Cooling liquid, preparation method of cooling liquid and liquid cooling system

Abstract

The invention provides a cooling liquid, a preparation method of the cooling liquid and a liquid cooling system, and relates to the technical field of heat dissipation systems. The cooling liquid provided by the invention comprises synthetic oil and a multi-branched auxiliary agent, the flash point of the synthetic oil is greater than 180 DEG C, and a molecular chain of the multi-branched auxiliary agent comprises at least two fluorocarbon branched chains (C-F). According to the cooling liquid provided by the invention, the high-flash-point synthetic oil is used as a main matrix component, so that the flash burning risk and the use cost in the use process of the cooling liquid are greatly reduced; a fluorocarbon branched chain in the multi-branched auxiliary agent has hydrophobic and oleophobic properties, so that the multi-branched auxiliary agent is insoluble in the synthetic oil, and F atoms have larger steric hindrance, so that the distance between synthetic oil molecules is increased, the intermolecular acting force is reduced, the viscosity of the synthetic oil is reduced, the flowability of the cooling liquid is improved, and the cooling liquid has higher heat dissipation efficiency. Therefore, the cooling liquid provided by the invention has the characteristics of low viscosity, strong heat conduction capability and high flash point.

Description

Technical Field

[0001] This application belongs to the technical field of heat dissipation systems, and particularly relates to a coolant, a method for preparing the coolant, and a liquid cooling system. Background Technology

[0002] In recent years, with the rapid development of technology and the digital economy, high-density, high-computing-power, and high-energy-consumption data centers have experienced explosive growth. The massive data throughput and computation have presented unprecedented challenges to data centers in terms of energy consumption and thermal management systems. Against this backdrop, liquid-cooled data centers, utilizing new liquid cooling technologies and equipment such as liquid-cooled servers, have emerged. Compared to air cooling, liquid cooling can deploy more high-density storage in limited space, better support the heat dissipation of high-power chips, ensure low-temperature chip operation, ensure safety and quiet operation, effectively reduce the PUE (Power Usage Effectiveness) value of data centers, facilitate IT expansion, and significantly reduce operation and maintenance costs by eliminating the need for high-cost components (such as centrifuges, chilled pumps, scroll compressors, and precision air conditioners).

[0003] The core of liquid cooling technology lies in the selection of heat exchange medium and the design and application of thermal management system. Its core refrigeration element is to immerse the entire server or its components in the coolant while it is in a charged state. Therefore, the coolant that serves as the heat exchange medium must have the characteristics of low viscosity, strong thermal conductivity, and high flash point.

[0004] Most coolants currently on the market cannot simultaneously achieve the above characteristics, and even if they do, their high cost limits their application. Summary of the Invention

[0005] The purpose of this application is to provide a coolant, a method for preparing the coolant, and a liquid cooling system, which aims to solve the problem that existing coolants cannot simultaneously achieve low viscosity, strong thermal conductivity, and high flash point.

[0006] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0007] In a first aspect, this application provides a coolant comprising a synthetic oil and a multibranching agent, wherein the synthetic oil has a flash point greater than 180°C and the multibranching agent comprises at least two fluorocarbon (CF) branches in its molecular chain.

[0008] According to some embodiments of the coolant described in this application, the coolant comprises, by weight, 90-99 parts of synthetic oil and 1-10 parts of multi-branching auxiliaries.

[0009] According to some embodiments of the coolant described in this application, the chemical formula of the multi-branching aid is: R-(CH2O-C x F 2x )n In the formula, n is a positive integer greater than or equal to 2; x is a positive integer greater than or equal to 2; and R is an organic group composed of C, H, and O.

[0010] According to some embodiments of the coolant described in this application, the synthetic oil is selected from one or more combinations of polyalphaolefin synthetic oil, natural gas synthetic oil, coal-derived synthetic oil, and ester synthetic oil;

[0011] And / or, the branching aid is selected from one or more combinations of di-terminated fluorinated compounds, tri-terminated fluorinated compounds, and tetra-terminated fluorinated compounds.

[0012] According to some embodiments of the coolant described in this application, the coolant further includes an antioxidant;

[0013] And / or, the coolant may also include a metal deactivator.

[0014] According to some embodiments of the coolant described in this application, when the coolant includes an antioxidant, the antioxidant is 0.5 to 3 parts by weight.

[0015] And / or, the antioxidant includes one or more combinations of phenolic antioxidants or amine antioxidants;

[0016] And / or, when the coolant includes a metal deactivator, the metal deactivator is present in an amount of 0.03 to 0.3 parts by weight;

[0017] And / or, the metal deactivator includes one or more combinations of benzotriazole and its derivatives.

[0018] Secondly, a method for preparing a coolant is provided, comprising the following steps:

[0019] Obtain a multibranching aid; the molecular chain of the multibranching aid includes at least two fluorocarbon branches (CF);

[0020] Obtain synthetic oil; the flash point of the synthetic oil is greater than 180°C;

[0021] The raw material components, including synthetic oil and multi-branching additives, are mixed to form a mixture, which is then used to obtain a coolant.

[0022] According to some embodiments of the preparation method described in this application, the steps for obtaining the multibranching aid include:

[0023] Polyols and perfluoroolefins are mixed and reacted to obtain branching aids.

[0024] According to some embodiments of the preparation method described in this application, the polyol includes one or more of the following: diol, triol, tetraol, and pentaol;

[0025] And / or, perfluoroolefins include one or more of the following: perfluoroethylene, perfluoropropylene, perfluorobutene, perfluoropentene, perfluorohexene, hexafluoropropylene dimer, perfluoroheptene, perfluorooctene, hexafluoropropylene trimer, and perfluorodecene.

[0026] According to some embodiments of the preparation method described in this application, before mixing raw material components including synthetic oil and multi-branching auxiliaries to prepare a mixed substance and obtaining a coolant, the method further includes:

[0027] Obtain antioxidants.

[0028] In the step of mixing raw material components, including synthetic oil and multi-branching auxiliaries, to prepare a mixture and obtain a coolant, the raw material components also include antioxidants.

[0029] According to some embodiments of the preparation method described in this application, before mixing raw material components including synthetic oil and multi-branching auxiliaries to prepare a mixed substance and obtaining a coolant, the method further includes:

[0030] Obtain metal deactivating agents.

[0031] In the step of mixing raw material components, including synthetic oil and multi-branching auxiliaries, to prepare a mixture and obtain a coolant, the raw material components also include a metal deactivator.

[0032] According to some embodiments of the preparation method described in this application, in the step of mixing raw material components including synthetic oil and multi-branching auxiliaries to prepare a mixed substance and obtain a coolant, the mixing process includes a stirring process, and the stirring speed is 50 r / min-100 r / min.

[0033] And / or, the temperature conditions for the mixed treatment are 30℃-50℃.

[0034] Thirdly, a liquid cooling system is provided, including a liquid cooling space, wherein the liquid cooling space is filled with the coolant described in any of the embodiments of the first subject matter.

[0035] Alternatively, the liquid-cooled space may be filled with a coolant prepared using the preparation method described in any of the embodiments of the second subject matter.

[0036] Compared to existing technologies, the beneficial effects of this application are as follows:

[0037] The coolant provided in this application uses high-flash-point synthetic oil as its main matrix component, which greatly reduces the risk of flashover and operating costs during coolant use. The hydrophobic and oleophobic properties of the fluorocarbon branches in the multi-branched additives make it insoluble in synthetic oil, and the greater steric hindrance of the fluorine atoms increases the distance between synthetic oil molecules, reduces intermolecular forces, thereby lowering the viscosity of the synthetic oil and increasing the fluidity of the coolant, resulting in higher heat dissipation efficiency. Therefore, the coolant in this application features low viscosity, high thermal conductivity, and a high flash point. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a flowchart of the first method for preparing coolant provided in the embodiments of this application.

[0040] Figure 2 This is a flowchart of a second method for preparing coolant provided in the embodiments of this application.

[0041] Figure 3 This is a flowchart of the third method for preparing coolant provided in the embodiments of this application. Detailed Implementation

[0042] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0043] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0044] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0045] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0046] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0047] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass described in the embodiments of this application can be a mass unit known in the chemical industry, such as μg, mg, g, or kg.

[0048] The core of liquid cooling technology lies in the selection of the liquid cooling medium and the design and application of the thermal management system. Its core refrigeration element is to immerse the entire server or its components in the coolant while it is in a charged state. Therefore, the coolant that serves as the heat exchange medium must have the characteristics of low viscosity, strong thermal conductivity, and high flash point.

[0049] Viscosity, also known as viscosity, refers to the resistance a fluid (gas or liquid) experiences during flow, i.e., the internal friction of the fluid. Generally, for liquids, the higher the viscosity, the lower the heat exchange efficiency.

[0050] Flash point refers to the lowest temperature at which a liquid vaporizes and ignites under specified test conditions using a certain ignition source. Flash ignition is the phenomenon where, when sufficient vapor is generated on the surface of a liquid and mixes with air to form a flammable gas, it produces a brief flash of light upon encountering an ignition source, resulting in immediate ignition. The lowest temperature at which flash ignition occurs is called the flash point. In this application, "high flash point" refers to a flash point greater than 180°C.

[0051] Currently, the coolants used in immersion liquid cooling on the international market are mainly divided into three categories: fluorinated fluids, silicone oils, and synthetic oils. Fluorinated fluids are prohibitively expensive, severely limiting their large-scale promotion and application. Silicone oils suffer from high viscosity, hydrolysis, and sedimentation, which negatively impact heat transfer, heat dissipation, and signal transmission. Synthetic oils are extremely inexpensive; while low-viscosity synthetic oils offer high heat dissipation efficiency due to their good fluidity, they typically have low flash points, posing a risk of flash fire. High-viscosity synthetic oils have correspondingly higher flash points, but their poor fluidity leads to a rapid decrease in the coolant's heat dissipation efficiency.

[0052] Therefore, none of the above coolants are suitable for widespread use, especially in the field of servers that carry big data.

[0053] In view of this, there is an urgent need to find a coolant that can simultaneously achieve low viscosity, strong thermal conductivity and high flash point to meet the needs of the server industry.

[0054] After researching existing coolants, the inventors discovered that the composition of existing coolants, which are mainly composed of synthetic oil, can be appropriately adjusted to change some of their properties, forming a composition that can meet the above requirements. Using this composition as a coolant can enable the coolant to meet the needs of the server industry.

[0055] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0056] In a first aspect, this application provides a coolant comprising a synthetic oil and a multibranching agent, wherein the synthetic oil has a flash point greater than 180°C and the multibranching agent comprises at least two fluorocarbon (CF) branches in its molecular chain.

[0057] Synthetic oil refers to a fluid prepared through chemical synthesis, where the raw materials undergo chemical reactions to form higher molecular weight compounds. As the base oil for the coolant in this application, the synthetic oil can be selected from one or more of Group III, Group IV, or Group V synthetic oils. Specifically, Group III synthetic oils include coal-derived synthetic oils or natural gas-derived synthetic oils; Group IV synthetic oils include polyalphaolefin synthetic oils; and Group V synthetic oils include synthetic esters, polyethers, alkylbenzenes, alkylnaphthalenes, silicone oils, etc.

[0058] However, regardless of the type of synthetic oil used, it must ultimately meet the characteristic of having a flash point greater than 180°C, thereby providing the coolant in this application with a high flash point characteristic, so that the coolant can meet the industry standard requirements for immersion cooling of servers (the industry standard requires that the flash point of the coolant applied to servers be greater than 160°C).

[0059] For example, in one specific embodiment, a single type of synthetic oil A with a flash point higher than 180°C can be directly selected as the synthetic oil ultimately used in the coolant; in another specific embodiment, a synthetic oil B with a flash point higher than 180°C can be selected, and another synthetic oil C with a flash point lower than 180°C can be selected, and synthetic oil B and synthetic oil C can be mixed and compounded to finally form a mixed type of synthetic oil with a flash point higher than 180°C.

[0060] In some embodiments, considering material costs and process implementation difficulties, the flash point of the synthetic oil is less than or equal to 250°C. This satisfies the high flash point requirement of the coolant, is easy to implement, and reduces material costs.

[0061] In some embodiments, the viscosity of the synthetic oil is less than 20 mm. 2 / s.

[0062] When the viscosity of synthetic oil is less than 20 mm 2 When the viscosity is / s, adding a small amount of multi-branching agent can reduce the viscosity of the coolant to the required range.

[0063] Optionally, in some embodiments of the coolant provided in this application, the synthetic oil may be further selected as one or more combinations of PAO (polyalphaolefin synthetic oil), GTL (natural gas synthetic oil), CTL (coal-derived synthetic oil), and A (ester synthetic oil).

[0064] The above-mentioned categories of synthetic oils have the characteristics of low impurities and good antioxidant properties, which can significantly improve the antioxidant properties and stability of synthetic oils and effectively extend their service life.

[0065] It is evident that the synthetic oil in this application, due to its flash point being higher than 180℃, endows the coolant with a high flash point characteristic, making the coolant less prone to flash fire during use and thus having high safety. However, this type of synthetic oil has high viscosity, resulting in low heat exchange efficiency.

[0066] The addition of branching additives can address the problems of high viscosity and low heat exchange efficiency in synthetic oils. Specifically, the branching additives selected in this application refer to additives whose molecular chains include at least two fluorocarbon (CF) branches. The principle by which these branching additives alter the properties of synthetic oils includes:

[0067] (1) The hydrophobic and oleophobic properties of the fluorocarbon branched chain make the multi-branching aid insoluble in synthetic oil. When the multi-branching aid is mixed with synthetic oil, it can reduce the interaction force between synthetic oil molecules.

[0068] (2) F atoms have large steric hindrance, which further increases the distance between synthetic oil molecules, reduces the intermolecular forces, and thus further reduces the viscosity of synthetic oil and increases its fluidity.

[0069] (3) Compounds containing fluorocarbon branches have low surface tension, which means that fewer bubbles are generated when synthetic oil and multi-branched additives are stirred and mixed during the preparation of coolant. This reduces the degree of decrease in the fluidity of coolant during use and improves the heat dissipation effect of coolant by reducing bubble generation.

[0070] For the reasons mentioned above, coolants containing multiple branching additives and synthetic oils have lower viscosity and higher heat dissipation efficiency.

[0071] The high flash point of synthetic oil gives the coolant in this application the characteristics of low viscosity, high thermal conductivity and high flash point.

[0072] Furthermore, the synthetic oil used as the base oil in the coolant provided in this application has extremely low cost, reducing the overall cost of the coolant. Moreover, this coolant is non-toxic, harmless, non-corrosive, colorless, and transparent, which further enables it to achieve almost zero wear on components immersed in it. It has good compatibility and a wide range of applications, and can be safely and efficiently applied to the thermal management of liquid cooling systems in next-generation high-performance data centers, large-scale models, edge computing, power batteries, and distributed energy storage.

[0073] In some embodiments of the coolant of this application, the general chemical formula of the multibranching aid is: R-(CH2O-C x F 2x ) n In the formula, n is a positive integer greater than or equal to 2; x is a positive integer greater than or equal to 2; and R is an organic group composed of C, H, and O.

[0074] It should be emphasized that although both n and x are positive integers greater than or equal to 2, there is no necessary connection between them. That is, n and x can be the same or different, depending on the specific type of branching agent. This application does not limit this.

[0075] In some embodiments, n can be any positive integer between 2 and 6; x can be any positive integer between 2 and 10.

[0076] In a specific implementation, the branching agent is selected from one or more combinations of di-terminated fluorinated compounds, tri-terminated fluorinated compounds, and tetra-terminated fluorinated compounds.

[0077] All of the above branched additives contain at least two fluorocarbon branches. Therefore, only a small amount needs to be added to reduce the viscosity of synthetic oil and improve heat exchange efficiency.

[0078] For example, the branching aid may be selected from one or more of 3,3-bis(tetrafluoroethoxymethyl)pentane, 2,2-bis(tetrafluoroethoxymethyl)-1-tetrafluoroethoxybutane or 2,2-bis(tetrafluoroethoxymethyl)-1,4-bis(tetrafluoroethoxy)propane.

[0079] The R group can be selected from one or more long-chain alkanes, ethers, esters, and aromatic compounds.

[0080] The R group segments composed of C, H, and O increase the compatibility between the branching aid and the synthetic oil, making the branching aid and the synthetic oil mix more evenly and less prone to precipitation.

[0081] The aforementioned branching aid consists of CHO group segments and CF group segments. The CHO group segments increase the compatibility between the branching aid and synthetic oil, while the CF group segments increase the distance between synthetic oil molecules and reduce their intermolecular forces. Therefore, when the branching aid molecules are uniformly dispersed in the synthetic oil, they can not only be compatible with the synthetic oil and reduce precipitation during coolant use, but also increase the uniformity of coolant composition and enhance heat dissipation. Furthermore, they can reduce the viscosity of the coolant, increase its fluidity, and give the coolant a better heat dissipation effect.

[0082] According to some embodiments of the coolant of this application, the coolant contains 90-99 parts by weight of synthetic oil and 1-10 parts by weight of multi-branching additive.

[0083] In one example, the coolant consists of synthetic oil and a branching agent, wherein the branching agent comprises 2 parts by weight when the synthetic oil comprises 98 parts by weight. In another example, the coolant consists of synthetic oil, a branching agent, and other additives, wherein the branching agent comprises less than 5 parts by weight when the synthetic oil comprises 95 parts by weight; for example, the branching agent may comprise 3 parts by weight and the other additives may comprise 2 parts by weight.

[0084] Understandably, the higher the weight percentage of branching additive, the lower the viscosity of the coolant, the greater its fluidity, and the higher its heat dissipation efficiency. Conversely, the lower the weight percentage of branching additive, the higher the viscosity of the coolant, the lower its fluidity, and the lower its heat dissipation efficiency. However, in general, the heat dissipation efficiency of coolants with branching additives is higher than that of coolants without branching additives.

[0085] In the above embodiments, by controlling the weight of the multi-branching additive to 1-10 parts, the heat dissipation efficiency of the coolant can be effectively improved while ensuring that the coolant is still based on synthetic oil, thus taking into account the coolant's low viscosity, high flash point, high heat dissipation efficiency, and low cost.

[0086] In some embodiments of the coolant in this application, the coolant components include antioxidants in addition to synthetic oil and branching additives.

[0087] Optionally, if the coolant includes an antioxidant, the antioxidant is in the form of 0.5 to 3 parts by weight, and / or the antioxidant includes one or more combinations of phenolic antioxidants or amine antioxidants.

[0088] An appropriate amount of antioxidant can improve the antioxidant properties of synthetic oils and extend the service life of coolants. In some embodiments of the coolant in this application, the coolant also includes metal deactivators.

[0089] Optionally, the metal deactivator is in the form of 0.03 to 0.3 parts by weight, and / or the metal deactivator includes one or more combinations of benzotriazole and its derivatives.

[0090] An appropriate amount of metal deactivators can improve the stability of synthetic oils, enabling the coolant to maintain good uniformity after long-term use and extending its service life.

[0091] In some embodiments of the coolant in this application, the coolant is composed of synthetic oil with a flash point greater than 180°C, multibranching aids, antioxidants, and metal deactivators.

[0092] In this embodiment, the definitions and types of synthetic oil, branching aid, antioxidant, and metal deactivator are the same as in any of the foregoing embodiments, and will not be repeated here.

[0093] In some other embodiments of the coolant of this application, the synthetic oil in the coolant is 90-99 parts by weight, the branching agent is 1-10 parts by weight, the antioxidant is 0.5-3 parts by weight, and the metal deactivator is 0.03-0.3 parts by weight.

[0094] For example, the weight percentage of synthetic oil can be 90 parts, 92 parts, 95 parts, 99 parts, etc. The weight percentage of branching auxiliaries can be 1 part, 3 parts, 6 parts, 7 parts, 10 parts, etc. The weight percentage of antioxidants can be 0.5 parts, 0.9 parts, 1.3 parts, 2.5 parts, 3 parts, etc. The weight percentage of metal deactivators can be 0.03 parts, 0.05 parts, 0.1 parts, 0.3 parts, etc.

[0095] For example, in one specific embodiment, the coolant comprises 92 parts of synthetic oil, 7 parts of branching agent, 0.9 parts of antioxidant and 0.1 parts of metal deactivator.

[0096] When a coolant contains synthetic oil, multi-branching additives, antioxidants, and metal deactivators, the antioxidants and metal deactivators can work synergistically to improve the antioxidant properties and stability of the synthetic oil, thus significantly extending the service life of the coolant.

[0097] Secondly, this application also provides a method for preparing a coolant. Figure 1 A flowchart of the preparation method of the first coolant provided in this application is shown. Please refer to it. Figure 1 The preparation method includes the following steps:

[0098] S100: Obtain a multibranching aid; the molecular chain of the multibranching aid includes at least two fluorocarbon branches (CF).

[0099] S200: Obtain synthetic oil; the flash point of synthetic oil is greater than 180℃.

[0100] S300: Raw material components including synthetic oil and multi-branching additives are mixed and processed to form a mixture, which is then used to obtain a coolant.

[0101] The synthetic oil and multibranching auxiliaries can be obtained either through self-preparation or by commercial purchase.

[0102] For example, according to some embodiments of the preparation method described in this application, the step of obtaining the multibranching aid includes:

[0103] Polyols and perfluoroolefins are mixed and reacted to obtain branching aids.

[0104] The general formula for this reaction is:

[0105] R-(CH2OH) n +n C x F 2x →R-(CH2O-C x F 2x ) n

[0106] The interpretations of n, x, and R in the above general reaction formula are the same as those in the aforementioned topic of coolant, that is, R in the above general reaction formula represents an organic group composed of C, H, and O, n is a positive integer greater than or equal to 2, and x is a positive integer greater than or equal to 2.

[0107] Polyols are a large class of alcohols containing two or more hydroxyl groups in their molecules. In the above general reaction formula, R-(CH2OH) is used. n As the general chemical formula for polyols, this represents the branching aid R-(CH2O-C). x F 2x ) nThe R group is provided by a polyol. The polyol includes one or more of the following: diol, triol, tetraol, and pentaol.

[0108] C x F 2x This is the general chemical formula for perfluoroolefins. In the above-mentioned reaction for generating branching aids, perfluoroolefins include one or more of the following: perfluoroethylene, perfluoropropylene, perfluorobutene, perfluoropentene, perfluorohexene, hexafluoropropylene dimer, perfluoroheptene, perfluorooctene, hexafluoropropylene trimer, and perfluorodecene.

[0109] The branching agent obtained through the above reaction has lower cost, higher purity, and the number of fluorocarbon branches in the branching agent is easier to control.

[0110] Mixing can be achieved by adding the raw material components of the coolant into the same container and mixing them by shaking, stirring, or other methods to obtain a mixed substance.

[0111] In some embodiments, the raw material components of the coolant may consist only of synthetic oil and branching additives.

[0112] In some embodiments, the raw material components of the coolant include synthetic oil, branching agents, and other substances.

[0113] The above process sequence is only an example. In the actual preparation of coolant, those skilled in the art can adjust the process sequence as needed. For example, S100 and S200 can be performed simultaneously or in any order, and other steps can be added. This application does not limit this.

[0114] The coolant prepared by this method uses high-flash-point synthetic oil as its main matrix component, significantly reducing the risk of flashover and operating costs during use. The hydrophobic and oleophobic properties of the fluorocarbon branches in the multi-branched additives make them insoluble in synthetic oils, and the greater steric hindrance of the F atoms increases the distance between synthetic oil molecules, reducing intermolecular forces and thus lowering the viscosity of the synthetic oil. This increases the fluidity of the coolant, resulting in higher heat dissipation efficiency. Therefore, the coolant prepared by the method described in this application exhibits low viscosity, high thermal conductivity, and a high flash point.

[0115] Furthermore, the synthetic oil used as the base oil in the coolant provided in this application has extremely low cost, reducing the overall cost of the coolant. Moreover, this coolant is non-toxic, harmless, non-corrosive, colorless, and transparent, which further enables it to achieve almost zero wear on components immersed in it. It has good compatibility and a wide range of applications, and can be safely and efficiently applied to the thermal management of liquid cooling systems in next-generation high-performance data centers, large-scale models, edge computing, power batteries, and distributed energy storage.

[0116] Figure 2 A flowchart illustrating the preparation method of the second coolant provided in this application is shown. Please refer to it. Figure 2 According to some embodiments of the preparation method described in this application, before mixing raw material components including synthetic oil and multi-branching auxiliaries to form a mixed substance and obtaining a coolant, the preparation method further includes:

[0117] S1100: Obtain antioxidants.

[0118] In the step of mixing raw material components, including synthetic oil and multi-branching auxiliaries, to form a mixture and obtain a coolant, the raw material components also include antioxidants.

[0119] Figure 3 A flowchart of the preparation method of the third coolant provided in this application is shown. Please refer to it. Figure 3 According to some embodiments of the preparation method described in this application, before mixing the raw material components including synthetic oil and multi-branching auxiliaries to form a mixed substance and obtaining the coolant, the above preparation method further includes:

[0120] S1200: Obtain metal deactivators.

[0121] In the step of mixing raw material components, including synthetic oil and multi-branching auxiliaries, to prepare a mixture and obtain a coolant, the raw material components also include a metal deactivator.

[0122] The possible weight proportions and types of substances of antioxidants and metal deactivators are the same as those explained in the subject of coolant, and will not be repeated here in this embodiment of the application.

[0123] In the above embodiments, antioxidants and metal deactivators can be added simultaneously, or only one of them can be added as needed. Antioxidants can improve the oxidation resistance of the coolant, while metal deactivators can improve the stability of the coolant. Both can extend the service life of the coolant from different aspects.

[0124] According to some embodiments of the preparation method of this application, in the step of mixing raw material components including synthetic oil and multi-branching auxiliaries to prepare a mixed substance and obtain a coolant, the mixing treatment includes stirring treatment, the stirring speed condition is 50 r / min-100 r / min, and / or, the mixing temperature condition is 30℃-50℃.

[0125] In S300, the purpose of stirring is to ensure that the raw material components are mixed evenly. The criterion for judging even mixing is that the mixed substance is visually homogeneous and clear.

[0126] In the above preparation method, the stirring can be done manually or automatically, and the stirring time and conditions can be determined according to the type and amount of materials in the mixing container, as long as the desired stirring effect can be achieved.

[0127] When the stirring speed is too slow, the dissolution and mixing of some substances in the mixture are slow, resulting in a longer stirring time and reduced preparation efficiency of the coolant. When the stirring speed is too fast, the mixture may splash and generate a large number of bubbles. Therefore, limiting the stirring speed to 50 r / min-100 r / min can accelerate the dissolution and mixing rate of each raw material component while reducing bubbles in the final coolant, resulting in a better preparation rate and effect.

[0128] When the stirring temperature is too low, the dissolution rate of the mixture slows down, the fluidity decreases, and it takes a longer time to mix evenly. When the stirring temperature is too high, some substances in the mixing container may denature, and the energy consumption of the stirring process also increases. Therefore, limiting the stirring temperature to 30-50℃ can accelerate the dissolution and mixing rate of each raw material component while maintaining the basic properties of each substance and reducing the energy consumption of the stirring process.

[0129] In this embodiment, the stirring speed can be controlled only to be 50 r / min-100 r / min, the stirring temperature can be controlled only to be 30℃-50℃, or both the stirring speed and the stirring temperature can be controlled simultaneously to satisfy the corresponding range.

[0130] Understandably, depending on the stirring conditions, after S300, the coolant can be defoamed or cooled. For example, the coolant can be left to stand for a period of time to achieve defoaming and cooling. Finally, the coolant can be filled or directly injected into products that need to be cooled.

[0131] Thirdly, this application provides a liquid cooling system, including a liquid cooling space filled with the coolant described in any embodiment of the first subject matter; or, the liquid cooling space filled with a coolant prepared using the preparation method described in any embodiment of the second subject matter.

[0132] Depending on the product being used, this liquid cooling space can be the internal space of a server chassis, the internal space of a battery casing, etc.

[0133] Since the liquid cooling system provided in this application uses the coolant described in any of the embodiments of the first subject matter, which has the characteristics of low viscosity, high thermal conductivity and high flash point, the liquid cooling system has faster cooling efficiency, reduced risk of flashover and higher safety during use.

[0134] The following description is based on specific embodiments.

[0135] Examples 1-6

[0136] Different types of PAO (polyalphaolefin synthetic oil), GTL (natural gas synthetic oil), CTL (coal-derived synthetic oil), and (A) ester synthetic oil were selected and blended in different proportions to form synthetic oils with a flash point >180℃. The performance parameters of the synthetic oils in Examples 1-6 are shown in Table 1 below:

[0137] Table 1

[0138]

[0139] In Table 1, the oxygen bomb test is an experimental method used to evaluate the antioxidant capacity of samples. The values ​​in the oxygen bomb test row represent the time that the synthetic oil in the corresponding column can resist oxidation reactions; generally, the longer the time, the better the antioxidant performance of the substance.

[0140] The viscosity, flash point, and oxygen bomb test values ​​in Table 1 can be understood as the viscosity characteristics, flash point values, and antioxidant capacity of the synthetic oils with different components in Examples 1-6 without the addition of additives.

[0141] Examples 7-10

[0142] Based on the synthetic oil in Example 6, different weight parts of antioxidants and metal deactivators were added to obtain the compositions in Examples 7-10, the performance parameters of which are shown in Table 2 below:

[0143] Table 2

[0144] Example 6 Example 7 Example 8 Example 9 Example 10 antioxidants / 0.5 copies 1 copy 2 copies 3 copies Metal deactivating agents / 0.03 copies 0.08 copies 0.1 copies 0.1 copies <![CDATA[Viscosity / mm 2 / s]]> 9.80 9.80 9.82 9.82 9.85 Oxygen bomb method / min ＜200 ＞500 ＞800 ＞1200 ＞1500 Dielectric constant 2.005 2.011 2.022 2.032 2.045

[0145] The dielectric constant is the ratio of the capacitance between two metal plates with the sample as the medium to the capacitance between the same two plates with air or a vacuum as the medium. It measures the energy storage performance of the sample. The dielectric constant represents the polarization of the sample (i.e., its ability to bind charges). The larger the dielectric constant, the stronger the ability to bind charges and the greater the obstruction to electrical signals.

[0146] A comparison of Examples 7-10 with Example 6 in Table 2 shows that the viscosity and dielectric constant of the compositions formed after adding antioxidants and metal deactivators to the synthetic oil are not significantly different compared to those without antioxidants and metal deactivators. This indicates that the addition of antioxidants and metal deactivators has almost no effect on the viscosity and dielectric constant of the compositions. Furthermore, the dielectric constant in all examples remains below 2.1, meeting the requirements for use of coolants in data centers.

[0147] Furthermore, a comparison of Examples 7-10 and Example 6 in Table 2 shows that after adding antioxidants and metal deactivators to the synthetic oil, the resulting composition exhibits a significant increase in the values ​​measured by the bomb oxidation method compared to the composition without antioxidants and metal deactivators, increasing from less than 200 minutes to at least 500 minutes. Moreover, the values ​​measured by the bomb oxidation method further increase with the increase in the mass fraction of antioxidants and metal deactivators.

[0148] As can be seen from the performance parameters of the compositions in Examples 6-10 above, the compositions formed after adding antioxidants and metal deactivators to synthetic oils have high stability, high flash point (a characteristic of the selected synthetic oils themselves), and no effect on electronic signal transmission.

[0149] Examples 11-17

[0150] Based on Example 10, different types and weight proportions of branching auxiliaries were added to obtain the compositions in Examples 11-17, the performance parameters of which are shown in Table 3 below:

[0151] Table 3

[0152] A comparison of Examples 11-17 and Example 10 in Table 3 shows that the addition of different types and mass fractions of branching agents to the compositions can lead to varying degrees of viscosity reduction. Furthermore, the compositions of Examples 11-17, after the addition of branching agents, remained colorless and transparent with no residual bubbles even after high-speed vigorous stirring, indicating that the added branching agents have an antifoaming effect.

[0153] Furthermore, a comparison of Examples 11-13 shows that, for the same branching agent, the viscosity of the composition is 9.01 when 1 part is added, 7.84 when 5 parts are added, and 6.86 when 10 parts are added. It is evident that when the same branching agent is added, the more parts by weight are added, the more significant the decrease in viscosity of the composition.

[0154] The comparison of Examples 14-16 shows that, with a fixed number of branching additives, the more carbon-fluorine branches the branching additive has, the lower the viscosity of the coolant. In other words, the more carbon-fluorine branches the branching additive has, the more significant the effect on reducing the viscosity of the coolant. To achieve the same viscosity, the number of weight parts of branching additives needed can be reduced.

[0155] In summary, the coolant provided in this application embodiment has the characteristics of low viscosity, high flash point, and high heat dissipation efficiency.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application, and all such modifications or substitutions should be covered within the scope of the claims of this application.

Claims

1. A coolant, characterized in that, It includes synthetic oil and multibranching aid, wherein the synthetic oil has a flash point greater than 180°C and the multibranching aid has at least two fluorocarbon (CF) branches in its molecular chain.

2. The coolant according to claim 1, characterized in that, The coolant, by weight, comprises 90-99 parts of synthetic oil and 1-10 parts of multi-branching auxiliaries.

3. The coolant according to claim 1, characterized in that, The general chemical formula of the multi-branching auxiliary is: R-(CH2O-C x F 2x ) n In the formula, n is a positive integer greater than or equal to 2; x is a positive integer greater than or equal to 2; and R is an organic group composed of C, H, and O.

4. The coolant according to claim 1, characterized in that, The synthetic oil is selected from one or more combinations of polyalphaolefin synthetic oil, natural gas synthetic oil, coal-derived synthetic oil, and ester synthetic oil; And / or, the branching aid is selected from one or more combinations of di-terminated fluorinated compounds, tri-terminated fluorinated compounds, and tetra-terminated fluorinated compounds.

5. The coolant according to any one of claims 1-4, characterized in that, The coolant also includes antioxidants; And / or, the coolant may also include a metal deactivator.

6. The coolant according to claim 5, characterized in that, When the coolant includes an antioxidant, the antioxidant is present in a weight ratio of 0.5 to 3 parts. And / or, the antioxidant includes one or more combinations of phenolic antioxidants or amine antioxidants; And / or, when the coolant includes a metal deactivator, the metal deactivator is present in a weight fraction of 0.03 to 0.3 parts; And / or, the metal deactivator includes one or more combinations of benzotriazole and its derivatives.

7. A method for preparing a coolant, characterized in that, Includes the following steps: Obtain a multibranching aid; the molecular chain of the multibranching aid includes at least two fluorocarbon branches (CF); Obtain synthetic oil; the flash point of the synthetic oil is greater than 180°C; The raw material components, including the synthetic oil and the multi-branching auxiliaries, are mixed to form a mixture, which yields a coolant.

8. The preparation method according to claim 7, characterized in that, The acquisition of the multi-branching auxiliary agent includes the following steps: A multibranching auxiliary agent is obtained by mixing polyols and perfluoroolefins and reacting them. And / or, the raw material components further include at least one of an oxygenating agent and a metal deactivating agent; And / or, the mixing process includes a stirring process, wherein the stirring speed is 50 r / min-100 r / min; And / or, the temperature conditions for the mixing process are 30℃-50℃.

9. The preparation method according to claim 7, characterized in that, The acquisition of the multibranching aid includes: mixing a polyol and a perfluoroolefin and reacting to obtain the multibranching aid, wherein the polyol includes one or more of diols, triols, tetraols, and pentaols; And / or, the perfluoroolefins include one or more of the following: perfluoroethylene, perfluoropropylene, perfluorobutene, perfluoropentene, perfluorohexene, hexafluoropropylene dimer, perfluoroheptene, perfluorooctene, hexafluoropropylene trimer, and perfluorodecene.

10. A liquid cooling system, characterized in that, Includes a liquid cooling space, wherein the liquid cooling space is filled with the coolant according to any one of claims 1-6; Alternatively, the liquid-cooled space may be filled with a coolant prepared using the preparation method described in any one of claims 7-9.

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