Cooling working medium and preparation method and application thereof

Abstract

The invention discloses a cooling working medium and a preparation method and application thereof. The cooling working medium comprises a first component, a second component and an antioxidant, the first component is a hexafluoropropylene tripolymer, and the second component is 1H, 1H, 5H-octafluoropentyl-1, 1, 2, 2-tetrafluoroethyl ether. The cooling working medium is high in environmental friendliness and good in compatibility with materials, and the service life of to-be-cooled electronic equipment is prolonged on the premise that the excellent temperature reduction effect is achieved.

Description

Technical Field

[0001] The present application relates to a cooling medium, and in particular to a cooling medium and a preparation method and application thereof. Background Art

[0002] The battery thermal management system is mainly to allow the battery pack to always work within a suitable temperature range, so as to maintain the best working state of the battery pack. The thermal management of the battery mainly includes functions such as cooling, heating and temperature balance. Generally speaking, the cooling modes are mainly divided into air cooling, liquid cooling, direct cooling and immersion cooling. Immersion liquid cooling is to immerse the heat-generating device in the coolant and rely on the circulation of the coolant to take away the heat. Compared with air cooling, liquid cooling and direct cooling technologies, immersion liquid cooling has excellent cooling efficiency and the best temperature uniformity, and the equipment structure is relatively simple, and there is no need to frequently add coolant. In addition, the sealing requirements of the container are not particularly high, which can greatly reduce costs while reducing the risk and impact of thermal runaway.

[0003] However, the cooling effect of existing immersion liquid cooling needs to be improved. Summary of the invention

[0004] In view of the defects or deficiencies in the prior art, the purpose of this application is to provide a cooling medium for an energy storage device and a preparation method and application thereof. The cooling medium is highly environmentally friendly and has good compatibility with materials. On the premise of having an excellent temperature reduction effect, it is also beneficial to improve the service life of the electronic equipment to be cooled.

[0005] The first aspect of the present application is to provide a cooling medium, which includes a first component, a second component and an antioxidant, the first component is hexafluoropropylene trimer, and the second component is 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether.

[0006] In some embodiments, the cooling medium satisfies any one or more of the following properties:

[0007] (1) The boiling point of the cooling medium is greater than or equal to 110°C and the pour point is less than -30°C;

[0008] (2) The kinematic viscosity of the cooling medium at 20°C is less than 2 mm 2 / s, the kinematic viscosity at 10℃ is less than 5mm 2 / s;

[0009] (3) The thermal conductivity of the cooling medium is greater than or equal to 0.06 W / m·K, and the specific heat is greater than or equal to 0.96 KJ / kg·k at 25°C;

[0010] (4) The breakdown voltage of the cooling medium is greater than 24 kV, and the volume resistivity is greater than 1×1012 Ω·cm;

[0011] (5) The GWP value of the cooling medium is less than 250.

[0012] In some embodiments, the cooling medium meets the following properties:

[0013] The kinematic viscosity of the above cooling medium at 20°C is greater than or equal to 1 mm 2 / s and less than 2mm 2 / s, kinematic viscosity at 10℃ is greater than or equal to 1mm 2 / s and less than 5mm 2 / s;

[0014] and / or;

[0015] The thermal conductivity of the above-mentioned cooling medium is greater than or equal to 0.06W / m·K and less than 1W / m·K; the specific heat of the above-mentioned cooling medium is greater than or equal to 0.96KJ / kg·k and less than 2J / kg·k, 25°C;

[0016] and / or;

[0017] The GWP value of the above-mentioned cooling medium is greater than 10 and less than 250.

[0018] In some embodiments, the hexafluoropropylene trimer includes a mixture of E-1,1,1,2,3,5,5,6,6,7,7,7-dodecafluoro-2,4-bis(trifluoromethyl)hept-3-ene, Z-1,1,1,2,3,5,5,6,6,7,7,7-dodecafluoro-2,4-bis(trifluoromethyl)hept-3-ene and 1,1,1,4,5,5-heptafluoro-3-(perfluoroethyl)-2,4-bis(trifluoromethyl)pent-2-ene.

[0019] In some embodiments, the mass ratio of the mixture to the 1,1,1,4,5,5-heptafluoro-3-(perfluoroethyl)-2,4-bis(trifluoromethyl)pent-2-ene is (50-70):(30-50).

[0020] In some embodiments, the mass ratio of the first component to the second component is (10-90):(90-10).

[0021] In some embodiments, the weight of the antioxidant is 0.1% to 5% of the total weight of the first component and the second component.

[0022] In some embodiments, the antioxidant includes any one or more of tea polyphenols, tert-butylhydroquinone, flavonoids, and 2,6-di-tert-butyl-p-cresol.

[0023] In some embodiments, the cooling medium further includes a corrosion inhibitor, and the mass of the corrosion inhibitor is 0.1% to 5% of the sum of the mass of the first component and the second component.

[0024] In some embodiments, the corrosion inhibitor includes any one or more of benzotriazole (BTA), 2-mercaptobenzothiazole (MBT) and tolutriazole (TTA).

[0025] The second aspect of the present application is to provide a method for preparing a cooling medium, the preparation method comprising the following process:

[0026] Mixing components: Mix the first component and the second component at a temperature of 0 to 10°C;

[0027] Prepare liquid cooling medium: add antioxidant to the above mixed components under stirring, the stirring speed is 200rpm~700rpm, and the stirring time is 10min~60min;

[0028] The first component is hexafluoropropylene trimer, and the second component is 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether.

[0029] The third aspect of the present application is to provide a cooling medium described in the first aspect or a cooling medium prepared by the preparation method described in the second aspect for use in immersion cooling of electronic equipment.

[0030] The fourth aspect of the present application is to provide an immersion cooling device, which includes a liquid reservoir containing the cooling medium described in the first aspect or the cooling medium prepared by the preparation method described in the second aspect.

[0031] Beneficial technical effects of this application:

[0032] The cooling medium prepared in the present application is highly environmentally friendly (low GWP) and has good compatibility with materials. On the premise of having an excellent temperature reduction effect, it is also beneficial to improve the service life of the electronic equipment to be cooled. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the structure of an immersion cooling device provided in some embodiments of the present application.

[0034] The reference numerals in the accompanying drawings represent the following:

[0035] 100: liquid storage tank; 110: cooling medium; 120: electronic equipment; 200: cooling subsystem; 300: cold source equipment. DETAILED DESCRIPTION

[0036] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0037] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0038] Unless expressly stated to the contrary, all ranges cited herein are inclusive.

[0039] The term "a" or "an" used in this application is used to describe the elements and components described in this application. This is done only for convenience and to provide a general sense of the scope of this application. This description should be understood to include one or at least one, and the singular also includes the plural, unless it is obvious that it is otherwise intended. "Multiple" means two or more.

[0040] The numbers in this application are approximate, regardless of whether the words "about" or "approximately" are used. The numerical values ​​of the numbers may vary by 1%, 2%, 5%, 7%, 8%, 10%, etc. Whenever a number with a value of N is disclosed, any number with a value of N+ / -1%, N+ / -2%, N+ / -3%, N+ / -5%, N+ / -7%, N+ / -8% or N+ / -10% will be explicitly disclosed, where "+ / -" means plus or minus, and the range between N-10% and N+10% is also disclosed.

[0041] Battery thermal management systems are of great significance to the safe and efficient operation of lithium-ion batteries. Immersion cooling technology has obvious advantages over traditional thermal management technologies in terms of temperature control performance and energy efficiency. With the rapid development of electric vehicles and energy storage power stations, research on immersion cooling systems has gradually received attention.

[0042] As the core of the thermal management system of immersed lithium batteries, the thermophysical properties of the coolant largely determine the operating performance of the lithium battery system.

[0043] The selection of coolant should be considered from the following perspectives: ① The coolant should be non-conductive, that is, low dielectric constant; ② The coolant should have excellent thermal conductivity, that is, high specific heat capacity and high thermal conductivity; ③ The coolant should not solidify or burn within the operating temperature range, that is, low freezing point (pour point), non-flammable or high flash point; ④ The coolant should be compatible with the materials of the lithium battery system, that is, it should have no corrosive effect on the materials in direct contact; ⑤ The premise for large-scale use of coolant is that it should be environmentally friendly, including zero ozone depletion potential (ODP) and low global warming potential (GWP).

[0044] The five commonly used types of coolants include electronic fluorinated fluids, hydrocarbons, esters, silicone oils, and water-based fluids.

[0045] Electronic fluorinated liquids include hydrofluoroethers (HFE) and hydrofluoroolefins (HFO). HFE and HFO are third-generation substitutes for high ODP and high GWP compounds. They have green properties of not damaging the ozone layer and low GWP, and are used as refrigerants, etc. In recent years, electronic fluorinated liquids have attracted much attention in the field of immersion cooling of power electronic equipment. Immersion phase change cooling using electronic fluorinated liquids is very useful for cooling high-power chips (>100W / cm 2 ) has potential advantages. In view of the low dielectric constant, material compatibility and non-flammable safety exhibited by electronic fluorinated fluids, they have also attracted attention in the field of battery thermal management. Novec7000 and SF33, as typical HFE and HFO electronic fluorinated fluids, respectively, have attracted the attention of researchers in the fields of battery single-phase cooling and phase change cooling. Electronic fluorinated fluids that can be phase-changed for cooling are suitable for extremely fast charging and discharging conditions of batteries. They have advantages in reducing the temperature difference of the battery body and temperature fluctuations under dynamic load conditions, and have great application potential. However, there is currently a lack of systematic research on the impact of electronic fluorinated fluids on battery life performance.

[0046] In order to solve the above technical problems, the present application discloses a cooling medium and its preparation method and application. The cooling medium comprises a first component, a second component and an antioxidant, the first component is hexafluoropropylene trimer, and the second component is 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether.

[0047] The cooling medium provided in the present application is highly environmentally friendly and has good compatibility with materials. On the premise of having an excellent temperature reduction effect, it is also beneficial to improve the service life of the electronic equipment to be cooled.

[0048] The cooling medium provided in this application can be used in a single-phase immersion liquid cooling system, as shown in the accompanying drawings of the specification. Figure 1 As shown, the cooling system includes an immersion cooling device, which includes a liquid reservoir 100, a cooling subsystem 200 connected to the liquid reservoir 100, and a cold source device 300 connected to the cooling subsystem 200. The liquid reservoir 100 contains the cooling medium 110 of the present application, and an electronic device 120 is immersed in the cooling medium 110.

[0049] The immersion cooling device provided in the present application circulates the cooling medium to dissipate heat through an external heat dissipation device to maintain the stability of the cooling medium in the liquid reservoir 100.

[0050] The electronic device 120 of the present application includes a battery-related power device, an energy storage device, a data center, etc.

[0051] Therefore, the cooling medium provided in this application has good application prospects.

[0052] The first aspect of the present application is to provide a cooling medium, which includes a first component, a second component and an antioxidant, the first component is hexafluoropropylene trimer, and the second component is 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether.

[0053] The hexafluoropropylene trimer in this application is also called perfluorononene. The hexafluoropropylene trimer mainly has the following three isomers: perfluoro-2,4-methylheptene (T-1), perfluoro-4-methyl-3-isopropylpentene-2 ​​(T-2), and perfluoro-2,4-dimethyl-3-ethylpentene-2 ​​(T-3). Among them, perfluoro-2,4-methylheptene (T-1) also includes two cis and trans isomers E and Z. The boiling points of the hexafluoropropylene trimer are all between 110 and 115 ° C, and the three can be converted into each other. T-1 has low activity, T-2 has strong reaction ability with nucleophiles, and T-3 has no ability to react with nucleophiles.

[0054]

[0055] The 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether in the present application is also referred to as hydrofluoroether-6512.

[0056] The cooling fluid prepared by compounding hexafluoropropylene trimer, antioxidant and 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether in the present application has the characteristics of strong environmental friendliness and good compatibility with materials. On the premise of having excellent temperature reduction effect, it is also beneficial to improve the service life of the electronic equipment to be cooled.

[0057] In some embodiments, the cooling medium satisfies any one or more of the following properties:

[0058] (1) The boiling point of the cooling medium is ≥110°C and the pour point is <-30°C;

[0059] (2) The kinematic viscosity of the cooling medium at 20°C is less than 2 mm 2 / s, kinematic viscosity at 10℃<5mm 2 / s;

[0060] (3) The thermal conductivity of the cooling medium is ≥ 0.06 W / m·K, and the specific heat is ≥ 0.96 (25°C) KJ / kg·k;

[0061] (4) The breakdown voltage of the cooling medium is greater than 24 kV, and the volume resistivity is greater than 1×10 12 Ω·cm;

[0062] (5) The GWP value of the cooling medium is less than 250.

[0063] The kinematic viscosity of the present application refers to the ratio between the dynamic viscosity of a fluid and the density ρ of the fluid at the same temperature. The kinematic viscosity of the present application is determined by conventional methods known in the art, such as testing according to GB / T 265-2004.

[0064] The thermal conductivity of the present application refers to the amount of heat transferred through an area of ​​1 square meter in 1 second under stable heat transfer conditions when the temperature difference between the two surfaces of a 1 meter thick material is 1 degree (K, ° C), and the unit is watt / meter·degree (W / (m·K), where K can be replaced by ° C). The determination method of the thermal conductivity of the present application includes conventional known methods in the art, such as testing using ASTM D2717.

[0065] The specific heat of the present application is the abbreviation of specific heat capacity, which refers to the heat capacity of a substance per unit mass, that is, the amount of heat absorbed or released when a unit mass of an object changes unit temperature. The determination method of the specific heat of the present application includes conventional known methods in the art, such as testing using ASTM E1269.

[0066] The breakdown voltage of this application refers to the voltage that causes dielectric breakdown. When a dielectric is subjected to a sufficiently strong electric field, it loses its dielectric properties and becomes a conductor, which is called dielectric breakdown, and the corresponding voltage is called breakdown voltage. The method for measuring the breakdown voltage of this application includes conventional methods known in the art, such as testing using GB / T 507-2002.

[0067] The volume resistivity of the present application refers to the impedance of a material to electric current per unit volume, and is used to characterize the electrical properties of the material. Generally, the higher the volume resistivity, the higher the efficiency of the material as an electrical insulating component. The method for determining the volume resistivity of the present application includes conventional known methods in the art, such as testing using GB / T5654.

[0068] The GWP value in this application is also known as the global warming potential, which is a key indicator for measuring the contribution of greenhouse gases to climate change. For example, you can refer to the IPCC Special report of Climate Change 1994 <Kyoto Protocol>.

[0069] In some embodiments, the cooling medium meets the following properties:

[0070] The kinematic viscosity of the above cooling medium at 20°C is greater than or equal to 1 mm 2 / s and less than 2mm 2 / s, kinematic viscosity at 10℃ is greater than or equal to 1mm 2 / s and less than 5mm 2 / s;

[0071] and / or;

[0072] The thermal conductivity of the above-mentioned cooling medium is greater than or equal to 0.06W / m·K and less than 1W / m·K; the specific heat of the above-mentioned cooling medium is greater than or equal to 0.96KJ / kg·k and less than 2J / kg·k, 25°C; and / or;

[0073] The GWP value of the above-mentioned cooling medium is greater than 10 and less than 250.

[0074] The present application discloses in these examples that the kinematic viscosity of the cooling medium at 20°C is 1 mm 2 / s、1.1mm 2 / s、1.2mm 2 / s, 1.216mm 2 / s, 1.234mm 2 / s, 1.289mm 2 / s、1.3mm 2 / s, 1.325mm 2 / s, 1.361mm 2 / s, 1.397mm 2 / s, 1.4mm 2 / s, 1.433mm 2 / s, 1.488mm 2 / s、1.5mm 2 / s, 1.506mm 2 / s、1.6mm 2 / s, 1.601mm 2 / s, 1.622mm 2 / s, 1.634mm 2 / s, 1.7mm 2 / s、1.8mm 2 / s, 1.9mm 2 / s or any of the values ​​satisfying the above range.

[0075] The present application discloses in these examples that the kinematic viscosity of the cooling medium at 10°C is 1 mm 2 / s、1.1mm 2 / s、1.2mm 2 / s、1.3mm 2 / s, 1.4mm 2 / s、1.5mm 2 / s, 1.516mm 2 / s, 1.542mm 2 / s、1.6mm 2 / s, 1.622mm 2 / s, 1.675mm2 / s, 1.7mm 2 / s, 1.728mm 2 / s, 1.756mm 2 / s, 1.773mm 2 / s, 1.780mm 2 / s, 1.784mm 2 / s、1.8mm 2 / s, 1.833mm 2 / s, 1.9mm 2 / s, 1.913mm 2 / s, 1.939mm 2 / s, 2.0mm 2 / s、3.0mm 2 / s, 4.0mm 2 / s, 4.3mm 2 / s, 4.5mm 2 / s、4.7mm 2 / s, 4.9mm 2 / s or any of the values ​​satisfying the above range.

[0076] In these embodiments, the present application discloses that the GWP value of the cooling medium is any one of 10, 11, 13, 15, 19, 20, 30, 37, 40, 49, 50, 60, 61, 62, 70, 72, 80, 84, 90, 100, 102, 108, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, and 240, or any one of the values ​​satisfying the above ranges.

[0077] In these embodiments, the present application discloses that the thermal conductivity of the cooling medium is any one of 0.06 W / m·K, 0.08 W / m·K, 0.098 W / m·K, 0.1 W / m·K, 0.105 W / m·K, 0.127 W / m·K, 0.142 W / m·K, 0.156 W / m·K, 0.171 W / m·K, 0.186 W / m·K, 0.207 W / m·K, 0.215 W / m·K, 0.226 W / m·K, 0.231 W / m·K, and 0.235 W / m·K, or any one of the values ​​satisfying the above ranges.

[0078] In these embodiments, the present application discloses that the specific heat of the cooling medium is greater than or equal to any one of 0.96KJ / kg·k, 1.213KJ / kg·k, 1.214KJ / kg·k, 1.226KJ / kg·k, 1.262KJ / kg·k, 1.286KJ / kg·k, 1.311KJ / kg·k, 1.333KJ / kg·k, 1.335KJ / kg·k, 1.350KJ / kg·k, 1.356KJ / kg·k, 1.359KJ / kg·k, 1.395KJ / kg·k, 1.406KJ / kg·k, and 1.5KJ / kg·k, or any one of the values ​​satisfying the above ranges.

[0079] In some embodiments, the above-mentioned hexafluoropropylene trimer includes a mixture of E-1,1,1,2,3,5,5,6,6,7,7,7-dodecafluoro-2,4-bis(trifluoromethyl)hept-3-ene, Z-1,1,1,2,3,5,5,6,6,7,7,7-dodecafluoro-2,4-bis(trifluoromethyl)hept-3-ene and 1,1,1,4,5,5-heptafluoro-3-(perfluoroethyl)-2,4-bis(trifluoromethyl)pent-2-ene, and the mass ratio of the mixture to 1,1,1,4,5,5-heptafluoro-3-(perfluoroethyl)-2,4-bis(trifluoromethyl)pent-2-ene is (50-70):(30-50).

[0080] The hexafluoropropylene trimer selected in these embodiments of the present application is conducive to synergizing with 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether to better improve the service life of the electronic equipment to be cooled.

[0081] The present application discloses in these embodiments that the mass ratio of the mixture to 1,1,1,4,5,5-heptafluoro-3-(perfluoroethyl)-2,4-bis(trifluoromethyl)pent-2-ene is any one of 50:50, 55:45, 60:40, 70:30 or any one of the values ​​satisfying the above ranges.

[0082] In some embodiments, the mass ratio of the first component to the second component is (10-90): (90-10). In these embodiments, the mass ratio of the first component to the second component is any one of 10:90, 15:85, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 85:15, 90:10 or any one of the above ranges.

[0083] In these embodiments, the mass of the antioxidant is 0.1% to 5% of the sum of the mass of the first component and the second component. In these embodiments, the mass of the antioxidant is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5.0%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%, 6.0%, 6.0%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.8%, 6.9%, 7. .4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5.0%, or any of the values ​​satisfying the above range.

[0084] In some embodiments, the antioxidants include one or more of tea polyphenols, tert-butylhydroquinone, flavonoids, and 2,6-di-tert-butyl-p-cresol.

[0085] The flavonoid compounds of the present application are a general term for a series of compounds formed by two benzene rings connected to each other by three carbon atoms, that is, a general term for a class of compounds with a C6-C3-C6 structure, including but not limited to flavanones, isoflavones, etc.

[0086] In some embodiments, the cooling medium further comprises a corrosion inhibitor, and the mass of the corrosion inhibitor is 0.1% to 5% of the mass of the first component and the second component. In these embodiments, the present application discloses that the mass of the corrosion inhibitor is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%, 6.1%, 6.2%, 6.3%, 6.4%, 6.5%, 6.6%, 6.7%, 6.8%, 6.9%, 7. Any of 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5.0% or any of the values ​​satisfying the above range.

[0087] In some embodiments, the corrosion inhibitor includes one or more of benzotriazole (BTA), 2-mercaptobenzothiazole (MBT) and tolutriazole (TTA).

[0088] The second aspect of the present application is to provide a method for preparing a cooling medium, the preparation method comprising the following process:

[0089] S1. Mixing components: Mix the first component and the second component at a temperature of 0 to 10°C;

[0090] S2. Prepare liquid cooling medium: add antioxidant to the mixed components under stirring, the stirring speed is 200 rpm to 700 rpm, and the stirring time is 10 min to 60 min;

[0091] The first component is hexafluoropropylene trimer, and the second component is 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether.

[0092] In these embodiments, the present application discloses that the stirring speed is any one of 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm, 500 rpm, 550 rpm, 600 rpm, 650 rpm, 700 rpm or any one of the values ​​satisfying the above ranges.

[0093] The present application discloses in these embodiments that the stirring time is any one of 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min or any one of the values ​​satisfying the above ranges.

[0094] In some embodiments, a corrosion inhibitor is further added to the mixed components.

[0095] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0096] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0097] Conventional techniques of inorganic chemistry within the art can be used in this application. In the following examples, efforts are made to ensure the accuracy of the numbers used (including amounts, temperatures, reaction times, etc.), but some experimental errors and deviations should be considered. The temperatures (in degrees Celsius) used in the following examples are expressed in ° C, and the pressure is atmospheric pressure or near atmospheric pressure. All pharmaceutical reagents are purchased at AR grade, and all reactions are carried out under argon protection. Unless otherwise noted, all reagents are obtained from commercial channels.

[0098] The properties of some raw materials used in the following examples of this application are shown in Table 1:

[0099] Table 1 Raw material properties list

[0100]

[0101] Among them, the test standards for dielectric constant, flammability, etc. in Table 1 are conventional measurement methods in this field.

[0102] Example 1

[0103] A method for preparing a cooling medium is provided, the method comprising the following steps:

[0104] S1. Mixing hexafluoropropylene trimer and hydrofluoroether-6512 in a mass ratio of 10:90 to obtain a mixed component;

[0105] S2. Add antioxidant (tert-butylhydroquinone) and corrosion inhibitor (2-mercaptobenzothiazole) at 0.5% of the mass of the mixed components, control the temperature to 0-10° C., stir at 300 rpm for 30 minutes, and mix evenly.

[0106] Example 1-1

[0107] A preparation method of a cooling medium is provided. The preparation method is different from that of Example 1 in that no corrosion inhibitor is added, and the rest is the same as that of Example 1.

[0108] Example 2-1

[0109] A preparation method of a cooling medium is provided, and the difference between the preparation method and Example 1 is that: hexafluoropropylene trimer and hydrofluoroether-6512 are mixed at a mass ratio of 15:85. An antioxidant (tert-butylhydroquinone) and a corrosion inhibitor (2-mercaptobenzothiazole) are added at 1% of the mass of the mixed components, the temperature is controlled at 0-10°C, and the mixture is stirred at a speed of 400 rpm for 20 minutes to be evenly mixed.

[0110] Example 2-2

[0111] A preparation method of a cooling medium is provided, which is different from that of Example 1 in that: hexafluoropropylene trimer and hydrofluoroether-6512 are mixed at a mass ratio of 30:70. An antioxidant (tea polyphenols) and a corrosion inhibitor (2-mercaptobenzothiazole) are added at 3% of the mass of the mixed components, the temperature is controlled at 0-10°C, and the mixture is stirred at a speed of 400 rpm for 20 minutes to be evenly mixed.

[0112] Example 2-3

[0113] A preparation method of a cooling medium is provided, and the difference between the preparation method and Example 1 is that: hexafluoropropylene trimer and hydrofluoroether-6512 are mixed at a mass ratio of 40:60. An antioxidant (2,6-di-tert-butyl-p-cresol) and a corrosion inhibitor (2-mercaptobenzothiazole) are added at 3% of the mass of the mixed components, the temperature is controlled at 0-10°C, and the mixture is stirred at a speed of 500 rpm for 40 minutes to be evenly mixed.

[0114] Embodiment 2-4

[0115] A preparation method of a cooling medium is provided, and the difference between the preparation method and Example 1 is that: hexafluoropropylene trimer and hydrofluoroether-6512 are mixed at a mass ratio of 50:50. An antioxidant (2,6-di-tert-butyl-p-cresol) and a corrosion inhibitor (benzotriazole) are added at 3% of the mass of the mixed components, respectively, the temperature is controlled at 0-10°C, and the mixture is stirred at a speed of 300 rpm for 60 minutes to be evenly mixed.

[0116] Embodiment 2-5

[0117] A preparation method of a cooling medium is provided, and the difference between the preparation method and Example 1 is that: hexafluoropropylene trimer and hydrofluoroether-6512 are mixed at a mass ratio of 60:40. An antioxidant (2,6-di-tert-butyl-p-cresol) and a corrosion inhibitor (methylbenzotriazole) are added at 5% of the mass of the mixed components, the temperature is controlled at 0-10°C, and the mixture is stirred at a speed of 700 rpm for 30 minutes to be evenly mixed.

[0118] Embodiment 2-6

[0119] A preparation method of a cooling medium is provided, and the preparation method is different from that of Example 1 in that: hexafluoropropylene trimer and hydrofluoroether-6512 are mixed at a mass ratio of 70:30. An antioxidant (tert-butylhydroquinone) and a corrosion inhibitor (2-mercaptobenzothiazole) are added at 3% of the mass of the mixed components, the temperature is controlled at 0-10°C, and the mixture is stirred at a speed of 600 rpm for 30 minutes to be evenly mixed.

[0120] Embodiment 2-7

[0121] A preparation method of a cooling medium is provided, and the difference between the preparation method and Example 1 is that: hexafluoropropylene trimer and hydrofluoroether-6512 are mixed at a mass ratio of 85:15. An antioxidant (tert-butylhydroquinone) and a corrosion inhibitor (2-mercaptobenzothiazole) are added at 1% of the mass of the mixed components, the temperature is controlled at 0-10°C, and the mixture is stirred at a speed of 400 rpm for 20 minutes to be evenly mixed.

[0122] Embodiment 2-8

[0123] A preparation method of a cooling medium is provided, and the preparation method is different from that of Example 1 in that: hexafluoropropylene trimer and hydrofluoroether-6512 are mixed at a mass ratio of 90:10. An antioxidant (tert-butylhydroquinone) and a corrosion inhibitor (2-mercaptobenzothiazole) are added at 0.5% of the mass of the mixed components, respectively, the temperature is controlled at 0-10°C, and the mixture is stirred at a speed of 300 rpm for 30 minutes to be evenly mixed.

[0124] Example 3-1

[0125] A method for preparing a cooling medium is provided, which is different from that of Example 1 in that a hexafluoropropylene trimer includes a mixture of E-1,1,1,2,3,5,5,6,6,7,7,7-dodecafluoro-2,4-bis(trifluoromethyl)hept-3-ene, Z-1,1,1,2,3,5,5,6,6,7,7,7-dodecafluoro-2,4-bis(trifluoromethyl)hept-3-ene and 1,1,1,4,5,5-heptafluoro-3-(perfluoroethyl)-2,4-bis(trifluoromethyl)pent-2-ene, and the mass ratio of the two is 50:50.

[0126] Example 3-2

[0127] A method for preparing a cooling medium is provided, which differs from that of Example 3-1 in that the mass ratio of the two is 70:30.

[0128] Example 3-3

[0129] A method for preparing a cooling medium is provided, which differs from Example 3-1 in that the mass ratio of the two is 60:40.

[0130] Comparative Example 1

[0131] Provided is a method for preparing a cooling medium, the method comprising mixing hexafluoropropylene trimer and hydrofluoroether-7100 at a mass ratio of 10:90, adding an antioxidant (tert-butylhydroquinone) and a corrosion inhibitor (2-mercaptobenzothiazole) at 0.5% of the mass of the mixed components, controlling the temperature to 0-10°C, stirring at a speed of 300 rpm for 30 minutes, and mixing evenly.

[0132] Comparative Example 2

[0133] Provided is a method for preparing a cooling medium, the method comprising mixing hexafluoropropylene trimer and hydrofluoroether-7200 at a mass ratio of 10:90, adding an antioxidant (tert-butylhydroquinone) and a corrosion inhibitor (2-mercaptobenzothiazole) at 0.5% of the mass of the mixed components, controlling the temperature to 0-10°C, stirring at a speed of 300 rpm for 30 minutes, and mixing evenly.

[0134] Comparative Example 3

[0135] Provided is a method for preparing a cooling medium, the method comprising mixing hexafluoropropylene trimer and hydrofluoroether-7300 at a mass ratio of 10:90, adding an antioxidant (tert-butylhydroquinone) and a corrosion inhibitor (2-mercaptobenzothiazole) at 0.5% of the mass of the mixed components, controlling the temperature to 0-10°C, stirring at a speed of 300 rpm for 30 minutes, and mixing evenly.

[0136] The hexafluoropropylene trimer used in the above-mentioned Example 1, Example 2 and Comparative Example of the present application is a product of our company, and the product model is DYG-0001.

[0137] Performance Test 1

[0138] According to the properties listed in Table 1 and the above test method, the specific values ​​of the embodiments and comparative examples are obtained, as shown in Table 2 below.

[0139] Table 2 Performance List 1

[0140]

[0141]

[0142] It can be seen from Table 2 that by comparing the comparative example and Example 1, the addition of HFE-7100 and HFE-7300 makes the GWP greater than the industry minimum requirement of 250, which is not suitable for battery liquid cooling. The operating temperature of the battery pack is generally high. The mixture with HFE-7100 and HFE-7200 has a low boiling point and a small thermal conductivity, and is not suitable for battery liquid cooling. Only the combination of hexafluoropropylene trimer and HFE-6512 has relatively better physical properties.

[0143] Performance Test 2

[0144] The ODCC-2023-09001 method was used to test the compatibility of the cooling fluids of Comparative Examples 1 to 3 and the embodiments with the materials in the battery pack. The test results are shown in Table 3 below.

[0145] Table 3 Performance List 2

[0146]

[0147]

[0148] It can be seen from Table 3 that by comparing the embodiments of the present application with the comparative examples, the design method provided by the present application is conducive to better compatibility with the metal materials or organic materials in the battery pack. At the same time, the compatibility between the cooling medium provided in Example 3 of the present application and the battery pack material is relatively optimal, which can ensure long-term stable operation of the system.

[0149] Performance Test 3

[0150] Coolant aging test:

[0151] Aging conditions: 50 mL of coolant was placed in a hydrothermal reactor and heated at 150°C for 7 days. The acid value of the coolant was then tested and compared before and after to evaluate the chemical stability of the coolant. Table 4 was obtained.

[0152] Table 4 Performance List 3

[0153]

[0154]

[0155] Combining Table 4, it can be seen that the use of each additive is crucial when comparing Example 1 and Example 1-1. Further comparison of the present embodiment and the comparative example shows that the acid value of the cooling medium provided by the present application does not change much after high temperature aging, and the chemical stability is relatively good.

[0156] Performance Test 4

[0157] The battery pack is immersed in comparative examples 1 to 3 and the embodiments, and then a cooling performance test is performed. The test method is as follows: the temperature sensors are respectively connected to the outer shell of the battery pack and the inside of the battery pack, and then the coolant of the present invention is added. Then, the maximum temperature of the battery pack outer shell and the inside of the battery pack can be measured by referring to the temperature measurement method of GB31241-2022. The results are shown in Table 5 below.

[0158] Table 5 Performance List 4

[0159] Example / Comparative Example Maximum temperature inside the battery pack / ℃ Battery pack shell maximum temperature / ℃ Comparative Example 1 56.2 51.3 Comparative Example 2 55.8 50.6 Comparative Example 3 55.6 50.4 Example 1 50.4 45.6 Example 1-1 50.6 45.9 Example 2-1 50.9 46.2 Example 2-2 51.2 46.3 Example 2-3 51.6 46.5 Embodiment 2-4 51.8 46.8 Embodiment 2-5 52.1 47.2 Embodiment 2-6 52.3 47.4 Embodiment 2-7 52.4 47.8 Embodiment 2-8 52.7 48.1 Example 3-1 49.5 44.2 Example 3-2 49.8 44.5 Example 3-3 50.2 44.2

[0160] As can be seen from Table 4 above, compared with the comparative example, the temperature of the battery in the embodiment of the present application drops significantly during the charging and discharging process, which shows that the cooling provided by the present application has excellent heat dissipation performance, and can control the battery to be used within its optimal operating temperature range, thereby extending the service life of the battery. Further combined with the various properties in the above list, it can be clearly known that the cooling medium provided by the present application has the characteristics of environmental friendliness. At the same time, it has good compatibility with the battery pack materials, and is conducive to extending the service life of the electronic equipment to be cooled while having an excellent temperature drop effect.

[0161] The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for a person skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

[0162] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. As mentioned throughout the specification and claims, "including" and "comprising" are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. The subsequent description of the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be determined by the definition of the attached claims.

[0163] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0164] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0165] The above is only a preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A cooling medium, characterized in that: The invention comprises a first component, a second component and an antioxidant, wherein the first component is hexafluoropropylene trimer, and the second component is 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether.

2. The cooling medium according to claim 1, characterized in that: The cooling medium meets any one or more of the following properties: (1) The boiling point of the cooling medium is greater than or equal to 110°C and the pour point is less than -30°C; (2) The kinematic viscosity of the cooling medium at 20°C is less than 2 mm 2 / s, the kinematic viscosity at 10℃ is less than 5mm 2 / s; (3) The thermal conductivity of the cooling medium is greater than or equal to 0.06 W / m·K; the specific heat is greater than or equal to 0.96 KJ / kg·k, 25°C; (4) The breakdown voltage of the cooling medium is greater than 24 kV, and the volume resistivity is greater than 1×10 12 Ω·cm; (5) The GWP value of the cooling medium is less than 250.

3. The cooling medium according to claim 2, characterized in that: The performance of the cooling medium is as follows: The kinematic viscosity of the cooling medium at 20°C is greater than or equal to 1 mm 2 / s and less than 2mm 2 / s, kinematic viscosity at 10℃ is greater than or equal to 1mm 2 / s and less than 5mm 2 / s; and / or; The thermal conductivity of the cooling medium is greater than or equal to 0.06 W / m·K and less than 1 W / m·K; the specific heat of the cooling medium is greater than or equal to 0.96 KJ / kg·k and less than 2 J / kg·k, 25°C; and / or; The GWP value of the cooling medium is greater than 10 and less than 250.

4. The cooling medium according to claim 1, characterized in that: The hexafluoropropylene trimer includes a mixture of E-1,1,1,2,3,5,5,6,6,7,7,7-dodecafluoro-2,4-bis(trifluoromethyl)hept-3-ene, Z-1,1,1,2,3,5,5,6,6,7,7,7-dodecafluoro-2,4-bis(trifluoromethyl)hept-3-ene and 1,1,1,4,5,5-heptafluoro-3-(perfluoroethyl)-2,4-bis(trifluoromethyl)pent-2-ene, and the mass ratio of the mixture to the 1,1,1,4,5,5-heptafluoro-3-(perfluoroethyl)-2,4-bis(trifluoromethyl)pent-2-ene is (50-70):(30-50).

5. The cooling medium according to claim 1, characterized in that: The mass ratio of the first component to the second component is (10-90):(90-10).

6. The cooling medium according to claim 1, characterized in that: The mass of the antioxidant is 0.1% to 5% of the mass of the first component and the second component; and / or; The antioxidant includes any one or more of tea polyphenols, tert-butylhydroquinone, flavonoids, and 2,6-di-tert-butyl-p-cresol.

7. The cooling medium according to claim 1, characterized in that: The cooling medium further includes a corrosion inhibitor, the mass of which is 0.1% to 5% of the mass of the first component and the second component; and / or; The corrosion inhibitor includes any one or more of benzotriazole, 2-mercaptobenzothiazole and tolutriazole.

8. A method for preparing a cooling medium, characterized in that: The process includes the following: Mixing components: Mix the first component and the second component at a temperature of 0 to 10°C; Prepare liquid cooling medium: add antioxidant to the mixed components under stirring, the stirring speed is 200 rpm to 700 rpm, and the stirring time is 10 min to 60 min; The first component is hexafluoropropylene trimer, and the second component is 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether.

9. A cooling medium according to any one of claims 1 to 7 or a cooling medium prepared by the preparation method according to any one of claim 8 for use in immersion cooling of electronic equipment.

10. An immersion cooling device, characterized in that: The device comprises a liquid reservoir, wherein the liquid reservoir contains the cooling medium described in any one of claims 1 to 7 or the cooling medium prepared by the preparation method described in any one of claim 8.

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