Immersed liquid cooling energy storage unit

Abstract

The invention discloses an immersed liquid cooling energy storage unit, and belongs to the technical field of battery thermal management. The unit comprises an energy storage box and at least one battery packaging body arranged in the energy storage box, wherein the battery packaging body comprises a flexible shell, a battery module contained in a sealed containing cavity of the flexible shell and internal immersion liquid for immersing the battery module; a flowing space allowing an external cooling medium to circulate is jointly defined between the flexible shell and the inner wall of the energy storage box, and therefore a double immersion cooling and physical isolation structure of internal immersion liquid, the flexible shell and the external cooling medium is formed. According to the invention, through the design of the modularized flexible battery packaging body, the battery module and the special immersion liquid thereof are independently sealed, so that the risk of cross contamination caused by thermal runaway is fundamentally isolated, and rapid maintenance of the module level is realized; meanwhile, decoupling of internal and external cooling media is achieved through the framework, high-performance insulating liquid can be adopted inside, low-cost cooling media can be adopted outside, and the system economy and the supply chain safety are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of battery energy storage technology, and in particular to a battery thermal management system, specifically an immersion liquid-cooled energy storage unit. Background Technology

[0002] Energy storage containers (or energy storage compartments) integrate core components such as battery cabinets (formed by rows of battery modules), battery management systems (BMS), power converters (PCS), and thermal management systems, enabling rapid deployment and flexible configuration. They are key equipment for energy storage and grid balancing. However, energy storage batteries pose a safety risk of thermal runaway due to the activity of their electrodes and the instability of their electrolytes.

[0003] Among various thermal management solutions, immersion liquid cooling systems have attracted attention due to their potential for efficient heat dissipation and extended battery life. Existing immersion liquid cooling solutions typically place multiple battery modules directly in a shared, rigid battery box and immerse them in an insulating coolant (such as fluorinated liquid or silicone oil). After absorbing heat, the coolant is driven by a circulation pump to flow throughout the system, dissipates heat through an external heat exchanger, and then flows back.

[0004] Although this direct contact method theoretically has high heat transfer efficiency, and the coolant can suppress thermal runaway to some extent, it still faces the following serious challenges in large-scale application and promotion:

[0005] 1. Systemic cross-contamination risk: This is the most fatal flaw in the current architecture. Multiple battery modules share the same coolant circulation system. If a single cell in a module experiences thermal runaway, leading to electrolyte leakage, the contaminated coolant will flow through the entire system, potentially accelerating the corrosion and failure of other healthy cells, triggering a chain reaction, and causing huge systemic safety and economic losses.

[0006] 2. Core medium relies on imports: To achieve a balance between insulation and thermal conductivity, mainstream solutions heavily rely on imported electronic fluorinated liquids (such as the 3M Novec series), which are costly and pose supply chain risks.

[0007] 3. Difficulty in long-term operation and maintenance: The unified coolant circuit is bulky, and the cost of replacing the coolant after it ages is extremely high; at the same time, most existing solutions are rigid integral structures, and when any battery unit fails, maintenance is extremely inconvenient, often requiring the entire system's coolant to be drained, resulting in poor maintainability.

[0008] It should be noted that the above description of the background technology is only for the purpose of providing a clear and complete explanation of the technical solutions of the present invention and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of the present invention. Summary of the Invention

[0009] The present invention aims to solve the problems of systemic cross-contamination risk, strong dependence on imported coolant, and poor overall maintainability in existing immersion liquid cooling technology.

[0010] To achieve the above objectives, the present invention provides an immersion liquid-cooled energy storage unit, comprising an energy storage tank and at least one battery package disposed therein. The battery package includes a flexible shell, a battery module housed within a sealed cavity of the flexible shell, an internal immersion liquid immersing the battery module, and an interface structure disposed on the flexible shell; wherein, the flexible shell and the inner wall of the energy storage tank together define a flow space for the circulation of external cooling medium; the interface structure is configured to provide a fluid channel to the cavity and an electrical connection path for the battery module.

[0011] As a further improvement of the present invention, the flexible shell has an opening for inserting a battery module, and a press-fit sealing strip is provided at the opening for controlling the opening and closing of the opening.

[0012] As a further improvement of the present invention, the interface structure includes a fluid filling part and an electrical connection part, wherein the fluid filling part is used to fill or drain the internal immersion liquid into the accommodating cavity, and the electrical connection part is used to realize the sealed connection between the electrical connection terminal of the battery module and the external circuit.

[0013] As a further improvement of the present invention, the electrical connection portion includes a mounting structure for mounting the battery management unit acquisition module; or, the electrical connection portions of multiple battery packages are respectively connected to a common battery management unit acquisition module by electrical connectors.

[0014] As a further improvement of the present invention, the flexible shell is made of a polymer barrier film or an aluminum-plastic composite film; the surface insulation resistance of the flexible shell is not less than 100MΩ and it can withstand a DC4500V voltage for 1 minute without breakdown; and / or, the flexible shell can withstand an internal static pressure of 0.1MPa to 0.3MPa without tearing.

[0015] As a further improvement of the present invention, the battery package also includes a fixing structure for constraining the deformation and position of the battery module.

[0016] As a further improvement of the present invention, a liquid cooling channel is provided at the bottom of the energy storage box. The liquid cooling channel is connected to the liquid inlet and is used to support the battery package.

[0017] As a further improvement of the present invention, the energy storage tank is provided with an inlet and an outlet that communicate with the flow space; the inlet is connected to the liquid cooling channel and is used to pressurize and input external cooling medium into the energy storage tank; the energy storage tank is provided with an overflow structure, the overflow inlet of the overflow structure is located at a set height and is connected to the outlet, so that the liquid level in the flow space is maintained at the set height by unpressurized overflow.

[0018] As a further improvement of the present invention, the liquid cooling channel is a loop channel, which includes multiple parallel channel tubes, and multiple injection holes are opened on the tube wall of the channel tube; preferably, the total flow area of ​​the injection holes on the channel tube located in the middle is smaller than the total flow area of ​​the injection holes on the channel tubes located on both sides.

[0019] As a further improvement of the present invention, the internal immersion liquid is an insulating and heat-conducting liquid; and / or

[0020] The external cooling medium is water, ethylene glycol aqueous solution, or insulating oil;

[0021] And / or, the energy storage box is composed of a basin-shaped box and a cover plate made of concrete composite material, and at least one energy storage cavity is formed inside the basin-shaped box.

[0022] Compared with the prior art, the immersion liquid-cooled energy storage unit provided by the present invention has the following significant advantages:

[0023] 1. Enhanced Safety and Risk Isolation: Each battery module is independently sealed in a flexible outer shell and internal immersion fluid, forming a closed unit. When a cell in any battery package experiences thermal runaway, the resulting contaminants are completely confined within that package, preventing contamination of other battery packages or the circulation loop of the external cooling medium. This fundamentally eliminates chain reactions and greatly enhances the overall safety and reliability of the energy storage system.

[0024] 2. Modular Design and Efficient Maintenance: Each battery package is an independent, prefabricated functional module. If a module malfunctions, simply shutting off its corresponding external flow channel allows the entire battery package to be quickly removed from the energy storage tank for replacement, simplifying the operation. This avoids the cumbersome process of draining, cleaning, and refilling the entire system coolant required in traditional solutions, resulting in high maintenance efficiency and short downtime.

[0025] 3. Reduced Costs and Supply Chain Security: Through an architecture of "decoupling internal and external media," necessary high-performance insulating fluids (in small quantities) can be used inside the sealed battery package, while large quantities of extremely low-cost water, ethylene glycol solutions, or ordinary insulating oils can be used in the external flow space. This significantly reduces dependence on imported expensive electronic fluorinated fluids and the overall system cost, enhancing the self-controllability of the supply chain.

[0026] 4. Provide safety redundancy and physical buffer: The flexible shell itself has a certain deformation capability, which can not only buffer the slight expansion of the battery cell during charging and discharging, but also provide a certain volume buffer when a large amount of gas is generated by thermal runaway, delaying the rapid rise in pressure and buying valuable time for the system to respond safely. Attached Figure Description

[0027] Figure 1 A schematic diagram of the principle structure of an immersion liquid-cooled energy storage unit provided by the present invention;

[0028] Figure 2 A schematic diagram of the structure of an energy storage box provided by the present invention;

[0029] Figure 3 This is a schematic diagram of assembling a battery module into a flexible shell, wherein the flexible shell is in an unfolded state.

[0030] Figure 4 This invention provides a schematic diagram of the packaging state of a battery package.

[0031] Figure 5 This is a schematic diagram illustrating another packaging state of a battery package provided by the present invention;

[0032] Figure 6 A schematic diagram of the liquid cooling flow channel of an immersion liquid-cooled energy storage unit provided by the present invention;

[0033] Figure 7 A three-dimensional structural schematic diagram of an immersion liquid-cooled energy storage unit provided by the present invention;

[0034] Figure 8 This is a schematic diagram illustrating the application of the immersion liquid-cooled energy storage unit provided by the present invention to a concrete energy storage tank.

[0035] Explanation of reference numerals in the attached figures:

[0036] 10 Energy storage box, 110 Energy storage cavity, 11 Basin-shaped box body, 111 Partition, 12 Cover plate, 101 Liquid inlet, 102 Liquid outlet, 13 Liquid cooling channel, 131 Channel pipe, 132 Water inlet branch pipe, 14 Overflow pipe, 141 Overflow inlet, 15 Sliding parts, 16 High pressure box.

[0037] 20 Battery package, 21 Flexible shell, 210 Receptacle, 211 Opening, 22 Battery module, 22a Electrical connection terminal, 23 Press-fit sealing strip, 24 Internal immersion liquid, 25 End plate, 26 Constraint band, 27 Interface structure, 271 Injection channel, 271a Seal, 272 Electrical connection tube, 273 Data acquisition and control box.

[0038] 30 External cooling medium;

[0039] 40 Flow space;

[0040] 50 Concrete energy storage cabin, 51 Track beam. Specific implementation manners

[0041] The present invention will be described in detail below in conjunction with the embodiments shown in the drawings. However, it should be noted that these embodiments are not limitations on the present invention. Any equivalent transformation or substitution in terms of function, method, or structure made by those of ordinary skill in the art based on these embodiments shall fall within the protection scope of the present invention.

[0042] Combined with Figures 1 to 7 As shown, a submersed liquid cooling energy storage unit provided by the present invention is characterized in that through the combination of a modular battery encapsulation body 20 and an energy storage box 10, a highly efficient, safe and easy-to-maintain double submersed cooling system is constructed.

[0043] Referring to Figure 2 As shown, the energy storage box 10 is the external structural support of the entire unit and the container for the external cooling medium. An inlet 101 and an outlet 102 communicating with the energy storage cavity 110 are provided on the energy storage box 10 for the inflow and outflow of the external cooling medium 30 to form a cooling cycle.

[0044] The energy storage box 10 is preferably made of a concrete composite material. In this preferred embodiment, the energy storage box 10 is configured with a basin-shaped box body 11 and a cover plate 12. The basin-shaped box body 11 refers to a basic container structure with one open side and the rest closed, and a complete energy storage space can be formed inside it, or it can be divided into multiple independent energy storage spaces by an integrally formed partition 111. The cover plate 12 covers the opening of the basin-shaped box body 11, thereby constructing one or more enclosed energy storage cavities 110 with high strength and high fire resistance. This concrete structure can effectively confine the high temperature and flame generated by battery thermal runaway inside it, providing valuable buffer time for fire response.

[0045] In other embodiments, the energy storage box 10 can also be made of metal (such as steel, aluminum alloy) or high-strength composite materials.

[0046] One or more battery encapsulation bodies 20 are arranged in the energy storage cavity 110 of the energy storage box 10. Combined with Figure 1 、 Figure 3 and Figure 4As shown, the core of the battery package 20 is a preformed flexible outer shell 21, which is made of a high-polymer barrier film or an aluminum-plastic composite film with high insulation, barrier properties, and flexibility. Actual measurements show that the surface insulation resistance of the flexible outer shell 21 is not less than 100 MΩ, and it can withstand a voltage of DC 4500 V for 1 minute without breakdown, ensuring extremely high electrical insulation safety between it and the external environment and the cooling medium. At the same time, the flexible outer shell 21 made of this material has excellent mechanical strength and can withstand an internal static pressure of 0.1 MPa to 0.3 MPa without tearing, which guarantees its structural integrity and reliability during long-term use and in cases where there may be slight gas generation inside.

[0047] As shown Figure 3 As shown, when the flexible outer shell 21 is in the unfolded state, a structure forming a sealed accommodation cavity 210 is formed inside it, and a sealable opening 211 is provided for loading the battery module 22. During assembly, first, the battery module 22 is placed into the accommodation cavity 210 through the opening 211 of the flexible outer shell 21, and then the opening 211 is sealed using a pressing sealing strip 23 (such as through a heat sealer or a mechanical pressing strip) to ensure the airtightness of the accommodation cavity 210.

[0048] The accommodation cavity 210 houses the battery module 22 and an internal immersion liquid 24 that completely submerges the battery module 22. The specific form of the battery module 22, as the core object to be encapsulated and cooled, can be flexible. It can either be an independent standard battery module composed of multiple battery cells connected in series and parallel, or multiple such independent standard modules can be further integrated into a larger battery module unit. Regardless of its specific composition, the battery module 22 as a whole is completely submerged in the internal immersion liquid 24 to achieve direct and efficient thermal management.

[0049] Filling the internal immersion liquid 24 into the accommodation cavity 210 has multiple purposes: First, it provides an insulated sealing environment for the battery module 22; second, it fills all the gaps between the battery module 22 and the inner wall of the flexible outer shell 21, excluding air, which is a poor heat conductor, so that the battery module 22 and the flexible outer shell 21 are closely "fitted" through the oil, greatly improving the heat conduction path; third, it fills the battery package 20 with liquid to balance the internal and external liquid static pressures of the flexible outer shell and prevent the external cooling medium 30 from infiltrating under pressure; finally, after filling with oil, it is convenient to visually observe whether there are leakage points on the flexible outer shell 21, providing an initial leak detection guarantee for the subsequent safe injection of the external cooling medium 30.

[0050] This encapsulation design, based on a flexible shell and pressure sealing, endows the battery package 20 with unique physical properties: it can be compressed to reduce volume when not in operation, facilitating transportation and storage; and it can be quickly opened and closed during maintenance, enabling efficient modular replacement. This design greatly improves the maintainability of the entire energy storage system and optimizes its economics throughout its entire lifecycle.

[0051] The internal immersion fluid 24 can be any commercially available, mature insulating and heat-conducting fluid, directly contacting and immersing all complex electrical components of the battery module 22, such as the tabs, plates, aluminum bars, and busbars. As a preferred, cost-effective embodiment, the internal immersion fluid 24 is mineral oil or synthetic ester, which significantly reduces costs while meeting basic insulation and heat conduction requirements. Since each battery module 22 is independently sealed within its own flexible outer shell 21, the internal immersion fluid 24 only needs to fill the small space between the battery module 22 and the outer shell. Its total usage is reduced by more than 90% compared to the traditional overall immersion scheme that directly fills all spaces in the entire energy storage tank 10 (or energy storage cavity 110) except for the battery module 22 with insulating fluid, thus significantly reducing the procurement and maintenance costs of expensive cooling media at the source. In other embodiments, depending on different performance and budget requirements, heat-dissipating silicone oil, hydrocarbon-based heat dissipation fluids (such as synthetic hydrocarbon PAO / GTL), ICL series modified organosilicon, or fluorinated fluids can be selected.

[0052] To ensure the battery module 22 is stably fixed within the flexible accommodating cavity 210 and to prevent deformation or displacement during use, the battery package 20 is provided with a fixing structure. This fixing structure is used to constrain the deformation and position of the battery module 22. In specific implementations, the following embodiments can be selected based on process and cost requirements:

[0053] In one implementation: (referring to...) Figure 4 As shown, the fixing structure is disposed on the outside of the flexible shell 21. The fixing structure includes two end plates 25 respectively attached to the wide surface of the flexible shell 21, and a constraint strap 26 in the form of a steel strip. The constraint strap 26 is wrapped and bound around the end plates 25 and the outside of the flexible shell 21, and is tightened by fasteners or welding, thereby forming a solid binding and limiting of the internal battery module 22 from the outside.

[0054] In another implementation, the reference Figure 5 As shown, the fixing structure is set inside the flexible shell 21, that is, within the accommodating cavity 210. First, the two end plates 25 are directly abutted against the two end faces of the battery module 22. Then, the battery module 22 and the end plates 25 are directly wrapped and bound together with the constraint straps 26 to form a tight whole. Subsequently, this bound whole is placed into the flexible shell 21 for subsequent sealing and electrolyte filling operations. This scheme allows the constraint force to act more directly on the battery module and results in a smoother appearance.

[0055] Regardless of the implementation method, this fixing structure can effectively suppress the expansion of the battery module 22 during charging and discharging, thereby improving its mechanical stability.

[0056] The interface structure 27 is disposed on the top of the flexible housing 21. In this embodiment, it is a composite functional structure configured to simultaneously provide a fluid passage to the accommodating cavity 210 and an electrical connection path for the battery module 22. Its specific configuration varies depending on the integration method of the electrical connection and battery management functions, and there are two main implementation methods.

[0057] In one implementation, such as Figure 4 As shown, the interface structure 27 mainly includes a sealable filling channel 271 and an electrical connection tube 272. The filling channel 271 is specifically used for filling or draining the internal immersion fluid 24 into the accommodating cavity 210. After filling, it can be sealed by a sealing element 271a (such as a sealing cap). The electrical connection tube 272 is used to lead out the busbar of the battery module 22 (i.e., the electrical connection terminal 22a of the main circuit) in a physically sealed manner. The led-out busbar can be directly connected in series or in parallel with the corresponding part of the adjacent battery package to form a high-voltage circuit, or it can be connected to the external main circuit cable. This method achieves basic electrical connection and sealed insulation.

[0058] In another implementation, such as Figure 5 As shown, each battery package 20 is configured as an intelligent module with built-in status acquisition function. The interface structure 27 integrates a sealable filling channel 271, and its electrical connection is specifically a data acquisition control box 273 located on top of the flexible housing 21. The data acquisition control box 273 is a rigid, openable, sealed cavity. Its rigid structure provides stable support and protection for the internally installed battery management unit acquisition module (i.e., the battery management system slave control board), and achieves reliable connection through a sealing structure (e.g., sealing with the flexible housing 21 using a sub-port and structural adhesive), together forming a rigid-flexible composite package. The acquisition module (not shown) is connected to the voltage and temperature sampling points inside the battery module 22 via internal wiring harnesses for real-time acquisition of battery status data, and is connected to an external communication bus and low-voltage power supply through a waterproof connector (not shown) on the data acquisition control box 273, thereby achieving intelligent management. The data acquisition control box 273 is specially designed at the top, with an opening for inserting the battery module 22 (… Figure 5 (Not shown in the figure) The modules are spatially staggered and do not interfere with each other (for example, the opening is located at the top edge of the flexible housing 21), thereby ensuring the independence of module assembly and maintenance and electrical function integration.

[0059] It should be noted that in a complete energy storage system, the energy storage tank 10 typically integrates a high-voltage tank 16 at one end or on the side. For example... Figure 7 As shown, the high-voltage box 16 is an independent, sealed electrical enclosure that houses the core high-voltage electrical components of this unit, such as: main circuit breakers, fuses, and contactors for current collection and switching control; pre-charge resistors, current sensors, and insulation monitoring modules for system protection; and the battery management unit (BMS) main control module responsible for battery cluster-level management (such as contactor control and protection logic). The electrical energy from each battery package 20 is collected through cables led out from its interface structure 27 and acquisition control box 273, and then fed into the high-voltage box 16. After processing by the aforementioned electrical components, the energy is supplied externally from the total output terminal of the high-voltage box 16, and then connected to the grid-side energy storage converter (PCS) for energy exchange. The battery package 20 and its acquisition module in this invention constitute the most basic battery management and cooling unit of the system.

[0060] The bottom of the energy storage cavity 110 is provided with a liquid-cooled flow channel 13 that serves both as a support and a flow guide, and the liquid-cooled flow channel 13 is connected to the liquid inlet 101.

[0061] As a preferred option, the liquid cooling channel 13 is a loop channel to ensure that the external cooling medium 30 is evenly distributed at the bottom of the energy storage cavity 110, eliminating flow dead zones.

[0062] As a specific implementation method of the loop flow channel, refer to Figure 6 As shown, the liquid cooling channel 13 consists of multiple parallel channel tubes 131. Multiple injection holes (not shown) are formed on the wall of the channel tubes 131 facing the battery package 20. External cooling medium 30 is ejected at high speed from these injection holes, providing active and enhanced impact cooling to the bottom of the battery package 20, further breaking down the thermal boundary layer and greatly improving local heat exchange efficiency. As an optimized implementation, the total flow area of ​​the injection holes on the channel tube 131 located in the middle can be designed to be smaller than the total flow area of ​​the injection holes on the channel tubes located on both sides, in order to balance the flow rate and cooling intensity in each region.

[0063] Since the external cooling medium 30 does not directly contact the battery module 22 and heat exchange occurs through the flexible outer shell 21, its performance requirements can be appropriately reduced, thus providing room for cost reduction. Water, ultrapure water, or ethylene glycol aqueous solutions with extremely low cost are preferred; in scenarios with higher requirements for insulation safety, various types of insulating oils can also be used.

[0064] An overflow pipe 14 is provided inside the energy storage chamber 110, which is connected to the liquid outlet 102. The overflow inlet 141 of the overflow pipe 14 is located at a preset height.

[0065] To achieve a compact structure and centralized management, the liquid inlet 101 and liquid outlet 102 are preferably arranged side-by-side on the front side wall of the energy storage tank 10. To achieve uniform cooling within each energy storage chamber 110, a fluid distribution system is provided inside the energy storage tank 10. For example, the design of the water inlet path and water return path is as follows:

[0066] Water inlet path: External cooling medium 30 flows from the liquid inlet 101 into a horizontally arranged water inlet distribution pipe (not shown). The water inlet distribution pipe extends along the length of the energy storage tank 10 (i.e., perpendicular to the front side wall) and is connected to the inlet of the liquid cooling channel 13 at the bottom of each energy storage cavity 110 arranged in parallel at the same horizontal level through multiple water inlet branch pipes 132, so as to ensure balanced liquid supply to each cavity.

[0067] Return water path: The external cooling medium 30 heated in each energy storage chamber 110 flows into the overflow pipe 14 through the overflow inlet 141 at the top. The overflowed medium flows into a horizontally arranged return water collection pipe (not shown). This main return water collection pipe also extends along the length of the energy storage tank 10 and eventually collects all the heat medium into the liquid outlet 102, completing the circulation inside the energy storage tank 10.

[0068] The complex distribution and collection piping is integrated inside the energy storage tank 10, with only the standard liquid inlet 101 and liquid outlet 102 exposed to the outside. This achieves a true "plug-and-play" modular design, where a single energy storage tank 10 can become a fully functional cooling subunit, greatly simplifying system integration and maintenance.

[0069] During operation, the low-temperature external cooling medium 30 is pumped pressurized into the liquid cooling channel 13 through the liquid inlet 101. The external cooling medium 30 rises from the bottom of the energy storage cavity 110 and, guided by the liquid cooling channel 13, flows through and surrounds the gaps between each battery package 20.

[0070] When the entire battery package 20 is fully immersed in the external cooling medium 30, its top, bottom, and all sidewalls are in direct contact with the cooling medium, forming a unique "six-sided water-surrounded" heat dissipation configuration. In this state, the heat generated by the battery module 22 during operation is first absorbed by the internal immersion liquid 24, and then efficiently transferred to the external cooling medium 30 surrounding its six surfaces through the walls of the flexible shell 21, achieving uniform and efficient heat dissipation without dead angles, especially with a significant cooling effect on the upper part of the battery module 22.

[0071] As the external cooling medium 30 heats up, its density decreases, causing it to continue rising. When the liquid level reaches the height of the overflow inlet 141 of the overflow pipe 14, the excess liquid flows out through the overflow pipe 14 and the outlet 102 via unpressurized overflow, returning to the external heat dissipation system for cooling. This overflow structure ensures that the liquid level within the flow space 40 remains stable at a preset constant height, thereby maintaining all battery packages 20 in a state of optimal heat dissipation with full immersion and "six-sided water surround." This "underwater operation" mode ensures that even if a battery package 20 experiences thermal runaway, it can be quickly submerged, cooled, and suffocated by the surrounding large amount of non-flammable external cooling medium 30, achieving intrinsic safety.

[0072] The immersion liquid-cooled energy storage unit provided by this invention has the following advantages:

[0073] In terms of safety, a multi-layered protection mechanism is established: the energy storage box 10 itself provides the first level of fire-resistant and explosion-proof structural protection, confining the risk of thermal runaway within the box; while the independent battery enclosure 20 serves as the second level of protection unit, its flexible outer shell 21 and internal immersion fluid 24 not only effectively suppress cell thermal runaway but also completely eliminate the risk of systemic cross-contamination caused by electrolyte leakage, preventing single-point failure from paralyzing the entire system. Furthermore, the external cooling medium 30 completely immerses the enclosure, providing the third level of intrinsic safety protection for "underwater" fire extinguishing and cooling.

[0074] In terms of thermal management, the system adopts a "decoupling of internal and external media" and "six-sided water ring" cooling architecture. The internal immersion liquid 24 achieves direct and close contact with the battery module 22 and efficient heat conduction, while the external cooling medium 30 achieves uniform and dead-zone-free circulation and liquid level control through the bottom optimized liquid cooling channel 13 and the top overflow structure, ensuring efficient heat dissipation and controllable temperature difference, which helps to improve the battery cycle life.

[0075] This architecture offers significant cost and maintenance advantages: the internal immersion fluid 24 is significantly reduced in volume due to its sealed enclosure, allowing for the use of more cost-effective domestic mineral oils and other media; externally, large quantities of low-cost water-based coolant can be used, thereby reducing reliance on expensive imported coolants and lowering the overall system cost. The modular enclosure design supports rapid replacement, greatly improving maintenance efficiency.

[0076] The immersion liquid-cooled energy storage units provided in the foregoing embodiments, with their modularity, high safety, and efficient heat dissipation characteristics, are particularly suitable as core modules for large-scale energy storage power stations. For example, multiple immersion liquid-cooled energy storage units of the present invention can be directly installed in the containment cavity of a large-scale energy storage power station as standard energy storage modules, forming a complete energy storage solution that can be deployed on a large scale.

[0077] As a preferred integration solution, the reference Figure 8 This illustrates that one or more submerged liquid-cooled energy storage units can be inserted as standard modules into the receiving cavity of the concrete energy storage tank 50. Specifically, the energy storage box 10 is conveniently installed in the receiving cavity of the concrete energy storage tank 50 by sliding engagement between its bottom sliding component 15 and the track beam 51 inside the concrete energy storage tank 50. Inside the energy storage box 10, the battery module is encapsulated by the battery encapsulation body 20 and operates the aforementioned dual submerged liquid cooling system.

[0078] This integrated solution achieves multiple layers of protection and functional synergy:

[0079] 1. Layered Safety Protection: The concrete energy storage chamber 50 provides the first layer of fire resistance and explosion-proof protection at the building level, while the submerged liquid-cooled energy storage unit provides the second layer of protection at the system level, namely "thermal runaway isolation and suppression". The combination of the two constructs a three-tiered defense system of "chamber-energy storage box-battery enclosure", achieving comprehensive safety protection from macro to micro levels.

[0080] 2. Synergistic Thermal Management: The concrete energy storage chamber 50 can serve as the structural support and installation foundation for the external heat dissipation circuit of the immersion liquid-cooled energy storage unit of the present invention. The external cooling medium 30 circulation system (including the inlet 101, outlet 102 and external pipelines) of the immersion liquid-cooled energy storage unit can be arranged based on the robust structure and internal space of the concrete chamber, achieving unified and efficient thermal management at the chamber level.

[0081] 3. Complementary Maintenance Systems: The track beams and sliding structure of the concrete energy storage compartment 50 support rapid pull-out and replacement of the entire energy storage box at level 10; while the modular and flexible packaging design of the battery encapsulation body 20 further allows for module-level maintenance inside the box. Together, these two systems form a tiered rapid maintenance system from "compartment level → box level → module level," greatly improving the system's maintainability and operational efficiency.

[0082] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

[0083] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0084] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An immersion liquid-cooled energy storage unit, characterized in that, include: Energy storage box; At least one battery package is disposed within the energy storage tank, the battery package comprising: A flexible outer shell, which forms a sealed accommodating cavity inside; The battery module is housed within the accommodating cavity; An internal immersion liquid is filled into the accommodating cavity and submerges the battery module. At least one interface structure is disposed on the flexible housing, the interface structure being configured to provide a fluid passage to the accommodating cavity and an electrical connection path for the battery module; The flexible outer shell and the inner wall of the energy storage tank together define a flow space for the external cooling medium to circulate.

2. The immersion liquid-cooled energy storage unit according to claim 1, characterized in that, The flexible outer shell has an opening for inserting the battery module, and a pressure sealing strip is provided at the opening for controlling the opening and closing of the opening.

3. The immersion liquid-cooled energy storage unit according to claim 1, characterized in that, The interface structure includes: A fluid injection section is used to inject or drain the internal immersion fluid into the accommodating cavity; An electrical connection section is used to achieve a sealed connection between the electrical connection terminal of the battery module and external wiring.

4. The immersion liquid-cooled energy storage unit according to claim 3, characterized in that, The electrical connection portion includes a mounting structure for mounting the battery management unit acquisition module; or, the electrical connection portions of multiple battery packages are respectively connected to a common battery management unit acquisition module via electrical connectors.

5. The immersion liquid-cooled energy storage unit according to claim 1, characterized in that, The flexible outer shell is made of a high polymer barrier film or an aluminum-plastic composite film; The surface insulation resistance of the flexible shell is not less than 100MΩ and it can withstand a DC4500V voltage for 1 minute without breakdown; and / or, the flexible shell can withstand an internal static pressure of 0.1MPa to 0.3MPa without tearing.

6. The immersion liquid-cooled energy storage unit according to claim 1, characterized in that, The battery package also includes a fixing structure for constraining the deformation and position of the battery module.

7. The immersion liquid-cooled energy storage unit according to claim 1, characterized in that, The bottom of the energy storage box is provided with a liquid cooling channel, which is connected to the liquid inlet and is used to support the battery package.

8. The immersion liquid-cooled energy storage unit according to claim 7, characterized in that, The energy storage tank is provided with an inlet and an outlet that communicate with the flow space; the inlet is connected to the liquid cooling channel and is used to pressurize and input external cooling medium into the energy storage tank; the energy storage tank is provided with an overflow structure, the overflow inlet of the overflow structure is located at a set height and is connected to the outlet, so that the liquid level in the flow space is maintained at the set height by unpressurized overflow.

9. The immersion liquid-cooled energy storage unit according to claim 7 or 8, characterized in that, The liquid cooling channel is a loop channel, which includes multiple parallel channel tubes, and multiple injection holes are opened on the tube wall of the channel tube; preferably, the total flow area of ​​the injection holes on the channel tube located in the middle is smaller than the total flow area of ​​the injection holes on the channel tubes located on both sides.

10. The immersion liquid-cooled energy storage unit according to claim 1, characterized in that, The internal immersion fluid is an insulating and thermally conductive fluid; and / or The external cooling medium is water, an aqueous ethylene glycol solution, or insulating oil; and / or, The energy storage box is composed of a basin-shaped box and a cover plate made of concrete composite material, and at least one energy storage cavity is formed inside the basin-shaped box.

Images