A semi-submerged energy storage device

Abstract

The application relates to the field of energy storage cabinets, in particular to a semi-submerged energy storage device. The device comprises an external sealed cabinet body and a sealed battery box arranged in the cabinet body, characterized in that the sealed battery box is connected to the top load-bearing frame of the external sealed cabinet body through multiple groups of flexible suspension members, so that a water storage space for storing liquid cooling medium is formed between the outer wall of the battery box and the inner wall of the cabinet body, and the battery box is arranged in the water storage space and partially submerged below the liquid level of the liquid cooling medium. Through the synergistic cooperation of the semi-submerged water sealing layout, the active heat management mechanism, the multi-stage sealing structure and the intelligent monitoring system, the application provides an energy storage system solution suitable for high safety requirement scenes.

Description

Technical Field

[0001] This application relates to the field of energy storage cabinets, and in particular to a semi-immersed energy storage device. Background Technology

[0002] In existing technologies, energy storage cabinets, as electrical energy storage devices, have been gradually applied in industrial, commercial, and some residential areas, mainly for balancing power loads, improving grid stability, and supporting the integration of renewable energy. Currently, most common energy storage cabinets employ air-cooling or liquid-cooling systems for thermal management and enhance safety through physical isolation, fire-resistant material wrapping, and the installation of gas extinguishing devices. These measures can, to some extent, suppress battery overheating or initial failures and have been verified to have basic reliability in standardized industrial scenarios.

[0003] However, existing safety solutions still have significant limitations when energy storage cabinets are deployed in compact, densely populated residential areas. Residential environments have higher safety requirements, and existing heat dissipation and fire prevention designs are mostly based on delaying the spread of fire or localized suppression, making it difficult to completely eliminate the risk of a chain reaction triggered by battery thermal runaway. For example, traditional air-cooling systems cannot quickly dissipate accumulated heat when a battery experiences an internal short circuit. Liquid cooling, while more efficient, has a complex structure and relies on continuous pump circulation; system failure could accelerate thermal runaway. Furthermore, commonly used fire extinguishing agents such as heptafluoropropane, while capable of extinguishing open flames, cannot continuously cool the battery cells, easily leading to reignition. More critically, existing energy storage cabinets typically completely enclose the battery pack within modules. When a battery cell fails and catches fire, the released high temperatures and flammable gases can easily accumulate inside the cabinet and spread to adjacent batteries, potentially causing an explosion of the entire module or even the cabinet. This potential risk is particularly acute in residential areas, not only causing property damage but also exacerbating public concerns about the safety of energy storage facilities, thus hindering the adoption of this technology in community settings.

[0004] Therefore, there is an urgent need to develop an energy storage cabinet safety technology that can fundamentally reduce the risk of thermal runaway and is particularly suitable for residential use scenarios. Utility Model Content

[0005] The purpose of this application is to overcome at least one deficiency of the existing technology and provide a semi-immersed energy storage device, which aims to solve the prominent technical problems faced by existing energy storage cabinets, especially in the context of compact and densely populated residential areas, such as the difficulty in suppressing battery thermal runaway, the risk of triggering chain reactions, and public safety concerns.

[0006] To achieve the above objectives, this application discloses a semi-immersed energy storage device, which includes an external sealed cabinet and a sealed battery box disposed inside the cabinet.

[0007] The sealed battery box is connected to the top load-bearing frame of the external cabinet through multiple sets of flexible suspension components, so that a water storage space is formed between the outer wall of the battery box and the inner wall of the cabinet, which is used to contain liquid cooling medium.

[0008] The battery box is arranged in the water storage space and is partially submerged below the liquid level of the liquid cooling medium, and at least the top of the battery box is above the set liquid level, thereby ensuring that the electrical connection interface is above the liquid surface.

[0009] To ensure stable system operation, the external sealed cabinet is equipped with water inlet and drainage pipes, and an overflow port to maintain a constant liquid level.

[0010] Furthermore, the energy storage device also includes an externally located cooling medium management module, which is connected to the water storage space and includes a circulating water pump, a heat exchanger, and a control unit.

[0011] Furthermore, the heat exchanger can be a gas-liquid heat exchanger, which uses a fan to drive ambient air and cooling water for non-contact heat exchange; or a liquid-liquid heat exchanger can be used to connect to an external high-efficiency cold source.

[0012] In a preferred embodiment, the liquid cooling medium is deionized water, which has excellent heat dissipation performance and can effectively cool down through vaporization heat absorption and continuous convection under extreme thermal runaway conditions, thereby suppressing the risk of thermal runaway and reignition. Compared with traditional gas extinguishing solutions, it has significant safety advantages.

[0013] In a preferred embodiment, the sealed battery box employs a multi-layer composite sealing structure, comprising, from the inside out, a metal structural layer, an electrical insulation layer, and an outer engineering plastic waterproof sealing layer to ensure long-term operational reliability. The top cover of the battery box integrates a sealed electrical connector.

[0014] In a preferred embodiment, the external sealed cabinet is provided with an observation window.

[0015] Optionally, a humidity sensor is installed inside the sealed battery box to monitor the sealing status inside the box in real time. Optionally, the sealed water storage space is equipped with a water level sensor, a temperature sensor, and a water conductivity sensor to comprehensively monitor the working status of the cooling medium.

[0016] In summary, this application provides an energy storage system solution suitable for high-safety-requirement scenarios through the coordinated use of a semi-submerged water-sealed layout, an active thermal management mechanism, a multi-stage sealing structure, and an intelligent monitoring system.

[0017] The beneficial effects listed above are not exhaustive of all advantages. Other potential beneficial effects and detailed technical implementation methods will be further disclosed in the embodiments or other descriptive sections of this application. Attached Figure Description

[0018] A better understanding of various aspects of this disclosure will be achieved by reading the following detailed description in conjunction with the accompanying drawings. The positions, dimensions, and extents of the structures shown in the drawings, etc., do not always represent actual positions, dimensions, and extents. In the drawings: Figure 1 This is a schematic diagram of the internal structure of one embodiment disclosed in this application. Detailed Implementation

[0019] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

[0020] It should be understood that the same reference numerals denote the same elements in all the accompanying drawings. For clarity, the dimensions of certain features may be modified in the drawings.

[0021] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this disclosure. All terms used in this specification (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. For the sake of brevity and / or clarity, techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail; however, where appropriate, such techniques, methods, and apparatus should be considered part of this specification.

[0022] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the relevant listed items.

[0023] This embodiment provides a highly secure semi-submersible energy storage device. (See also...) Figure 1The core components of the device include an external sealed cabinet 100, a sealed battery box 200 suspended inside the cabinet, an annular sealed water storage space 300 formed between the battery box 200 and the inner wall of the cabinet 100, and a cooling medium management component 400 connected to the water storage space 300.

[0024] The external sealed cabinet 100 is an airtight structure welded or assembled from corrosion-resistant metal plates, with a load-bearing frame 110 fixedly installed on its inner top side. The sealed battery box 200 is suspended from the load-bearing frame 110 by an array of flexible suspension components 210. The flexible suspension components 210 must meet specific mechanical and chemical performance requirements, with a breaking strength relative to the total weight of the battery box 200 having a safety factor of not less than 5, and its material must have the ability to withstand long-term immersion in deionized water. Examples include, but are not limited to, stainless steel wire ropes covered with polyurethane sheaths or woven slings made of ultra-high molecular weight polyethylene.

[0025] The design length of component 210 needs to allow for a certain margin to ensure that the suspension system can adaptively fine-tune when the dimensions of the battery box 200 and the internal battery module change due to thermal expansion and contraction, thus avoiding excessive internal stress.

[0026] The sealed battery box 200 is configured to be partially submerged in a sealed water storage space 300 filled with cooling medium. Through thermo-hydraulic calculations and buoyancy balance optimization, the proportion of the submerged volume of the battery box 200 to its total volume is set between 70% and 95%, preferably between 80% and 90%.

[0027] With this design, the top of the battery box 200 is always higher than the preset maximum working liquid level L_max, so that the explosion-proof electrical connectors, management units and other key components integrated on the top of the box are in a dry area, while most of the surface area of ​​the box can be in direct contact with the cooling medium and carry out efficient heat exchange.

[0028] To maintain stable system operation and achieve thermal management, the external sealed cabinet 100 is equipped with inlet and outlet pipes connected to the sealed water storage space 300, and has an overflow port to stabilize the system liquid level within a set range. The cooling medium management component 400 forms a forced circulation loop, which includes a circulating water pump 410, a heat exchanger 420, and a system control unit. The heat exchanger 420 can be selected according to the application scenario: in normal environments, a gas-liquid heat exchanger combined with a fan can be preferred to utilize ambient air for cooling; for high heat density or high temperature environments, a liquid-liquid heat exchanger can be selected to connect to an external cold source such as a refrigeration unit to improve cooling efficiency. Based on the feedback signals from the temperature sensor installed in the water storage space 300 and / or the temperature sensor (not shown) installed inside the battery box 200, the system control unit dynamically adjusts the speed of the circulating water pump 410 and the airflow of the fan or the opening of the heat exchange valve through PID or more advanced algorithms, thereby accurately controlling the battery temperature within a set target range, such as 15°C to 55°C.

[0029] The cooling medium is preferably deionized water. Its technical advantage lies in its dual function: during normal operation, it efficiently dissipates the heat generated by the battery through convection heat transfer; in extreme cases such as thermal runaway of the battery, this structure can provide a fundamental safety protection mechanism.

[0030] To ensure absolute reliability throughout the system's lifespan, the sealed battery box 200 employs a multi-layer composite sealing structure. Its walls, from the inside out, consist of: a metal structural load-bearing layer (such as S30408 ​​stainless steel), an electrical insulation layer 203 (such as sprayed epoxy insulating paint), and an outermost engineering plastic waterproof sealing layer 204 (such as FRP polypropylene). The seal between the box and the top cover utilizes fluororubber O-rings, and is pre-tightened with evenly distributed bolts to achieve an IP67 or higher protection rating. All interfaces penetrating the box, including the electrical connector 201, sampling line interface, fluid interface, and observation window, are sealed using mature static sealing technology.

[0031] Furthermore, the energy storage cabinet integrates multiple intelligent monitoring and linkage protection mechanisms. First, a high-precision humidity sensor is installed inside the sealed battery box 200 to monitor the humidity of the atmosphere inside the box in real time. When the system control unit detects that the humidity value exceeds the first safety threshold (e.g., relative humidity > 60%RH) through the sensor, it will determine that there is a level one risk of seal failure and trigger an audible and visual alarm. If the humidity continues to rise and exceeds a higher second safety threshold (e.g., relative humidity > 85%RH), the control unit will immediately activate the safety linkage procedure, including sending an emergency fault signal to the higher-level monitoring system and instructing the battery management system to cut off the power supply to the battery main circuit to prevent potential electrical short circuit risks.

[0032] Secondly, a water level sensor, a temperature sensor, and an online water conductivity sensor are installed within the sealed water storage space 300. These sensors are used to comprehensively monitor the state of the cooling medium. The control unit uses the water level sensor signal to issue a low liquid level alarm; the temperature sensor signal is used for thermal management control; and the online water conductivity sensor is used to monitor changes in the purity of deionized water in real time. To maintain water quality, The device in this embodiment is particularly suitable for residential energy storage scenarios where safety requirements are extremely high. During operation, when the energy storage system is charging routinely at night or discharging in response to grid dispatch, the heat generated by the battery is rapidly dissipated by the surrounding deionized water through efficient natural convection and forced circulation. Unlike traditional air-cooled systems in residential areas that may generate noise, this device relies on the enormous heat capacity of water to achieve lower noise and gentler temperature control, effectively preventing the formation of hot spots.

[0033] In extreme situations, such as thermal runaway caused by a short circuit within the battery, this device demonstrates a fundamental advantage over existing technologies. Traditional gaseous fire extinguishing agents within the enclosure can only temporarily extinguish open flames and cannot cope with the continuous exothermic reactions inside the battery, resulting in a very high risk of reignition. In this device, however, the faulty battery cell is completely submerged in deionized water, the cooling medium. The enormous heat released during thermal runaway immediately triggers a large amount of vaporization and heat absorption in the water; this phase change process can instantly absorb far more heat than the gaseous fire extinguishing agent. Simultaneously, the entire water chamber acts as a massive heat capacity, providing uninterrupted, deep, enveloping cooling to the fault point through continuous convection, dissipating heat at its source and preventing the battery temperature from maintaining combustion conditions. This mechanism avoids and reduces the possibility of reignition.

[0034] More importantly, the sealed battery box itself constitutes a second physical barrier to suppress the spread of thermal runaway. Even if a single cell within the box fails, the high-temperature ejecta and flammable gases it releases are strictly confined within the independent sealed battery box, preventing them from spreading throughout the entire cabinet space and igniting adjacent battery modules as in traditional cabinets. This "box-like" isolation design strictly limits potential accidents to the smallest unit, greatly reducing the overall risk.

[0035] Therefore, this device provides a solution for sensitive scenarios such as residential areas through a synergistic mechanism of "normal high-efficiency cooling with water medium + phase change heat absorption and continuous cooling under extreme conditions + physical isolation of battery cells". It can fundamentally prevent fires, suppress explosions and eliminate the risk of reignition, effectively addressing the public's core concerns about the safety of energy storage facilities.

[0036] In summary, this embodiment, through the synergistic effect of the aforementioned semi-immersed water-sealed structure, active thermal management loop, multi-stage sealing design, and intelligent monitoring and protection system, discloses in detail a highly safe energy storage solution capable of effectively managing battery thermal behavior and suppressing thermal runaway under extreme conditions. Those skilled in the art, based on the above disclosure in this specification, can reproduce this invention without inventive effort and achieve its beneficial effects. Any simple modifications and equivalent substitutions based on the essence of this embodiment should be covered within the protection scope of this application.

Claims

1. A semi-submersible energy storage device, comprising an external sealed cabinet and a sealed battery box disposed inside the cabinet, characterized in that, The sealed battery box is connected to the top load-bearing frame of the external sealed cabinet through multiple sets of flexible suspension components, so that a water storage space is formed between the outer wall of the battery box and the inner wall of the cabinet. This water storage space is used to contain liquid cooling medium. The battery box is arranged in the water storage space and is partially submerged below the liquid level of the liquid cooling medium, and at least the top of the battery box is above the set liquid level. The external sealed cabinet is provided with water inlet pipe and water outlet pipe, and is equipped with an overflow port.

2. The semi-submersible energy storage device according to claim 1, characterized in that, The energy storage device also includes an externally located cooling medium management module connected to the water storage space and including a circulating water pump, a heat exchanger, and a control unit.

3. The semi-submersible energy storage device according to claim 2, characterized in that, The heat exchanger is a gas-liquid heat exchanger, which uses a fan to drive ambient air and cooling water for non-contact heat exchange; or, the heat exchanger is a liquid-liquid heat exchanger, which can be connected to an external cold source.

4. The semi-submersible energy storage device according to claim 1, characterized in that, The liquid cooling medium is deionized water.

5. The semi-submersible energy storage device according to claim 1, characterized in that, The sealed battery box adopts a multi-layer composite sealing structure, which includes a metal structural layer, an electrical insulation layer and an outer engineering plastic waterproof sealing layer from the inside out; the top cover of the battery box integrates a sealed electrical connector.

6. The semi-submersible energy storage device according to claim 1, characterized in that, The external sealed cabinet is equipped with an observation window.

7. The semi-submersible energy storage device according to claim 1, characterized in that, The sealed battery box is equipped with a humidity sensor to monitor the sealing status of the box in real time.

8. The semi-submersible energy storage device according to claim 1, characterized in that, The water storage space is equipped with a water level sensor, a temperature sensor, and a water conductivity sensor to comprehensively monitor the working status of the cooling medium.

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