Foam extinguishing agent suitable for energy storage battery fire as well as preparation method and application of foam extinguishing agent

Abstract

The invention relates to the field, in particular to a foam extinguishing agent suitable for an energy storage battery fire as well as a preparation method and application thereof. The mass percent of each component is as follows: 15%-25% of a nonionic surfactant, 0%-10% of an anionic surfactant, 2%-5% of an ampholytic surfactant, 5%-10% of an antifreeze agent, 5%-10% of a cosolvent, 1%-10% of an emulsifier, 2%-5% of a thickening agent, 1%-5% of a preservative and the balance of water, and the thickening agent comprises low-density polyethylene; according to the foam extinguishing agent, the electrical insulating property, the after-combustion resistance and the environmental protection property of the foam extinguishing agent are improved, the conductivity can be reduced through the combination of multiple surfactants, and the electrical safety in the fire extinguishing process is ensured; low-density polyethylene is introduced as a thickening agent, so that the drainage time is prolonged, the foam stability is enhanced, and the foam can cover the surface of the battery for a long time, continuously isolate oxygen, absorb heat and inhibit the spreading of thermal runaway.

Description

Technical Field

[0001] The present invention relates to the field, and specifically relates to a foam fire extinguishing agent applicable to energy storage battery fires, a preparation method thereof, and an application thereof. Background Art

[0002] The high proportion of renewable energy poses higher requirements for the flexible regulation ability of the power system, and energy storage has ushered in a development opportunity; lithium-ion batteries have developed extremely rapidly due to many advantages such as large energy density and power density, high energy conversion efficiency, long cycle life, and environmental friendliness. However, the frequent safety accidents of energy storage power stations cannot be ignored, which have seriously affected the development of the energy storage industry.

[0003] Lithium battery fires are complex and difficult to extinguish, showing typical characteristics such as high combustion rate, rapid temperature rise, easy reignition, and easy explosion. Targeted fire extinguishing means need to have long-term anti-reignition ability and adopt effective methods to gradually weaken the influence of lithium-ion battery thermal runaway until it is eliminated. However, currently, gas fire extinguishing technologies such as perfluoromethylcyclohexanone and heptafluoropropane commonly used in energy storage batteries have disadvantages such as poor cooling effect, easy reignition of the battery, toxicity and corrosiveness during the fire extinguishing process, and there is an urgent need to find new fire protection technologies to replace them.

[0004] Foam fire protection technology can produce a gas-liquid two-phase fire extinguishing medium with low water content, taking into account the advantages of gas and liquid fire extinguishing, bringing new opportunities for the safe development of energy storage systems. Foam fire extinguishing agents are concentrated solutions of some chemical substances. After being mixed and diluted with water in a specified ratio and mixed with air, they produce foam to implement fire extinguishing. The foam adheres to the thermally out-of-control battery, forming a foam blanket with a uniform and dense structure, which can isolate oxygen, interrupt the chemical chain reaction, prevent heat radiation, and suffocate the fire; each bubble is composed of gas and a water outer wall, and the 360° outer surface in the radial direction absorbs heat and cools down quickly; the foam can wrap the combustible gas, and at the same time, the water contained in it continuously takes away heat through evaporation and liquid separation, effectively preventing the battery from reigniting.

[0005] Suppressing energy storage battery fires needs to consider the characteristics of easy reignition of the battery, avoiding causing secondary electrical accidents, and reducing the impact on other non-out-of-control batteries. Therefore, compared with traditional fire-fighting foams, foams applicable to suppressing energy storage battery fires have strict requirements for liquid separation time, electrical insulation, and environmental friendliness. Traditional foam fire extinguishing agents do not consider the parameter of conductivity, and it is difficult to balance high environmental friendliness (using fluorine-free surfactants) and high performance. Summary of the Invention

[0006] In view of the problems mentioned in the prior art, the present invention proposes a foam fire extinguishing agent applicable to energy storage battery fires, a preparation method thereof, and an application thereof. The foam fire extinguishing agent of the present invention not only reduces the conductivity compared with traditional foam fire extinguishing agents, but also increases the liquid separation time of the foam fire extinguishing agent. At the same time, the foam fire extinguishing agent of the present invention does not contain fluorocarbon surfactants and does not pollute the environment after use.

[0007] To achieve the above object, the present invention adopts the following technical solutions: First invention, a foam fire extinguishing agent suitable for energy storage battery fires according to the present invention, the components of which include: non-ionic surfactant, anionic surfactant, amphoteric surfactant, antifreeze, cosolvent, emulsifier, thickener, preservative; The mass percentages of each component are as follows: non-ionic surfactant 15% - 25%, anionic surfactant 0% - 10%, amphoteric surfactant 2% - 5%, antifreeze 5% - 10%, cosolvent 5% - 10%, emulsifier 1 - 10%, thickener 2% - 5%, preservative 1% - 5%, and the balance is water; The thickener includes low-density polyethylene.

[0008] As a further improvement of the present invention, the components include a combination of one of non-ionic surfactant and anionic surfactant with amphoteric surfactant, antifreeze, cosolvent, emulsifier, thickener, preservative.

[0009] As a further improvement of the present invention, the non-ionic surfactant includes one or more of polyethylene glycol, alkyl polyglycoside, fatty alcohol polyoxyethylene ether; The anionic surfactant includes one or more of α-olefin sulfonate, fatty alcohol polyoxyethylene ether sulfate, sodium lauryl polyether sulfate, sodium dodecyl sulfate, ammonium dodecyl sulfate; The amphoteric surfactant includes at least one of coconut oil amide propyl betaine and lauryl amide propyl betaine.

[0010] As a further improvement of the present invention, the density of the low-density polyethylene is 0.910 - 0.940 g / cm 3 .

[0011] As a further improvement of the present invention, the emulsifier includes at least one of octylphenol polyoxyethylene ether and triethanolamine; The cosolvent includes at least one of diethylene glycol monobutyl ether, ethylene glycol, and absolute ethanol; The antifreeze includes at least one of diethylene glycol monobutyl ether, ethylene glycol, and absolute ethanol.

[0012] As a further improvement of the present invention, the preservative includes at least one of sodium benzoate and sodium sorbate.

[0013] Second aspect, the present invention provides a preparation method of a foam fire extinguishing agent suitable for energy storage battery fires, including the following steps: Add non-ionic surfactant to water with a water temperature of 20 - 25°C and stir for 5 - 10 min; Add an anionic surfactant and stir for 10 - 15 min; Add an amphoteric surfactant and stir at a speed of 1000 - 1500 rpm for 10 - 15 min; Add a cosolvent and an antifreeze agent and stir at a speed of 500 - 1000 rpm for 5 - 10 min; Add an emulsifier and stir at a speed of 500 - 1000 rpm for 10 - 15 min; Add a thickener; Add a preservative and stir evenly for 45 min - 1 h; Let the prepared solution stand for 30 min - 1 h, and then filter to obtain a foam fire extinguishing agent suitable for energy storage battery fires.

[0014] As a further improvement of the present invention, the process of adding the amphoteric surfactant is as follows: After water and ethanol are miscible in a mass ratio of 1.3:1, stir and add the amphoteric surfactant at a speed of 500 - 1000 rpm for 5 - 10 min, where the mass ratio of water, ethanol, and the amphoteric surfactant in the solution is 1.3:1:0.6.

[0015] As a further improvement of the present invention, the process of adding the thickener is as follows: Add low - density polyethylene to excessive water, heat and stir, with the heating temperature of 60 - 80 °C and the stirring speed of 500 - 1000 rpm for 20 - 30 min; During heating, perform ultrasonic - assisted dissolution on the low - density polyethylene, where the ultrasonic power is 80 - 100 W and the ultrasonic treatment is for 20 - 30 min; Filter the dissolved solution; The mass ratio of water to low - density polyethylene is 15:1 - 30:1.

[0016] In a third aspect, the present invention proposes an application of a foam fire extinguishing agent suitable for energy storage battery fires in the disposal of energy storage battery fires.

[0017] The present invention has achieved the following technical effects compared with the prior art: The foam fire extinguishing agent of the present invention improves the performance of the foam fire extinguishing agent in terms of electrical insulation, anti-re-ignition ability and environmental friendliness, and effectively solves the key problems such as insufficient cooling of gas fire extinguishing agents, easy re-ignition, fluorine-containing toxicity, etc. in the prior art. Compared with traditional foam fire extinguishing agents that do not consider conductivity parameters, the present invention can reduce the conductivity through the combination of various surfactants, ensuring the electrical safety during the fire extinguishing process; secondly, by introducing low-density polyethylene as a thickening agent, the drainage time is significantly extended. Low-density polyethylene can form a reticular structure in the foam fire extinguishing agent, enhancing the foam stability, enabling it to cover the battery surface for a long time, continuously isolating oxygen and absorbing heat, thereby inhibiting the spread of thermal runaway. In addition, the present invention abandons traditional fluorocarbon surfactants and adopts a fluorine-free environmental protection formula, which not only avoids the long-term pollution of the environment by fluorine-containing compounds but also ensures the high efficiency of the fire extinguishing agent.

[0018] The preparation method of the foam fire extinguishing agent of the present invention realizes the full mixing and reaction of each component by adding components step by step and precisely controlling the stirring speed and stirring time. For example, when adding amphoteric surfactants, since non-ionic surfactants and amphoteric surfactants are not easily dissolved sufficiently, a mixed solvent of water and ethanol is added for addition, improving its dissolution efficiency; in addition, due to the high viscosity of low-density polyethylene, water and an ultrasonic device are selected to assist in dissolving low-density polyethylene, solving the problems of high viscosity and slow dissolution of low-density polyethylene. Brief Description of the Drawings

[0019] Figure 1 Drainage rate and drainage time of Example 1, Comparative Example 2, and Comparative Example 3.

[0020] Figure 2 Optical microscope images of the foams prepared for Example 1 and Comparative Example 2.

[0021] Figure 3 Relationship between the core components of the foam fire extinguishing agent (non-ionic surfactant polyethylene glycol, thickening agent polyethylene oxide) and foam conductivity, 25% drainage time.

[0022] Figure 4 Charge and discharge curves before and after the battery is soaked in the foam. Detailed Description of the Invention

[0023] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present invention. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0024] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0025] In addition, the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0026] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0028] It should be understood that when used in this specification and the appended claims, the terms "comprises" and "comprising" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their groups.

[0029] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0030] It should be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0031] Various schematic structural diagrams according to the disclosed embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures and their relative sizes and positional relationships are only exemplary, and may actually deviate due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes and relative positions according to actual needs.

[0032] The embodiments of the present invention will be described in detail below with reference to the drawings.

[0033] A foam fire extinguishing agent suitable for energy storage battery fires according to the present invention, the components of which include: non-ionic surfactant, anionic surfactant, amphoteric surfactant, antifreeze, cosolvent, emulsifier, thickener, preservative.

[0034] In the embodiment, three non-ionic surfactants, anionic surfactants, and amphoteric surfactants are selected for foaming. It should be noted that the present invention includes not only the combination of non-ionic surfactants, anionic surfactants, and amphoteric surfactants, but also the combination of non-ionic surfactants and amphoteric surfactants, and the combination of anionic surfactants and amphoteric surfactants.

[0035] The non-ionic surfactants in the embodiment include one or more of polyethylene glycol, alkyl polyglycoside, and fatty alcohol polyoxyethylene ether; The anionic surfactants include one or more of alpha-olefin sulfonate, sodium lauryl ether sulfate, sodium lauryl polyether sulfate, sodium dodecyl sulfate, and ammonium dodecyl sulfate; The amphoteric surfactants include at least one of cocamidopropyl betaine and lauramidopropyl betaine.

[0036] The thickener in this embodiment includes low-density polyethylene, which can improve the drainage time of the foam fire extinguishing agent, and preferably has a density of 0.910 - 0.940 g / cm 3Polyethylene, with less low-density polyethylene used, high viscosity, and stable performance, can improve the liquid separation performance of the foam fire extinguishing agent. It should be noted that polyethylene is a crystalline polymer, which can be divided into high-pressure polyethylene, medium-pressure polyethylene, and low-pressure polyethylene according to its production method, and correspondingly obtain low-density polyethylene, medium-density polyethylene, and high-density polyethylene. In this embodiment, low-density polyethylene powder (500 - 1500 mesh, with a fine powder size of 5 - 20 μm) is selected. Compared with medium-density polyethylene and high-density polyethylene, low-density polyethylene has the advantage of being easy to process and form. Moreover, due to the weak intermolecular force of low-density polyethylene, the risk of material rupture can be reduced, ensuring the stability and persistence of the foam.

[0037] In this embodiment, the emulsifier includes at least one of octylphenol polyoxyethylene ether and triethanolamine, which is used to increase the water retention time of the foam and enhance the stability of the foam.

[0038] In this embodiment, the cosolvent includes at least one of diethylene glycol butyl ether, ethylene glycol, and absolute ethanol, which is used to promote the dissolution of the surfactant.

[0039] In this embodiment, the antifreeze includes at least one of diethylene glycol butyl ether, ethylene glycol, and absolute ethanol, which is used to improve the frost resistance of the foam fire extinguishing agent.

[0040] In this embodiment, the preservative includes at least one of sodium benzoate and sodium sorbate, which is used to extend the shelf life of the foam fire extinguishing agent.

[0041] The water in this embodiment can be one of tap water, pure water, and deionized water.

[0042] The present invention provides a method for preparing a foam fire extinguishing agent applicable to energy storage battery fires, which includes the following steps: Step 1: Add a non-ionic surfactant to water with a water temperature of 20 - 25 °C and stir for 5 - 10 min; Step 2: Add an anionic surfactant and stir for 10 - 15 min; The process of adding an amphoteric surfactant is as follows: After water and ethanol are mutually dissolved according to a mass ratio of 1.3:1, the amphoteric surfactant is stirred and added, with a stirring speed of 500 - 1000 rpm and stirred for 5 - 10 min. Among them, the volume ratio of water, ethanol, and the amphoteric surfactant in the solution is 1.3:1:0.6. The prepared solution is added to the solution obtained in Step 2, with a stirring speed of 1000 - 1500 rpm and stirred for 10 - 15 min; Step 4: Add a cosolvent and an antifreeze, with a stirring speed of 500 - 1000 rpm and stir for 5 - 10 min; Step 5: Add an emulsifier, with a stirring speed of 500 - 1000 rpm and stir for 10 - 15 min; Step 6. The process of adding the thickener is as follows: Add low-density polyethylene to excessive water, heat and stir. The heating temperature is 60-80°C, the stirring speed is 500-1000 rpm, and stir for 20-30 min. During heating, ultrasonic-assisted dissolution of polyethylene is carried out, where the ultrasonic power is 80-100 W and ultrasonic treatment is carried out for 20-30 min. After sufficient dissolution, the solution is filtered to remove impurities, and the mass ratio of water to polyethylene is 15:1-30:1. In the embodiment, due to the high viscosity of low-density polyethylene, it is not easy to stir evenly. Therefore, adding water and an ultrasonic crusher can assist in accelerating the dissolution of low-density polyethylene.

[0043] Step 7. Add the preservative and stir evenly for 45 min to 1 h. Step 8. After allowing the prepared solution to stand for 30 min to 1 h, filter it to obtain a foam fire extinguishing agent suitable for energy storage battery fires.

[0044] Example 1 Its components include 23% polyethylene glycol, 2% lauramidopropyl betaine, 8% absolute ethanol, 2% diethylene glycol monobutyl ether, 4% triethanolamine, 1% low-density polyethylene, 1% sodium benzoate, and 59% deionized water.

[0045] Step 1. Add 39.67 kg of deionized water with a water temperature of 20°C to the container, add 23 kg of polyethylene glycol, and stir for 5 min at a stirring speed of 1000 rpm. Step 2. After dissolving 4.33 kg of water, 3.33 kg of ethanol, and 2 kg of lauramidopropyl betaine with each other, add the resulting solution to the solution in Step 1 and stir for 10 min at a stirring speed of 1000 rpm. Step 3. Add 4.67 kg of absolute ethanol and 2 kg of diethylene glycol monobutyl ether and stir for 10 min at a stirring speed of 1000 rpm. Step 4. Add 4 kg of triethanolamine and stir for 10 min at a stirring speed of 500 rpm. Step 5. Heat and stir 15 kg of deionized water with a water temperature of 60°C and 1 kg of low-density polyethylene at a stirring speed of 500 rpm for 20 min. During the stirring process, use an ultrasonic crusher to ultrasonically treat the low-density polyethylene with an ultrasonic power of 80 W for 20 min. After the low-density polyethylene is dissolved, filter it, and add the filtered solution to the solution in Step 4. Step 6. Add 1 kg of sodium benzoate and stir the whole for 45 min at a stirring speed of 1500 rpm. Step 7. Allow the prepared solution to stand for 30 min, filter it to obtain a foam fire extinguishing agent suitable for energy storage battery fires.

[0046] Example 2 Its components include 23% alkyl polyglycoside, 2% lauramidopropyl betaine, 8% absolute ethanol, 2% ethylene glycol, 4% triethanolamine, 1% low-density polyethylene, 1% sodium benzoate, and 59% deionized water.

[0047] Step 1: Add 24.67 kg of deionized water at a water temperature of 25°C to a container, add 23 kg of alkyl polyglycoside, and stir for 10 min at a stirring speed of 1000 rpm. Step 2: After dissolving 4.33 kg of water, 3.33 kg of ethanol, and 2 kg of lauramidopropyl betaine together, add the resulting solution to the solution in Step 1, and stir for 15 min at a stirring speed of 1500 rpm. Step 3: Add 4.67 kg of absolute ethanol and 2 kg of ethylene glycol, and stir for 10 min at a stirring speed of 1000 rpm. Step 4: Add 4 kg of triethanolamine, and stir for 15 min at a stirring speed of 1000 rpm. Step 5: Heat and stir 30 kg of deionized water at a water temperature of 80°C and 1 kg of low-density polyethylene at a stirring speed of 1000 rpm for 30 min. During the stirring process, use an ultrasonic crusher to ultrasonically treat the low-density polyethylene with an ultrasonic power of 100 W for 30 min. After dissolution, filter, and add the filtered solution to the solution in Step 4. Step 6: Add 1 kg of sodium benzoate, and stir the whole for 1 h at a stirring speed of 1500 rpm. Step 7: Let the prepared solution stand for 1 h, and after filtration, obtain a foam fire extinguishing agent suitable for energy storage battery fires.

[0048] Example 3 Its components include 11.5% polyethylene glycol, 11.5% sodium lauryl polyether sulfate, 2% lauramidopropyl betaine, 8% absolute ethanol, 2% diethylene glycol monobutyl ether, 4% triethanolamine, 1% low-density polyethylene, 1% sodium sorbate, and 59% deionized water.

[0049] Step 1: Add 32.17 kg of deionized water at a water temperature of 22.5°C to a container, add 11.5 kg of polyethylene glycol, and stir for 7.5 min at a stirring speed of 1250 rpm. Step 2: Add 11.5 kg of sodium lauryl polyether sulfate, and stir for 10 min at a stirring speed of 1000 rpm. Step 3: After dissolving 4.33 kg of water, 3.33 kg of ethanol, and 2 kg of lauramidopropyl betaine together, add the resulting solution to the solution in Step 1, and stir for 12.5 min at a stirring speed of 1250 rpm. Step 3: Add 4.67 kg of absolute ethanol and 2 kg of diethylene glycol butyl ether, stir for 7.5 min at a stirring speed of 750 rpm; Step 4: Add 4 kg of triethanolamine, stir for 5 min at a stirring speed of 500 rpm; Step 5: Heat and stir 22.5 kg of deionized water at a water temperature of 70 °C and 1 kg of low-density polyethylene, with a stirring speed of 700 rpm for 15 min. During the stirring process, use an ultrasonic crusher to ultrasonically treat the low-density polyethylene with an ultrasonic power of 90 W for 25 min; After the low-density polyethylene is dissolved, filter it, and add the filtered solution to the solution in Step 4; Step 6: Add 1 kg of sodium sorbate, and stir the whole for 45 min at a stirring speed of 12,500 rpm; Step 7: Let the prepared solution stand for 45 min, and after filtration, obtain a foam fire extinguishing agent suitable for energy storage battery fires.

[0050] Comparative Example 1 Its components include 23% sodium lauryl polyether sulfate, 2% lauramidopropyl betaine, 8% absolute ethanol, 2% diethylene glycol butyl ether, 4% triethanolamine, 1% low-density polyethylene, 1% sodium benzoate, and 59% deionized water.

[0051] Step 1: Add 39.67 kg of deionized water at a water temperature of 20 °C to a container, add 23 kg of sodium lauryl polyether sulfate, and stir for 10 min at a stirring speed of 1000 rpm; Step 2: After 4.33 kg of water, 3.33 kg of ethanol, and 2 kg of lauramidopropyl betaine are mutually dissolved, add the obtained Solution A to the solution in Step 1, and stir for 15 min at a stirring speed of 1500 rpm; Step 3: Add 4.67 kg of absolute ethanol and 2 kg of diethylene glycol butyl ether, stir for 5 min at a stirring speed of 500 rpm; Step 4: Add 4 kg of triethanolamine, stir for 5 min at a stirring speed of 500 rpm; Step 5: Heat and stir 15 kg of deionized water at a water temperature of 60 °C and 1 kg of low-density polyethylene, with a stirring speed of 500 rpm for 20 min. During the stirring process, use an ultrasonic crusher to ultrasonically treat the low-density polyethylene with an ultrasonic power of 80 W for 20 min; After the low-density polyethylene is dissolved, filter it, and add the filtered solution to the solution in Step 4; Step 6: Add 1 kg of sodium benzoate, and stir the whole for 1 h at a stirring speed of 1500 rpm; Step 7: Let the prepared solution stand for 30 min, and after filtration, obtain a foam fire extinguishing agent suitable for energy storage battery fires.

[0052] Comparative Example 2 Its components include 23% polyethylene glycol, 2% lauramidopropyl betaine, 8% absolute ethanol, 2% diethylene glycol butyl ether, 4% triethanolamine, 0% low-density polyethylene, 1% sodium benzoate, and 60% deionized water.

[0053] Step 1: Add 55.67 kg of deionized water at a water temperature of 20°C to a container, add 23 kg of polyethylene glycol, stir for 10 min, and the stirring speed is 1000 rpm; Step 2: After dissolving 4.33 kg of water, 3.33 kg of ethanol, and 2 kg of lauramidopropyl betaine, add the resulting solution A to the solution in Step 1, stir for 10 min, and the stirring speed is 1000 rpm; Step 3: Add 4.67 kg of ethylene glycol and 2 kg of diethylene glycol butyl ether, stir for 10 min, and the stirring speed is 1000 rpm; Step 4: Add 4 kg of triethanolamine, stir for 10 min, and the stirring speed is 1000 rpm; Step 5: Add 1 kg of sodium benzoate, stir the whole for 1 h, and the stirring speed is 1500 rpm; Step 7: Let the prepared solution stand for 30 min, and after filtration, a foam fire extinguishing agent suitable for energy storage battery fires is obtained.

[0054] Comparative Example 3 Its components include 23% polyethylene glycol, 2% lauramidopropyl betaine, 8% absolute ethanol, 2% diethylene glycol butyl ether, 4% triethanolamine, 2% low-density polyethylene, 1% sodium benzoate, and 58% deionized water.

[0055] Step 1: Add 23.67 kg of deionized water at a water temperature of 20°C to a container, add 23 kg of polyethylene glycol, stir for 10 min, and the stirring speed is 1000 rpm; Step 2: After dissolving 4.33 kg of water, 3.33 kg of ethanol, and 2 kg of lauramidopropyl betaine, add the resulting solution A to the solution in Step 1, stir for 10 min, and the stirring speed is 1000 rpm; Step 3: Add 4.67 kg of absolute ethanol and 2 kg of diethylene glycol butyl ether, stir for 10 min, and the stirring speed is 1000 rpm; Step 4: Add 4 kg of triethanolamine, stir for 10 min, and the stirring speed is 1000 rpm; Step 5: Heat and stir 30 kg of deionized water at a water temperature of 60°C and 2 kg of low-density polyethylene, the stirring speed is 1000 rpm, stir for 30 min, and use an ultrasonic crusher to ultrasonically treat the low-density polyethylene during the stirring process, the ultrasonic power is 100 W, and ultrasonically treat for 30 min; After the low-density polyethylene is dissolved, filter it and add the filtered solution to the solution in step 4; Step 6: Add 1 kg of sodium benzoate and stir the whole for 1 hour at a stirring speed of 1500 rpm; Step 7: Let the prepared solution stand for 45 minutes, and filter it to obtain a foam fire extinguishing agent suitable for energy storage battery fires.

[0056] The conductivity and 25% liquid separation time of the foam fire extinguishing agents prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested, and the results are shown in Table 1 below: Table 1 Conductivity, 25% liquid separation time test data results

[0057] As shown in Table 1, adding nonionic surfactant polyethylene glycol or APG0810 can significantly reduce the conductivity of the foam fire extinguishing agent, and polyethylene glycol has a stronger ability to reduce conductivity; using low-density polyoxyethylene as a thickener and increasing the mass ratio can increase the liquid separation time of the foam fire extinguishing agent by 25%. Figure 1 .

[0058] The foams prepared in Example 1 and Comparative Example 2 were characterized by optical microscopy. Figure 2 . The foam structure of Example 1 is tightly arranged to form a hexagonal honeycomb arrangement; the foam structure of Comparative Example 2 is sparse to form a circular structure arrangement, and the water film at the edge of the foam is thicker. Due to the absence of thickener addition, the foam fire extinguishing agent has poor foaming performance and cannot form a tightly arranged foam structure. At the same time, the liquid separation time is short and the foam water film is thicker. After adding the thickener, the initial average diameter of the foam increases, the coarsening speed of the foam slows down, and the diameter distribution of the foam is more uniform.

[0059] In the embodiment, the nonionic surfactant added is polyethylene glycol, and the conductivity and 25% liquid separation time of the foam fire extinguishing agent with different mass ratios of nonionic surfactant polyethylene glycol and thickener polyethylene are plotted, as shown in FIG. Figure 3 As shown, it can be clearly seen that as the mass ratio of the nonionic surfactant polyethylene glycol increases, the conductivity decreases significantly, and the liquid separation time also slowly decreases; as the mass ratio of the thickener increases, the foam conductivity increases slightly, and the liquid separation time is significantly improved. Comprehensively evaluating the conductivity and liquid separation time, Example 1 and Comparative Example 3 have better effects.

[0060] Therefore, based on the component-property regulation relationships between the core components of the foam extinguishing agent, the non-ionic surfactant polyethylene glycol, and the thickener polyethylene, and the conductivity and 25% liquid separation time, the content of the non-ionic surfactant polyethylene glycol and the thickener polyethylene can be increased or decreased according to different application scenarios and requirements to produce foam extinguishing agents with different performance focuses.

[0061] In this embodiment, to verify that the foam medium has no effect on the electrical performance of the battery and will not cause electrical short circuits, a foam full immersion of a lithium iron phosphate battery with a capacity of 280 Ah was prepared using the foam extinguishing agent of Example 1, and the charge and discharge conditions of the battery before and after foam immersion were observed and compared.

[0062] As Figure 4 shown, the experimental results show that the battery immersed in foam is consistent with the battery without added foam in the charge and discharge trend. Since the temperature of the battery immersed in foam decreases by about 2°C, the charge and discharge capacity of the battery decreases slightly. The charge and discharge test of the battery immersed in foam fully verifies that the low-conductivity foam extinguishing agent proposed by the present invention will not cause battery short circuits and has no effect on the electrical performance of the battery during the foam spraying and fire extinguishing process.

[0063] The foregoing shows and describes the basic principles, main features, and advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed within the present invention. Any reference signs in the claims should not be construed as limiting the claimed rights.

[0064] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment contains only one independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A foam fire extinguishing agent applicable to energy storage battery fires, characterized in that, Its components include: non-ionic surfactant, anionic surfactant, amphoteric surfactant, antifreeze, cosolvent, emulsifier, thickener, preservative; The mass percentages of each component are as follows: non-ionic surfactant 15% - 25%, anionic surfactant 0% - 10%, amphoteric surfactant 2% - 5%, antifreeze 5% - 10%, cosolvent 5% - 10%, emulsifier 1 - 10%, thickener 2% - 5%, preservative 1% - 5%, and the balance is water; The thickener includes low-density polyethylene.

2. The foam fire extinguishing agent applicable to energy storage battery fires according to claim 1, wherein The components include a combination of one of non-ionic surfactant and anionic surfactant and amphoteric surfactant, antifreeze, cosolvent, emulsifier, thickener, preservative.

3. The foam fire extinguishing agent applicable to energy storage battery fires according to claim 2, wherein, The non-ionic surfactant includes one or more of polyethylene glycol, alkyl polyglycoside, fatty alcohol polyoxyethylene ether; The anionic surfactant includes one or more of α-olefin sulfonate, fatty alcohol polyoxyethylene ether sulfate, sodium lauryl polyether sulfate, sodium dodecyl sulfate, ammonium dodecyl sulfate; The amphoteric surfactant includes at least one of cocoamidopropyl betaine and lauramidopropyl betaine.

4. The foam fire extinguishing agent applicable to energy storage battery fires according to claim 1, wherein The density of the low-density polyethylene is 0.910 - 0.940 g / cm 3 .

5. The foam fire extinguishing agent applicable to energy storage battery fires according to claim 1, wherein, The emulsifier includes at least one of octylphenol polyoxyethylene ether and triethanolamine; The cosolvent includes at least one of diethylene glycol monobutyl ether, ethylene glycol, and absolute ethanol; The antifreeze includes at least one of diethylene glycol monobutyl ether, ethylene glycol, and absolute ethanol.

6. The foam fire extinguishing agent applicable to energy storage battery fires according to claim 1, characterized in that, The preservative includes at least one of sodium benzoate and sodium sorbate.

7. The preparation method of a foam fire extinguishing agent applicable to energy storage battery fires according to any one of claims 1 to 6, characterized in that, It includes the following steps: Add non-ionic surfactant to water with a water temperature of 20 - 25°C, and stir for 5 - 10 min; Add anionic surfactant, and stir for 10 - 15 min; Add amphoteric surfactant, with a stirring speed of 1000 - 1500 rpm, and stir for 10 - 15 min; Add cosolvent and antifreeze, with a stirring speed of 500 - 1000 rpm, and stir for 5 - 10 min; Add emulsifier, with a stirring speed of 500 - 1000 rpm, and stir for 10 - 15 min; Add thickener; Add preservative, and stir evenly for 45 min - 1 h; Let the prepared solution stand for 30 min - 1 h, and then filter to obtain a foam fire extinguishing agent suitable for energy storage battery fires.

8. The foam fire extinguishing agent applicable to energy storage battery fires according to claim 7, wherein The process of adding amphoteric surfactant is: dissolve water and ethanol in a mass ratio of 1.3:1, then stir and add amphoteric surfactant, with a stirring speed of 500 - 1000 rpm, and stir for 5 - 10 min, where the mass ratio of water, ethanol, and amphoteric surfactant in the solution is 1.3:1:0.

6.

9. The foam fire extinguishing agent applicable to the fire of energy storage batteries according to claim 1, characterized in that, The process of adding thickener is: add low-density polyethylene to excessive water, heat and stir, with a heating temperature of 60 - 80°C, a stirring speed of 500 - 1000 rpm, and stir for 20 - 30 min; During heating, perform ultrasonic-assisted dissolution on low-density polyethylene, where the ultrasonic power is 80 - 100 W, and ultrasonic for 20 - 30 min; Filter the dissolved solution; The mass ratio of water to low-density polyethylene is 15:1 - 30:

1.

10. Use of the foam fire extinguishing agent applicable to energy storage battery fires as described in any one of claims 1 to 6 in the disposal of energy storage battery fires.

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