Energy storage system safety protection structure and protection method based on underground water pool soaking

Abstract

The invention discloses an energy storage system safety protection structure based on underground water pool soaking and a protection method. The energy storage system safety protection structure comprises a containing pool, a battery device, an independent wiring device and an electrical connection assembly. The accommodating tank is constructed underground, and an accommodating cavity in the accommodating tank is filled with a liquid cooling medium; the battery device is immersed in the medium and comprises a battery shell as well as a plurality of battery modules and high-voltage wiring terminals which are arranged in the shell; the independent wiring device is physically isolated from the accommodating cavity and is internally provided with a battery management system and a control relay; the electrical connection assembly connects the battery device and the independent wiring device through a power cable provided with a first watertight joint and a communication cable provided with a second watertight joint. The invention aims to provide the safety protection method and device for the energy storage system based on underground water pool soaking so as to provide heat dissipation, fire prevention and protection of an intrinsic safety level for a battery system in a physical isolation and medium soaking mode.

Description

Technical Field

[0001] This invention relates to the field of energy storage system safety protection technology, and in particular to a safety protection structure and method for energy storage systems based on immersion in underground water tanks. Background Technology

[0002] With the large-scale deployment of new energy storage systems, their safety and reliability have become a key bottleneck restricting the industry's development. Existing energy storage systems have systemic shortcomings in thermal management, fire safety, and user psychological acceptance: traditional air-cooled or liquid-cooled heat dissipation solutions have low energy efficiency, complex structures, and the risk of single-point failure; while fire-fighting measures for lithium battery thermal runaway are mostly passive remedial measures, which are difficult to prevent the fire from spreading within the battery pack, resulting in a high risk of reignition. At the same time, the high-level sealing structures used to meet outdoor protection requirements often sacrifice ease of maintenance and long-term reliability. These potential risks combined have led to significant public concerns about deploying energy storage facilities in residential areas, industrial and commercial parks, and other similar settings.

[0003] Current technologies lack an integrated solution that can simultaneously address thermal runaway, efficient heat dissipation, and permanent fire hazards at their physical root causes. Traditional improvement approaches often involve adding features to existing systems, such as enhancing cooling or adding fire extinguishing agents, failing to fundamentally change the unfavorable environment in which the battery operates. Therefore, there is an urgent need to develop a safety protection method and device for energy storage systems based on underground water tank immersion to address the overall low safety and low user acceptance caused by thermal management failures, fire risks, and insufficient protection capabilities in energy storage systems. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a safety protection structure and method for an energy storage system based on immersion in an underground water tank, which further improves the heat dissipation, fire prevention and protection functions of the battery.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] In a first aspect, this application provides a safety protection structure for an energy storage system based on underground water tank immersion, comprising: a containment tank, a battery device, an independent wiring device, and an electrical connection assembly; the containment tank is constructed underground, and the containment tank has a containment cavity inside; the containment cavity is used to fill a liquid cooling medium; the battery device is immersed in the liquid cooling medium in the containment cavity, and the battery device includes a battery casing, multiple battery modules disposed within the battery casing, and a high-voltage wiring terminal; the high-voltage wiring terminal connects the multiple battery modules; the independent wiring device is physically isolated from the containment cavity; the independent wiring device is equipped with a battery management system; the electrical connection assembly includes a power cable and a communication cable, one end of the power cable is connected to the high-voltage wiring terminal through a first watertight connector, and the other end of the power cable is connected to the independent wiring device; one end of the communication cable is connected to the battery module through a second watertight connector, and the other end of the communication cable is connected to the independent wiring device.

[0007] Furthermore, the containment pool is also equipped with a liquid heat circulation system; the liquid heat circulation system includes a water pump and heat exchange pipes buried in the soil around the containment pool; both ends of the heat exchange pipes are connected to the containment cavity and are connected in series with the water pump to form a closed loop.

[0008] Furthermore, the battery housing includes an inner shell, an outer shell, and a liquid cooling layer located between the inner shell and the outer shell; the liquid cooling layer forms cooling channels, and the inlet and outlet of the cooling channels both penetrate the outer shell to connect to the receiving cavity respectively.

[0009] Furthermore, a fireproof partition is provided between adjacent battery modules.

[0010] Furthermore, the battery casing has an IP68 protection rating; the independent wiring device has an IP65 protection rating.

[0011] Furthermore, the containment pool is a reinforced concrete structure with a waterproof and anti-corrosion coating on its inner wall.

[0012] Furthermore, the top of the containing pool is provided with a cover plate.

[0013] Furthermore, the liquid cooling medium is deionized water.

[0014] Secondly, this application provides a safety protection method for energy storage systems based on underground water tank immersion, applied to the safety protection structure of the energy storage system based on underground water tank immersion as described above, including the following steps:

[0015] A primary heat dissipation path is formed: the heat generated by the battery module is conducted to the liquid cooling layer and absorbed by the liquid cooling medium flowing through the liquid cooling layer;

[0016] A secondary heat dissipation path is formed: the liquid cooling medium that absorbs heat flows out from the liquid cooling layer and mixes with the liquid cooling medium in the receiving cavity for heat exchange;

[0017] A three-stage heat dissipation path is formed: through the liquid thermal circulation system, the liquid cooling medium in the containment cavity is driven to flow through the heat exchange pipeline buried in the soil, and the heat is finally released to the ground.

[0018] Furthermore, the safety protection method for energy storage systems based on underground water tank immersion also includes the following steps:

[0019] Monitoring steps: The battery management system monitors the voltage and temperature of each battery module and the insulation resistance of the system in real time.

[0020] Judgment Steps: The battery management system classifies the monitored operating parameters; the classification judgment includes normal judgment, warning step, and protection step.

[0021] Warning procedure: If any parameter reaches the preset warning threshold, a warning signal will be issued;

[0022] Active protection steps: If any parameter reaches a preset danger threshold, the control relay of the independent wiring device is immediately instructed to disconnect the high-voltage connection between the battery device and the external circuit.

[0023] Passive protection step: The fire caused by thermal runaway of the battery device is physically isolated by the liquid cooling medium in the containment tank. Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. Based on the fact that the containment pool is constructed underground and its containment cavity is filled with liquid cooling medium, the battery device is immersed in the liquid cooling medium. Utilizing the high specific heat capacity of the liquid and the stability of the ground temperature, a huge, efficient, and natural heat dissipation environment without additional power is provided for the battery system, achieving inherently efficient thermal management. By physically isolating the battery device, which includes high-voltage terminals, from the independent wiring device of the built-in battery management system and control relays, and connecting the two through electrical connection components with watertight connectors, high-energy components prone to thermal runaway and arcing risks are placed in a non-flammable liquid medium, while the sensitive battery management system and control relays are placed in a dry and safe environment. This achieves physical separation of power supply and control from the system architecture, fundamentally eliminating the possibility of electrical fire spread. The power cable has a first watertight connector and the communication cable has a second watertight connector, ensuring the sealing reliability of the battery device under long-term immersion conditions, while also providing a foundation for system maintainability. This structural design, through the coordinated layout of underground immersion and above-ground control, systematically and fundamentally solves the heat dissipation, fire protection, and safety problems of energy storage systems.

[0025] 2. Based on the water pump installed in the containment cavity and connected in series with the heat exchange pipeline buried in the surrounding soil to form a closed loop, a liquid heat circulation system is constructed. The water pump drives the liquid cooling medium in the containment cavity to flow through the underground heat exchange pipeline, making full use of the earth as a larger natural cold source, and continuously and efficiently transferring the heat generated by the battery to the deep soil. This significantly improves the heat dissipation capacity and temperature uniformity of the entire system, overcomes the problem of local heat accumulation that may occur when relying solely on static immersion, and further optimizes and enhances the passive heat dissipation effect of the device.

[0026] 3. By incorporating a liquid cooling layer between the inner and outer shells of the battery casing and forming a cooling channel communicating with the receiving cavity, a secondary enhanced heat dissipation path for the battery module is constructed. The liquid cooling medium enters the cooling channel within the liquid cooling layer through the channel inlet, undergoes efficient heat exchange with the battery module, and then flows out through the channel outlet. This structure significantly increases the effective contact area between the battery cell and the cooling medium, enabling rapid heat dissipation from the battery's internal core to the external cavity cooling medium, effectively reducing the battery's operating temperature and internal temperature difference. This design, by introducing a built-in liquid cooling layer structure, effectively supplements and enhances the overall immersion heat dissipation.

[0027] 4. By installing fireproof partitions between adjacent battery modules, the potential propagation path of thermal runaway within the battery pack is further blocked, enhancing safety redundancy. By setting the battery casing and independent wiring device to IP68 and IP65 protection levels respectively, the long-term reliable operating benchmarks for key components under different environments are clearly defined. The use of a reinforced concrete structure with an internal waterproof and anti-corrosion coating in the containment tank ensures the robustness and durability of the underground main load-bearing structure and the sealing structure. The installation of an openable sealing cover on top of the containment tank ensures both protection and system maintainability. The selection of water or a flame-retardant insulating liquid as the liquid cooling medium balances heat dissipation efficiency and intrinsic safety. These designs, by refining the materials, grades, and structures of key components, collectively enhance the overall structural protection effectiveness and engineering feasibility. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the safety protection structure of the energy storage system based on underground water tank immersion according to the present invention;

[0029] Figure 2 for Figure 1 A magnified view of point A shown below;

[0030] Figure 3 This is a schematic diagram of the battery device shown in the present invention;

[0031] Figure 4 This is a schematic diagram of the independent wiring device shown in this invention;

[0032] Figure 5 This is a cross-sectional view of the thermal management of the energy storage system for underground water tank immersion as shown in this invention;

[0033] Figure 6 This is a flowchart illustrating the safety protection method for an energy storage system based on underground water tank immersion according to the present invention.

[0034] In the diagram: 100, containment tank; 200, containment cavity; 300, battery unit; 301, battery casing; 302, inner casing; 303, outer casing; 304, liquid cooling layer; 305, battery module; 306, high-voltage terminal block; 307, fireproof partition; 400, independent wiring device; 401, battery management system; 402, control relay; 500, electrical connection assembly; 600, liquid thermal circulation system; 601, water pump; 602, heat exchange pipeline; 700, sealing cover; 801, first watertight joint; 802, second watertight joint; 900, lifting bracket. Detailed Implementation

[0035] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0036] It should be noted that when an element is described as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is described as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementations.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0038] See Figures 1-6A preferred embodiment of the present invention is as follows: a safety protection structure for an energy storage system based on underground water tank immersion includes: a containment tank 100, a battery device 300, an independent wiring device 400, and an electrical connection assembly 500; the containment tank 100 is constructed underground, and the interior of the containment tank 100 has a containment cavity 200; the containment cavity 200 is used to fill a liquid cooling medium; the battery device 300 is immersed in the liquid cooling medium in the containment cavity 200, and the battery device 300 includes a battery housing 301, a plurality of battery modules 305 disposed within the battery housing 301, and a high-voltage terminal. The battery module 306 is a high-voltage terminal block 306 that connects to multiple battery modules 305. An independent wiring device 400 is physically isolated from the housing 200. A battery management system 401 is installed inside the independent wiring device 400. An electrical connection assembly 500 includes a power cable and a communication cable. One end of the power cable is connected to the high-voltage terminal block 306 via a first watertight connector 801, and the other end is connected to the independent wiring device 400. One end of the communication cable is connected to the battery module 305 via a second watertight connector 802, and the other end is connected to the independent wiring device 400. The core function of this invention is to systematically and fundamentally solve the heat dissipation, fire prevention, and protection problems of energy storage systems by immersing the battery device 300 in the liquid cooling medium of the housing 100 and physically isolating it from the independent wiring device 400 above ground.

[0039] The safety protection structure mainly includes an underground containment pool 100, a battery device 300 immersed in a liquid cooling medium within the pool, an independent wiring device 400 located in a dry environment above ground, and an electrical connection assembly 500 connecting the two. The battery device 300 includes a battery casing 301, a battery module 305, and high-voltage terminals 306. The battery cells within the battery device 300 can utilize relatively safer chemical systems such as lithium iron phosphate. The independent wiring device 400 integrates the slave control unit, sampling circuit, and control relay 402 of the battery management system 401. The main control unit of the BMS can be flexibly selected to be external or integrated into the box, depending on system complexity and layout requirements. Power cables and communication cables serve as connecting bridges and are equipped with critical first watertight connectors 801 and second watertight connectors 802 to ensure reliable sealing under long-term immersion.

[0040] The heat generated by the battery device 300 during operation is directly transferred to the surrounding liquid cooling medium, utilizing the high specific heat capacity of the liquid and the stability of the ground temperature to achieve efficient heat dissipation. At the same time, high-voltage components that are prone to heat generation and have the risk of electric arcing are enclosed in a non-flammable medium, while the sensitive battery management and control unit is placed in an independent, dry, and safe environment. Physical isolation fundamentally cuts off the path of electrical fire spread. The system transmits power and communicates signals via cables.

[0041] First, an underground containment tank 100 is constructed and filled with liquid cooling medium. The assembled battery device 300 is then immersed in the containment cavity 200. The immersion process can be flexibly adjusted according to actual heat dissipation requirements and system configuration, and it is not necessary to completely immerse the entire battery device 300. For example, in specific application scenarios, some modules or specific heat-generating areas of the battery device 300 can be immersed in the liquid cooling medium to utilize the medium's efficient heat exchange performance for targeted cooling, while other parts can be cooled using other auxiliary heat dissipation measures, thereby achieving an optimal balance between heat dissipation efficiency and cost. An independent wiring device 400 is installed above ground, along with a battery management system 401 and a control relay 402. Power cables and communication cables, each with a first watertight connector 801 and a second watertight connector 802, are used to reliably connect the high-voltage terminals 306 of the battery device 300 to the corresponding ports in the junction box, ultimately forming a collaborative operation system that combines underground immersion heat dissipation with above-ground control and protection. During maintenance, the liquid level can be lowered or drained through the drain port located at the bottom of the container 100 to expose the battery device 300, allowing for replacement or repair.

[0042] It is understandable that, based on the fact that the containment pool 100 is constructed underground and its containment cavity 200 is filled with liquid cooling medium, immersing the battery device 300 in the liquid cooling medium, and utilizing the high specific heat capacity of the liquid and the stability of the ground temperature, provides a huge, efficient, and natural heat dissipation environment for the battery system without the need for additional power, thus achieving essentially efficient thermal management; and based on the physical isolation of the battery device 300, which includes the high-voltage terminal block 306, from the independent wiring device 400 with the built-in battery management system 401 and control relay 402, and connecting the two through a watertight connector... The electrical connection components 500 are connected, placing high-energy components prone to thermal runaway and arcing risks in a non-flammable liquid medium, while placing the sensitive battery management system 401 and control relays 402 in a dry and safe environment. This achieves physical separation of power supply and control from a system architecture perspective, fundamentally eliminating the possibility of electrical fire spread. The power cable has a first watertight connector 801, and the communication cable has a second watertight connector 802, ensuring the sealing reliability of the battery device 300 under long-term immersion conditions, while also providing a foundation for system maintainability. This structural design, through the coordinated layout of underground immersion and above-ground control, systematically and fundamentally solves the heat dissipation, fire protection, and safety challenges of energy storage systems.

[0043] Preferably, the containment tank 100 is further provided with a liquid thermal circulation system 600; the liquid thermal circulation system 600 includes a water pump 601 located in the containment cavity 200 and a heat exchange pipe 602 buried in the soil surrounding the containment tank 100; both ends of the heat exchange pipe 602 are connected to the containment cavity 200 and are connected in series with the water pump 601 to form a closed loop. The core function of this liquid thermal circulation system 600 is to enhance heat dissipation through active circulation, efficiently transfer battery heat to the surrounding soil, overcome the problem of local heat accumulation during static immersion, and significantly improve the system's heat dissipation capacity and temperature uniformity.

[0044] The system mainly consists of a water pump 601 installed inside the containment cavity 200 and a heat exchange pipeline 602 pre-buried in the soil around the containment pool 100. The two ends of the heat exchange pipeline 602 are respectively connected to the internal space of the containment cavity 200 and connected in series with the water pump 601 to form a closed liquid circulation loop.

[0045] When the water pump 601 starts, it drives the liquid cooling medium in the containment cavity 200 to flow into the heat exchange pipeline 602 buried in the soil. As the liquid cooling medium flows through the pipeline, it continuously transfers the heat generated by the battery to the surrounding soil, which has a relatively low and stable temperature. After the heat exchange is completed, the cooled medium flows back to the containment cavity 200 to cool the battery device 300 again, thus forming a continuous and efficient heat transfer cycle.

[0046] It is understandable that a liquid heat circulation system 600 is constructed by setting a water pump 601 in the containment cavity 200 and connecting it in series with the heat exchange pipeline 602 buried in the surrounding soil to form a closed loop. The water pump 601 drives the liquid cooling medium in the containment cavity 200 to flow through the underground heat exchange pipeline 602, making full use of the earth as a larger natural cold source, and continuously and efficiently transferring the heat generated by the battery to the deep soil. This significantly improves the heat dissipation capacity and temperature uniformity of the entire system, overcomes the problem of local heat accumulation that may occur when relying solely on static immersion, and further optimizes and enhances the passive heat dissipation effect of the device.

[0047] Preferably, the battery casing 301 includes an inner casing 302, an outer casing 303, and a liquid cooling layer 304 located between the inner casing 302 and the outer casing 303. The liquid cooling layer 304 has cooling channels, and the inlet and outlet of the cooling channels penetrate the outer casing 303 to connect to the receiving cavity 200. The core function of this liquid cooling layer 304 structure is to construct a built-in secondary enhanced heat dissipation path for the battery module 305, enabling rapid heat removal from the battery's internal core to the external cooling medium.

[0048] The battery casing 301 adopts a double-layer casing design. The connection and sealing of its key components can be achieved using laser welding technology to ensure the long-term reliability and sealing integrity of the liquid cooling layer 304. It is composed of an inner casing 302 for carrying the battery module 305, an outer casing 303 for external protection, and a liquid cooling layer 304 sandwiched between the two. The liquid cooling layer 304 has specific cooling channels machined inside, and the channel inlet and outlet both pass through the outer casing 303 (the penetration structure is sealed with a waterproof device), so that the internal space of the channel is directly connected to the receiving cavity 200 of the receiving pool 100. The liquid medium of the receiving pool 100 can be directly used to form an integrated internal liquid cooling structure, liquid cooling of the receiving pool 100, and thermal circulation liquid cooling.

[0049] When the liquid cooling medium in the containment cavity 200 is driven by natural convection or external circulation, part of the medium enters the cooling channel of the liquid cooling layer 304 from the inlet. The channel wall is in close contact with the battery module 305 and performs efficient heat exchange, carrying away the heat generated by the battery. The medium with increased temperature flows out from the outlet and flows back into the main cooling medium of the containment cavity 200, thereby greatly increasing the heat dissipation area and effectively supplementing and enhancing the overall immersion heat dissipation mode. As an optional enhanced heat dissipation implementation method, a heat sink can also be installed on the outer wall of the battery casing 301 or in the channel of the liquid cooling layer 304. This heat sink is directly immersed in the liquid cooling medium of the containment pool 100, and its expanded heat dissipation surface area further accelerates the rate of heat diffusion to the surrounding medium.

[0050] It is understandable that by setting a liquid cooling layer 304 between the inner shell 302 and the outer shell 303 of the battery housing 301 and forming a cooling channel communicating with the receiving cavity 200, a secondary enhanced heat dissipation path is constructed for the battery module 305. The liquid cooling medium can enter the cooling channel within the liquid cooling layer 304 through the channel inlet, and after efficient heat exchange with the battery module 305, it flows out from the channel outlet. This structure greatly increases the effective contact area between the battery cell and the cooling medium, realizing rapid heat dissipation from the battery core to the cooling medium in the external cavity, effectively reducing the operating temperature of the battery body and the internal temperature difference. This design, by introducing the built-in liquid cooling layer 304 structure, effectively supplements and enhances the overall immersion heat dissipation.

[0051] Preferably, a fireproof partition 307 is also provided between adjacent battery modules 305. The core function of the fireproof partition 307 is to achieve physical and thermal isolation between battery modules 305, and to prevent chain reactions caused by thermal runaway of a single module.

[0052] Fireproof partition 307 is vertically installed between two adjacent battery modules 305 inside the battery housing 301, providing a liquid cooling channel gap of not less than 5mm between the battery modules 305. Liquid cooling layer 304 is installed in the liquid cooling channel gap to enhance the cooling effect inside the battery pack. The partition is made of non-combustible and heat-insulating material, and its size matches the internal space of the battery housing 301, thereby dividing the battery compartment into multiple independent units.

[0053] When a battery module 305 experiences thermal runaway and rapidly releases heat, its adjacent fireproof partition 307 can effectively block the direct impact of high-temperature flames and heat, and confine the thermal impact to the unit where the faulty module is located for a certain period of time. This provides a critical time window for the battery management system 401 to detect the fault and cut off the circuit, thereby preventing the accident from spreading to the entire battery device 300.

[0054] Preferably, the battery housing 301 has an IP68 protection rating, and the independent wiring device 400 has an IP65 protection rating. The core function of this differentiated protection rating design is to provide precisely matched protection capabilities for the battery device 300, which is submerged for extended periods, and the junction box, which is located in a dry ground environment, ensuring the sealing reliability and electrical safety of the system during long-term operation in complex environments.

[0055] The battery casing 301 adopts the highest level of IP68 protection standard, ensuring that it can be completely submerged in liquid cooling medium for a long time without water ingress; the independent wiring device 400 adopts IP65 protection level, which can effectively prevent the intrusion of external dust and low-pressure water spray from all directions, meeting the protection requirements in dry ground environments.

[0056] When the battery device 300 operates in the liquid cooling medium of the containment tank 100, the IP68 protection rating ensures the absolute sealing of its internal battery module 305 and high-voltage wiring; while the independent wiring device 400, located on the ground, with its IP65 protection rating, is sufficient to resist the effects of dust and moisture in the daily environment, ensuring the stable operation of the battery management system 401 and the control relay 402 in a dry and clean environment. Together, they form a protection system that is highly adapted to their respective operating environments.

[0057] Preferably, the containment tank 100 is a reinforced concrete structure with a waterproof and corrosion-resistant coating on its inner wall. The core function of the containment tank 100 structure is to provide a robust, durable, and absolutely leak-proof support environment for the underground immersion energy storage system, ensuring the long-term stable storage of the liquid cooling medium and preventing pollution of the surrounding soil.

[0058] The main body of the containment pool 100 is constructed by on-site casting of reinforced concrete, forming a rigid integral structure buried underground. To further enhance its sealing and durability, a continuous waterproof and anti-corrosion coating is applied to the entire inner wall surface of the pool, forming a barrier that combines physical and chemical properties.

[0059] The robust reinforced concrete structure withstands the lateral pressure of the surrounding soil and the hydrostatic pressure of the liquid cooling medium inside the pool, ensuring long-term structural stability. At the same time, the waterproof and anti-corrosion coating on the inner wall effectively isolates the cooling medium from the erosion of the concrete foundation and prevents the medium from leaking through the capillary pores of the concrete, together ensuring the structural safety and sealing integrity of the containment pool 100 throughout its entire service life.

[0060] Furthermore, the structural form of the containment pool 100 is not limited to cast-in-place reinforced concrete. It can be flexibly selected according to project needs, cost control, construction conditions, and life cycle. For example, a sealed tank made of corrosion-resistant steel can be used to improve structural strength and factory production; a box made of engineering plastics (such as PP and HDPE) can be used to take advantage of its excellent corrosion resistance and insulation; fiberglass (FRP) can be used to achieve lightweight and large-size prefabrication due to its high strength-to-weight ratio and impermeability; or a prestressed concrete structure can be used to meet the ultimate requirements of crack resistance and durability for ultra-large capacity pools.

[0061] Preferably, the top of the containment pool 100 is provided with a cover plate. The core function of this cover plate is that it acts as a load-bearing structural barrier, ensuring the airtightness of the top of the containment pool 100, effectively blocking external foreign objects, and bearing daily loads to protect the equipment inside the pool. At the same time, it provides a safe and convenient passage for the installation, inspection, and maintenance of the battery device 300. This robust and practical design eliminates users' psychological concerns about the structural safety and weak points of the underground water tank, significantly improving the public acceptance and deployment feasibility of this solution in sensitive scenarios such as residential areas and commercial areas.

[0062] The sealing cover 700 forms a sealing fit with the top opening of the container 100 through the sealing strips set around its periphery; the cover is horizontally slidably connected to the top of the container through the guide rail mechanism, and a locking mechanism is provided on one side. The cover is internally integrated with a lifting bracket 900 driven by a gear and rack mechanism. The bracket is connected to the electrical connection component 500 through a linkage mechanism, so that the horizontal sliding opening action of the cover can form a mechanical linkage with the lifting bracket 900 and the disconnection of the battery electrical connection.

[0063] When the cover needs to be unlocked and opened for maintenance, the gear and rack mechanism starts to operate as the cover slides open horizontally. On the one hand, it drives the lifting support 900 to move upward to the ready lifting position. On the other hand, it triggers a mechanical emergency stop switch through the linkage mechanism to cut off the circuit between the battery device 300 and the outside, ensuring that the subsequent lifting operation is carried out in an absolutely safe state where the battery is completely de-energized and there are no live wires.

[0064] Preferably, the liquid cooling medium is deionized water or a flame-retardant insulating liquid. The core function of selecting the liquid cooling medium is to meet the system's high-efficiency heat dissipation requirements while also ensuring electrical insulation safety and inherent fire resistance.

[0065] The liquid cooling medium is directly filled into the containment cavity 200 of the containment pool 100, immersing the entire battery device 300; the specific selection is of two types: one is a water-based medium with low cost and high specific heat capacity (such as deionized water), and the other is a synthetic ester or mineral oil insulating liquid with higher cost but also insulation and flame retardant properties.

[0066] The heat generated during battery operation is directly transferred to the surrounding liquid cooling medium. If a water-based medium is used, it mainly relies on its high specific heat capacity to absorb and store heat. If a flame-retardant insulating liquid is used, its inherent high flash point and insulating properties can actively suppress the generation of electric arcs and block the combustion chain while efficiently dissipating heat, providing a deeper level of safety for the system.

[0067] Preferably, the safety protection method for an energy storage system based on underground water tank immersion includes the following steps: forming a primary heat dissipation path: the heat generated by the battery module 305 is conducted to the liquid cooling layer 304 and absorbed by the liquid cooling medium flowing through the liquid cooling layer 304; forming a secondary heat dissipation path: the heat-absorbing liquid cooling medium flows out from the liquid cooling layer 304 and mixes and exchanges heat with the liquid cooling medium in the containment cavity 200; forming a tertiary heat dissipation path: through the liquid thermal circulation system 600, the liquid cooling medium in the containment cavity 200 is driven to flow through the heat exchange pipe 602 buried in the soil, and the heat is finally released to the ground. The core function of this multi-stage heat dissipation method is to construct a three-stage coordinated heat dissipation path from the inside out, realizing the step-by-step transfer and efficient dissipation of battery heat, ensuring the inherent safety and extremely high reliability of the system's thermal management.

[0068] The heat dissipation path is based on three spatially connected heat dissipation structures: the primary path relies on the liquid cooling layer 304 and its cooling channels inside the battery casing 301; the secondary path relies on the liquid cooling medium body filled in the containment pool 100; and the tertiary path relies on the liquid thermal circulation system 600 composed of the water pump 601 and the underground heat exchange pipeline 602.

[0069] The battery heat is first rapidly dissipated through the liquid cooling layer 304 by the internal flowing medium (primary path); the heated medium is mixed with a large amount of low-temperature medium in the containment cavity 200 to achieve preliminary temperature equalization and heat dissipation (secondary path); finally, the system pumps the heated medium in the cavity into the underground heat exchange pipeline 602 through the heat circulation pump, and uses the huge heat capacity of the earth to continuously and stably release heat into the deep soil. The cooled medium flows back to the containment pool 100, thus forming a complete and efficient three-stage heat dissipation cycle.

[0070] Preferably, the safety protection method for an energy storage system based on underground water tank immersion includes the following steps: Monitoring steps: The battery management system 401 monitors the voltage, temperature, and insulation resistance of each battery module 305 in real time; Judgment steps: The battery management system 401 performs graded judgment on the monitored operating parameters; Early warning steps: If any parameter reaches a preset early warning threshold, an early warning signal is issued; Active protection steps: If any parameter reaches a preset danger threshold, the control relay 402 is immediately instructed to disconnect the high-voltage connection between the battery device 300 and the external circuit; Passive protection steps: Any fire caused by thermal runaway of the battery device 300 is physically isolated by the liquid cooling medium in the containment tank 100. The core function of this safety protection method is to achieve early warning and intrinsic safety protection against potential risks of the system through a multi-level linkage control logic of "monitoring-judgment-early warning-protection-isolation".

[0071] This method relies on the battery management system 401's ability to collect real-time operating parameters of the battery module 305, the control relay 402's ability to disconnect the high-voltage circuit, and the physical isolation capability of the liquid cooling medium in the containment tank 100, forming a complete hardware foundation from signal perception to final execution and protection.

[0072] The battery management system 401 continuously analyzes and monitors data. When parameters become abnormal and reach the warning threshold, it issues an early warning, providing a window for manual intervention. If the parameters continue to deteriorate and reach the danger threshold, the system will immediately drive the control relay 402 to cut off the high-voltage connection and achieve electrical isolation. Even if the battery experiences thermal runaway in extreme cases, the heat it generates and potential ignition sources will be completely enveloped and cooled by the surrounding non-flammable liquid cooling medium, thereby achieving final physical isolation and preventing the accident from escalating.

[0073] Throughout the thermal management process of the entire system, heat is continuously transferred from high-temperature areas to low-temperature areas. When the ambient temperature is 35℃, the core temperature of the battery cell can reach a maximum of 45℃. The heat is first conducted to the surface of the battery pack, maintaining its temperature at approximately 40℃. The heat on the surface of the battery pack is rapidly carried away by the surrounding liquid cooling medium with a flow velocity of not less than 0.1m / s. The temperature diffuses radially outward from the heat source and gradually decreases, stabilizing the water temperature at around 30℃. Subsequently, through the liquid thermal circulation system 600, this heat is transported to the heat exchange pipes 602 buried in the soil constant-temperature layer (temperature constant at 25℃), ultimately releasing the heat continuously to the ground, completing an efficient heat dissipation cycle from the battery cell to the soil.

[0074] In summary, this solution is based on immersing the battery device 300 in a liquid cooling medium within a containment pool 100 constructed below ground. Utilizing the high specific heat capacity of the liquid and the stability of ground temperature, it provides the battery system with a large, efficient, and naturally heat-dissipating environment that requires no additional power, achieving fundamentally efficient thermal management. Simultaneously, by physically isolating the battery device 300, which includes high-voltage terminals 306, from the independent wiring device 400 containing the built-in battery management system 401 and control relays 402, and connecting the two via an electrical connection assembly 500 with a first watertight connector 801 and a second watertight connector 802, the system architecture achieves physical separation of power supply and control, fundamentally eliminating the possibility of electrical fire spread. To further enhance heat dissipation, the scheme incorporates a water pump 601 within the containment cavity 200, connected in series with a heat exchange pipeline 602 buried in the surrounding soil to form a closed-loop circulation system 600, continuously transferring heat to the ground. A liquid cooling layer 304 is also installed between the inner shell 302 and outer shell 303 of the battery casing 301, forming a cooling channel connected to the containment cavity 200, thus creating a secondary enhanced heat dissipation path for the battery module 305. Furthermore, specific design elements such as fireproof partitions 307 between adjacent battery modules 305, setting the protection levels of the battery casing 301 and independent wiring device 400 to IP68 and IP65 respectively, using a reinforced concrete structure with an internal waterproof and anti-corrosion coating for the containment pool 100, installing an openable sealing cover 700 on the pool top, and selecting water or a flame-retardant insulating liquid as the cooling medium, collectively and systematically enhance the overall efficiency and engineering feasibility of the energy storage system in terms of heat dissipation, fire protection, protection, and maintainability.

[0075] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0076] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0077] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A safety protection structure for an energy storage system based on underground water tank immersion, characterized in that, include: A container (100) is constructed below ground level, and the container (100) has a container cavity (200) inside; the container cavity (200) is used to fill a liquid cooling medium; A battery device (300) is immersed in a liquid cooling medium in a receiving cavity (200). The battery device (300) includes a battery housing (301), a plurality of battery modules (305) disposed within the battery housing (301), and a high-voltage terminal (306). The high-voltage terminal (306) connects to the plurality of battery modules (305). An independent wiring device (400) is physically isolated from the receiving cavity (200); a battery management system (401) is installed inside the independent wiring device (400); An electrical connection assembly (500) includes a power cable and a communication cable. One end of the power cable is connected to a high-voltage terminal block (306) via a first watertight connector (801), and the other end of the power cable is connected to the independent wiring device (400). One end of the communication cable is connected to a battery module (305) via a second watertight connector (802), and the other end of the communication cable is connected to the independent wiring device (400).

2. The safety protection structure for an energy storage system based on underground water tank immersion as described in claim 1, characterized in that, The containment tank (100) is also provided with a liquid heat circulation system (600); the liquid heat circulation system (600) includes a water pump (601) and a heat exchange pipeline (602) buried in the soil around the containment tank (100); the two ends of the heat exchange pipeline (602) are connected to the containment cavity (200) and are connected in series with the water pump (601) to form a closed loop.

3. The safety protection structure for an energy storage system based on underground water tank immersion as described in claim 1, characterized in that, The battery housing (301) includes an inner shell (302), an outer shell (303), and a liquid cooling layer (304) located between the inner shell (302) and the outer shell (303); the liquid cooling layer (304) forms a cooling channel, and the channel inlet and channel outlet of the cooling channel both penetrate the outer shell (303) to connect to the receiving cavity (200) respectively.

4. The safety protection structure for an energy storage system based on underground water tank immersion as described in claim 3, characterized in that, A fireproof partition (307) is provided between adjacent battery modules (305).

5. The safety protection structure for an energy storage system based on underground water tank immersion as described in claim 1, characterized in that, The battery casing (301) has an IP68 protection rating; the independent wiring device (400) has an IP65 protection rating.

6. The safety protection structure for an energy storage system based on underground water tank immersion as described in claim 5, characterized in that, The containment pool (100) is a reinforced concrete structure with a waterproof and anti-corrosion coating on its inner wall.

7. The safety protection structure for an energy storage system based on underground water tank immersion according to claim 3, characterized in that, The top of the container (100) is provided with a cover plate.

8. The safety protection structure for an energy storage system based on underground water tank immersion according to claim 1, characterized in that, The liquid cooling medium is deionized water.

9. A safety protection method for energy storage systems based on underground water tank immersion, characterized in that, The energy storage system safety protection structure based on underground water tank immersion as described in claim 3 further includes the following steps: A primary heat dissipation path is formed: the heat generated by the battery module (305) is conducted to the liquid cooling layer (304) and absorbed by the liquid cooling medium flowing through the liquid cooling layer (304); A secondary heat dissipation path is formed: the liquid cooling medium that absorbs heat flows out from the liquid cooling layer (304) and mixes and exchanges heat with the liquid cooling medium in the receiving cavity (200); A three-stage heat dissipation path is formed: the liquid cooling medium in the containment cavity (200) is driven by the liquid thermal circulation system (600) to flow through the heat exchange pipeline (602) buried in the soil, and the heat is finally released to the ground.

10. The safety protection method for an energy storage system based on underground water tank immersion according to claim 9, characterized in that, Monitoring steps: The battery management system (401) monitors the voltage, temperature and insulation resistance of each battery module (305) in real time. Judgment Step: The battery management system (401) performs a graded judgment on the monitored operating parameters; the graded judgment includes a normal judgment, a warning step, and a protection step; Warning procedure: If any parameter reaches the preset warning threshold, a warning signal will be issued; Passive protection steps: If any parameter reaches the preset danger threshold, the control relay (402) of the independent wiring device (400) is immediately instructed to disconnect the high voltage connection between the battery device (300) and the external circuit; Active protection steps: The fire caused by thermal runaway of the battery device (300) is physically isolated by the liquid cooling medium in the containment pool (100).

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