat exchanger is arranged first in series with the extension TES modules.

[0011] FIG. 3B shows a second exemplary configuration of the lead TES module in which the TES heat exchanger is arranged last in series with the extension TES modules.

[0012] FIG. 3C shows a third exemplary configuration of the lead TES module in which the TES heat exchanger is arranged in parallel with the extension TES modules.

DETAILED DESCRIPTION

[0013] For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the disclosure is thereby intended. It is further understood that the present disclosure includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the disclosure as would normally occur to one skilled in the art to which this disclosure pertains.

Overview

[0014] A thermal management system having integrated thermal energy storage is described herein. In the exemplary embodiment of the disclosure, the thermal management system is a heat pump system for heating and cooling a building. However, although the features of the disclosure are primarily described with respect to a heat pump system, it should be appreciated that the thermal management system may similarly comprise an air conditioner for cooling a building, a thermal management system for heating or cooling a motor vehicle, or any other thermal management system that operates using similar principles, such as a refrigerator or freezer.

[0015] The thermal energy storage of the thermal management system is advantageously provided in a modular structure including a lead thermal energy storage module and one or more extension thermal energy storage modules. The lead thermal energy storage module is advantageously designed to connect, in a modular manner, with an arbitrary number of the extension thermal energy storage modules to expand the total thermal energy storage capacity of the modular thermal energy storage. Each thermal energy storage module provides nominal thermal energy storage capacity to the thermal management system such that any desired heating or cooling capacity can be provided.

[0016] This modular thermal energy storage provides flexibility in system size and cost. For example, some buildings and markets may benefit from smaller thermal energy storage that can store up to, for example, 5 kWh of thermal energy, while others might need a larger amount of thermal energy storage that stores up to, for example, 20-40 kWh of thermal energy. The modular thermal energy storage 200 also provides flexibility in the physical layout of the thermal energy storage that is adaptable according to an available footprint. Additionally, the modular thermal energy storage 200 enables favorable economies of scale because they can be manufactured and deployed at a lower cost per kWh at higher production volumes. Moreover, the modular thermal energy storage 200 has greater ease of installation because it can be installed piece by piece, avoiding the use of a crane that might be required to install a single, large, and heavy thermal energy storage unit. Finally, the modular thermal energy storage has a more robust system design, resulting in a lower probability of failure per module, with easier replacement should a failure occur.

Exemplary Heat Pump System Having Integrated Thermal Energy Storage

[0017] In an effort to provide a better understanding of the features of the disclosure, an exemplary thermal management system in the form of a heat pump system is described in detail, which incorporates thermal energy storage.

[0018] FIG. 1 shows exemplary components of a heat pump system 100 for a building having integrated thermal energy storage. In the illustrated example, the heat pump system 100 includes an outside air heat exchanger 104, an inside air heat exchanger 108, a refrigerant loop 112, a compressor 116, and an expander 120. Additionally, the heat pump system 100 includes or is integrated with thermal energy storage module 130 by way of a plurality of switchable valves 140.

[0019] The outside air heat exchanger 104 is configured to transfer heat between a first environment, i.e., including outside air 106, and a refrigerant circulating through the refrigerant loop 112. Structurally, in at least some embodiments, the outside air heat exchanger 104 includes a series of coiled metal tubes or metal fins (not shown), through which the refrigerant circulates, that increase the surface area for heat exchange and facilitate the efficient absorption or dissipation of thermal energy. The outside air heat exchanger 104 is arranged outside of the building and, in at least some embodiments, is provided in a housing, e.g., metal casing, (not shown) to protect it from environmental factors. Additionally, in some embodiments, a fan is mounted inside the housing to blow air over the coiled tubes or fins of the outside air heat exchanger 104 to provide greater heat transfer.

[0020] The inside air heat exchanger 108 is configured to transfer heat between the refrigerant circulating through the refrigerant loop 112 and a second environment, i.e., including inside air 110. Structurally, in at least some embodiments, the inside air heat exchanger 108 includes a series of coiled metal tubes or metal fins (not shown), through which the refrigerant circulates, that increase the surface area for heat exchange and facilitate the efficient absorption or dissipation of thermal energy. The inside air heat exchanger 108 is arranged inside of the building and, in at least some embodiments, is arranged within an indoor ventilation system, such that a fan mounted within the ventilation system blows air through the coiled tubes or fins of the outside air heat exchanger 104 to distribute conditioned air throughout the building.

[0021] The refrigerant loop 112 is a closed, continuous loop system that circulates refrigerant through the various components of the heat pump system 100, enabling the transfer of thermal energy. In some embodiments, the refrigerant loop 112 may more broadly take the form of a thermal energy transport fluid loop that circulates thermal energy transport fluid, including refrigerants, water, glycol solutions (antifreeze), or the like. Thus, references herein to the refrigerant and the refrigerant loop 112 should be understood to alternatively incorporate any thermal energy transport fluid. The refrigerant loop 112 consists of tubing that connects the components of the heat pump system 100, including the outside air heat exchanger 104, the inside air heat exchanger 108, the compressor 116, and the expander 120. The refrigerant flows through these components in a cyclic process, in some cases undergoing phase changes between liquid and gas as it absorbs or releases heat. Additionally, as will be discussed in greater detail below, the refrigerant loop 112 also connects with the thermal energy storage 130 by way of the plurality of switchable valves 140 to store thermal energy in and release thermal energy from the thermal energy storage 130.

[0022] The compressor 116 is positioned in the refrigerant loop 112 along a first circulation path between the inside air heat exchanger 108 and the outside air heat exchanger 104. The compressor 116 is configured to compress and circulate the refrigerant through the refrigerant loop 112. The compressor 116 includes a motor that uses electrical energy to compress the refrigerant to increase both the pressure and the temperature of the refrigerant, generally after the refrigerant has absorbed heat from elsewhere along the refrigerant loop 112. In some embodiments, the heat pump system 100 includes multiple compressors 116.

[0023] The expander 120 is positioned in the refrigerant loop 112 along a second circulation path between the inside air heat exchanger 108 and the outside air heat exchanger 104, which is different from the first circulation path including the compressor 116. The expander 120 is configured to further regulate the pressure of the refrigerant as it moves through the refrigerant loop 112. Particularly, the expander 120 includes an expansion valve or capillary tube configured to lower both the pressure and the temperature of the refrigerant, generally after the refrigerant has released heat elsewhere along the refrigerant loop 112. In some embodiments, the heat pump system 100 includes multiple expanders 120.

[0024] It should be appreciated that the illustrated embodiment of the heat pump system 100 is in the form of an air-source heat pump. However, in alternative embodiments, the heat pump system 100 may take the form of a ground-source (geothermal) heat pump or a water-source heat pump. Ground-source (geothermal) heat pumps transfer heat between the building and the ground or groundwater. These systems use underground refrigerant loops that absorb heat from the earth or release heat to the earth, which remains at a relatively constant temperature year-round. Similarly, water-source heat pumps exchange heat with a water tank in the building or with a body of water, such as a lake, river, or well, or. These systems draw heat from the water for heating or discharge heat into the water for cooling.

[0025] In any case, the heat pump system 100 advantageously includes the thermal energy storage 130. The thermal energy storage 130 is configured to store excess thermal energy for later release. Particularly, the thermal energy storage 130 captures excess thermal energy when the heat pump system 100 is producing more thermal energy than is needed for immediate use. For example, during periods of high heat pump efficiency or low demand, the heat pump system 100 can divert excess thermal energy into the thermal energy storage 130. When demand increases or the heat pump system 100 is not operating optimally, the stored thermal energy can be released back into the refrigerant loop 112 to meet heating or cooling needs. This process helps balance the load, reduce peak energy consumption, and improve overall system efficiency.

[0026] The thermal energy storage 130 typically consists of one or more insulated storage tanks (not shown) filled with a thermal storage medium, such as water or phase-change materials. In the illustrated embodiment, the thermal energy storage 130 includes phase-change materials 134 and a TES heat exchanger 138. The TES heat exchanger 138 is connected in the refrigerant loop 112 via the plurality of switchable valves 140 that are operated to direct the flow of refrigerant between the thermal energy storage 130 and the rest of the heat pump system 100. In some embodiments, the thermal energy storage 130 has its own compressor or expander (not shown) such that it is easier to retrofit existing designs compared to fully relying on the compressor 116 and expander 120 of the heat pump system 100. The compressor within the thermal energy storage 130 could be optimized particularly for the thermal energy storage 130, and thus could be more efficient and lower cost.

[0027] The phase-change materials 134 in the thermal energy storage 130 are substances that store and release thermal energy through phase changes, typically from solid to liquid or vice versa. It should be appreciated that phase-change materials 134 may alternatively include any other thermal storage medium, such as water. When the heat pump system 100 generates excess thermal energy, the phase-change materials 134 can absorb thermal energy and undergo a phase change, effectively storing the thermal energy at a constant temperature. Conversely, when there is a demand for thermal energy, the phase-change materials 134 can release the stored thermal energy as they revert to their original phase.

[0028] The TES heat exchanger 138 in the thermal energy storage 130 is configured to transfer heat between the refrigerant circulating through the refrigerant loop 112 and the phase-change materials 134. Structurally, in at least some embodiments, the TES heat exchanger 138 includes a series of coiled metal tubes or metal fins (not shown), through which the refrigerant circulates. The TES heat exchanger 138 is arranged within or adjacent to the phase-change materials 134 to maximize the contact surface area and ensure efficient heat exchange.

[0029] The TES heat exchanger 138 is connected in the piping between an inlet connection and an outlet connection (not shown) of the thermal energy storage 130, such that refrigerant from the refrigerant loop 112 can flow through the TES heat exchanger 138 to store or release thermal energy in the phase-change materials 134. It should be appreciated that the inlet connection and outlet connection of the thermal energy storage 130 do not necessarily refer to specific refrigerant connections, since the refrigerant may flow in either direction through the thermal energy storage 130. Thus, the inlet connection and outlet connection of the thermal energy storage 130 should be understood as interchangeable.

[0030] The plurality of switchable valves 140 are suitably arranged and operated to manage the storage and release of thermal energy within the thermal energy storage 130, as well as direct the flow of refrigerant through the outside air heat exchanger 104 and/or the inside air heat exchanger 108. In some embodiments, the plurality of switchable valves 140 may include multi-way valves (e.g., 3-way valves), or equivalent arrangements of multiple valves. The plurality of switchable valves 140 may include a wide variety of possible configurations that enable the thermal energy storage 130 to be selectively bypassed in a first switching state, selectively connected in series with the outside air heat exchanger 104 in a second switching state, and selectively connected in series with the inside air heat exchanger 108 in a third switching state.

[0031] Additionally, in some embodiments, the plurality of switchable valves 140 have a configuration that enables the compressor 116 and/or the expander 120 to, in different switching states, be selectively connected in the refrigerant loop 112 between the outside air heat exchanger 104 and TES heat exchanger 138, selectively connected in the refrigerant loop 112 between the TES heat exchanger 138 and the inside air heat exchanger 108, and selectively connected in the refrigerant loop 112 between the outside air heat exchanger 104 and the inside air heat exchanger 108. Finally, in some embodiments, the plurality of switchable valves 140 have a configuration that enables the compressor 116 and/or the expander 120 to, in different switching states, be reversed in the refrigerant loop 112.

[0032] In at least some embodiments, the heat pump system 100 further includes a controller 150 configured to manage the overall operation of the heat pump system 100. To these ends, the controller 150 is configured to monitor a variety of parameters including, for example, inside and outside temperatures, refrigerant flow rates at different points in the refrigerant loop 112, and a compressor frequency of the compressor 116. By continuously monitoring these parameters, the controller 150 makes real-time adjustments to the operation of the heat pump system 100, such as modulating the speed of the compressor 116 or adjusting the plurality of switchable valves 140 to store thermal energy in the thermal energy storage 130 or release thermal energy from the thermal energy storage 130.

[0033] The controller 150 is configured to selectively operate the heat pump system 100 in either a heating mode, a cooling mode, or a standby mode. In the standby mode, the heat pump system 100 is not actively heating or cooling but remains ready to engage when needed.

[0034] In the heating mode, the heat pump system 100 operates by transferring heat from the outside air to the inside of a building using the refrigerant loop 112. The controller 150 operates the compressor 116 to compress the refrigerant, increasing its temperature and pressure. The higher-temperature, higher-pressure refrigerant from the compressor 116 is circulated through the inside air heat exchanger 108, where it releases heat to warm the inside air 110. Next, the refrigerant passes through the expander 120, where it undergoes a reduction in pressure and temperature. The lower-temperature, lower-pressure refrigerant from the expander 120 is circulated through the outside air heat exchanger 104, where it absorbs heat from the outside air, even in cold conditions. The refrigerant then returns to the compressor 116 to repeat the cycle.

[0035] In the cooling mode, the heat pump system 100 works in reverse to transfer heat from inside the building to the outside environment. The controller 150 operates the compressor 116 to compress the refrigerant, increasing its temperature and pressure. The higher-temperature, higher-pressure refrigerant from the compressor 116 is circulated through the outside air heat exchanger 104, where it releases heat into the outside air 106. Next, the refrigerant passes through the expander 120, where it undergoes a reduction in pressure and temperature. The lower-temperature, lower-pressure refrigerant from the expander 120 is circulated through the inside air heat exchanger 108, where it absorbs heat from the inside air 110. The refrigerant then returns to the compressor 116 to repeat the cycle.

[0036] In addition to operating the heat pump system 100 in the conventional heating or cooling modes, the controller 150 operates the plurality of switchable valves 140 to control the heat pump system 100 to store thermal energy in the thermal energy storage 130 or to release thermal energy from the thermal energy storage 130 in either of the heating and cooling modes, as needed.

[0037] When the heat pump system 100 operates to store thermal energy in the thermal energy storage module 130 (i.e., in a charging mode), the controller 150 operates the plurality of switchable valves 140 in a specific manner to direct refrigerant flow from the compressor 116 or from the expander 120 towards the thermal energy storage module 130. In the charging mode, the controller 150 operates the compressor 116 to circulate the refrigerant such that excess thermal energy generated during operation, is transferred to the thermal energy storage module 130 instead of being released into the inside air 110 or released into the outside air 106. Particularly, in the cooling mode, the thermal energy storage module 130 stores thermal energy absorbed from inside air 110 for the purpose of cooling the environment. Conversely, in the heating mode, the thermal energy storage module 130 stores thermal energy absorbed from outside air 106.

[0038] When the heat pump system 100 operates to release thermal energy from the thermal energy storage module 130 (i.e., in a discharging mode), the controller 150 operates the plurality of switchable valves 140 in a specific manner to direct refrigerant flow from the thermal energy storage module 130 to the inside air heat exchanger 108 or to the outside air heat exchanger 104. In the discharging mode, the controller 150 operates the compressor 116 to circulate the refrigerant such that thermal energy is released from the thermal energy storage module 130 instead of being absorbed from the outside air 106 or absorbed from the inside air 110. Particularly, in the heating mode, the thermal energy storage module 130 releases thermal energy into the inside air 110 for the purpose of heating the building. Conversely, in the cooling mode, the thermal energy storage module 130 releases thermal energy into the outside air 106.

[0039] In some embodiments, the controller 150 incorporates intelligent algorithms that determine the optimal times for charging and discharging the thermal energy storage 130 based on predictive analytics of energy demand, weather forecasts, and electricity tariff rates. The controller 150 adjusts the operation of the compressor 116 and adjusts the flow paths of the refrigerant loop 112 using the plurality of switchable valves 140 to store or release thermal energy in the thermal energy storage 130, to minimize energy costs, maximize efficiency, and prolong the lifetime of the heat pump system 100.

Modular Thermal Energy Storage

[0040] FIG. 2 shows exemplary components of a modular thermal energy storage 200 for integration into a heat pump system. The modular thermal energy storage 200 is an exemplary embodiment of the thermal energy storage 130 of the heat pump system 100. The modular thermal energy storage 200 includes a lead TES (thermal energy storage) module 210 and one or more extension TES modules 250A-B. The lead TES module 210 is advantageously designed to connect, in a modular manner, with an arbitrary number of the extension TES modules 250A-B to expand the total thermal energy storage capacity of the modular thermal energy storage 200.

[0041] The lead TES module 210 includes a thermal storage medium, in particular phase-change materials 220 which are essentially similar to the phase-change materials 134 discussed previously. Additionally, the lead TES module 210 includes a TES heat exchanger 230, which is essentially similar to the TES heat exchanger 138 discussed previously. The TES heat exchanger 230 is connected such that the refrigerant flows through the TES heat exchanger 230 and is arranged with respect to the phase-change materials 220 so as to exchange thermal energy between the refrigerant and the phase-change materials 220. The phase-change materials 220 and the TES heat exchanger 230 are provided in a housing, e.g., metal casing, a container, or other rigid housing (not shown) to protect it from environmental factors. Additionally, the phase-change materials 220 and/or the housing is provided with a suitable amount of insulation for preventing or slowing thermal energy transfer between the phase-change materials 220 and the ambient environment.

[0042] The lead TES module 210 has four fluid connectors including a first fluid connector 212, a second fluid connector 214, a third fluid connector 216, and a fourth fluid connector 218. The first fluid connector 212 and the second fluid connector 214 function as a primary inlet and a primary outlet for connecting the lead TES module 210 into the refrigerant loop 112 of the heat pump system 100. In particular, the first and second fluid connectors 212, 214 are connected to the refrigerant loop 112 by way of the plurality of switchable valves 140, such that the refrigerant flows through the first fluid connector 212 and the second fluid connector 214. In one configuration, the refrigerant flows into the first fluid connector 212 (i.e., as the primary inlet) and out of the second fluid connector 214 (i.e., as the primary outlet). In another configuration, the refrigerant flows into the second fluid connector 214 (i.e., as the primary inlet) and out of the first fluid connector 212 (i.e., as the primary outlet).

[0043] The third fluid connector 212 and the fourth fluid connector 214 function as an auxiliary inlet and an auxiliary outlet for connecting the lead TES module 210 with the extension TES modules 250A-B to expand the total thermal energy storage capacity of the modular thermal energy storage 200. Within the lead TES module 210, the first fluid connector 212 is connected to the third fluid connector 216 such that the refrigerant flows between the first fluid connector 212 to the third fluid connector 216. Likewise, the fourth fluid connector 218 is connected to the second fluid connector 214 such that the refrigerant flows between the second fluid connector 214 and the fourth fluid connector 218. In one configuration, the refrigerant flows from the first fluid connector 212 and out to the extension TES modules 250A-B via the third fluid connector 216 (i.e., as an auxiliary outlet) and flows from the extension TES modules 250A-B into the fourth fluid connector 218 (i.e., as an auxiliary inlet) and to the second fluid connector 214. In a reverse configuration, the refrigerant flows from the second fluid connector 214 and out to the extension TES modules 250A-B via the fourth fluid connector 218 (i.e., as an auxiliary outlet) and flows from the extension TES modules 250A-B into the third fluid connector 216 (i.e., as an auxiliary inlet) and to the first fluid connector 212.

[0044] The TES heat exchanger 230 of the lead TES module 210 may be connected with respect to the fluid connectors of the lead TES module 210 in a variety of configurations such that the TES heat exchanger 230 is arranged first in series with the extension TES modules 250A-B, arranged last in series with the extension TES modules 250A-B, or arranged in parallel with the extension TES modules 250A-B.

[0045] FIG. 3A shows a first exemplary configuration 300A of the lead TES module 210 in which the TES heat exchanger 230 is arranged first in series with the extension TES modules 250A-B. Particularly, the TES heat exchanger 230 is connected between the first fluid connector 212 and the third fluid connector 216 by copper/metal piping within the lead TES module 210.

[0046] FIG. 3B shows a second exemplary configuration of the lead TES module 210 in which the TES heat exchanger 230 is arranged last in series with the extension TES modules 250A-B. Particularly, the TES heat exchanger 230 is connected between the second fluid connector 214 and the fourth fluid connector 218 by copper/metal piping within the lead TES module 210.

[0047] FIG. 3C shows a third exemplary configuration of the lead TES module 210 in which the TES heat exchanger 230 is arranged in parallel with the extension TES modules 250A-B. Particularly, the TES heat exchanger 230 is connected between the first fluid connector 212 and the second fluid connector 214, as well as connected between the third fluid connector 216 and the fourth fluid connector 217, by copper/metal piping within the lead TES module 210. Additionally, the first fluid connector 212 is connected to the third fluid connector 216 and the second fluid connector 214 is connected to the fourth fluid connector 218, such that the TES heat exchanger 230 can be arranged in parallel with the extension TES modules 250A-B.

[0048] In some embodiments, the lead TES module 210 is integrated with the heat pump system 100 in a manner enabling the compressor 116 and expander 120 of the heat pump 100 to also be used to circulate refrigerant through the modular thermal energy storage 200. However, as can be seen in FIGS. 4A-C, in some embodiments, the lead TES module 210 further includes an integrated compressor 310 and an integrated expander 320. In this way, the lead TES module 210 can be easily retrofitted into an existing thermal management system whose compressor(s) are not designed to support thermal energy storage. Instead, the lead TES module 210 is tied into the copper/metal piping of the refrigerant loop 212 that runs between the indoor and outdoor units. In some cases, this may also enable easier placement of the modular thermal energy storage 200 indoors, where the insulation requirements are less stringent, but space may be more limited.

[0049] The compressor 310 is connected between the first fluid connector 212 and the third fluid connector 216 by copper/metal piping within the lead TES module 210. Conversely, the expander 320 is connected between the second fluid connector 214 and the fourth fluid connector 218 by copper/metal piping within the lead TES module 210. In the embodiment of FIG. 3A, the TES heat exchanger 230 is arranged in series with the compressor 310 along the copper/metal piping between the first fluid connector 212 and the third fluid connector 216, particularly between the compressor 310 and the third fluid connector 216. Conversely, in the embodiment of FIG. 3B, the TES heat exchanger 230 is arranged in series with the expander 320 along the copper/metal piping between the second fluid connector 214 and the fourth fluid connector 218. Finally, in the embodiment of FIG. 3C, the TES heat exchanger 230 is arranged in series between the compressor 310 and the expander 320 along the copper/metal piping between the first fluid connector 212 and the second fluid connector 214.

[0050] With continued reference to FIG. 2, the extension TES modules 250A-B are connected between the third fluid connector 216 and the fourth fluid connector 218 of the lead TES module 210 by copper/metal piping extending between the lead TES module 210 and the extension TES modules 250A-B. In some embodiments, the lead TES module 210 incorporates a bypass valve and copper/metal piping (not shown) configured to selectively connect the third fluid connector 216 and the fourth fluid connector 218 for installations in which no extension TES modules are utilized.

[0051] In some embodiments, the copper/metal piping extending between the lead TES module 210 and the extension TES modules 250A-B are permanently or semi-permanently connected via brazing, welding, or soldering. In some embodiments, the copper/metal piping extending between the lead TES module 210 and the extension TES modules 250A-B are directly connected via a connecting device, such as a leak-free quick-connect device, that is configured to connect pipes in an impermanent and removable manner.

[0052] In the illustrated embodiment, the extension TES modules 250A-B are connected in series with one another between the third fluid connector 216 and the fourth fluid connector 218 of the lead TES module 210. However, it should be appreciated that, in alternative embodiments, the extension TES modules 250A-B may be connected in parallel with one another between the third fluid connector 216 and the fourth fluid connector 218, or with some arbitrary combination of series and parallel connections. Moreover, although only two extension TES modules 250A-B are illustrated, an arbitrary number of such extension TES modules can be connected to the lead TES module 210. In at least some embodiments, each extension TES module 250A-B is structurally identical and has a same mass of thermal storage medium.

[0053] Each extension TES module 250A-B includes two fluid connectors including a respective fifth fluid connector 252 and a respective sixth fluid connector 254. Additionally, each extension TES module 250A-B includes a respective thermal storage medium, in particular phase-change materials 260, which are essentially similar to the phase-change materials 134 discussed previously. Additionally, each extension TES module 250A-B includes a respective TES heat exchanger 270, which is essentially similar to the TES heat exchanger 138 discussed previously.

[0054] The TES heat exchanger 270 is arranged with respect to the phase-change materials 260 so as to exchange thermal energy between the refrigerant and the phase-change materials 260. The phase-change materials 260 and the TES heat exchanger 270 are provided in a housing, e.g., metal casing, a container, or other rigid housing (not shown) to protect it from environmental factors. Additionally, the phase-change materials 260 and/or the housing is provided with a suitable amount of insulation for preventing or slowing thermal energy transfer between the phase-change materials 270 and the ambient environment.

[0055] Within each extension TES module 250A-B, the respective TES heat exchanger 270 is connected between the respective fifth fluid connector 252 and the respective sixth fluid connector 254 by copper/metal piping within the extension TES module 250A-B. In this way, refrigerant flows through the respective TES heat exchanger 270. In one configuration, the refrigerant flows into the respective fifth fluid connector 252 (i.e., as an inlet), through the respective TES heat exchanger 270, and out of the respective sixth fluid connector 254 (i.e., as an outlet). In a reverse configuration, the refrigerant flows into the respective sixth fluid connector 254 (i.e., as an inlet), through the respective TES heat exchanger 270, and out of the respective fifth fluid connector 252 (i.e., as an outlet).

[0056] In some embodiments, to interconnect the extension TES modules 250A-B with the lead TES module 210, the respective fifth fluid connector 252 of each of the extension TES modules 250A-B is connected either to the third fluid connector 216 of the lead TES module 210 or to the respective sixth fluid connector 254 of another of the extension TES modules 250A-B. Likewise, the respective sixth fluid connector 254 of each of the extension TES modules 250A-B is connected either to the fourth fluid connector 218 of the lead TES module 210 or to the respective fifth fluid connector 252 of another of the extension TES modules 250A-B.

[0057] Unlike the lead TES module 210, the extension TES modules 250A-B do not include their own compressor and expander and do not require direct integration with the heat pump system 100 (i.e., they are not directly connected to the plurality of switchable valves 140 of the heat pump system 100). However, in at least some embodiments, the modular thermal energy storage 200 further includes an auxiliary fluid pump 280 connected in line with the extension TES modules 250A-B. The auxiliary fluid pump 280 is configured to aid in circulating the refrigerant through the piping of the modular thermal energy storage 200. Particularly, in the case of a large number of extension TES modules 250A-B and/or a long total pipe length through the system, the compressor 116 of the heat pump system 100 and/or the compressor 310 of the lead TES module 210 cannot overcome the excessive pressure drop through the system without the aid of the auxiliary fluid pump 280.

[0058] In one configuration, as illustrated in FIG. 2, the auxiliary fluid pump 280 is connected in the piping between the third fluid connector 216 of the lead TES module 210 and the TES modules 250A-B. In an alternative configuration, the auxiliary fluid pump 280 is connected in the piping between the extension TES modules 250A-B and the fourth fluid connector 218 of the lead TES module 210. In another alternative configuration, the auxiliary fluid pump 280 is connected in the piping between two of the extension TES modules 250A-B.

[0059] While the disclosure has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the disclosure are desired to be protected.