Flame-retardant coolant and method for producing the same, immersion-type energy storage device, data center
Patent Information
- Application Number
- CN202611241552.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-17
- Publication Date
- 2026-09-22
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Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage safety technology, specifically to flame-retardant coolants and their preparation methods, submerged energy storage devices, data centers, and electrical equipment. Background Technology
[0002] Submerged energy storage technology can optimize the thermal management system of energy storage batteries, suppress battery thermal runaway, effectively solve battery thermal safety problems, improve the safety and cycle life of battery operation, and maintain the stability of the power grid system, which is of great significance to promoting the healthy and sustainable development of the new energy industry.
[0003] As the core of submerged energy storage technology, the thermophysical properties of coolant directly affect the operating performance of submerged energy storage devices. Currently, the coolants used in domestic and foreign submerged thermal management systems are mainly divided into: fluorinated liquids, hydrocarbons, esters, and silicone oils. The basic selection principles mainly include: (1) high insulation performance to ensure non-conductivity; (2) excellent thermal conductivity to ensure timely heat dissipation; (3) excellent flame retardant performance to prevent the spread of thermal runaway; (4) material compatibility to avoid corrosion of lithium battery system materials; (5) environmental friendliness, including zero ozone depletion potential (ODP) and low global warming potential (GWP); (6) wide temperature range performance to ensure good applicability in extremely cold or high temperature environments.
[0004] However, existing coolants struggle to simultaneously achieve fluidity, insulation, and flame retardancy under extremely cold conditions.
[0005] It should be noted that the above statements are only used to provide background information related to this application and do not necessarily constitute prior art. Summary of the Invention
[0006] In a first aspect, this application proposes a flame-retardant coolant, comprising: mineral oil, a flame retardant, and a low-temperature modifier; the flame retardant comprises tetrachloroethylene; the low-temperature modifier is a liquid, and comprises phenylalkanes and cyclohexanes; the phenylalkanes comprise C1-C5 alkyl-substituted benzenes, and the cyclohexanes comprise C1-C5 alkyl-substituted cyclohexanes. Thus, by adding the low-temperature modifier, the poor low-temperature performance of both mineral oil and the flame retardant is simultaneously improved, allowing the low-cost advantage of mineral oil and the flame-retardant advantage of tetrachloroethylene to be fully utilized, resulting in a flame-retardant coolant with good low-temperature fluidity, good flame-retardant properties, and good insulation properties.
[0007] In some embodiments, the mass ratio of the phenylalkane to the cyclohexane is (1-5):1; optionally, (1-2):1. Optimizing the mass ratio of phenylalkane to cyclohexane is beneficial for further reducing the pour point of the coolant and improving its insulation performance. When the amount of phenylalkane and cyclohexane added is moderate, the proportion of benzene rings and six-membered rings in the coolant system is more suitable, and the two are more likely to combine, making the system more homogeneous and stable, and significantly improving the flowability and insulation performance.
[0008] In some embodiments, the flame-retardant coolant comprises: 5-50 parts by weight of mineral oil, 40-85 parts by weight of flame retardant, 5-20 parts by weight of phenylalanine, and 5-20 parts by weight of cyclohexane. This improves the coolant's low-temperature fluidity and insulation properties.
[0009] In some embodiments, the phenylalkane includes at least one selected from toluene, ethylbenzene, propylbenzene, butylbenzene, and pentylbenzene. The longer the alkyl chain and the larger the molecular weight, the worse the fluidity, causing it to slowly change from liquid to solid. Therefore, the aforementioned low molecular weight phenylalkane is preferable.
[0010] In some embodiments, the cyclohexane includes at least one selected from methylcyclohexane, ethylcyclohexane, propylcyclohexane, butylcyclohexane, and pentylcyclohexane. The longer the alkyl chain and the larger the molecular weight, the worse the fluidity, causing it to slowly change from liquid to solid. Therefore, the aforementioned low molecular weight cyclohexanes are preferable.
[0011] In some embodiments, the mineral oil includes at least one of No. 10 mineral transformer oil, No. 25 mineral transformer oil, and No. 45 mineral transformer oil. Thus, the mineral oil, as the primary liquid carrier, provides fundamental protection for insulation performance.
[0012] In a second aspect, this application proposes a method for preparing the aforementioned flame-retardant coolant, comprising: mixing mineral oil, a flame retardant, and a low-temperature modifier to obtain the flame-retardant coolant; wherein the flame retardant comprises tetrachloroethylene; the low-temperature modifier is a liquid, and the low-temperature modifier comprises phenylalkanes and cyclohexanes; the phenylalkanes comprise C1-C5 alkyl-substituted benzenes, and the cyclohexanes comprise C1-C5 alkyl-substituted cyclohexanes. Therefore, the method provided by this application is simple, and the resulting coolant not only has the advantages of low cost, high flame retardancy, low viscosity, and good heat dissipation, but also significantly improves low-temperature performance and insulation performance, making it suitable for extremely cold regions and high-insulation scenarios.
[0013] In some embodiments, the mixing temperature is 40°C-60°C; and / or the mixing rate is 600 r / min-1000 r / min; and / or the mixing time is 5 h-12 h. Thus, mineral oil, flame retardant, and low-temperature modifier can be thoroughly mixed, and benzene rings and six-membered rings can be uniformly distributed in the coolant, lowering the system's pour point and thereby better utilizing the low-temperature modifier's role in improving flowability and insulation properties.
[0014] In a third aspect, this application proposes a submersible energy storage device, comprising the flame-retardant coolant described in the first aspect of this application or a flame-retardant coolant prepared using the method described in the second aspect of this application. Because it employs the aforementioned flame-retardant coolant, the submersible energy storage device of this application possesses all the advantages of the flame-retardant coolant, which will not be elaborated further here.
[0015] In a fourth aspect, this application proposes a data center comprising the flame-retardant coolant described in the first aspect of this application or a flame-retardant coolant prepared using the method described in the second aspect of this application. Because it employs the aforementioned flame-retardant coolant, the data center of this application possesses all the advantages of the flame-retardant coolant, which will not be elaborated further here.
[0016] In a fifth aspect, this application proposes an electrical appliance including the data center described in the fourth aspect. Because it employs the aforementioned flame-retardant coolant, the electrical appliance of this application possesses all the advantages of the flame-retardant coolant, which will not be elaborated further here. Detailed Implementation
[0017] The embodiments of this application are described in detail below, but unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the following description is provided to enable those skilled in the art to fully understand this application and is not intended to limit the subject matter of the claims.
[0018] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit this application; unless otherwise stated, the values of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this application).
[0019] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are open-ended expressions, meaning they include what is specified in this application but do not exclude other aspects.
[0020] In the description of this application, all figures disclosed herein, whether or not the words "approximately" or "about" are used, are approximate values. Each figure may vary by less than 10% or by a difference that is considered reasonable by one of the art, such as 1%, 2%, 3%, 4%, or 5%.
[0021] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values of 1 and 2 are listed, and if maximum range values of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in this article; "0-5" is just a shortened representation of these numerical combinations.
[0022] In the description of this application, "A and / or B" can include any of the cases of A alone, B alone, or A and B, where A and B are merely examples and can be any technical feature connected by "and / or" in this application.
[0023] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.
[0024] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.
[0025] Among related technologies, fluorinated liquids possess excellent flame retardant properties and material compatibility, but their insulation properties are relatively poor, posing a safety risk of leakage and short circuits during long-term operation. Enhancing their insulation performance remains a major challenge for this type of product. In contrast, hydrocarbons, esters, and silicone oils exhibit good insulation properties, but their flame retardancy and low-temperature fluidity are poor, typically requiring the introduction of halogenated hydrocarbons as flame retardants to improve their flame retardant performance.
[0026] Common halogenated unsaturated hydrocarbons include tetrachloroethylene, hexachloropropylene, and hexachlorobutadiene. Although hexachloropropylene has a relatively low pour point, its cost is high, as is hexachlorobutadiene, making large-scale application difficult. Therefore, this application selects tetrachloroethylene, which has a lower cost, as a flame retardant. The base oils in coolant mainly include silicone oil, synthetic esters, and mineral oil. Compared to silicone oil and synthetic esters, mineral oil has better compatibility with tetrachloroethylene and is less expensive. Therefore, this application selects mineral oil, which has a lower cost, as the base oil.
[0027] Tetrachloroethylene, as a relatively stable halogenated hydrocarbon with good compatibility with mineral oils, high flame retardancy, and low cost, is the best choice as a flame retardant for mineral oils. However, tetrachloroethylene has a pour point of approximately -21°C, while traditional mineral oils (such as No. 25 mineral transformer oil) have a pour point of approximately -30°C. The low-temperature fluidity of the flame-retardant oil formed by these two substances is very poor, failing to meet the application requirements of coolants in extremely cold regions. Furthermore, chlorinated hydrocarbons have poor insulation properties, are prone to breakdown, and have poor long-term stability, generating free chloride ions. This leads to a significant decrease in the insulation performance of the flame-retardant oil system, posing a potential short-circuit risk when used as a coolant for energy storage and other electrical equipment. Therefore, significantly reducing the pour point of the tetrachloroethylene flame-retardant oil system, improving its low-temperature fluidity, and simultaneously enhancing its insulation performance are crucial for improving its application value.
[0028] In a first aspect, this application proposes a flame-retardant coolant, comprising: mineral oil, a flame retardant, and a low-temperature modifier; the flame retardant comprises tetrachloroethylene; the low-temperature modifier is a liquid, and comprises phenylalkanes and cyclohexanes; the phenylalkanes comprise C1-C5 alkyl-substituted benzenes, and the cyclohexanes comprise C1-C5 alkyl-substituted cyclohexanes. Thus, by adding the low-temperature modifier, the poor low-temperature performance of both mineral oil and the flame retardant is simultaneously improved, allowing the low-cost advantage of mineral oil and the flame-retardant advantage of tetrachloroethylene to be fully utilized, resulting in a flame-retardant coolant with good low-temperature fluidity, good flame-retardant properties, and good insulation properties.
[0029] This system boasts advantages such as low cost, high flame retardancy, low viscosity, and good heat dissipation. Mineral oil, as the primary liquid carrier, provides a fundamental guarantee for insulation performance. Flame retardants prevent the coolant from being damaged when exposed to high temperatures or ignition sources, thus maintaining insulation performance. Low-temperature modifiers can directly synergize with mineral oil and flame retardants to improve coolant performance. Specifically, this application uses small-molecule phenylalkanes and small-molecule cyclohexanes as low-temperature modifiers. On one hand, small-molecule phenylalkanes and cyclohexanes contain a high proportion of rigid structures (benzene rings, six-membered rings), increasing their steric hindrance and making them less prone to crystallization. The large steric hindrance of these rigid small molecules dispersed throughout the coolant mixture disrupts molecular crystallization, hindering the formation and growth of crystal nuclei, thereby significantly reducing the system's pour point. Furthermore, small-molecule cyclohexanes have low viscosity and good fluidity, effectively filling the complex molecular gaps created by phenylalkanes and tetrachloroethylene, reducing the overall viscosity of the system, enhancing intermolecular fluidity, and making it more difficult for molecules to be fixed in lattice positions at low temperatures. Phenylalkanes are responsible for strongly disrupting the long-range order of the crystal lattice, while small cyclohexane molecules promptly fill and lubricate the disrupted micro-regions, preventing them from reforming into an ordered structure and ensuring the uniform dispersion of phenylalkane molecules, thus inhibiting phenylalkane self-aggregation. Phenylalkanes and cyclohexanes synergistically construct a highly disordered, dynamic, and stable liquid environment at the molecular scale, thereby significantly reducing the system's freezing point.
[0030] Benzene rings possess rigidity, which can disrupt crystal nucleation and lower the freezing point. Simultaneously, their π-bonded electron conjugated system exerts a strong force on chlorinated hydrocarbons, causing aggregation and resulting in a non-uniform system. Therefore, at low temperatures, partial crystallization and partial non-crystallization may occur. In contrast, small-molecule six-membered rings exhibit low viscosity, low-temperature dispersion characteristics, and a stronger intermolecular affinity for the benzene ring, thus improving its dispersion and preventing aggregation. However, six-membered rings lack the strong anti-penetration properties, immobilization of chlorinated hydrocarbons, and strong lattice disruption capabilities of benzene rings. Therefore, both must be used simultaneously.
[0031] As an example, phenylalkanes include C1-C5 alkyl-substituted benzenes, such as methyl-substituted benzenes, ethyl-substituted benzenes, propyl-substituted benzenes, butyl-substituted benzenes, or pentyl-substituted benzenes, etc.
[0032] The benzene ring possesses a delocalized π-electron conjugated system, which has good stability. It requires high energy to excite or ionize its electrons, which is equivalent to introducing an electronically stabilizing group into the system. This increases the dielectric strength of the entire system, making it more difficult to be broken down by an electric field, which is beneficial to improving the breakdown voltage of the coolant.
[0033] As an example, cyclohexanes include C1-C5 alkyl-substituted cyclohexanes, such as methyl-substituted cyclohexane, ethyl-substituted cyclohexane, propyl-substituted cyclohexane, butyl-substituted cyclohexane, or pentyl-substituted cyclohexane, etc.
[0034] As an example, flame retardants include chlorinated C2-C6 unsaturated hydrocarbons, such as chlorinated C2 unsaturated hydrocarbons, chlorinated C3 unsaturated hydrocarbons, chlorinated C4 unsaturated hydrocarbons, chlorinated C5 unsaturated hydrocarbons, or chlorinated C6 unsaturated hydrocarbons, etc.
[0035] The chlorine atoms in the tetrachloroethylene molecule have high electronegativity, and the stable π electron cloud of the benzene ring can strongly attract and bind them, greatly reducing the probability of generating free electrons or being ionized. At the same time, the small molecule cyclohexane makes the system uniformly dispersed and less prone to self-aggregation, which significantly increases the energy barrier for charge migration, resulting in extremely high volume resistivity and breakdown voltage. This significantly improves the insulation performance of the coolant and has good application prospects.
[0036] In some embodiments, the mass ratio of phenylalkanes to cyclohexanes is (1-5):1, for example, 1:1, 2:1, 3:1, 4:1, or 5:1. In other embodiments, the mass ratio of phenylalkanes to cyclohexanes is (1-2):1. Optimizing the mass ratio of phenylalkanes to cyclohexanes is beneficial for further reducing the pour point of the coolant and improving its insulation performance. When the amount of phenylalkanes and cyclohexanes added is moderate, the proportion of benzene rings and six-membered rings in the coolant system is more suitable, and the two are more likely to combine, making the system more homogeneous and stable, and significantly improving the flowability and insulation performance.
[0037] In some embodiments, the flame-retardant coolant comprises: 5-50 parts by weight of mineral oil, 40-85 parts by weight of flame retardant, 5-20 parts by weight of phenylalanine, and 5-20 parts by weight of cyclohexane. This improves the coolant's low-temperature fluidity and insulation properties.
[0038] As an example, mineral oil can be in quantities of 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, or 50 parts by weight.
[0039] As an example, the flame retardant can be 40 parts by weight, 50 parts by weight, 60 parts by weight, 70 parts by weight, 80 parts by weight, or 85 parts by weight, etc.
[0040] As an example, phenylalkanes can be in quantities of 5 parts by mass, 10 parts by mass, 15 parts by mass, or 20 parts by mass, etc.
[0041] As an example, cyclohexane can be in quantities of 5 parts by mass, 10 parts by mass, 15 parts by mass, or 20 parts by mass, etc.
[0042] In some embodiments, the phenylalkane includes at least one selected from toluene, ethylbenzene, propylbenzene, butylbenzene, and pentylbenzene. The longer the alkyl chain and the larger the molecular weight, the worse the fluidity, causing it to slowly change from liquid to solid. Therefore, the aforementioned low molecular weight phenylalkane is preferable.
[0043] In some embodiments, the cyclohexane includes at least one selected from methylcyclohexane, ethylcyclohexane, propylcyclohexane, butylcyclohexane, and pentylcyclohexane. The longer the alkyl chain and the larger the molecular weight, the worse the fluidity, causing it to slowly change from liquid to solid. Therefore, the aforementioned low molecular weight cyclohexanes are preferable.
[0044] In some embodiments, the mineral oil includes at least one of No. 10 mineral transformer oil, No. 25 mineral transformer oil, and No. 45 mineral transformer oil. The selection of these mineral oils offers several advantages. First, they act as a stable medium, preventing the separation of other components in the coolant (such as flame retardants and low-temperature modifiers), and ensuring that these components are uniformly dissolved in the coolant system, guaranteeing consistent coolant performance. Second, these mineral oils possess a high specific heat capacity, enabling them to absorb a large amount of heat while experiencing relatively little temperature rise. Furthermore, these mineral oils are low in cost and easily suitable for industrial-scale production.
[0045] In a second aspect, this application proposes a method for preparing the aforementioned flame-retardant coolant, comprising: mixing mineral oil, a flame retardant, and a low-temperature modifier to obtain the flame-retardant coolant; wherein the flame retardant comprises tetrachloroethylene; the low-temperature modifier is a liquid, and the low-temperature modifier comprises phenylalkanes and cyclohexanes; the phenylalkanes comprise C1-C5 alkyl-substituted benzenes, and the cyclohexanes comprise C1-C5 alkyl-substituted cyclohexanes. Therefore, the method provided by this application is simple, and the resulting coolant not only has the advantages of low cost, high flame retardancy, low viscosity, and good heat dissipation, but also significantly improves low-temperature performance and insulation performance, making it suitable for extremely cold regions and high-insulation scenarios.
[0046] In some embodiments, the mixing temperature is 40°C-60°C, for example, 40°C, 45°C, 50°C, 55°C, or 60°C. By limiting the mixing temperature within the above range, it is beneficial to ensure that the components in the flame-retardant coolant are mixed uniformly to form a homogeneous system, thus avoiding the deterioration of coolant performance caused by uneven mixing.
[0047] In some embodiments, the mixing speed is 600 r / min to 1000 r / min, for example, 600 r / min, 700 r / min, 800 r / min, 900 r / min, or 1000 r / min. By limiting the mixing speed within the above range, sufficient momentum can be provided for the mixing of mineral oil, flame retardant, and low-temperature modifier, enabling the components to come into rapid contact with each other.
[0048] In some embodiments, the mixing time is 5h-12h, for example, 5h, 6h, 7h, 8h, 9h, 10h, 11h, or 12h. By limiting the mixing time to the above range, it can be ensured that the mineral oil, flame retardant, and low-temperature modifier are fully mixed, and each component has sufficient time to diffuse throughout the mixture, which can promote the uniform dissolution of the low-temperature modifier into the mineral oil.
[0049] By controlling the above mixing conditions, mineral oil, flame retardant, and low-temperature modifier can be fully mixed, and benzene rings and six-membered rings can be evenly distributed in the coolant, reducing the pour point of the system and thus better leveraging the role of the low-temperature modifier in improving fluidity and insulation performance.
[0050] It should be noted that there are no special limitations on the mixing method; other commonly used methods can also be used in this application. As an example, the mixing method can be stirring.
[0051] In a third aspect, this application proposes a submersible energy storage device, comprising the flame-retardant coolant described in the first aspect of this application or a flame-retardant coolant prepared using the method described in the second aspect of this application. Because it employs the aforementioned flame-retardant coolant, the submersible energy storage device of this application possesses all the advantages of the flame-retardant coolant, which will not be elaborated further here.
[0052] In some embodiments, the submersible energy storage device includes a housing, an energy storage structure disposed within the housing, and a flame-retardant coolant filled within the housing.
[0053] In a fourth aspect, this application proposes a data center comprising the flame-retardant coolant described in the first aspect of this application or a flame-retardant coolant prepared using the method described in the second aspect of this application. Because it employs the aforementioned flame-retardant coolant, the data center of this application possesses all the advantages of the flame-retardant coolant, which will not be elaborated further here.
[0054] In some embodiments, the data center is a physical facility designed for centralized storage, processing, and exchange of data, including servers, storage devices, network equipment, and supporting systems (such as power supply systems, cooling systems, etc.), and is a core infrastructure for cloud computing and internet services. The cooling system may include the aforementioned flame-retardant coolant for server heat dissipation.
[0055] In a fifth aspect, this application proposes an electrical appliance including the data center described in the fourth aspect. Because it employs the aforementioned flame-retardant coolant, the electrical appliance of this application possesses all the advantages of the flame-retardant coolant, which will not be elaborated further here.
[0056] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.
[0057] The following specific embodiments illustrate the solution of this application. It should be noted that these embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.
[0058] Example 1 Preparation of coolant: Weigh 50 parts by weight of No. 25 mineral transformer oil, 40 parts by weight of tetrachloroethylene, 5 parts by weight of ethylbenzene and 5 parts by weight of methylcyclohexane, mix them, and stir at 45℃ and 800r / min for 6 hours to obtain coolant.
[0059] Example 2 Preparation of coolant: Weigh 5 parts by mass of No. 25 mineral transformer oil, 85 parts by mass of tetrachloroethylene, 5 parts by mass of ethylbenzene, and 5 parts by mass of methylcyclohexane, mix them, and stir at 55℃ and 800r / min for 6 hours to obtain coolant.
[0060] Example 3 Preparation of coolant: Weigh 30 parts by weight of No. 25 mineral transformer oil, 60 parts by weight of tetrachloroethylene, 5 parts by weight of ethylbenzene and 5 parts by weight of methylcyclohexane, mix them, and stir at 45℃ and 800r / min for 6 hours to obtain coolant.
[0061] Example 4 Preparation of coolant: Weigh 30 parts by mass of No. 25 mineral transformer oil, 40 parts by mass of tetrachloroethylene, 10 parts by mass of ethylbenzene and 10 parts by mass of methylcyclohexane, mix them, and stir at 45℃ and 800r / min for 6 hours to obtain coolant.
[0062] Example 5 Preparation of coolant: Weigh 10 parts by mass of No. 25 mineral transformer oil, 40 parts by mass of tetrachloroethylene, 20 parts by mass of ethylbenzene, and 20 parts by mass of methylcyclohexane, mix them, and stir at 45℃ and 800r / min for 6 hours to obtain coolant.
[0063] Example 6 Preparation of coolant: Weigh 50 parts by weight of No. 25 mineral transformer oil, 40 parts by weight of tetrachloroethylene, 3 parts by weight of ethylbenzene and 3 parts by weight of methylcyclohexane, mix them, and stir at 45℃ and 800r / min for 6 hours to obtain coolant.
[0064] Example 7 Preparation of coolant: Weigh 10 parts by mass of No. 25 mineral transformer oil, 40 parts by mass of tetrachloroethylene, 25 parts by mass of ethylbenzene, and 25 parts by mass of methylcyclohexane, mix them, and stir at 45℃ and 800r / min for 6 hours to obtain coolant.
[0065] Example 8 Preparation of coolant: Weigh 50 parts by weight of No. 25 mineral transformer oil, 40 parts by weight of tetrachloroethylene, 25 parts by weight of ethylbenzene and 5 parts by weight of methylcyclohexane, mix them, and stir at 45℃ and 800r / min for 6 hours to obtain coolant.
[0066] Example 9 Preparation of coolant: Weigh 50 parts by weight of No. 25 mineral transformer oil, 40 parts by weight of tetrachloroethylene, 10 parts by weight of ethylbenzene and 5 parts by weight of methylcyclohexane, mix them, and stir at 45℃ and 800r / min for 6 hours to obtain coolant.
[0067] Example 10 Preparation of coolant: Weigh 50 parts by weight of No. 25 mineral transformer oil, 40 parts by weight of tetrachloroethylene, 5 parts by weight of ethylbenzene and 10 parts by weight of methylcyclohexane, mix them, and stir at 45℃ and 800r / min for 6 hours to obtain coolant.
[0068] Comparative Example 1 Preparation of coolant: Weigh 50 parts by weight of No. 25 mineral transformer oil, 40 parts by weight of tetrachloroethylene, and 10 parts by weight of ethylbenzene, and mix them at 45℃ and 800r / min for 6 hours to obtain coolant.
[0069] Comparative Example 2 Preparation of coolant: Weigh 50 parts by weight of No. 25 mineral transformer oil, 40 parts by weight of tetrachloroethylene, and 10 parts by weight of methylcyclohexane, and mix them at 45℃ and 800r / min for 6 hours to obtain coolant.
[0070] Comparative Example 3 Preparation of coolant: Weigh 50 parts by weight of No. 25 mineral transformer oil, 40 parts by weight of tetrachloroethylene, and 10 parts by weight of polymethyl methacrylate type pour point depressant (commercial petroleum pour point depressant), and mix them at 45℃ and 800r / min for 6 hours to obtain coolant.
[0071] Comparative Example 4 Preparation of coolant: Weigh 50 parts by weight of No. 25 mineral transformer oil, 40 parts by weight of tetrachloroethane, 5 parts by weight of ethylbenzene, and 5 parts by weight of methylcyclohexane, mix them, and stir at 45℃ and 800r / min for 6 hours to obtain coolant.
[0072] Comparative Example 5 Preparation of coolant: Weigh 50 parts by weight of No. 25 mineral transformer oil and 40 parts by weight of tetrachloroethylene, and mix them at 45℃ and 800r / min for 6 hours to obtain coolant.
[0073] Table 1 below lists the relevant parameters of the above embodiments and comparative examples.
[0074] Table 1
[0075] The insulation and safety performance of the coolants obtained in the above embodiments and comparative examples were tested, and the results are shown in Table 2.
[0076] Physicochemical performance testing: The freezing point, breakdown voltage, and insulation resistance of the examples and comparative samples were tested according to the test methods in GB / T 510, GB / T 507, and GB / T 5654. Safety performance test: Five 100% SOC battery cells (rated capacity 45Ah, operating voltage range 2.5V-4.2V) were placed in a cell holder in series to simulate a five-cell series module. The middle cell was overcharged, and the module was externally fixed with a clamp. The module was immersed in coolant. After setting, it was continuously charged at 1C until overcharging triggered thermal runaway. Charging was then stopped, and the coolant was observed to see if any combustion or explosion occurred.
[0077] Table 2
[0078] As can be seen from Table 2, compared with the coolants of Comparative Examples 1-5, the coolants of Examples 1-10 have lower pour points and better insulation and flame retardant properties.
[0079] In Example 10, the coolant contained phenylalkanes and cyclohexanes in a mass ratio of 1:2. The system contained a large number of six-membered rings, which resulted in a small decrease in the stability of the coolant system, thus leading to a slight decrease in low-temperature performance and insulation properties.
[0080] In Comparative Example 1, the low-temperature modifier used was only ethylbenzene. The benzene ring has rigidity and can destroy crystal nucleus growth while lowering the freezing point. At the same time, the π-bonded electron conjugated system has a strong force on chlorinated hydrocarbons. Such a strong force will cause them to aggregate, resulting in an inhomogeneous system. Therefore, at low temperatures, some parts will crystallize and some will not crystallize.
[0081] The low-temperature modifier in Comparative Example 2 uses only methylcyclohexane, which results in an excessive number of six-membered rings. The increase in free small molecules leads to a decrease in the insulation performance of the system.
[0082] Adding a polymethacrylate-type pour point depressant to the coolant in Comparative Example 3 resulted in poor flowability improvement, leading to poor insulation performance of the coolant.
[0083] The flame retardant in the coolant of Comparative Example 4 is tetrachloroethane, which has a poor synergistic effect with the low-temperature modifier of this application, resulting in a poor flame retardant effect of the coolant.
[0084] The coolant in Comparative Example 5 did not contain a low-temperature modifier, resulting in a higher freezing point and poorer insulation performance.
[0085] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.
Claims
1. A flame-retardant coolant, characterized in that, include: Mineral oil, flame retardant, low-temperature modifier; The flame retardant includes tetrachloroethylene; The low-temperature modifier is a liquid, and the low-temperature modifier includes phenylalkanes and cyclohexanes; The phenylalkanes include C1-C5 alkyl-substituted benzenes, and the cyclohexanes include C1-C5 alkyl-substituted cyclohexanes.
2. The flame-retardant coolant according to claim 1, characterized in that, The mass ratio of the phenylalkane to the cyclohexane is (1-5):1; optionally, (1-2):
1.
3. The flame-retardant coolant according to claim 1, characterized in that, include: 5-50 parts by weight of mineral oil, 40-85 parts by weight of flame retardant, 5-20 parts by weight of phenylalkanes and 5-20 parts by weight of cyclohexanes.
4. The flame-retardant coolant according to claim 1 or 2, characterized in that, The phenylalkane includes at least one selected from toluene, ethylbenzene, propylbenzene, butylbenzene, and pentylbenzene; and / or, The cyclohexane hydrocarbons include at least one of methylcyclohexane, ethylcyclohexane, propylcyclohexane, butylcyclohexane, and pentylcyclohexane.
5. The flame-retardant coolant according to claim 1 or 2, characterized in that, The mineral oil includes at least one of No. 10 mineral transformer oil, No. 25 mineral transformer oil, and No. 45 mineral transformer oil.
6. A method for preparing the flame-retardant coolant according to any one of claims 1-5, characterized in that, include: Mineral oil, flame retardant, and low-temperature modifier are mixed to obtain the flame-retardant coolant; The flame retardant includes tetrachloroethylene; the low-temperature modifier is a liquid and includes phenylalkanes and cyclohexanes; the phenylalkanes include C1-C5 alkyl-substituted benzenes, and the cyclohexanes include C1-C5 alkyl-substituted cyclohexanes.
7. The method according to claim 6, characterized in that, The mixing temperature is 40℃-60℃; and / or, The mixing rate is 600 r / min - 1000 r / min; and / or, The mixing time is 5h-12h.
8. A submersible energy storage device, characterized in that, The flame-retardant coolant includes any one of claims 1-5 or a flame-retardant coolant obtained by the method described in any one of claims 6-7.
9. A data center, characterized in that, The flame-retardant coolant includes any one of claims 1-5 or a flame-retardant coolant obtained by the method described in any one of claims 6-7.
10. An electrical appliance, characterized in that, This includes the immersion energy storage device as described in claim 8 or the data center as described in claim 9.