Thermal management system and energy storage station for sodium electric energy storage device

Abstract

The present invention relates to a thermal management system and energy storage station for a sodium-electric energy storage device. The thermal management system includes: an above-ground heat exchanger disposed within the sodium-electric energy storage device; an above-ground temperature sensor disposed within the sodium-electric energy storage device; multiple underground heat exchangers that can be dispersedly buried underground at the site where the sodium-electric energy storage device is located; multiple underground temperature sensors that can be buried underground and adjacent to the multiple underground heat exchangers; a control pipeline that connects the above-ground heat exchanger and each underground heat exchanger and includes a control valve group and a drive pump; and a control unit that is electrically connected to the control valve group, the drive pump, the above-ground temperature sensor, and each underground temperature sensor. The thermal management system can effectively manage the thermal state of the sodium-electric energy storage device and has the advantages of energy saving, high efficiency, low cost, and compact size, which is conducive to promoting the popularization and application of sodium-electric energy storage devices.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of energy storage stations. More specifically, the present invention relates to a thermal management system and an energy storage station for a sodium-ion battery energy storage device. Background Art

[0002] With the vigorous development of renewable energy around the world, energy storage technology has become a key pillar of energy transformation. Among them, sodium-ion energy storage devices are increasingly attracting widespread attention in the industry due to their low cost, high safety, and long cycle life, and are regarded as highly promising next-generation large-scale energy storage solutions. However, sodium-ion battery packs, as the core component of sodium-ion energy storage devices, generate a large amount of heat during the charging and discharging process. If the heat accumulation is not effectively controlled, it will directly threaten the performance stability and cycle life of the sodium-ion battery pack and may even cause catastrophic safety accidents. Therefore, effective thermal management is crucial for sodium-ion energy storage devices.

[0003] Currently, existing thermal management technologies are largely tailored for lithium-ion energy storage devices. For cooling, for example, these systems often rely excessively on air cooling and / or liquid cooling, or even simply layer geothermal heat generation on top of both. While these systems offer excellent temperature control performance, when directly applied to sodium-ion energy storage devices, they become bulky and overpowered, resulting in significant energy waste and a significant increase in overall cost.

[0004] Therefore, to truly leverage the advantages of sodium-ion battery energy storage devices, it is imperative to break through the constraints of existing lithium-ion battery thermal management thinking and develop an innovative thermal management system specifically designed for the characteristics of sodium-ion battery energy storage devices. This new system must achieve comprehensive improvements in energy efficiency, efficiency, cost-effectiveness, and compactness to promote the popularization and application of sodium-ion battery energy storage devices. Summary of the Invention

[0005] In order to solve one or more of the technical problems mentioned above, the present invention provides a thermal management system and energy storage station for a sodium-based energy storage device. The thermal management system can effectively manage the thermal state of the sodium-based energy storage device and has the advantages of energy saving, high efficiency, low cost and compact size, which is conducive to promoting the popularization and application of sodium-based energy storage devices.

[0006] According to a first aspect of the present invention, a thermal management system for a sodium-electric energy storage device is provided, comprising: an above-ground heat exchanger disposed within the sodium-electric energy storage device; an above-ground temperature sensor disposed within the sodium-electric energy storage device; a plurality of underground heat exchangers that can be dispersedly buried underground at the site where the sodium-electric energy storage device is located; a plurality of underground temperature sensors that can be buried underground and adjacent to the plurality of underground heat exchangers; a control pipeline connected to the above-ground heat exchanger and each of the underground heat exchangers, and comprising a control valve group and a drive pump; and a control unit electrically connected to the control valve group, the drive pump, the above-ground temperature sensor, and each of the underground temperature sensors. The control unit is configured to, based on detection results from the above-ground temperature sensor and each of the underground temperature sensors, start and stop the drive pump and switch the operating state of the control valve group, so as to alternately select one of the plurality of underground heat exchangers as a selected object to be connected to the above-ground heat exchanger, so that a heat exchange medium can be driven by the drive pump and circulate between the selected object and the above-ground heat exchanger.

[0007] According to a second aspect of the present invention, there is provided an energy storage station, which includes a sodium-electric energy storage device and a thermal management system as described in the first aspect of the present invention.

[0008] In the aforementioned thermal management system and energy storage station, geothermal heat is cleverly integrated into the sodium-ion battery storage device, enabling cooling or heating of the device using geothermal energy. Above-ground and underground temperature sensors then monitor temperature changes in the device and underground in real time, enabling the control unit to automatically adjust the thermal management system's cooling or heating strategy based on the detection results. This allows the sodium-ion battery storage device, particularly the sodium-ion battery pack, to be efficiently cooled using geothermal heat during hot weather, while also heating it during cold weather, ensuring that the battery pack operates within its optimal temperature range. This improves battery performance stability and cycle life, while preventing safety incidents caused by heat accumulation. Furthermore, since the above-ground heat exchanger and underground temperature sensor are located within the sodium-ion battery storage device, while the underground heat exchanger and underground temperature sensor are buried underground, the bulky air and liquid cooling equipment required above ground, as is the case with existing technologies, is eliminated. This effectively reduces the ground surface footprint of the thermal management system and avoids the bulkiness of the energy storage station. It can be seen that the present invention not only effectively solves many defects of sodium-ion energy storage devices in thermal management, but also achieves a comprehensive improvement in the system in terms of energy saving, high efficiency, cost-effectiveness and compactness, providing solid technical support for the popularization and application of sodium-ion energy storage devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present invention are shown in an illustrative and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0010] Figure 1 This is a usage state diagram of a thermal management system for a sodium battery energy storage device according to an embodiment of the present invention;

[0011] Figure 2 for Figure 1 A front view of a first underground heat exchanger of the thermal management system shown;

[0012] Figure 3 for Figure 2 A top view of the first underground heat exchanger is shown;

[0013] Figure 4 for Figure 2 A cross-sectional view of the liquid outlet section of the spiral tube of the first underground heat exchanger is shown.

[0014] Explanation of the accompanying drawings: 1. Ground heat exchanger; 21. First underground heat exchanger; 22. Second underground heat exchanger; 23. Third underground heat exchanger; 31. First underground temperature sensor; 311. Spiral tube; 312. Core column; 3112. Heat exchange support rib; 31a. Liquid inlet section; 31b. Liquid outlet section; 31c. Cylindrical spiral section; 32. Second underground temperature sensor; 33. Third underground temperature sensor; 4. Control pipeline; 411. First reversing valve; 412. Second reversing valve; 42. Drive pump; 5. Ground temperature sensor; 7. Insulation material; 100. Thermal management system; 200. Sodium electric energy storage device; 2001. Sodium ion battery pack. DETAILED DESCRIPTION

[0015] The following will be combined with the accompanying drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the embodiments described are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0016] Figure 1 FIG. 1 is a diagram showing the use state of a thermal management system for a sodium electric energy storage device according to an embodiment of the present invention; FIG. Figure 1As shown, an embodiment of the present invention provides a thermal management system 100 for a sodium-ion energy storage device 200. The thermal management system 100 includes: an above-ground heat exchanger 1 disposed within the sodium-ion energy storage device 200; multiple underground heat exchangers (e.g., a first underground heat exchanger 21, a second underground heat exchanger 22, and a third underground heat exchanger 23) buried underground at the site where the sodium-ion energy storage device 200 is located; and control piping 4 connecting the above-ground heat exchanger 1 to each of the underground heat exchangers. The above-ground heat exchanger 1 is disposed within the sodium-ion energy storage device 200, preferably within or on the surface of the sodium-ion battery pack 2001 of the sodium-ion energy storage device 200, to ensure that the heat exchange medium (water or oil) flowing therethrough can cool or heat the interior of the sodium-ion energy storage device 200. Multiple underground heat exchangers can be dispersedly buried underground at the site where the sodium-ion energy storage device 200 is located, allowing the heat exchange medium (water or oil) flowing therethrough to exchange heat with soil in different areas, thereby utilizing geothermal energy. The control pipeline 4 includes a control valve group (for example, a first reversing valve 411 and a second reversing valve 412) and a drive pump 42, wherein the control valve group can alternately select one of multiple underground heat exchangers as a selected object to be connected to the ground heat exchanger 1, so that the heat exchange medium can be driven by the drive pump 42 and circulate between the selected object and the ground heat exchanger 1.

[0017] It should be emphasized that although Figure 1 Only one above-ground heat exchanger 1 and one sodium-ion battery pack 2001 are shown, but this should not be understood as a protection limitation of the present invention. In addition to including one above-ground heat exchanger 1 and being adapted to a sodium-electric energy storage device 200 having only one sodium-ion battery pack 2001, the thermal management system 100 of the embodiment of the present invention may also include multiple above-ground heat exchangers 1 connected in sequence and be adapted to a sodium-electric energy storage device 200 having multiple sodium-ion battery packs 2001.

[0018] The thermal management system 100 also includes: an above-ground temperature sensor 5 disposed within the sodium-ion energy storage device 200; multiple underground temperature sensors (e.g., a first underground temperature sensor 31, a second underground temperature sensor 32, and a third underground temperature sensor 33) buried underground and adjacent to the multiple underground heat exchangers; and a control unit electrically connected to the control valve assembly, the drive pump 42, the above-ground temperature sensor 5, and each of the underground temperature sensors. The above-ground temperature sensor 5 is used to detect the internal temperature of the sodium-ion energy storage device 200 and is preferably located within or on the surface of the sodium-ion battery pack 2001 of the sodium-ion energy storage device 200 to ensure that the above-ground temperature sensor 5 can directly detect the temperature of the sodium-ion battery pack 2001. The multiple underground temperature sensors are used to detect the soil temperature in the area closest to the underground heat exchanger. The control unit is configured to: based on the detection results of the above-ground temperature sensor 5 and each underground temperature sensor, start and close the drive pump 42 and switch the working state of the control valve group, so as to alternately select one of the multiple underground heat exchangers as the selected object to be connected to the above-ground heat exchanger 1, so that the heat exchange medium can be driven by the drive pump 42 and circulate between the selected object and the above-ground heat exchanger 1.

[0019] In terms of specific implementation, the aforementioned control unit of the present invention generally includes a processor (e.g., a CPU), memory, and electronic components connected to the processor, etc., which are well known to those skilled in the art and will not be described in detail here. It should be noted that the number of processors, memory, and necessary electronic components is not limited and can be adjusted according to actual needs. For example, if the control unit needs to be disassembled into multiple control modules, the multiple control modules can each perform different tasks of the control unit and, when necessary, communicate and collaborate to complete one or more tasks.

[0020] Next, combine Figure 1 and Figure 2The following describes the use of the thermal management system 100 of this embodiment. During hot weather, when the drive pump 42 is activated, the heat exchange medium begins to circulate within the thermal management system 100. The hotter heat exchange medium first flows through the aboveground heat exchanger 1, absorbing heat from the sodium-ion battery pack 2001 and raising its temperature. Subsequently, the heated heat exchange medium, propelled by the drive pump 42, enters a preselected underground heat exchanger, where it releases heat into the cooler soil, causing its own temperature to drop. The cooled heat exchange medium is then returned to the aboveground heat exchanger 1 by the drive pump 42, repeating the cycle and continuously dissipating heat from the sodium-ion battery pack 2001 underground, thereby achieving cooling and ensuring that the sodium-ion battery pack 2001 operates efficiently at a suitable temperature. During cold weather, when the drive pump 42 is activated, the heat exchange medium also begins to circulate, but this time it first flows through the preselected underground heat exchanger. Because the underground soil temperature is relatively high, the heat exchange medium absorbs heat from the soil, causing its own temperature to rise. Next, the heated heat exchange medium driven by drive pump 42 reaches the aboveground heat exchanger 1, where it releases heat to the cooler sodium-ion battery pack 2001, providing heat. The heat exchange medium is then returned to the underground heat exchanger by drive pump 42, where it continuously absorbs heat from the soil and transfers it to the sodium-ion battery pack 2001. This cycle repeats, heating the sodium-ion battery pack 2001 and ensuring that it operates efficiently at an appropriate temperature.

[0021] In the present invention, by cleverly combining a ground heat exchanger 1, an underground heat exchanger, and a control line 4, the aim is to utilize geothermal energy to cool or heat the sodium-ion energy storage device 200. The ground temperature sensor 5 and the underground temperature sensor then monitor the temperature changes of the sodium-ion energy storage device 200 and the underground in real time, thereby ensuring that the control unit 100 can automatically adjust the cooling or heating strategy of the thermal management system 100 for the sodium-ion energy storage device 200 based on the detection results. This not only allows the sodium-ion energy storage device 200, particularly the sodium-ion battery pack 2001, to be efficiently cooled by geothermal energy during hot seasons, but also allows the sodium-ion battery pack 2001 to be heated by geothermal energy during cold seasons, ensuring that the sodium-ion battery pack 2001 operates within the optimal temperature range, thereby improving the performance stability and cycle life of the sodium-ion battery pack 2001 and avoiding safety accidents caused by heat accumulation. Furthermore, since the ground heat exchanger 1 and the ground temperature sensor 5 are disposed within the sodium-ion energy storage device 200, while the underground heat exchanger and underground temperature sensor are buried underground, there is no need to use relatively large air cooling and liquid cooling equipment on the ground, as is required in the prior art. In this way, the thermal management system 100 can effectively reduce the floor space occupied and avoid the bloated volume of the energy storage station. It can be seen that the present invention not only effectively solves the many thermal management deficiencies of the sodium-ionized energy storage device 200, but also achieves comprehensive improvements in the system's energy efficiency, efficiency, cost-effectiveness, and compactness, providing solid technical support for the popularization and application of the sodium-ionized energy storage device 200.

[0022] As an example, the multiple underground heat exchangers include a first underground heat exchanger 21, a second underground heat exchanger 22, and a third underground heat exchanger 23. Correspondingly, the control valve assembly has a first operating state, a second operating state, and a third operating state. In the first operating state, the control valve assembly connects the first underground heat exchanger 21 with the aboveground heat exchanger 1, allowing the heat exchange medium, driven by the drive pump 42, to circulate between the first underground heat exchanger 21 and the aboveground heat exchanger 1. In the second operating state, the control valve assembly connects the second underground heat exchanger 22 with the aboveground heat exchanger 1, allowing the heat exchange medium, driven by the drive pump 42, to circulate between the second underground heat exchanger 22 and the aboveground heat exchanger 1. In the third operating state, the control valve assembly connects the third underground heat exchanger 23 with the aboveground heat exchanger 1, allowing the heat exchange medium, driven by the drive pump 42, to circulate between the third underground heat exchanger 23 and the aboveground heat exchanger 1. By setting multiple operating states for the multiple underground heat exchangers and the control valve assembly, underground heat exchangers in different locations can be flexibly used according to actual needs. For example, different underground heat exchangers can be used in rotation to allow the soil time to recover its temperature. For another example, the underground heat exchanger with the best heat exchange effect with the above-ground heat exchanger 1 can be selected to achieve a more efficient thermal management strategy.

[0023] In order to adapt to the first underground heat exchanger 21, the second underground heat exchanger 22 and the third underground heat exchanger 23, and accurately obtain the soil temperature of their respective areas, the multiple underground temperature sensors may include a first underground temperature sensor 31, a second underground temperature sensor 32 and a third underground temperature sensor 33, which are used to detect the soil temperature near the first underground heat exchanger 21, the second underground heat exchanger 22 and the third underground heat exchanger 23 in turn.

[0024] In order to ensure that the control unit automatically controls the start and stop of the driving pump 42 and the working state of the control valve group according to the detection results of the above-ground temperature sensor 5 and the underground temperature sensor, thereby achieving temperature regulation of the sodium energy storage device 200, the control unit is configured to: respond to T0 [T0', T0"], start the driving pump 42, and start the first working state, the second working state or the third working state of the control valve group when the thermal management system 100 is started for the first time, and restore the working state of the control valve group at the end of the previous operation when the thermal management system 100 is started subsequently; in response to T0 [T0', T0"], turn off the driving pump 42. Then, the control unit is further configured to: when the control valve group is in the first working state: in response to |T0-T1|> T, maintain the control valve group in the first working state; in response to |T0-T1|≤ T, and |T0-T2|> T, control the control valve group to switch to the second working state; in response to |T0-T1|≤ T, |T0-T2|≤ T, and |T0-T3|> T, control the control valve group to switch to the third working state; in response to |T0-T1|≤ T, |T0-T2|≤ T, and |T0-T3|≤ T, maintain the control valve group in the first working state. Then, the control unit is further configured to: when the control valve group is in the second working state: in response to |T0-T2|> T, maintain the control valve group in the second working state; in response to |T0-T2|≤ T, and |T0-T3|> T, control the control valve group to switch to the third working state; in response to |T0-T2|≤ T, |T0-T3|≤ T, and |T0-T1|> T, control the control valve group to switch to the first working state; in response to |T0-T2|≤ T, |T0-T3|≤ T, and |T0-T1|≤ T, maintain the control valve group in the second working state. Then, the control unit is further configured to: when the control valve group is in the third working state: in response to |T0-T3|> T, maintain the control valve group in the third working state; in response to |T0-T3|≤ T, and |T0-T1|> T, control the control valve group to switch to the first working state; in response to |T0-T3|≤ T, |T0-T1|≤ T, and |T0-T2|> T, control the control valve group to switch to the second working state; in response to |T0-T3|≤ T, |T0-T1|≤ T, and |T0-T2|≤ T, maintains the control valve group in the third working state. Wherein: T0 is the detection result of the above-ground temperature sensor 5, unit is °C; T0' and T0" are the upper limit (e.g., 10°C) and lower limit (e.g., 28°C) of the set temperature range, unit is °C; T1 is the detection result of the first underground temperature sensor 31, unit is °C; T2 is the detection result of the second underground temperature sensor 32, unit is °C; T3 is the detection result of the third underground temperature sensor 33, unit is °C; T is the set temperature difference threshold (for example, 3, 4, or 5) in °C.

[0025] Through the above control logic, the control unit can compare the temperature difference between the soil temperature around different underground heat exchangers and the temperature of the sodium-ion energy storage device 200 based on real-time temperature monitoring data, automatically start and stop the driving pump 42 and switch the working status of the control valve group, and select the underground heat exchanger with higher current heat exchange efficiency to better control the temperature of the sodium-ion energy storage device 200 within the set optimal temperature range, thereby ensuring the performance stability and cycle life of the sodium-ion battery pack 2001.

[0026] In this embodiment, in addition to two three-position four-way reversing valves, the control valve group can also use more valves to implement corresponding control. Any method that can meet the three working state requirements of the control valve group falls within the scope of protection claimed by the present invention. Taking the implementation of two three-position four-way reversing valves as an example, the control valve group includes a first reversing valve 411 and a second reversing valve 412, wherein the first reversing valve 411 includes a first port, a second port, and a third port that are connected to the inlet of the first underground heat exchanger 21, the inlet of the second underground heat exchanger 22, and the inlet of the third underground heat exchanger 23, respectively, and a fourth port that is connected to the outlet of the above-ground heat exchanger 1; the second reversing valve 412 includes a fifth port, a sixth port, and a seventh port that are connected to the outlet of the first underground heat exchanger 21, the outlet of the second underground heat exchanger 22, and the outlet of the third underground heat exchanger 23, respectively, and an eighth port that is connected to the inlet of the above-ground heat exchanger 1. The drive pump 42 is located between the aboveground heat exchanger 1 and the first reversing valve 411, or between the aboveground heat exchanger 1 and the second reversing valve 412. When the control valve assembly is in the first operating state, the first reversing valve 411 is in its first operating state. For example, the actuator of the first reversing valve 411 moves the valve core within the first reversing valve 411 to a specific position, connecting the fourth port with the first port. Simultaneously, the second reversing valve 412 is also in its first operating state and, using a similar principle, connects the eighth port with the fifth port. At this point, the first reversing valve 411 and the second reversing valve 412 cooperate to connect the first underground heat exchanger 21 with the aboveground heat exchanger 1, allowing the heat exchange medium to be driven by the drive pump 42 and circulate between the first underground heat exchanger 21 and the aboveground heat exchanger 1. When the control valve assembly is in the second operating state, the first reversing valve 411 is in its second operating state and connects the fourth port to the second port. The second reversing valve 412 is also in its second operating state and connects the eighth port to the sixth port. At this point, the first reversing valve 411 and the second reversing valve 412 cooperate to connect the second underground heat exchanger 22 to the aboveground heat exchanger 1, allowing the heat exchange medium to be driven by the drive pump 42 and circulate between the second underground heat exchanger 22 and the aboveground heat exchanger 1. When the control valve assembly is in the third operating state, the first reversing valve 411 is in its third operating state and connects the fourth port to the third port. The second reversing valve 412 is also in its third operating state and connects the eighth port to the seventh port. At this point, the first reversing valve 411 and the second reversing valve 412 cooperate to connect the third underground heat exchanger 23 to the aboveground heat exchanger 1, allowing the heat exchange medium to be driven by the drive pump 42 and circulate between the third underground heat exchanger 23 and the aboveground heat exchanger 1.

[0027] As an example, Figure 2 and Figure 3As shown, each underground heat exchanger, represented by the first underground heat exchanger 21, the second underground heat exchanger 22, and the third underground heat exchanger 23, can include a liquid inlet section 31a, a liquid outlet section 31b, and a cylindrical spiral section 31c. The liquid inlet section 31a is connected to the top of the cylindrical spiral section 31c and, after extending above the surface of the aforementioned site (the site where the sodium energy storage device 200 is located), is connected to the control pipeline 4. The liquid outlet section 31b is connected to the bottom of the cylindrical spiral section 31c and, after extending above the surface of the aforementioned site, is connected to the control pipeline 4. Because the cylindrical spiral section 31c, as the main heat exchange component, is buried underground and has a large area of ​​contact with the soil, it can maximize the utilization of underground space for heat exchange. The liquid inlet section 31a and the liquid outlet section 31b ensure the smooth flow of heat exchange medium into and out of the cylindrical spiral section 31c and facilitate connection to the control pipeline 4.

[0028] Preferably, the cylindrical spiral segments 31c of the first, second, and third underground heat exchangers 21, 22, and 23 are buried at a depth of 10-30m underground. The orthographic projections of the central axes of the first, second, and third underground heat exchangers 21, 22, and 23 on the ground surface of the aforementioned site form the three vertices of an equilateral triangle, and the orthographic projection of the central axis of the sodium energy storage device 200 on the ground surface of the aforementioned site falls within the equilateral triangle. Because the soil temperature at a depth of 10-30m is relatively stable and less affected by surface temperature fluctuations, and closer to the geothermal constant temperature layer, each underground heat exchanger can utilize the stable ground temperature (16°C-22°C) while also taking into account the economic feasibility and feasibility of burial. That is, if the depth is too shallow, it may be significantly affected by the surface temperature, while if it is too deep, the burial cost will be higher. At the same time, since the first underground heat exchanger 21, the second underground heat exchanger 22 and the third underground heat exchanger 23 are arranged in an equilateral triangle, they can be relatively evenly distributed in the underground area around the sodium electricity energy storage device 200, thereby more fully and evenly utilizing the geothermal resources underground in the site.

[0029] exist Figure 2 and Figure 4In the preferred embodiment shown, each underground heat exchanger includes a spiral tube 311 having an inlet and an outlet, a core column 312 inserted into the spiral tube 311 along the extension direction of the spiral tube 311, and a flow channel formed between the spiral tube 311 and the core column 312 and connecting the inlet and outlet of the spiral tube 311. The spiral tube 311 includes a tube body 3111 and a plurality of heat exchange ribs 3112 arranged at intervals along the circumference and fixed to the inner wall of the tube body 3111. The plurality of heat exchange ribs 3112 are used to secure the core column 312 within the tube body 3111. Each heat exchange rib 3112 extends from the inlet of the spiral tube 311 along the flow channel to the outlet of the spiral tube 311. During use, the heat exchange medium flows into the inlet of the spiral tube 311, flows in a spiral shape in the flow channel between the spiral tube 311 and the core column 312, exchanges heat with the tube body 3111 of the spiral tube 311 and the heat exchange ribs 3112, and then flows out of the outlet of the spiral tube 311. Due to the spiral structure of the spiral tube 311, the occupancy of the core column 312, and the enhanced heat exchange effect of the heat exchange ribs 3112, the underground heat exchanger can efficiently exchange heat with the surrounding soil.

[0030] To address the comprehensive requirements of the underground heat exchanger, including heat transfer performance, corrosion resistance, mechanical strength, cost, and processability, and to optimally match material properties with functional requirements, the spiral tube 311 can be made of stainless steel or copper, and the core 312 can be made of resin or rubber. This ensures long-term stable operation and efficient heat transfer. As a preferred example, the spiral tube 311 is made of 304L stainless steel, and the core 312 is made of high-density polyethylene (HDPE). This can triple the lifespan of the underground heat exchanger and significantly reduce maintenance frequency and costs.

[0031] The thermal management system 100 also includes a thermal insulation material 7, which can be a polyurethane foam material or sponge. The thermal insulation material 7 is used to wrap the portion of the control line 4 exposed between the sodium-electric energy storage device 200 and the ground of the aforementioned site, and is also used to wrap the portion of each underground heat exchanger that is above a predetermined depth underground, where the predetermined depth underground ranges from 3m to 8m, preferably 5m. When it is necessary to cool the sodium-electric energy storage device 200, the thermal insulation material 7 can reduce the heat exchange between the control line 4 and the upper part of the underground heat exchanger and the external environment, reduce the heat loss of the heat exchange medium during transportation, and improve the cooling efficiency. Similarly, when it is necessary to heat the sodium-electric energy storage device 200, the thermal insulation material 7 can reduce the heat absorption of the control line 4 and the upper part of the underground heat exchanger from the external environment, reduce the heat absorption of the heat exchange medium during transportation, and improve the heating efficiency.

[0032] In an embodiment not shown, an energy storage station is also provided, which includes the sodium-electric energy storage device 200 and the thermal management system 100 mentioned above. Among them, the sodium-electric energy storage device 200 is the core component of the energy storage station, which is used to store and release electrical energy. The thermal management system 100 achieves efficient, intelligent and energy-saving thermal management of the sodium-electric energy storage device 200 by cleverly combining the above-ground heat exchanger 1, the underground heat exchanger, the control unit, and the optimized structural design and material selection. This energy storage station can not only make full use of geothermal resources and reduce operating energy consumption, but also improve the performance stability, cycle life and safety of the sodium-electric energy storage device 200, providing a solid technical guarantee for the large-scale application of sodium-electric energy storage technology, and has significant economic and social benefits.

[0033] In the above description of this application, unless otherwise expressly specified or limited, terms such as "fixed," "mounted," "connected," or "connected" should be understood in a broad sense. For example, with respect to the term "connected," it can mean a fixed connection, a detachable connection, or an integral connection; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean internal communication between two elements or an interaction between two elements. Therefore, unless otherwise expressly specified in this application, those skilled in the art can understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0034] According to the above description of the present application, those skilled in the art may also understand that the terms used below, such as "upper", "lower", and other terms indicating orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings of the present application. They are only for the purpose of facilitating the explanation of the scheme of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the devices or elements involved must have the specific orientation, be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms cannot be understood or interpreted as limitations on the scheme of the present invention.

[0035] In addition, the terms "first" or "second" used in this application to refer to numbers or ordinal numbers are used for descriptive purposes only and should not be understood as explicitly or implicitly indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, the meaning of "plurality" is at least two, such as two, three or more, etc., unless otherwise clearly and specifically defined.

[0036] Although a number of embodiments of the present invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art may devise numerous modifications, variations, and alternatives without departing from the concept and spirit of the present invention. It should be understood that in practicing the present invention, various alternatives to the embodiments of the present invention described herein may be employed. The appended claims are intended to define the scope of the present invention and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A thermal management system for a sodium electric energy storage device, characterized in that: include: a ground heat exchanger disposed in the sodium-electric energy storage device; a ground temperature sensor, which is disposed in the sodium-electric energy storage device; A plurality of underground heat exchangers, which can be dispersedly buried underground at the site where the sodium-electric energy storage device is located; A plurality of underground temperature sensors, which can be buried underground and are adjacent to the plurality of underground heat exchangers; a control pipeline connected to the above-ground heat exchanger and each of the underground heat exchangers, and comprising a control valve group and a drive pump; a control unit electrically connected to the control valve group, the drive pump, the above-ground temperature sensor, and each of the underground temperature sensors, and configured to, based on detection results of the above-ground temperature sensor and each of the underground temperature sensors, start and stop the drive pump and switch the working state of the control valve group, so as to alternately select one of the plurality of underground heat exchangers as a selected object to be connected to the above-ground heat exchanger, so that a heat exchange medium can be driven by the drive pump and circulate between the selected object and the above-ground heat exchanger; The multiple underground heat exchangers include a first underground heat exchanger, a second underground heat exchanger, and a third underground heat exchanger. The control valve group has a first working state, a second working state, and a third working state. In the first working state, the control valve group connects the first underground heat exchanger with the above-ground heat exchanger; in the second working state, the control valve group connects the second underground heat exchanger with the above-ground heat exchanger; in the third working state, the control valve group connects the third underground heat exchanger with the above-ground heat exchanger. The plurality of underground temperature sensors include a first underground temperature sensor, a second underground temperature sensor, and a third underground temperature sensor for sequentially detecting soil temperatures near the first underground heat exchanger, the second underground heat exchanger, and the third underground heat exchanger; The control unit is configured to: In response to T0 [T0', T0"], starting the driving pump, and starting the first working state, the second working state or the third working state of the control valve group when the thermal management system is started for the first time, and restoring the working state of the control valve group used at the end of the last operation of the thermal management system when the thermal management system is started subsequently; In response to T0 [T0', T0"], turn off the driving pump; When the control valve group is in the first working state: in response to |T0-T1|≤ T, and |T0-T2|> T, control the control valve group to switch to the second working state; in response to |T0-T1|≤ T, |T0-T2|≤ T, and |T0-T3|> T, controlling the control valve group to switch to the third working state; When the control valve group is in the second working state: in response to |T0-T2|≤ T, and |T0-T3|> T, control the control valve group to switch to the third working state; in response to |T0-T2|≤ T, |T0-T3|≤ΔT, and |T0-T1|> T, controlling the control valve group to switch to the first working state; When the control valve group is in the third working state: in response to |T0-T3|≤ T, and |T0-T1|> T, control the control valve group to switch to the first working state; in response to |T0-T3|≤ T, |T0-T1|≤ T, and |T0-T2|> T, controlling the control valve group to switch to the second working state; Wherein: T0 is the detection result of the above-ground temperature sensor, in °C; T0' and T0" are the upper and lower limits of the set temperature range, in °C; T1 is the detection result of the first underground temperature sensor, in °C; T2 is the detection result of the second underground temperature sensor, in °C; T3 is the detection result of the third underground temperature sensor, in °C; T is the set temperature difference threshold, in °C.

2. The thermal management system according to claim 1, characterized in that The control valve group includes a first reversing valve and a second reversing valve, the first reversing valve includes a first port, a second port and a third port connected to the inlet of the first underground heat exchanger, the inlet of the second underground heat exchanger and the inlet of the third underground heat exchanger in sequence, and a fourth port connected to the outlet of the above-ground heat exchanger, the second reversing valve includes a fifth port, a sixth port and a seventh port connected to the outlet of the first underground heat exchanger, the outlet of the second underground heat exchanger and the outlet of the third underground heat exchanger in sequence, and an eighth port connected to the inlet of the above-ground heat exchanger; when the control valve group is in the first working state, the first reversing valve is in its first working condition and connects the fourth port to the first port, the second The reversing valve is also in its first working condition and connects the eighth work port with the fifth work port. When the control valve group is in the second working state, the first reversing valve is in its second working condition and connects the fourth work port with the second work port. The second reversing valve is also in its second working condition and connects the eighth work port with the sixth work port. When the control valve group is in the third working state, the first reversing valve is in its third working condition and connects the fourth work port with the third work port. The second reversing valve is also in its third working condition and connects the eighth work port with the seventh work port. The driving pump is arranged between the ground heat exchanger and the first reversing valve, or between the ground heat exchanger and the second reversing valve.

3. The thermal management system according to claim 1, wherein: Each of the underground heat exchangers includes a spiral tube having an inlet and an outlet, a core column inserted in the spiral tube along the extension direction of the spiral tube, and a flow channel formed between the spiral tube and the core column and connecting the inlet and outlet of the spiral tube, wherein the spiral tube includes a tube body and a plurality of heat exchange ribs arranged at intervals along the circumferential direction and fixed on the inner wall of the tube body, and the plurality of heat exchange ribs are used to fix the core column in the tube body.

4. The thermal management system according to claim 3, characterized in that: The spiral tube is made of stainless steel or copper tube, and the core column is made of resin or rubber.

5. The thermal management system according to claim 1, wherein: The first underground heat exchanger, the second underground heat exchanger and the third underground heat exchanger all include a liquid inlet section, a liquid outlet section and a cylindrical spiral section, wherein the liquid inlet section is connected to the top of the cylindrical spiral section and is connected to the control pipeline after extending out of the ground of the site, and the liquid outlet section is connected to the bottom of the cylindrical spiral section and is connected to the control pipeline after extending out of the ground of the site.

6. The thermal management system according to claim 5, characterized in that: The cylindrical spiral sections of the first underground heat exchanger, the second underground heat exchanger and the third underground heat exchanger are buried at a depth of 10m-30m underground. The orthographic projections of the central axes of the first underground heat exchanger, the second underground heat exchanger and the third underground heat exchanger on the ground of the site constitute the three vertices of an equilateral triangle, and the orthographic projection of the central axis of the sodium electric energy storage device on the ground of the site falls within the equilateral triangle.

7. The thermal management system according to claim 1, wherein: The thermal management system also includes insulation material, which is used to wrap the portion of the control pipeline exposed between the sodium-electric energy storage device and the ground of the site, and is also used to wrap the portion of each underground heat exchanger that is above a predetermined underground depth, where the predetermined underground depth ranges from 3m to 8m.

8. An energy storage station, characterized in that: The invention comprises a sodium electric energy storage device and a thermal management system according to any one of claims 1 to 7.

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