Dual-protection energy storage cabinet and prevention and control method therefor

Abstract

A dual-protection energy storage cabinet and a prevention and control method therefor. The dual-protection energy storage cabinet comprises a cabinet body (1), an energy storage module, and a dual-protection module, wherein the energy storage module and the dual-protection module are arranged in the cabinet body (1). The energy storage module comprises a plurality of battery modules (2), the battery modules (2) are sequentially arranged in the cabinet body (1) from top to bottom, and at least one column of battery modules (2) are arranged in the cabinet body (1). The dual-protection module comprises a water tank (4), a high-temperature resistant assembly (5), and fire-proof and explosion-proof assemblies (6), wherein the high-temperature resistant assembly (5) comprises a high-temperature resistant pipe (51), a heat exchange member (52), and air exhaust fans (53), and the high-temperature resistant pipe (51) is connected to the heat exchange member (52) and the water tank (4) and a liquid circulation pipeline is formed; and each battery module (2) is provided with a fire-proof and explosion-proof assembly (6).

Description

A double-protection energy storage cabinet and its prevention and control method Technical Field

[0001] The present invention relates to the technical field related to daily safety protection of energy storage cabinets, and in particular to a dual-protection energy storage cabinet and a prevention and control method thereof. Background Art

[0002] In recent years, my country's energy storage industry has been developing at an accelerating pace. It not only plays a vital role in the generation, transmission, and distribution, and load-side of large power grids, shaving peak loads and improving power quality, but is also increasingly being used in distributed energy resources within user-side microgrids. Grid energy storage is becoming an increasingly important component of my country's energy consumption, creating a huge market demand. Lithium-ion batteries, with their high energy density, long cycle life, environmental friendliness, and low self-discharge, are widely used in energy storage power stations, consumer electronics, and new energy vehicles. They are particularly popular in energy storage devices, making them the preferred battery.

[0003] The fire safety of lithium-ion batteries in energy storage systems has long been a hot topic of research. On the one hand, lithium-ion batteries, due to their high energy density and rapid charge-discharge and heat generation, present significant fire risks and hazards, making them a major source of fire hazard. On the other hand, lithium-ion batteries have their own unique characteristics in terms of fire characteristics, the use and management of firefighting facilities, and so on, which differ from the fire hazards of traditional warehouses.

[0004] Lithium ions migrate between the positive and negative electrodes to facilitate charging and discharging in lithium-ion batteries, making them one of the highest-performing rechargeable batteries available. However, lithium-ion batteries differ significantly from "lithium batteries." These batteries use manganese dioxide and thionyl chloride as the positive electrode materials and lithium as the negative electrode counterbalance. They store energy without charging, a characteristic characteristic of the assembled battery. Internal short circuits are often caused by lithium crystallization during charge and discharge cycles, and charging is generally prohibited. Therefore, lithium-ion batteries cannot be equated with "lithium batteries" for fire safety purposes. The charge and discharge cycles of lithium-ion batteries generate extremely complex chemical reactions within them. The SEI film on the negative electrode surface is thermally stable and, subject to temperature constraints, decomposes upon reaching a critical point. Exposure of the negative electrode is often caused by the SEI film. Direct contact between the exposed surface and the electrolyte generates a violent reduction reaction accompanied by the release of flammable gases and significant heat. When the cell temperature reaches around 190°C, this is often due to the heat released by the decomposition of the SEI film, which is also the primary cause of positive electrode decomposition. Atomic oxygen is rapidly released during the decomposition of the positive electrode. This highly reactive atomic oxygen is the root cause of the direct and violent oxidative decomposition of the electrolyte, which in turn causes a large amount of heat to accumulate in the battery cell in a short period of time. Potential thermal side reactions occur when the temperature or charging voltage is too high, causing the battery cell temperature and pressure to rise rapidly due to heat accumulation, leading to thermal runaway. The amount of thermal decomposition at the positive electrode is greater than that at the negative electrode, and the thermal stability of the battery cell varies significantly depending on the positive electrode material.

[0005] During battery use, dendrites, impurities and dust from the battery manufacturing process, such as those caused by being dropped, squeezed, impacted, overcharged or over-discharged, can deteriorate and form micro-shorts, piercing the separator. The released energy causes a temperature rise, and the chemical reactions in the battery materials caused by this temperature rise further expand the short-circuit path, generating a larger short-circuit current. This cumulative and mutually reinforcing damage leads to thermal runaway. External short circuits, on the other hand, can occur due to improper handling. The excessive discharge current from an external short circuit can easily cause the battery cell to heat up. The high temperature damages the separator inside the cell, causing an internal short circuit and potentially causing combustion and explosion. Typically, 95% of thermal runaway in lithium-ion batteries stems from internal short circuits. These short circuits progress quickly and are short-lived, often leading to thermal runaway in around 50 seconds. Thermal runaway then causes the lithium-ion battery to rapidly combust. Lithium-ion batteries have unique combustion characteristics, characterized by intense combustion, rapid heat spread, and the violent reactions of reactive metals to generate products. Under these conditions, fire spreads rapidly. The smoke and toxicity produced by intense combustion are extremely dangerous, causing lithium-ion batteries to release large amounts of toxic and harmful gases and dust particles during combustion, which seriously harm the human body. Furthermore, uncontrollable fires are highly likely to cause explosions, making them extremely difficult to extinguish and reignite. Conventional physical methods can only extinguish fires caused by lithium-ion batteries; they cannot effectively suppress the re-ignition caused by the fire by isolating oxygen and severing the combustion chain. Therefore, extinguishing fires caused by lithium-ion batteries is much more difficult than extinguishing fires of other types.

[0006] An integrated energy storage cabinet primarily consists of a battery cabinet, a bidirectional converter for energy storage, a control system, and a backend monitoring and management system. The core component of the energy storage cabinet is the battery cabinet, whose subunits are the battery modules. While lithium-ion batteries offer excellent performance, they can experience thermal runaway due to internal heat accumulation when subjected to abuse conditions such as overheating, overcharging, and short circuits, potentially leading to fire and explosion. Due to energy density and space limitations, energy storage cabinets are typically arranged relatively tightly together, without personnel to monitor the operating conditions within the container in real time. Therefore, if a fire caused by thermal runaway within a battery cabinet is not promptly extinguished and cooled, the fire can easily spread between battery modules, between battery cabinets, and even between energy storage containers, resulting in large-scale fires and explosions, posing a significant threat to personnel and property. Therefore, developing fire response strategies suitable for energy storage cabinet fires is crucial to ensuring the safe operation of energy storage systems.

[0007] Currently, research on lithium-ion battery energy storage cabinet fire prevention and control technologies is still in its early stages both domestically and internationally. Although many institutions have conducted related research, they all use a single traditional fire extinguishing agent and fire extinguishing system design. Given that the surface temperature of a battery thermal runaway fire is no less than 900°C, these methods cannot simultaneously achieve the fire prevention and control requirements of rapid flame extinguishing, rapid subsequent cooling, and long-term suppression, thereby achieving ideal fire prevention and control results. A detailed analysis is as follows:

[0008] (1) Chemical gas fire extinguishing equipment such as halogenated hydrocarbons (heptafluoropropane, etc.) and perfluorohexanone

[0009] The main application methods are pipe network fire extinguishing systems and cabinet fire extinguishing devices, which use temperature, smoke or gas detectors to send fire alarms. After receiving the alarm signal, the device is activated to extinguish the fire. Its fire extinguishing mechanism is to cut off the combustion chain and has no cooling or temperature reduction effect. The temperature will not drop by more than 50°C after extinguishing the open flame for 30 minutes, and it is easy to reignite.

[0010] (2) Inert gas fire extinguishing equipment

[0011] The main application method is a pipe network fire extinguishing system, which uses temperature, smoke or gas detectors to generate fire alarms. After receiving the alarm signal, the device is activated to extinguish the fire. However, it has the following main shortcomings: in terms of fire extinguishing, when the gas fire extinguishing system is activated, a large amount of fire extinguishing gas will be sprayed into the protected area, causing the air pressure in the protected area to increase instantly. In terms of application, the heat generated by the fire will also increase the indoor air pressure. The larger the fire and the longer the spraying time, the greater the air pressure rise. Therefore, the enclosure structure of the protected area should consider the allowable pressure to withstand the internal pressure, pressure relief ports and automatic pressure relief valves. In terms of equipment, due to the high concentration of inert gas fire extinguishing agents, the design dosage is large in the fire protection design of energy storage power stations, the area occupied is large, and the working pressure is high (up to 23.2MPa), which poses a risk of safety hazards. In terms of cooling, the cooling effect of the high-pressure gas spray is very small. The temperature does not drop by more than 100°C 30 minutes after the open fire is extinguished, which makes it easy for the fire to re-ignite.

[0012] (3) Dry powder fire extinguishing equipment

[0013] The primary application methods are pipe network fire extinguishing systems and suspended fire extinguishing devices. These devices use temperature, smoke, or gas detectors to generate fire alarms, and upon receiving the alarm signal, they activate the device to extinguish the fire. However, due to the poor circulation performance of dry powder fire extinguishing agents, not only does it require space for the circulation of the agent during the energy storage power station design, but dry powder fire extinguishing agents also have no cooling effect, making it very easy for fires to reignite after being extinguished, leading to large-scale fires out of control. Not only does it have no cooling effect, but it also generates heat, accelerating the temperature rise of the energy storage station and further increasing the fire's intensity, making the results very unsatisfactory.

[0014] (4) Aerosol fire extinguishing equipment

[0015] The main application method is cabinet-type fire extinguishing equipment, which relies on the generation of chemical gas smoke to extinguish fires. The fire extinguishing efficiency is low, and not only does it have no cooling effect, but it also generates heat by itself, accelerating the temperature rise of the energy storage power station, causing the fire to further increase, and the effect is very unsatisfactory.

[0016] (5) Water sprinkler fire extinguishing equipment

[0017] Water sprinkler systems are highly mature technology, and their cooling effects after fire extinguishing are ideal. They are suitable for energy storage systems composed of multiple containers, but they also have significant drawbacks. Regarding the fire extinguishing medium, water's conductive properties can cause short circuits and damage to the batteries within the energy storage station after a fire is extinguished, rendering them unusable. Furthermore, large quantities of water are required to extinguish open flames and maintain post-exposure suppression, potentially multiples the volume of the protected object. Furthermore, due to the large volume, firefighting pools must be built near the energy storage station, occupying significant space.

[0018] (6) Water mist fire extinguishing equipment

[0019] The primary application is a pipe network fire extinguishing system, which extinguishes fires by absorbing large amounts of heat and isolating the air. This makes it suitable for localized firefighting in unobstructed locations. However, within energy storage cabinets, battery cells are closely spaced and confined. The water mist spray cannot reach the fire point and is blocked by partitions or various obstacles, preventing it from achieving its cooling and isolating effect, effectively preventing fire extinguishing and temperature suppression.

[0020] (7) Foam fire extinguishing equipment

[0021] The primary application is a pipe network fire extinguishing system, which isolates combustibles from combustion-supporting gases to extinguish the fire. This system is suitable for energy storage systems composed of multiple containers. While this can control initial fires, the lack of cooling allows the battery to continue to heat up, leading to thermal runaway and spontaneously generating combustible and combustion-supporting gases such as oxygen and hydrogen. This prevents effective isolation, ultimately leading to foam failure and ineffective fire extinguishing and subsequent suppression.

[0022] CN104882639A discloses a method and device for suppressing and preventing thermal runaway in lithium-ion batteries. This method uses liquid inert gas, sprayed in a specific volume, pattern, and duration, to extinguish and cool faulty lithium-ion battery packs. However, the spray temperature is set between 60°C and 140°C. Forced cooling is employed when the battery pack temperature is elevated, which constitutes overprotection and can cause irreversible damage to the battery pack. Furthermore, some types of liquid inert gas are completely impractical due to cost and storage limitations.

[0023] US6599656B2 discloses a method for preventing thermal runaway in lithium-ion batteries. This method involves adding a tank filled with carbon dioxide or a mixture of nitrogen and argon to the lithium-ion battery pack. Upon detecting an abnormality, this high-pressure inert gas is sprayed around the battery, expelling combustible gases and oxygen, thereby achieving flame retardancy. However, battery combustion only exacerbates the thermal runaway process, not the progression of it. Therefore, spraying high-pressure inert gas cannot completely prevent the spread of thermal runaway within the battery pack.

[0024] US20130312947A1 and US20130316198A1 disclose a lithium-ion battery pack design that uses coolant injection to extinguish fires. During normal use, the refrigerant is stored in a tank as a high-pressure liquid. When the BMS detects an emergency situation such as thermal runaway, high-pressure refrigerant (R-123) is ejected from a pre-set pipe, extinguishing the flames, vaporizing on the surface of the thermally runaway battery, absorbing a large amount of heat, and diluting the flammable electrolyte, thereby blocking the spread of thermal runaway and protecting the entire battery pack. R-123 is often used as a refrigerant in appliances such as air conditioners and refrigerators, but its fire-extinguishing effectiveness is not ideal. Furthermore, R-123 is a greenhouse gas that damages the ozone layer, leading some countries to restrict its use.

[0025] CN106684499A discloses a method for suppressing and preventing thermal runaway of lithium-ion batteries. The method uses a liquid refrigerant to spray and cool faulty lithium-ion batteries and extinguish fires. When a battery cell reaches a certain temperature, the spray device is activated. The liquid refrigerant's latent heat of vaporization is 0.1 to 10 times the heat released by the battery cell during thermal runaway. The spraying method is continuous or intermittent. The liquid refrigerant is selected from liquid nitrogen, liquid argon, and liquid carbon dioxide. It has relatively high storage requirements, requires additional energy storage cabinet space, and is relatively costly.

[0026] The various fire control devices, systems, and methods mentioned above all separate fire protection and cooling to solve these two problems. The optimal operating temperature of energy storage cabinet batteries is between 20-30°C. Therefore, if a dual-protection module can be installed in the energy storage cabinet, it can not only provide the optimal operating temperature for the energy storage cabinet battery pack, but also quickly reduce the temperature before thermal runaway occurs, preventing fire and explosion, and ensuring the safety of equipment and personnel. Summary of the Invention

[0027] In response to the above-mentioned technical problems to be solved, the present invention provides a dual-protection energy storage cabinet and a prevention and control method thereof, which can simultaneously realize the dual protection functions of daily cooling and overheating prevention of the energy storage cabinet and fire prevention and control.

[0028] In order to achieve the above object, the technical solution of the present invention is as follows:

[0029] A double-protection energy storage cabinet comprises a cabinet body, an energy storage module, and a double-protection module, wherein the energy storage module and the double-protection module are arranged in the cabinet body;

[0030] The energy storage module includes a plurality of battery modules, which are arranged in sequence from top to bottom in a cabinet, and at least one column of battery modules is provided in the cabinet;

[0031] The dual-protection module includes a water tank, a high-temperature protection component and a fire and explosion-proof component. The high-temperature protection component includes a high-temperature protection pipeline, a heat exchanger and an exhaust fan. The high-temperature protection pipeline connects the heat exchanger and the water tank to form a liquid circulation pipeline; there are multiple exhaust fans, and each battery module is equipped with an exhaust fan; each battery module is equipped with a fire and explosion-proof component, and the fire and explosion-proof component includes a fire and explosion-proof pipeline and a high-pressure nozzle. The fire and explosion-proof pipeline is connected to the water tank, and one end of the fire and explosion-proof pipeline is connected to the high-pressure nozzle, and the high-pressure nozzle is arranged in the battery module; the water tank is provided with a refrigeration component, and a liquid refrigerant is provided in the water tank, and the liquid refrigerant is provided with an ice melting agent.

[0032] In the above technical solution, preferably, the battery module includes a drawer cabinet and a plurality of battery cells, and the plurality of battery cells are arranged in series in rows in the drawer cabinet, and at least two rows of battery cells are fixedly provided in each drawer cabinet, and the battery cells in adjacent rows are arranged at intervals; the four side walls of the drawer cabinet and the connecting seams of the bottom plate are waterproofed, and the height of the four side walls of the drawer cabinet is higher than the height of the battery cells.

[0033] In the above technical solution, preferably, the heat exchange element adopts a combination of a heat exchanger and an exhaust fan and is arranged on the top of the cabinet body, the exhaust fan is arranged on a side wall of the drawer cabinet, and the side wall of the drawer cabinet opposite to the exhaust fan is provided with ventilation holes; the cold air after heat exchange by the heat exchanger is blown into the cavity on one side of all the drawer cabinets through the exhaust fan, and then flows through the ventilation holes into the drawer cabinet for cooling, and is discharged through the exhaust fan to form a heat dissipation channel.

[0034] In the above technical solution, preferably, the water tank is provided with a refrigeration compressor, the water tank is provided with a water outlet pipe and a water inlet pipe, the water outlet pipe is provided with a booster pump, the high-temperature protection pipe is provided with a water inlet pipe and a water outlet pipe, the water inlet pipe is connected to the water outlet pipe and the water inlet of the heat exchanger, and the water outlet pipe is connected to the water inlet pipe and the water outlet of the heat exchanger.

[0035] In the above technical solution, preferably, the fireproof and explosion-proof component also includes a main pipe and a solenoid valve. The main pipe is connected to the water outlet pipe. One end of the fireproof and explosion-proof pipe is connected to the water tank through the main pipe, and the other end is connected to the solenoid valve and the high-pressure nozzle.

[0036] In the above technical solution, preferably, one section of the fire and explosion prevention pipeline penetrates through one side wall of the drawer cabinet, and the solenoid valve and the high-pressure nozzle are respectively arranged on the inner and outer sides of the side wall of the drawer cabinet.

[0037] The present invention also provides a prevention and control method for a double-prevention energy storage cabinet. The prevention and control method uses the above-mentioned double-prevention energy storage cabinet; the prevention and control method monitors the temperature Ti of the battery module and the temperature Tc of each battery cell in real time, and selects a working mode according to the temperature Ti of the battery module and the temperature Tc of the battery cell. The working modes at least include a high-temperature prevention mode and a fire and explosion prevention mode.

[0038] In the above technical solution, preferably, the high-temperature prevention mode and the fire and explosion prevention mode are not carried out simultaneously.

[0039] In the above technical solution, preferably, the prevention and control method has a low-temperature liquid refrigerant in the water tank, and the temperature of the low-temperature liquid refrigerant is lower than 20°C.

[0040] In the above technical solution, preferably, the high-temperature prevention mode is: set the high-temperature prevention temperature as T1, monitor the temperature Ti of the battery module, and when Ti>T1 and is lower than the lowest fire and explosion prevention temperature, run the high-temperature prevention mode.

[0041] In the above technical solution, preferably, the water tank is connected to the high-temperature prevention pipeline, and the heat exchange element is turned on at the same time. A low-temperature cold air formed by heat exchange of the low-temperature liquid refrigerant in the water tank through the heat exchange element is formed in the cabinet body; through the operation of the exhaust fan, the low-temperature cold air flows to the inside of the drawer cabinet through the ventilation holes and is discharged through the exhaust fan to form a heat dissipation channel.

[0042] In the above technical solution, preferably, the fire and explosion prevention mode includes the following steps:

[0043] S1, set the first fire and explosion prevention temperature T3 and the second fire and explosion prevention temperature T4, T1<T3<T4, set the first water level line and the second water level line. The height of the first water level line is lower than the height of the battery cell; the height of the second water level line is higher than the height of the battery cell and lower than the height of the ventilation hole of the drawer cabinet, so that the low-temperature liquid refrigerant cannot flow out of the drawer cabinet;

[0044] S2, monitor the temperature Tc of each battery cell. If the temperature Tc of one or some battery cells is higher than T3, then perform S3;

[0045] S3, when T4>Tc>T3, the high-temperature prevention mode is closed, the fire and explosion prevention pipeline corresponding to the battery module where the battery cell is located is opened, and the fire and explosion prevention pipeline is connected to the water tank. The corresponding high-pressure nozzle sprays the low-temperature liquid refrigerant to soak the battery cell part of the battery module. When the liquid level reaches the first water level line, the corresponding fire and explosion prevention pipeline is closed;

[0046] S4, if the temperature Tc of the battery cell after being submerged decreases, close the corresponding fire and explosion prevention pipeline and check whether the battery cell is faulty;

[0047] If the temperature of the battery cell continues to rise after being submerged, proceed to S5;

[0048] S5, when the battery cell temperature Tc ≥ T4, the high-pressure nozzle continues to inject the low-temperature refrigerant liquid. When the liquid level reaches the second water level line, the corresponding fire and explosion-proof pipeline is closed, all battery cells in the battery module are submerged, and the safety valve of the battery cell is opened. Only the interior of the battery cell with the safety valve opened flows into the low-temperature liquid refrigerant.

[0049] In the above technical solution, preferably, a waterproof cover is provided outside each battery cell, and the electrodes and the safety valve on the top of the battery cell are exposed from the waterproof cover.

[0050] In the above technical solution, preferably, before the high temperature protection mode or the fire and explosion protection mode, the room temperature liquid refrigerant in the water tank is pre-processed into a low temperature liquid refrigerant of minus 20°C through a refrigeration component, and the low temperature liquid refrigerant is maintained in a liquid state through an ice melting agent.

[0051] As a preferred embodiment, the ice-melting agent is industrial salt, which can be commercially available industrial salt and meets the relevant safety, fire and explosion protection requirements; the best liquid refrigerant containing the ice-melting agent is industrial salt water with a mass percentage concentration of 3-5%.

[0052] The dual-protection energy storage cabinet and its prevention and control method provided by the present invention have the following advantages over the prior art:

[0053] (1) The dual-protection energy storage cabinet and its control method of the present invention have newly designed structures that are resistant to high temperatures and fire and explosions. They are improvements based on the original energy storage cabinet, with low cost, and are applicable to existing energy storage cabinets or any customized energy storage cabinets. The high-temperature protection components and fire and explosion protection components optimize the use of the space structure to a great extent by laying out multiple pipelines in the existing energy storage cabinet, given the limited space. This does not increase the cost of the energy storage cabinet. Furthermore, the high-temperature protection mode uses a water circulation method to save energy.

[0054] (2) The dual-protection energy storage cabinet and its prevention and control method of the present invention make the temperature distribution in the energy storage cabinet more uniform by using low-temperature liquid refrigerant as the most important cooling medium in the high-temperature protection mode, ensuring that the temperature in the energy storage cabinet can keep the battery in a good performance state, avoiding the performance differentiation of the battery cells in the battery due to uneven battery temperature, affecting the service life of the energy storage cabinet, and solving the problems of poor air convection heat exchange effect and poor heat exchange effect in the energy storage cabinet.

[0055] (3) The dual-protection energy storage cabinet and its prevention and control method of the present invention, by utilizing low-temperature liquid refrigerant as the most important fire-proof and explosion-proof cooling medium, can not only achieve a cooling balance effect for the battery module, but also ensure the absolute safety of the battery. At the same time, it directly cools the inside of the battery cell from the source to achieve rapid cooling to avoid thermal runaway, thereby protecting the battery cell to the greatest extent.

[0056] (4) It is worth mentioning that the dual-protection module of the present invention can simultaneously maintain the optimal operating temperature of the battery stably, thereby ensuring that the battery can achieve the maximum theoretical value of the number of charge and discharge cycles and extend the battery life; more importantly, it is precisely because the high-temperature protection component can continuously maintain the optimal battery operating temperature and is always below 33 degrees Celsius, so once the abnormal temperature rise of the battery occurs, it can be quickly identified and quickly cooled within a controllable temperature range, eliminating the risk of thermal runaway and subsequent fire or explosion of the battery; therefore, high-temperature protection and fire and explosion protection are not two separate modules with independent functions, but dual-protection components with synergistic effects, and the corresponding prevention and control methods can effectively identify dangerous situations and ensure maximum safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] FIG1 is a schematic structural diagram of a dual-protection energy storage cabinet according to the present invention.

[0058] FIG2 is a schematic diagram of the connection position of the fireproof and explosion-proof assembly of the present invention.

[0059] FIG3 is a schematic structural diagram of the fireproof and explosion-proof assembly of the present invention.

[0060] FIG4 is a schematic structural diagram of a battery module of the present invention.

[0061] FIG5 is a schematic diagram of the application of the fire and explosion prevention mode of the present invention.

[0062] FIG6 is a flow chart of the prevention and control method of the present invention.

[0063] Description of the numbers in the figure:

[0064] 1. Cabinet; 11. Battery compartment cabinet; 12. Energy storage converter cabinet; 13. Air outlet; 2. Battery module; 21. Battery cell; 22. Drawer cabinet; 23. Ventilation hole; 3. Energy storage converter; 4. Water tank; 41. Refrigeration compressor; 42. Water outlet pipe; 421. Booster pump; 43. Water inlet pipe; 5. High-temperature protection component; 51. High-temperature protection pipe; 511. Water inlet pipe; 512. Water outlet pipe; 52. Heat exchanger; 521. Copper tube and aluminum fin heat exchanger; 522. Exhaust fan; 53. Exhaust fan; 6. Fire and explosion-proof components; 61. Fire and explosion-proof pipe; 62. High-pressure nozzle; 63. Solenoid valve; 64. Main pipeline; I. First water level line; II. Second water level line. DETAILED DESCRIPTION

[0065] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0066] Figures 1 to 5 are schematic diagrams of the structure of the dual-protection energy storage cabinet provided by the present invention. As shown in Figure 1, the dual-protection energy storage cabinet includes an energy storage module, a dual-protection module, and a control module (not shown), each of which is disposed within a cabinet body 1. The control module can independently control the energy storage module and the dual-protection module. The energy storage module includes multiple battery modules 2 and an energy storage converter 3. The corresponding cabinet body 1 is divided into a battery compartment cabinet 11 and an energy storage converter cabinet 12. The energy storage converter cabinet 12 and the battery compartment cabinet 11 are arranged at different heights, and an air outlet 13 is provided on the mating surface. Alternatively, ventilation windows are provided on both sides of the energy storage converter cabinet 12 to form a return air duct. In other words, multiple battery modules are arranged sequentially within the battery compartment cabinet 11 in a space-saving manner based on the cabinet body shape and power supply requirements. This will not be described in detail here.

[0067] As shown in Figure 4 , the battery module 2 comprises a drawer cabinet 22 and multiple battery cells 21. In this embodiment, a 1P252S280AH battery cell is used as the smallest energy storage unit. Multiple battery cells 21 are arranged in series in rows within the drawer cabinet 22. Each battery cell 21 is protected by a waterproof cover, with the electrodes and safety valve at the top of the battery cell 21 exposed from the cover. Each drawer cabinet 22 houses at least two rows of battery cells 21, with adjacent rows spaced apart to form a battery module 2. The drawer cabinet 22 has no top panel, resulting in an open top. The four side walls and the joints on the bottom panel are waterproofed to ensure leak-proofing and prevent secondary damage to other battery modules. Various existing waterproofing methods, such as waterproof silicone strips and waterproof coatings, can be used to address the weather and environmental characteristics of different regions. The four side walls of the drawer cabinet 22 are taller than the battery cells 21. A ventilation hole 23 is provided on one side of the drawer cabinet 22, with the bottom edge of the ventilation hole 23 higher than the top of the battery cell 21.

[0068] The dual-protection module is installed within the battery compartment cabinet 11 and includes a water tank 4, a high-temperature protection assembly 5, and a fire and explosion protection assembly 6. The high-temperature protection assembly 5 includes a high-temperature protection pipeline 51, a heat exchanger 52, and an exhaust fan 53. The high-temperature protection pipeline 51 connects the heat exchanger 52 and the water tank 4. A solenoid valve switch (not shown) is installed at the junction of the high-temperature protection pipeline 51 and the heat exchanger 52. The heat exchanger 52 is a copper tube and aluminum fin heat exchanger 521 and an exhaust fan 522, installed at the top of the battery compartment cabinet 11. Multiple exhaust fans 53 are installed, one for each battery module drawer 22. As a way to save energy and ensure efficiency, the exhaust fans 53 are installed on the side walls of the battery module drawer, preferably away from the heat exchanger 52 to create the largest and widest heat dissipation channel. In this embodiment, the exhaust fan 53 is arranged on the side wall opposite to the ventilation hole 23, that is, the exhaust fan 53 and the ventilation hole 23 are respectively located on the two opposite side walls of the drawer cabinet 22, and the ventilation hole 23 and the heat exchange element 52 are located on the same side, so that the cold air from the heat exchange element flows from the ventilation hole 23 into the interior of the drawer cabinet 22.

[0069] To further ensure the dual-protection performance, a refrigeration compressor 41 can be added to the water tank 4. In this embodiment, the liquid refrigerant in the water tank 4 can be cooled when the electricity price is low, so as to be used to cool the heat generated by the battery cells when the energy storage module is working during the day. The water tank 4 is an insulated water tank. The water tank 4 is provided with an outlet pipe 42 and an inlet pipe 43. The high-temperature protection pipe 51 connects the copper tube aluminum fin heat exchanger 521 and the water tank and forms a liquid circulation pipeline, that is, the high-temperature protection pipe 51 is provided with an inlet pipe 511 and an outlet pipe 512. The inlet pipe 511 is connected to the outlet pipe 42, and the outlet pipe 512 is connected to the inlet pipe 43. Along the flow direction of the liquid refrigerant, the liquid circulation pipeline refers to the water tank 4 - outlet pipe 42 - inlet pipe 511 - copper pipe of the copper tube aluminum fin heat exchanger 521 - outlet pipe 512 - inlet pipe 43 - water tank 4. The water outlet pipe 42 is also equipped with an adjustable booster pump 421, which uses a commercially available adjustable-speed booster pump. In this embodiment, the water tank 4 and the refrigeration compressor 41 are located at the bottom of the battery compartment cabinet 11. In other embodiments, the water tank 4 and the refrigeration compressor 41 can be located at the top of the battery compartment cabinet 11. The water tank 4 also has a water inlet for replenishing liquid refrigerant.

[0070] Figures 2 to 4 are structural schematic diagrams and partial enlarged views of the fire and explosion-proof assembly. As shown in Figure 2, the fire and explosion-proof assembly 6 is adaptively set according to the number of battery modules. Each battery module is equipped with a fire and explosion-proof assembly 6. The fire and explosion-proof assembly 6 includes a main pipeline 64, a fire and explosion-proof pipeline 61, a high-pressure nozzle 62 and a solenoid valve 63, wherein the main pipeline 64 is connected to the water outlet pipeline 42, one end of the fire and explosion-proof pipeline 61 is connected to the water tank 4 through the main pipeline 64, and the other end is connected to the solenoid valve 63 and the high-pressure nozzle 62, and a three-way valve is provided at the connection between the water outlet pipeline 42, the main pipeline 64 and the water inlet pipe 511. The solenoid valve 63 switches the high-pressure nozzle 62, which is located on a side wall of the drawer cabinet 22. As shown in Figures 2 and 3, a portion of the fire and explosion-proof piping 61 runs through the side wall of the drawer cabinet, with the solenoid valve and high-pressure nozzle located on the inner and outer sides of the drawer cabinet side wall. In other words, the liquid refrigerant ejected from the high-pressure nozzle 62 is sprayed directly into the corresponding battery module 2, while the fire and explosion-proof piping 61 can spray the liquid refrigerant in the water tank into the interior of the battery module 2. In this embodiment, the high-pressure nozzle is positioned below the top of the battery cell 21. The high-pressure nozzle is made of copper and is a high-pressure spray nozzle, resistant to high pressure, high temperature, and explosion. Therefore, when the solenoid valve is opened, the liquid refrigerant in the water tank 4 is converted into fine water droplets through the outlet pipe 42, the main pipe 64, the fire and explosion-proof piping 61, and then through the high-pressure nozzle 62, which are continuously sprayed at high pressure into the battery module 2, particularly into the remaining space in the drawer cabinet.

[0071] In this embodiment, the control module includes a monitoring unit and a control unit. The monitoring unit includes a water temperature sensor, a water pressure sensor, a liquid level sensor, and multiple temperature sensors. A water temperature sensor and a liquid level sensor are provided in the water tank 4 to measure the temperature and liquid level of the liquid refrigerant in the water tank 4. The liquid level sensor is a static pressure type liquid level sensor and is provided at the bottom of the water tank 4. A water pressure sensor is provided in the water outlet pipe 42 of the water tank. Temperature sensors are provided inside and outside the energy storage cabinet to monitor the temperature inside the cabinet and the external environment. In this embodiment, the temperature sensor inside the energy storage cabinet is used to monitor the temperature inside the battery compartment cabinet 11, primarily for detecting the temperature of the heat dissipation channel. A temperature sensor is provided at the lower end of the bottom plate of each drawer cabinet 22 to monitor the temperature of the adjacent battery module 2 below, that is, the average temperature of all battery cells in a battery module 2. A temperature sensor is provided on the top plate of the battery compartment cabinet 11 to monitor the temperature inside the topmost drawer cabinet 22. In addition, each battery cell 21 is provided with a temperature sensor to monitor the temperature of each battery cell. The temperature sensor is provided at the top of the battery cell, i.e., the area not covered by the waterproof cover. In order to ensure the dual protection effect, multiple temperature sensors can be set up in the cabinet as a dynamic monitoring data source for the temperature in the cabinet, such as the heat exchanger, battery compartment cabinet and energy storage converter cabinet air outlet 13, and near the exhaust fan 53 of each drawer cabinet 22. This can not only ensure that each battery is in the best working condition, but also ensure that the battery cells that may be in danger are identified at the first time, thereby minimizing the risk.

[0072] FIG6 is a flow chart of the prevention and control method of the present invention. A low-temperature liquid refrigerant is provided in the water tank. The temperature of the low-temperature liquid refrigerant is lower than 20°C. The battery module temperature Ti and the temperature Tc of each battery cell are constantly monitored. Different working modes are selected according to the temperature Ti of the battery module and the temperature Tc of the battery cell. The two working modes are not performed simultaneously. The two working modes are:

[0073] (1) Anti-high temperature mode

[0074] Set the high temperature protection temperature to T1 and monitor the battery module temperature Ti. The high temperature protection temperature or the high temperature protection temperature range can be set according to the use environment. In this embodiment, the temperature range is used for specific explanation. The same applies to setting only one high temperature protection temperature.

[0075] The optimal operating temperature range of battery cells is 20-30°C. During peak discharge, the battery cells usually begin to heat up, which means that the battery module begins to heat up and the temperature can reach as high as 40°C. To ensure the optimal working state and performance of the battery module, the dual-protection energy storage cabinet of the present invention can provide two high-temperature protection modes according to different temperatures: fast cooling mode and slow cooling mode. Specifically:

[0076] Step 1) Set the high temperature protection temperature range to T1~T2. When T2>Ti>T1, run the slow cooling mode, that is, step 2); when T3>Ti>T2, run the fast cooling mode, that is, step 3);

[0077] In this embodiment, T1=22°C and T2=27°C are set.

[0078] Step 2) When T2 > Ti > T1, slow cooling mode is activated. The control module activates the booster pump and shifts it to a low gear, reducing displacement and flow rate, thereby lowering energy consumption. Simultaneously, the solenoid valve of the copper tube aluminum fin heat exchanger 521 is activated. This rapidly generates low-temperature cold air within the cabinet 1, generated by heat exchange through the copper tube aluminum fin heat exchanger 521 and the low-temperature liquid refrigerant in the water tank 4. This cold air, driven by the operation of the exhaust fans 522 and 53, flows through the ventilation holes 23 to the various locations within the cabinet, particularly the drawers 22 of the battery modules, achieving cooling. When Ti is detected to be less than T1, ventilation is stopped to prevent the cabinet temperature from dropping too low, potentially affecting battery performance.

[0079] Step 3) When T3 > Ti > T2, the rapid cooling mode is activated. The control module maintains the booster pump and adjusts it to high speed. This rapidly generates cold air within the cabinet 1, generated by the low-temperature liquid refrigerant in the water tank 4 and heat exchanged through the copper tube aluminum fin heat exchanger 521. This cold air, driven by the exhaust fans 522 and 53, rapidly flows through the ventilation holes 23 to the interior of the cabinet, particularly to the drawers 22 of the battery modules, achieving rapid cooling. When the Ti temperature decreases to meet the conditions of T2 > Ti > T1, the system switches to slow cooling mode.

[0080] (2) Fire and explosion prevention mode

[0081] The core design essence of the present invention is to prevent the occurrence of thermal runaway in the earliest stage of the risk. Before the battery module undergoes thermal runaway and explodes, the temperature is quickly reduced and maintained at a low temperature without damaging the original function of the battery module, thereby minimizing the risk and preserving the function of the battery module.

[0082] As described above, the control module of the present invention simultaneously monitors the battery module temperature Ti and the temperature Tc of each battery cell. Thermal runaway in lithium-ion batteries occurs quickly and is difficult to control once it enters. Therefore, enabling early identification and rapid response to suspected or dangerous situations, mitigating risks, is the most important technical benefit of the present invention.

[0083] In this embodiment, the fire prevention and explosion prevention mode of the prevention and control method specifically includes the following steps:

[0084] S1. Set the first fire and explosion prevention temperature T3 and the second fire and explosion prevention temperature T4, where T1 < T3 < T4. Set the first water level line I and the second water level line II. The height of the first water level line I is lower than the height of the battery cell 21; the height of the second water level line II is higher than the height of the battery cell 21 and lower than the height of the ventilation hole of the drawer cabinet, so that the liquid cannot flow out of the drawer cabinet.

[0085] In this embodiment, preferably, T3 = 60 °C and T4 = 80 °C.

[0086] In this embodiment, the height of the first water level line I is lower than the height of the battery cell 21 and is located at three - quarters of the height of the battery cell; the second water level line II is lower than the lower edge of the air inlet of the back panel of the drawer cabinet 22 and the lower edge of the air outlet of the exhaust fan 53, and can completely immerse the battery cell.

[0087] When the fire and explosion prevention mode is activated, the high - temperature prevention mode stops.

[0088] S2. Monitor the temperature Tc of each battery cell. If the temperature Tc of a certain battery cell is higher than T3, then proceed to S3.

[0089] S3. When T4 > Tc > T3, the high - temperature prevention mode is turned off. That is, when it is detected that the temperature of the battery cell 21 is greater than 60 °C, the fire and explosion prevention mode is activated. The feedback signal of the temperature sensor of this battery cell is sent to the control system. At this time, the control system controls the booster pump to operate at high speed, controls the three - way valve to close the flow of the high - temperature prevention pipeline and stops the heat exchanger, and at the same time cuts off the DC - side circuit breaker of the energy storage cabinet, opens the main pipeline 64, and opens the solenoid valve 63 on the fire and explosion prevention pipeline 61 corresponding to the battery module 2 with high temperature. At this time, the high - pressure nozzle 62 in the drawer cabinet 22 quickly sprays a large amount of low - temperature liquid refrigerant, and a large amount of liquid refrigerant rushes into the drawer cabinet 22. When the liquid level reaches the first water level line I, the solenoid valve 63 on the corresponding fire and explosion prevention pipeline 61 is closed. At this time, all the battery cells 21 of this battery module 2 are immersed in the liquid refrigerant, which can achieve rapid cooling and maintain the cooling effect. At this time, this immersion water level line can ensure that 70 - 80% of the height of the dangerous battery cell is within the immersion line, thus ensuring the fire and explosion prevention effect and preventing the temperature rise of the remaining battery cells in this battery module.

[0090] The setting of the first water level line I will not immerse the electrodes of the battery cell 21 because the electrodes of this battery cell are set at the top, and the battery cell 21 itself is wrapped with a waterproof sleeve to ensure that there will be no short - circuit phenomenon due to the sprayed liquid refrigerant.

[0091] S4. Continuously monitor the temperature Tc of the battery cell. If the temperature Tc of the battery cell after submersion drops and does not rise within ten minutes, then take out this battery module 2, drain the liquid, and check the faulty battery cell 21. If it is damaged, replace it; if the temperature of the battery cell after submersion continues to rise, then proceed to S5.

[0092] S5: When the battery cell temperature Tc ≥ T4, that is, when the temperature Tc of the battery cell 21 rises to above 80°C, the DC side circuit breaker of the energy storage cabinet is cut off, and the high-pressure nozzle is opened to inject low-temperature refrigerant liquid again. When the liquid level reaches the second water level line II, the corresponding fire and explosion prevention pipeline is closed. At this time, the water level submerges each battery cell 21. The safety valve on the top of the battery cell is opened, and liquid refrigerant will flow into the battery cell, directly cooling the interior of the battery cell 21 from the source to achieve rapid cooling and avoid thermal runaway.

[0093] The liquid refrigerant in the water tank uses a cryogenic liquid below 20°C, preferably an ultra-cold liquid prepared by adding a de-icing agent to water at -20°C. A 0-20°C cryogenic liquid refrigerant can also provide heat protection, fire protection, and explosion protection. However, its efficiency is lower, requiring the heat protection components to operate continuously during the battery cell discharge. For fire and explosion protection, the battery cell cools down more slowly than a -20°C ultra-cold liquid refrigerant. Example 1

[0094] The prevention and control method of this embodiment pre-cools the liquid refrigerant in the water tank 4 to -20°C via a refrigeration compressor to produce an ultra-low temperature liquid refrigerant, and maintains the liquid refrigerant in a liquid state via an ice-melting agent. The inventors have found through extensive experimental research that industrial brine with a mass percentage concentration of 3-5% can be used as the optimal liquid refrigerant for the dual-protection energy storage cabinet of the present invention.

[0095] In this embodiment, during low-electricity-price periods, electricity energy exchange is used to cool the room-temperature liquid refrigerant, i.e., industrial brine, to below -20°C and insulated within a water tank 4. During high-electricity-price periods, electricity is no longer used for cooling. Instead, ultra-low-temperature industrial brine is used as the ultra-low-temperature liquid refrigerant via a high-temperature protection component to provide cooling energy within the cabinet, achieving refrigeration and cooling. During cooling, the ultra-low-temperature industrial brine flows from the water tank 4 through the high-temperature protection pipeline, is converted into ultra-low-temperature air by a heat exchanger 52, and then enters the battery compartment cabinet 11. Independent exhaust fans 53 within each battery module 2 cooperate with the heat exchanger 52 to allow the ultra-low-temperature air to flow through each battery module 2. Heat within the battery cells 21 is removed from the drawer cabinet 22 through heat exchange with the ultra-low-temperature air in the gaps within the drawer cabinet 22, and then discharged from the energy storage converter cabinet's return air duct through the air outlet 13 located at the top of the battery compartment cabinet 11.

[0096] In order to ensure the double protection effect, there should be enough liquid refrigerant in the water tank 4, and the water pressure sensor is set to detect the water pressure and the liquid level detector is set to detect the water level. In the high temperature protection mode, the liquid refrigerant circulates in the pipeline and does not consume water. The amount of liquid refrigerant is only consumed in the fire and explosion protection mode. When the water volume drops to half, liquid and industrial salt need to be supplemented. Verification experiment

[0097] The prevention and control effects of the dual-protection energy storage cabinet of the present invention are verified through actual application scenarios, as follows:

[0098] (1) Verification of liquid refrigerant antifreeze effect

[0099] Industrial brine with mass percentage concentrations of 2%, 3% and 5% (industrial salt must comply with the requirements of GB / T5462-2003) was placed in separate water tanks for testing. The industrial brine in the water tank was circulated at a flow rate of no more than 0.1m / s, and the state of the industrial brine in the water tank at different temperatures was tested. Among them, the industrial brine with a concentration of 2% will gradually freeze 2-3 hours after being cooled to minus 10℃, so the liquid refrigerant cannot achieve an effective working state at this concentration; while the industrial brine with a concentration of 3% and 5% can still maintain a liquid state at minus 20℃ while maintaining this concentration. The current observation period is two months, and no ice has been found in the water tank and all pipelines.

[0100] (2) Verification of high temperature protection effect

[0101] The high temperature protection effect verification experiment was continued using 3% concentration industrial salt water.

[0102] During periods of low electricity prices, typically from 11 PM to 7 AM, a refrigeration compressor converts industrial brine into a low-temperature liquid refrigerant at -20°C, which is stored in a water tank. A preset high-temperature protection temperature range is set between 22°C and 27°C. During peak daytime electricity demand, if the battery module temperature exceeds 27°C, the control unit controls the booster pump to operate at high speed, accelerating the dissipation of cold air from the low-temperature liquid refrigerant through heat exchanger 6, thereby rapidly lowering the battery module temperature. If the battery module temperature is between 22°C and 27°C, booster pump 421 operates at low speed to cool the battery module, then returns to detect the battery module temperature, re-evaluating the operating mode.

[0103] The energy storage cabinet in this experiment uses a 300kWh battery capacity, a 120kW PCS energy storage converter 3, a set discharge power of 100kW, and a water tank filled with 200L of industrial brine. If the energy storage cabinet enters the discharge phase, it will be fully discharged within 3 hours during peak electricity price periods, discharging 300kWh at 0.3C. During the discharge phase, this dual-protection energy storage cabinet is set to operate in a rapid cooling mode every half hour. The flow rate of the ultra-low-temperature industrial brine in the high-temperature protection pipeline is approximately 0.54m / s. After 5 minutes of operation, the temperature at the outlet of the exhaust fan 53 of battery module 2 was detected to be approximately 19°C, achieving rapid cooling. When the temperature of battery module 2 drops below 27°C, the slow cooling mode is activated again, with a water flow rate of approximately 0.31m / s, and the temperature at the outlet of the exhaust fan 53 is detected to be approximately 22°C.

[0104] The temperature inside the water tank, battery module 2, and battery compartment is monitored over a 24-hour operating cycle to evaluate the performance of the heat protection system. Generally, the low electricity price period is from 11 PM to 7 PM. During this period, the industrial brine is first cooled to -20°C over approximately two hours. After 3-4 hours, the temperature rises by 1°C, and then it is cooled again to -20°C. This cycle continues until the low electricity price period ends at 7 PM, when the refrigeration compressor stops operating and enters standby mode. After 7 PM, the high electricity price period begins, during which the ultra-low temperature industrial brine maintains its temperature and releases cooling capacity. During peak electricity price periods, the entire cooling capacity is released within three hours, with the system operating in a half-hour cycle. This cycle lasts six times, with the temperature rising by 2°C each time, for a total of 12°C. In addition to the three hours of heat protection mode, the industrial brine also undergoes a 13-hour standby period during high electricity price periods, with the temperature rising by 3-4°C. Therefore, the industrial brine temperature is approximately -4°C before entering the next low electricity price cooling cycle.

[0105] (3) Fire and explosion prevention effect verification test

[0106] The fire and explosion prevention experiments were continued under the structure of the above-mentioned double-proof energy storage cabinet. A total of 8 battery modules 2 were set up in the energy storage cabinet. After each battery module was installed with a battery cell, the remaining effective space was about 25L. The volume ratio of the integrated volume of the battery cell to the remaining space was about 3:2. 200L of industrial salt water was used. The redundant water volume was mainly to provide sufficient water source for the fire and explosion prevention mode to ensure sufficient water volume during the fire and explosion prevention mode.

[0107] This is a destructive experiment. According to the results, it takes about 50 seconds for a single battery cell in a battery module to fail, causing an internal short circuit and subsequent thermal runaway. Therefore, the fire and explosion-proof components of the energy storage cabinet should be cooled within 30 seconds. By manually applying external force to destroy a battery cell in battery module 2, a rapid temperature rise occurs. The battery cell temperature Tc rises to 60°C in about 15 seconds, and the fire and explosion prevention mode is immediately activated. The flow rate of ultra-low temperature industrial brine in the fire and explosion prevention pipeline is 1.8m 3 / h, the high-pressure nozzle can quickly liquid to the first water level line I within 8 seconds, stop injecting liquid, soak for ten minutes, and detect that the battery cell temperature Tc is about 30℃.

[0108] Within 5 seconds after the ultra-low temperature liquid refrigerant starts to be injected, even if it has not reached the first water level line I, the temperature Tc of the battery cell will begin to drop or stop rising. If the battery cell temperature Tc does not drop and continues to rise, it will rise to 80°C in about 25 seconds. At this time, the high-pressure nozzle 62 continues to inject ultra-low temperature liquid refrigerant. The flow rate of industrial brine in the fire and explosion proof pipeline is 1.8m 3 / h. Once the high-pressure nozzle is turned on, it can quickly fill a battery module 2 within 10 seconds, that is, the liquid level reaches the second water level line II. At the same time, the safety valve of the battery cell 21 is opened, and the temperature Tc of the battery cell is detected to be around 30°C. If the same situation occurs in the other seven battery modules at the same time, the water volume in the water tank is sufficient to immerse the battery cells of the eight battery modules, ensuring an adequate fire and explosion-proof water source.

[0109] In other embodiments, if there are more battery modules, such as more than 8, and at the same time all battery modules have battery cell temperatures higher than 60°C, the liquid refrigerant in the water tank can be replenished when operating in fire and explosion protection mode, and the refrigeration compressor can be turned on for rapid cooling.

[0110] The dual-protection energy storage cabinet provided by the present invention can effectively maintain energy balance and be environmentally friendly through cheap and environmentally friendly liquid refrigerants. The inventors have found through a large number of experiments that this energy storage cabinet does not require an industrial salt concentration of more than 15% as in the prior art to achieve efficient maintenance of the liquid state, thereby achieving temperature control and maintaining a better working stability. This has a synergistic effect with the structural design of the high-temperature protection component 5 and the fire and explosion protection component 6 provided by the present invention.

[0111] The above examples are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, they are not intended to limit the present invention. Therefore, any simple modifications, equivalent variations, and modifications to the above examples that do not depart from the technical solution of the present invention and are based on the technical essence of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A double-protection energy storage cabinet, characterized in that: It includes a cabinet, an energy storage module, and a double-protection module, wherein the energy storage module and the double-protection module are arranged in the cabinet; The energy storage module includes a plurality of battery modules, which are arranged in sequence from top to bottom in a cabinet, and at least one row of battery modules is provided in the cabinet; The double-protection module includes a water tank, a high-temperature protection component and a fire-proof and explosion-proof component. The high-temperature protection component includes a high-temperature protection pipeline, a heat exchanger and an exhaust fan. The high-temperature protection pipeline connects the heat exchanger and the water tank to form a liquid circulation pipeline; there are multiple exhaust fans, and each battery module is equipped with an exhaust fan; each battery module is equipped with a fire-proof and explosion-proof component, and the fire-proof and explosion-proof component includes a fire-proof and explosion-proof pipeline and a high-pressure nozzle. The fire-proof and explosion-proof pipeline is connected to the water tank, and one end of the fire-proof and explosion-proof pipeline is connected to the high-pressure nozzle, and the high-pressure nozzle is arranged in the battery module; the water tank is provided with a refrigeration component, and the water tank is provided with a liquid refrigerant, and the liquid refrigerant is provided with an ice-melting agent.

2. The double-protection energy storage cabinet according to claim 1 is characterized in that: The battery module includes a drawer cabinet and a plurality of battery cells. The plurality of battery cells are arranged in series in rows in the drawer cabinet. At least two rows of battery cells are fixedly provided in each drawer cabinet, and battery cells in two adjacent rows are arranged at intervals. The four side walls of the drawer cabinet and the connecting seams of the bottom plate are waterproofed, and the height of the four side walls of the drawer cabinet is higher than the height of the battery cells.

3. The double-protection energy storage cabinet according to claim 2 is characterized in that: The heat exchange element is a combination of a heat exchanger and an exhaust fan and is arranged on the top of the cabinet body. The exhaust fan is arranged on a side wall of the drawer cabinet, and a ventilation hole is arranged on the side wall of the drawer cabinet opposite to the exhaust fan. The cold air after heat exchange by the heat exchanger is blown into the cavity on one side of all the drawer cabinets through the exhaust fan, and then flows into the drawer cabinet through the ventilation hole for cooling, and is discharged through the exhaust fan to form a heat dissipation channel.

4. The double-protection energy storage cabinet according to claim 3 is characterized in that: The water tank is provided with a refrigeration compressor, the water tank is provided with a water outlet pipeline and a water inlet pipeline, the water outlet pipeline is provided with a booster pump, the high temperature protection pipeline is provided with a water inlet pipe and a water outlet pipe, the water inlet pipe is connected to the water outlet pipeline and the water inlet of the heat exchanger, and the water outlet pipe is connected to the water inlet pipeline and the water outlet of the heat exchanger.

5. The double-protection energy storage cabinet according to claim 4 is characterized in that: The fireproof and explosion-proof assembly also includes a main pipeline and a solenoid valve. The main pipeline is connected to the water outlet pipeline. One end of the fireproof and explosion-proof pipeline is connected to the water tank through the main pipeline, and the other end is connected to the solenoid valve and the high-pressure nozzle.

6. The double-protection energy storage cabinet according to claim 4 is characterized in that: A section of the fireproof and explosion-proof pipeline passes through a side wall of the drawer cabinet, and the solenoid valve and the high-pressure nozzle are respectively arranged on the inner and outer sides of the side wall of the drawer cabinet.

7. A prevention and control method for a double-defense energy storage cabinet, characterized in that: The prevention and control method adopts the double-protection energy storage cabinet described in any one of claims 3 to 6; the prevention and control method monitors the battery module temperature Ti and each battery cell temperature Tc in real time, and selects a working mode according to the battery module temperature Ti and the battery cell temperature Tc, and the working mode at least includes a high temperature protection mode and a fire and explosion protection mode.

8. The prevention and control method of the double-defense energy storage cabinet according to claim 7 is characterized in that: The high temperature protection mode and the fire and explosion protection mode are not performed simultaneously.

9. The prevention and control method of the double-defense energy storage cabinet according to claim 7 is characterized in that: In the prevention and control method, a low-temperature liquid refrigerant is arranged in the water tank, and the temperature of the low-temperature liquid refrigerant is lower than 20°C.

10. The prevention and control method of the double-defense energy storage cabinet according to claim 9 is characterized in that: The high temperature protection mode is: setting the high temperature protection temperature to T1, monitoring the battery module temperature Ti, and when Ti>T1 and lower than the lowest fire and explosion prevention temperature, running the high temperature protection mode.

11. The prevention and control method of the double-defense energy storage cabinet according to claim 10, characterized in that: The water tank is connected to the high-temperature prevention pipeline. Meanwhile, the heat exchange component is turned on, and low-temperature cold air is formed in the cabinet after the low-temperature liquid refrigerant in the water tank exchanges heat through the heat exchange component. Through the operation of the air extraction fan, the low-temperature cold air flows to the inside of the drawer cabinet through the ventilation holes and is discharged through the air extraction fan to form a heat dissipation channel.

12. The prevention and control method of the double-defense energy storage cabinet according to claim 9 is characterized in that: The fire and explosion prevention mode includes the following steps: S1. Set the first fire and explosion prevention temperature T3 and the second fire and explosion prevention temperature T4, where T1 < T3 < T4. Set the first water level line and the second water level line. The height of the first water level line is lower than the height of the battery cell; the height of the second water level line is higher than the height of the battery cell and lower than the height of the ventilation holes of the drawer cabinet, so that the low-temperature liquid refrigerant cannot flow out of the drawer cabinet. S2. Monitor the temperature Tc of each battery cell. If the temperature Tc of one or some battery cells is higher than T3, then proceed to S3. S3. When T4 > Tc > T3, the high-temperature prevention mode is turned off, and the fire and explosion prevention pipeline corresponding to the battery module where the battery cell is located is opened. The fire and explosion prevention pipeline is connected to the water tank, and the corresponding high-pressure nozzle sprays low-temperature liquid refrigerant to immerse part of the battery cells of the battery module. When the liquid level reaches the first water level line, the corresponding fire and explosion prevention pipeline is closed. S4. If the temperature Tc of the battery cell drops after being submerged, close the corresponding fire and explosion prevention pipeline and check whether the battery cell is faulty. If the temperature of the battery cell continues to rise after being submerged, then proceed to S5. S5. When the temperature Tc of the battery cell ≥ T4, the high-pressure nozzle continues to inject low-temperature refrigerant liquid. When the liquid level reaches the second water level line, close the corresponding fire and explosion prevention pipeline. All the battery cells in the battery module are submerged, and the safety valve of the battery cell is opened. Only low-temperature liquid refrigerant flows into the inside of the battery cell with the safety valve opened.

13. The control method according to claim 12, characterized in that: A waterproof sleeve is sleeved outside each battery cell, and the electrodes and the safety valve at the top of the battery cell are exposed outside the waterproof sleeve.

14. The control method according to claim 9, characterized in that: Before the high-temperature prevention mode or the fire and explosion prevention mode, the normal-temperature liquid refrigerant in the water tank is made into a low-temperature liquid refrigerant at -20°C through the refrigeration component, and the low-temperature liquid refrigerant is maintained in a liquid state through the ice melting agent.

15. The control method according to claim 14, characterized in that: The ice melting agent is industrial salt.

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