Explosion-proof box for batteries

Abstract

An explosion-proof box for a battery includes an outer housing (6), an inner housing (8) installed inside the outer housing, and a flame filter (2) penetrating both the outer housing and the inner housing, where the flame filter includes an exhaust passage (21) for discharging gas generated in the inner housing to the outside of the outer housing, and a pocket (23) installed on the inner surface of the exhaust passage for absorbing thermal energy. This explosion-proof box can mitigate safety problems caused by the spread of flames when a battery burns and explodes during transportation.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to a Chinese patent application, application number 202220091230.3, titled "Explosion-proof box for batteries," submitted to the National Intellectual Property Administration of the People's Republic of China on January 14, 2022, and all of its contents are incorporated into this application by reference.

[0002] FIELD OF THE INVENTION The present application relates to the field of battery technology, and more particularly to an explosion-proof box for batteries. [Background technology]

[0003] When transporting batteries, especially batteries that have already experienced problems, it is necessary to consider how to prevent the batteries from burning and exploding, and how to prevent further damage. Currently, the requirements for using explosion-proof boxes are not simply to prevent the spread of runaway energy inside the battery by explosively shutting off the runaway energy after it has run out of control, thereby avoiding threats to the safety of people and property in the surrounding area, but rather to enable the energy of the battery product itself to be controlled and made safe. Summary of the Invention

[0004] Technical issues In view of the above problems, the present application provides an explosion-proof box for batteries that can alleviate safety problems caused by the spread of flames when batteries burn and explode during transportation.

[0005] technical solution The technical solutions adopted in the embodiments of this application are as follows:

[0006] A first aspect provides an explosion-proof box for a battery. The explosion-proof box includes an outer housing, an inner housing installed inside the outer housing, and a flame filter. The flame filter penetrates both the outer housing and the inner housing. The flame filter includes an exhaust passage and a pocket. The exhaust passage is used to exhaust gas generated in the inner housing to the outside of the outer housing. The pocket is installed on the inner surface of the exhaust passage and is used to absorb thermal energy.

[0007] In the technical solution of the embodiment of this application, when a battery burns in an explosion-proof box, the flame energy is insulated by the inner housing, and only a small amount of heat is transferred to the outer housing. The smoke generated when the battery burns can be discharged through the exhaust passage, but the flame energy can be absorbed through the pockets installed in the flame filter, thereby effectively preventing the flame from spreading.

[0008] In some embodiments, a thermal insulating space is provided between the inner housing and the outer housing, and the thermal insulating space is used to prevent contact-type thermal conduction of energy from the inner housing to the outer housing. By physically separating the inner housing and the outer housing, bridge thermal conduction from the inner housing to the outer housing can be avoided, and the temperature of the outer housing can be kept below a predetermined safe temperature.

[0009] In some embodiments, a support member is installed between the outer housing and the inner housing, and the support member supports the inner housing so as to form a thermal insulation space between the inner housing and the outer housing. In the explosion-proof box of the embodiment of the present application, the outer housing and the inner housing are separated by the support member. A small amount of the support member supports the inner housing to the outer housing, and at the same time, a thermal insulation space is formed between the inner housing and the outer housing, physically separating the inner housing and the outer housing, preventing bridge heat conduction from the inner housing to the outer housing, and ensuring that the temperature of the outer housing is below a predetermined safe temperature.

[0010] In some embodiments, the outer housing includes a heat-shielding material, such that when the battery burns, the heat generated by the combustion is blocked by the heat-shielding material of the outer housing rather than being conducted to the external environment.

[0011] In some embodiments, the inner housing comprises a ceramic material, and with this design, when the battery burns, the heat generated by the combustion is blocked by the ceramic material of the inner housing rather than being conducted to the outer housing, achieving the effect of heat dissipation.

[0012] In some embodiments, a ceramic insulating plate is provided around the inner wall of the explosion-proof box. When a battery experiences thermal runaway inside the explosion-proof box, the battery's combustion flame will burn the ceramic insulating plate around the inner wall of the explosion-proof box, and the heat of the flame will be transmitted through the ceramic insulating plate to provide a first layer of insulation. A small amount of heat will then be transmitted to the outer housing of the explosion-proof box, which will act as a secondary insulator to ensure that the surface temperature of the explosion-proof box remains below 100°C.

[0013] In some embodiments, the flame filter removably penetrates both the outer housing and the inner housing. When a battery burns in the explosion-proof box, the flame filter penetrates both the outer housing and the inner housing, allowing smoke generated when the battery placed in the inner housing burns to be discharged through the flame filter. Because the flame filter connects the interior space of the explosion-proof box with the external environment, the pressure in the inner housing is reduced, preventing the battery from exploding inside the explosion-proof box.

[0014] In some embodiments, the pockets are metal rings arranged on the inner surface of the exhaust passage. In this design, the pockets act as flame absorbers. When a battery burns in the explosion-proof box and the flame passes through the exhaust passage, the energy of the flame is absorbed by the metal rings arranged on the inner surface of the exhaust passage, preventing the flame from burning into the environment outside the explosion-proof box.

[0015] In some embodiments, the explosion-proof box is provided with a bracket, and the battery is removably connected to the bracket. By installing the battery in the explosion-proof box, the battery is fixed to the bracket, and contact and impact between the battery and the inner housing of the explosion-proof box can be avoided.

[0016] In some embodiments, the explosion-proof box has an opening through which the battery can enter and be housed in the inner housing. By providing the opening in the explosion-proof box, the battery can be inserted into or removed from the explosion-proof box when the opening is open, and can be protected when the opening is closed.

[0017] In some embodiments, the opening is fitted with a removable high temperature weatherstripping, which is advantageous because it prevents flames from escaping through the opening into the environment outside the explosion proof enclosure.

[0018] In some embodiments, the explosion-proof box further includes a box door, and the high-temperature weather strip is sealed at the gap of the box door. The seams of the box door of the explosion-proof box are sealed with a high-temperature resistant weather strip, which can effectively prevent the high-temperature resistant weather strip from melting under high temperature and causing a fire to erupt.

[0019] In some embodiments, the edge corners of the outer housing are ferrous edge corners, which improves the impact resistance of the explosion proof box.

[0020] The above description is merely a summary of the technical solution of the present application, which can be implemented in accordance with the content of the specification, so as to make the technical solution of the present application more clearly understandable, and to make the above and other objectives, features and advantages of the present application more apparent, the following particularly cites specific embodiments of the present application for description. [Brief explanation of the drawings]

[0021] To more clearly illustrate the technical concepts in the embodiments of this application, the following briefly introduces the drawings that may be used in the embodiments or illustrative technical descriptions. It is obvious that the drawings in the following description are only a few embodiments of this application, and those skilled in the art can obtain other drawings based on these without expending any creative effort. [Figure 1] FIG. 2 is a structural schematic diagram of an explosion-proof box for batteries in some embodiments of the present application. [Figure 2] FIG. 1 is a structural schematic diagram of a flame filter of an explosion-proof box for batteries in some embodiments of the present application. [Figure 3] FIG. 3 is a partially enlarged schematic view of a portion A of the flame filter of the explosion-proof box for the battery in FIG. 2 according to some embodiments of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0022] The following describes in detail the embodiments of the technical solution of the present application in conjunction with the drawings. The following embodiments are only used to more clearly explain the technical solution of the present application, and are merely examples, which do not limit the protection scope of the present application.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art relating to the present application. The terms used herein are solely for the purpose of describing specific embodiments and are not intended to limit this application. The terms “including” and “having” and any variations thereof in the description of the specification, claims, and drawings of this application are intentionally intended to cover the non-exclusive “including.”

[0024] In the description of the embodiments of the present application, the technical terms "first," "second," etc. are only intended to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order, or hierarchical relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically limited.

[0025] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. Appearances of this phrase in various locations throughout the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, independent, or alternative embodiments. Those skilled in the art can explicitly or implicitly understand that the embodiments described herein can be combined with other embodiments.

[0026] In the description of the embodiments of this application, the term "and / or" simply refers to a relation that describes related objects and indicates that three relations may exist. For example, A and / or B may represent three cases: A alone, a combination of A and B, and B alone. In addition, the character " / " in this specification generally indicates that the related objects before and after it are in an "or" relation.

[0027] In describing the embodiments of the present application, the term "plurality" refers to two or more (including two); similarly, "sets" refers to two or more (including two sets); and "plurality" refers to two or more (including two).

[0028] In describing the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are orientations or positional relationships shown in the drawings, and are intended solely for the convenience and simplification of the description of the embodiments of the present application. They do not indicate or imply that the devices or elements referred to have a specific orientation or must be configured and operated in a specific orientation, and therefore should not be construed as limitations on the embodiments of the present application.

[0029] In the description of the embodiments of the present application, unless otherwise clearly defined or limited, the technical terms "attached," "connected," "connected," "fixed," etc. should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or integration, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, internal communication between two elements, or an interactive relationship between two elements. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application according to specific circumstances.

[0030] At present, in view of the development of the market situation, the application of power batteries is becoming more and more widespread. Power batteries are not only applied to energy storage power systems such as hydroelectric power, thermal power, wind power and solar power plants, but also widely used in electric transportation tools such as electric bicycles, electric motorcycles and electric cars, as well as in multiple fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, their market demand is also constantly increasing.

[0031] As the application scenarios of batteries become more and more, the demand for battery safety also becomes greater, and the technology of battery explosion-proof boxes is being developed.

[0032] A commonly seen explosion-proof box is a double explosion-proof waterproof explosion-proof box for storage batteries. The waterproof effect of this waterproof explosion-proof box can prevent short circuits of the storage batteries, and the explosion-proof frame on the outside of the box can effectively prevent the storage batteries from being damaged by external impacts. An automatically controlled lighting device is installed inside the box, and the lighting lights will automatically turn on when the door is opened.

[0033] The explosion-proof working principle of this technology is to prevent the explosion of battery products caused by external factors, and the conditions for using this waterproof explosion-proof box are that the energy of the battery product itself must be able to be controlled and made safe. However, this waterproof explosion-proof box cannot truly prevent the runaway energy inside the battery from exploding and threatening the safety of people and property in the surrounding area after the energy inside the battery has runaway.

[0034] The applicant has focused on the technical problem of how to effectively block the shock diffusion, heat diffusion, and flame diffusion of the energy generated after the battery (including the series of lithium iron phosphate, ternary, lead acid, and fuel, hereinafter collectively referred to as battery) goes out of control and control it inside the box.

[0035] In some cases, explosion-proof battery boxes are used to provide secondary explosion prevention, but the explosion-proof box of this application is intended for use when transporting and storing problematic batteries.

[0036] According to the technical solution of this application, the explosion-proof box adopts a double-layered inner and outer wall insulation design, and there is no through-hole heat conductor inside or outside the explosion-proof box, thereby avoiding heat conduction caused by heat bridges.The explosion-proof box adopts a double-layered inner and outer wall insulation design, and there is no through-hole heat conductor inside or outside the box, thereby avoiding heat conduction caused by heat bridges, thereby effectively preventing the temperature inside the box from diffusing to the outer surface of the box, and effectively ensuring that the outer surface temperature of the explosion-proof box does not exceed 100 Celsius (°C).

[0037] According to the technical solution of this application, a detachable smoke flue gas filter is designed. The smoke flue gas filter's structural design can effectively prevent the high-pressure gas from being extruded after battery combustion. The smoke flue gas filter's structural design can block the flame and prevent it from escaping from the explosion-proof box, while allowing nanometer-sized carbon powder particles and smoke gas to pass through. The detachable design of the smoke flue gas filter facilitates rapid replacement after reaching the end of its service life.

[0038] According to the technical solution of this application, a removable high-temperature weather strip is used in the door gap of the explosion-proof box. The use of the high-temperature weather strip in the door gap of the explosion-proof box prevents flames from leaking through the gap and prevents heat from being transmitted to the outer surface of the explosion-proof box, and the removable design of the weather strip makes it easy to quickly replace it after it is damaged.

[0039] The explosion-proof box disclosed in the embodiments of the present application is mainly used for storing and transporting battery cells. In particular, the explosion-proof box disclosed in the embodiments of the present application is mainly used for storing and transporting battery cells, battery modules, or battery packs that have already encountered problems, i.e., batteries that may be subject to combustion and explosion. It should be understood that the battery referred to below may be a battery cell, a battery module, or a battery pack. For ease of discussion, the following will all be exemplified by a battery.

[0040] The explosion-proof box disclosed in the embodiments of the present application can be used in a battery, and the battery can be used in a power consumption device such as, but not limited to, a vehicle, a ship, or an aircraft. A power supply system comprising the battery cell, battery module, or battery pack disclosed in the embodiments of the present application can be used to configure the power consumption device, which can mitigate and automatically adjust the deterioration of the expansion force of the battery core, replenish the consumed electrolyte, and improve the stability of battery performance and battery life.

[0041] The explosion-proof box of the embodiment of the present application is used for a battery, and the battery may be used for a power-consuming device, and the power-consuming device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a steamship, a spacecraft, etc. Here, the electric toy may include a stationary or mobile electric toy, such as a game console, an electric car toy, an electric steamship toy, and an electric airplane toy, and the spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc.

[0042] According to some embodiments of the present application, an explosion-proof box for a battery is provided. Referring to FIGS. 1 to 3 , the explosion-proof box includes an outer housing 6, an inner housing 8 installed inside the outer housing 6, and a flame filter 2. The flame filter 2 penetrates both the outer housing 6 and the inner housing 8. The flame filter 2 includes an exhaust passage 21 and a pocket 23. The exhaust passage 21 is used to exhaust gas generated in the inner housing 8 to the outside of the outer housing 6. The pocket 23 is installed on the inner surface of the exhaust passage 21 and is used to absorb thermal energy.

[0043] According to some embodiments of the present application, the explosion-proof box adopts a double-wall insulation design with no through-hole heat conductors inside or outside the box, and heat conduction through heat bridges is avoided, effectively preventing the temperature inside the explosion-proof box from diffusing to the outside of the box and ensuring that the temperature on the outside of the explosion-proof box does not exceed 100°C. In the technical solution of the embodiments of the present application, when a battery burns in the explosion-proof box, the flame energy is insulated by the inner housing 8, and only a small amount of heat is transferred to the outer housing 6. The smoke generated during battery combustion can be exhausted through the exhaust passage 21, while the flame energy can be absorbed by the pocket 23 installed in the flame filter 2, thereby effectively preventing the flame from spreading.

[0044] In some embodiments, an insulating space is provided between the inner housing 8 and the outer housing 6, and this insulating space is used to prevent contact heat conduction of energy from the inner housing 8 to the outer housing 6.

[0045] If the battery overheats inside the explosion-proof box, the combustion flame from the battery will scorch the ceramic insulation plate 5 surrounding the inner wall of the explosion-proof box. After the heat from the flame provides a first layer of insulation through the ceramic insulation plate 5, a small amount of heat is transferred to the outer housing 6 of the explosion-proof box. The outer housing 6 of the explosion-proof box also employs a high heat-shielding material to provide secondary insulation for the transferred heat, ensuring that the surface temperature of the explosion-proof box remains below 100°C.

[0046] By physically separating the inner housing 8 and the outer housing 6, bridging heat conduction from the inner housing 8 to the outer housing 6 can be avoided, and the temperature of the outer housing 6 can be kept below a predetermined safe temperature.

[0047] In some embodiments, a support member is installed between the outer housing 6 and the inner housing 8, and the support member supports the inner housing 8 so as to form an insulating space between the inner housing 8 and the outer housing 6.

[0048] The support members may be embedded bolts. With embedded bolts, point contact rather than surface contact is achieved between the inner housing 8 and the outer housing 6, and a spatial gap exists between the inner housing 8 and the outer housing 6.

[0049] In the explosion-proof box of the embodiment of this application, the outer housing 6 and the inner housing 8 are separated by a support member. The small amount of support member allows the inner housing 8 to be supported by the outer housing 6, while at the same time forming an insulating space between the inner housing 8 and the outer housing 6. This physically separates the inner housing 8 and the outer housing 6, avoiding bridging heat conduction from the inner housing 8 to the outer housing 6, and ensuring that the temperature of the outer housing 6 is kept below a predetermined safe temperature.

[0050] In some embodiments, the outer housing 6 includes a heat insulating material.

[0051] The explosion-proof box outer housing 6 may be made of ultra-high performance concrete.

[0052] High-performance concrete manufacturing is abbreviated as UHPC (Ultra-High Performance Concrete). UHPC material can withstand high-intensity impacts. The strength of the concrete is significantly improved by methods such as adding water-reducing agents and ultrafine powders to the concrete. Water-reducing agents significantly reduce the water content in the concrete. Ultrafine powders are added to the concrete as an admixture and thoroughly mixed to effectively reduce the gaps between the aggregates, maximizing the reduction of the mass of mixed air and improving the density of the material. Concrete treated using these methods is called HPC (High Performance Concrete), and theoretically, the pressure resistance capacity of HPC can reach a strength of 120 megapascals (MPA).

[0053] The edge corners of the outer housing 6 of the explosion-proof box are made of iron to reinforce the explosion-proof box and improve the impact resistance of the explosion-proof box.

[0054] With this design, when the battery burns, the heat generated by the combustion is blocked by the heat-shielding material of the outer housing 6 and is not conducted to the external environment.

[0055] In some embodiments, inner housing 8 comprises a ceramic material.

[0056] Ceramic materials are a type of inorganic non-metallic material made from natural or synthetic compounds through molding and high-temperature sintering. They have advantages such as high melting points, high hardness, high wear resistance, and oxidation resistance. Ceramic materials generally have high melting points (often above 2000°C) and excellent chemical stability at high temperatures. Their thermal conductivity is lower than that of metallic materials, making them good insulating materials. At the same time, their linear expansion coefficient is lower than that of metals, and they have good dimensional stability when temperature changes. The radiation mechanism of ceramic materials is generated by the two-phonon and multi-phonon non-resonant effects of random vibrations. Highly emissive ceramic materials, such as silicon carbide, metal oxides, and borides, all have extremely strong infrared-activated polar vibrations, and these polar vibrations have extremely strong anharmonic effects, so their absorption coefficients in the dual-frequency and frequency domains are generally on the order of 100 to 100 cm-1, which corresponds to the relatively low reflectivity of the residual reflection band in the medium-intensity absorption region, and is therefore advantageous for forming a relatively flat, strong radiation band.

[0057] Generally, radiation bands with high thermal radiation efficiency extend from the strong resonant wavelength to the entire short-wavelength two-phonon combination frequency range, including some multi-phonon combination regions. This is a common feature of the radiation bands of many highly emissive ceramic materials, and it can be said that the strong radiation bands are mainly due to two-phonon combination radiation in this frequency range. With a few exceptions, the radiation bands of emissive ceramics are generally concentrated in the two-phonon and three-phonon ranges greater than 5 meters (m). Therefore, for infrared emissive ceramics, radiation in the 1-5 m frequency range is mainly due to intraband transitions of free carriers or direct transitions from electron impurity energy levels to the conduction band, while radiation above the 5 m frequency range is mainly due to two-phonon combination radiation.

[0058] With this design, when the battery burns, the heat generated by the combustion is not conducted to the outer housing 6 but is blocked by the ceramic material of the inner housing 8, thereby achieving the effect of heat dissipation.

[0059] In some embodiments, the flame filter 2 removably extends through both the outer housing 6 and the inner housing 8 .

[0060] According to some embodiments of this application, a detachable smoke and flame filter 2 is adopted. The structural design of the smoke and flame filter 2 effectively prevents the expulsion of high-pressure gas after the combustion of the battery. The structural design of the smoke and flame filter 2 blocks the flame and prevents it from being ejected from the outer housing 6 of the explosion-proof box, while allowing the passage of nanometer-order carbon powder particles and smoke gas. The detachable design of the smoke and flame filter 2 facilitates quick replacement after the service life has been reached.

[0061] The flame filter 2 may also be a pipe flame arrestor. A pipe flame arrestor is a safety device for preventing hydrogen gas flames from spreading outwards. It consists of many solid materials (fire-resistant elements) with fine passages or gaps through which the gas can pass. Because it is required that the gaps or passages of the fire-resistant elements be as small as possible, after the flame enters the flame arrestor, it is divided into many fine flame streams by the fire-resistant elements, and the flame streams are extinguished by heat transfer (the gas is cooled) and the Knudsen effect.

[0062] When a battery burns in the explosion-proof box, the flame filter 2 penetrates both the outer housing 6 and the inner housing 8. As a result, exhaust fumes generated during the combustion of the battery located in the inner housing 8 can be discharged through the flame filter 2. Because the flame filter 2 connects the internal space of the explosion-proof box to the external environment, it reduces the pressure in the inner housing 8 and prevents the battery inside the explosion-proof box from exploding.

[0063] In some embodiments, the pockets 23 are a plurality of metallic rings disposed on the interior surface of the exhaust passage 21 .

[0064] Flame arrestors are designed and manufactured based on the principle that when a flame passes through narrow pores in a heat conductor, it is extinguished due to heat loss. The fire-resistant layer structure of flame arrestors can be gravel, wire mesh, or corrugated. Most flame arrestors are made of solid materials that allow gas to pass through many fine, uniform or non-uniform passages or pores, and these passages or pores must be as small as possible, just small enough to allow the flame to pass through. In this way, after entering the flame arrestor, the flame is divided into many fine flame streams and extinguished. The mechanisms by which flames can be extinguished are heat transfer and the Knudsen effect.

[0065] When a deflagration occurs in a pipe, the flame passes through a narrow metal passageway, transferring some of its heat to the metal walls and losing heat in the process. The narrower the passageway the flame passes through, the more heat it loses in flight. Of course, to ensure the flame can be effectively extinguished, the spacing of the metal passageway must be matched to the explosive mixture. Experiments can reveal the maximum spacing for each material, which can then be used to determine the specifications and characteristics of the flame arrestor to ensure the flame can be effectively extinguished.

[0066] One of the necessary conditions for combustion is to reach a certain temperature, i.e., the ignition point. If the temperature falls below the ignition point, the combustion will stop. According to this principle, if the temperature of the burning material is reduced below its ignition point, the spread of the flame can be prevented. After the flame passes through many fine passages in the refractory element, it breaks down into a few fine flames. The refractory element prevents the flame from spreading by increasing the contact area between the fine flames and the passage walls as much as possible, enhancing heat transfer and reducing the flame temperature below the ignition point.

[0067] Knudsen effect of flame arrestors Combustion is not a direct reaction between molecules. Instead, molecules are excited by external energy, which breaks molecular bonds and generates activated molecules. These activated molecules then split into short-lived, active radicals. These radicals collide with other molecules to generate new products. At the same time, new radicals are generated and continue to react with other molecules. When combustible gas passes through a narrow passage in a refractory element, the probability of collisions between radicals and the passage walls increases, and the number of radicals participating in the reaction decreases. When the passage in the flame arrestor becomes narrow enough, radical collisions with the passage walls become dominant, and the number of radicals rapidly decreases, making it impossible for the reaction to continue. That is, the combustion reaction cannot continue to propagate through the flame arrestor.

[0068] As the size of the flame arrestor passage decreases, the probability of collisions between radicals and reactants decreases, but the probability of collisions between radicals and the passage walls increases, thus promoting the reduction of radical reactions. When the passage size decreases to a certain value, the Knudsen effect creates conditions that prevent the flame from continuing to propagate, and the flame is arrested. Therefore, the Knudsen effect is the primary mechanism for flame arrest.

[0069] The flame passes through the tiny passages in the fire-resistant element, where it cools down. Once the flame is broken down into smaller pieces, the heat removed through the passages is sufficient to lower the temperature below the ignition point of the flammable material and extinguish the flame.

[0070] According to the interpretation of the Knudsen effect, when the passage narrows to a certain extent, the collision of radicals with the pipe wall becomes dominant, resulting in a large reduction in the number of radicals and making it impossible for the combustion reaction to continue. Therefore, the size of the passage that can just extinguish the flame under certain conditions (0.1 MPa, 20°C) is defined as the "Maximum Experimental Safe Gap" (MESG). The size of the passage in the refractory element is a crucial factor in determining the performance of the flame arrestor, and the MESG value varies depending on the gas.

[0071] As shown in Figures 1-3, the flame from the battery combustion burns the flame filter 2. When the flame passes through the pocket 23 in the flame filter 2, the heat is instantly absorbed by heat transfer, preventing the flame from passing through the flame filter 2. At the same time, the inner housing 8 for the explosion-proof box and the outer housing 6 for the explosion-proof box are made of ceramic heat insulating plates and high-thermal insulation materials, so the flame is controlled. The fire cannot spread near the flame filter 2. The pocket 23 may be a narrow, fine metal pore.

[0072] In this design, the pocket 23 serves to absorb the flame. When a battery burns in the explosion-proof box and the flame passes through the exhaust passage 21, the energy of the flame is absorbed by the metal rings arranged on the inner surface of the exhaust passage 21, preventing the flame from burning into the environment outside the explosion-proof box.

[0073] In some embodiments, the explosion-proof box is provided with a bracket 4, and the battery is removably connected to the bracket 4.

[0074] As shown in Figure 1, by adopting a separate design for the entire explosion-proof box and the bracket 4, it is possible to easily fix the heavy battery to the explosion-proof box and to easily remove the heavy battery from the explosion-proof box.

[0075] By installing the battery in the explosion-proof box, the battery is fixed to the bracket 4, and contact and impact between the battery and the inner housing 8 of the explosion-proof box can be avoided.

[0076] In some embodiments, the explosion-proof box is provided with an opening through which the battery can enter and be housed in the inner housing 8 .

[0077] As shown in Figure 1, the box door 7 of the explosion-proof box is opened, the bracket 4 is removed with a forklift, the batteries that need to be transported are secured to the bracket 4, the bracket 4 and batteries are then placed together in the explosion-proof box with the forklift, and the box door 7 of the explosion-proof box is closed and locked.

[0078] By providing an opening in the explosion-proof box, the battery can be placed in or removed from the explosion-proof box when the opening is open, and can be protected when the opening is closed.

[0079] In some embodiments, the opening is fitted with a removable high temperature weatherstripping 1 .

[0080] According to some embodiments of the present application, a removable high-temperature resistant weatherstrip 1 is employed in the door opening gap of the explosion-proof box. The employment of the high-temperature resistant weatherstrip 1 in the door opening gap of the explosion-proof box prevents flames from leaking through the gap and prevents the temperature from being transmitted to the outer surface of the box body, and the removable design of the weatherstrip 1 makes it easy to quickly replace it after it is damaged.

[0081] When a fire breaks out inside the explosion-proof box and the temperature reaches a certain level, the fire-resistant and flame-retardant weatherstrip 1 can block the flow of air to prevent the flames from spreading. Therefore, the effect of the fire-resistant and flame-retardant weatherstrip 1 is quite significant.

[0082] The main raw material used in producing fire-resistant and flame-retardant weatherstrip 1 is expanded graphite, which also has certain advantages. For example, expanded graphite is made by chemically treating natural flake graphite, and fire-resistant and flame-retardant weatherstrip 1 is obtained by compounding and processing it with an adhesive. In some embodiments, weatherstrip 1 expands quickly at temperatures above 200°C, has strong flexibility, excellent cold resistance, and is resistant to water, acids, alkalis, and salts, demonstrating its distinct advantages and allowing it to effectively prevent the spread of fire during use.

[0083] Due to its expansive properties and high-temperature resistance, expanded graphite is an excellent sealing material and is widely used in fire weatherstripping. Various types of expandable sealing adhesive tapes are manufactured by kneading, vulcanizing, and molding expanded graphite with rubber materials, inorganic flame retardants, accelerators, vulcanizing agents, reinforcing agents, and fillers. The expanded graphite can also be bonded to a carrier with an adhesive. The carbide formed at high temperatures provides shear resistance, effectively preventing the graphite from sliding. Flame-retardant expanded graphite is an excellent flame retardant for plastics. It is non-toxic and non-polluting, and can achieve ideal flame retardancy whether used alone or mixed with other flame retardants. Expanded graphite achieves the same flame retardancy by using much less of the additive than conventional flame retardants. Its working principle is that at high temperatures, the expandable graphite expands rapidly, suffocating the flame, and the resulting graphite expansion material covers the surface of the substrate, blocking heat energy radiation and contact with oxygen. The acid groups in the intermediate layer are released during expansion, which also promotes carbonization of the substrate, thereby achieving good results in various flame retardant methods.

[0084] In paint applications, adding expanded graphite microparticles to ordinary paints can produce highly effective flame-retardant anti-static paints, improving their high-temperature resistance and fire-prevention performance. The large amount of lightweight, non-combustible carbon layer formed during a fire can effectively block heat radiation to the substrate, effectively protecting the substrate. In addition, because graphite is a good conductor, the resulting paint can prevent static charge aggregation, achieving the dual effects of fire protection and anti-static.

[0085] As shown in Figure 1, the flames from the battery combustion scorch the gaps in the door 7 of the explosion-proof box. The seams of the door 7 of the explosion-proof box are sealed with high-temperature resistant weatherstrips 1, which effectively prevent flames from escaping after melting under high temperatures.

[0086] Such a design is advantageous because it prevents flames from leaking through the opening into the external environment of the explosion-proof box.

[0087] According to some embodiments of this application, the use of the explosion-proof box is as shown in Figure 1: the explosion-proof box door 7 is opened, the battery bracket 4 is removed with a forklift, the batteries that need to be transported are fixed to the bracket 4, the battery bracket 4 and batteries are then lifted together with the forklift and placed in the explosion-proof box, the explosion-proof box door 7 is closed and locked, and by adopting a design in which the entire explosion-proof box and the battery bracket 4 are separated, heavy batteries are made easier to fix and to put into or take out of the explosion-proof box.

[0088] The outer housing 6 of the explosion-proof box is made of UHPC material, which allows it to withstand high-strength impacts. The edges of the outer housing 6 of the explosion-proof box are made of iron, reinforcing the explosion-proof box and improving its impact resistance.

[0089] If a battery experiences thermal runaway internally, the energy from the flame is generally transferred to the outside through three paths.

[0090] Flame Energy Transfer Path 1: The combustion flame from the battery scorches the ceramic insulation board 5 around the inner wall of the explosion-proof box. After the heat from the flame provides first-layer insulation through the ceramic insulation board 5, a small amount of heat is transferred to the outer housing 6 of the explosion-proof box. The outer housing 6 of the explosion-proof box also employs high heat-shielding material to provide secondary insulation for the transferred heat, ensuring that the surface temperature of the box remains below 100°C.

[0091] Flame energy transfer path 2: The flame from the battery combustion burns the exhaust flame filter 2. When the flame passes through the narrow, fine metal pores in the exhaust flame filter 2, heat is instantly absorbed by heat transfer, preventing the flame from passing through the flame filter 2. Furthermore, since the inner wall of the explosion-proof box and the outer housing 6 of the explosion-proof box employ ceramic insulation boards and high heat-shielding materials, the temperature of the flame is controlled near the exhaust flame filter 2, preventing the fire from spreading.

[0092] Flame Energy Transfer Path 3: The flames from the battery combustion scorch the gaps in the explosion-proof box door 7. The seams of the explosion-proof box door 7 are sealed with high-temperature resistant weatherstrips 1. The high-temperature resistant weatherstrips 1 melt when exposed to high temperatures, effectively preventing flames from escaping.

[0093] Finally, it should be noted that the above embodiments are merely intended to illustrate the technical solutions of the present application and are not intended to limit the same. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified or some or all of the technical features therein may be replaced with equivalents. Such modifications or replacements do not deviate from the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and should all be included in the scope of the claims and description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in the embodiments may be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions encompassed within the scope of the claims. [Explanation of symbols]

[0094] 1-Weatherstrip, 2-Flame filter, 21-Exhaust passage, 23-Pocket, 4-Bracket, 5-Insulation board, 6-Outer housing, 7-Box door, 8-Inner housing, 9-Stand.

Claims

1. 1. An explosion-proof enclosure for batteries, comprising: an outer housing (6); an inner housing (8) installed inside the outer housing (6); a flame filter (2) penetrating both the outer housing (6) and the inner housing (8), wherein the flame filter (2) comprises: an exhaust passage (21) for discharging gas generated in the inner housing (8) to the outside of the outer housing (6); a pocket (23) disposed on the inner surface of the exhaust passage (21) for absorbing thermal energy; The pocket (23) is a plurality of metal ring-shaped parts arranged on the inner surface of the exhaust passage (21).

2. 2. The explosion-proof box for a battery according to claim 1, wherein a heat insulating space is provided between the inner housing (8) and the outer housing (6), and the heat insulating space is used to prevent contact-type heat conduction of energy from the inner housing (8) to the outer housing (6).

3. 3. The explosion-proof box for a battery according to claim 2, wherein a support member is installed between the outer housing (6) and the inner housing (8), and the support member supports the inner housing (8) so as to form the thermal insulation space between the inner housing (8) and the outer housing (6).

4. 2. The explosion-proof box for batteries according to claim 1, wherein the outer housing (6) comprises a heat-shielding material which is ultra-high performance concrete (UHPC).

5. 2. The explosion-proof box for batteries according to claim 1, wherein the inner housing (8) comprises a ceramic material.

6. 2. The explosion-proof box for batteries according to claim 1, wherein a ceramic heat insulating plate (5) is provided around the inner wall of the explosion-proof box.

7. 2. The explosion-proof box for batteries according to claim 1, wherein the flame filter (2) removably penetrates both the outer housing (6) and the inner housing (8).

8. 2. The explosion-proof box for a battery according to claim 1, wherein a bracket (4) is installed on the explosion-proof box, and the battery is removably connected to the bracket (4).

9. 2. The explosion-proof box for a battery according to claim 1, wherein the explosion-proof box has an opening through which the battery can enter and be housed in the inner housing (8).

10. 10. The explosion-proof box for batteries according to claim 9, wherein the opening is provided with a removable high-temperature weather strip (1) for preventing flames from leaking through the opening to the environment outside the explosion-proof box.

11. The explosion-proof box for batteries according to claim 10, wherein the explosion-proof box further comprises a box door (7), and the high-temperature weather strip (1) is sealed in a gap of the box door (7).

12. 12. The explosion-proof box for a battery according to claim 1, wherein all edge corners of the outer housing are ferrous edge corners.

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