Mineral oil type charging pile cooling liquid and preparation method thereof

Abstract

The invention relates to the technical field of charging pile liquid cooling, in particular to mineral oil type charging pile cooling liquid and a preparation method thereof.The mineral oil type charging pile cooling liquid is prepared from, by mass, 98.9-99.78 parts of mineral type base oil, 0.2-1.0 part of antioxidant and 0.02-0.1 part of heat stabilizer, the mineral type base oil is prepared from mineral oil through hydrotreating treatment, pour point depressing refining and supplementary refining processes. The mineral oil type charging pile cooling liquid provided by the invention has good insulativity, oxidation resistance and thermal stability, can be in direct contact with a heating unit, can quickly transfer heat of a charging gun and a charging cable, is seamless in contact, and has the characteristics of quick cooling response, high heat transfer efficiency and good temperature uniformity; the working safety requirement of the high-power charging pile can be met, stable performance of the cooling liquid under the working condition is ensured, the service life of the cooling liquid is prolonged, and long-term stable operation of the high-power charging pile is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid cooling for charging piles, and is a mineral oil-based charging pile coolant and a preparation method thereof. Background Art

[0002] In recent years, as a green means of transportation, new energy electric vehicles have been vigorously promoted. With the rapid popularization of electric vehicles, consumers require the convenience of using electric vehicles, and the demand for rapid charging of electric vehicles is becoming stronger and stronger. Choosing high-power charging technology can shorten the charging time. However, during the rapid charging process of charging piles, the heat generated is so large that if it is not dissipated in time, it will cause extremely serious safety accidents, and the demand for efficient thermal management is more urgent.

[0003] High-power charging technology is the trend of development. Adopting high-power super-fast charging technology, the equipment has a high energy density and a fast temperature rise. The traditional air-cooling method can no longer meet the heat dissipation requirements. At present, using the liquid-cooling method for high-power charging piles is an effective solution. The liquid-cooling method includes cold plate liquid cooling and immersion liquid cooling, and immersion liquid cooling is more efficient than cold plate liquid cooling. During the operation of the charging pile, the surface temperature of the charging cable is high. Using a charging pile coolant with good antioxidant properties and stable performance can extend the service life of the charging pile coolant and improve the heat dissipation efficiency of the charging pile.

[0004] At present, regarding the status quo of charging pile coolants in China, the coolants are mainly oils, water, aqueous solutions of propylene glycol or ethylene glycol, etc. Water, aqueous solutions of propylene glycol or ethylene glycol are non-insulators, and no insulation requirements are imposed on oils either. Therefore, the cooling method adopts indirect cooling by cold plates. Since the working voltage of high-power charging piles is as high as 1000V, once leakage occurs, it will cause fatal damage to the equipment. For example, the Chinese patent document with the publication number CN217902783U discloses a liquid-cooled charging cable for a charging pile, and the coolant used in its liquid-cooled charging cable for a charging pile is water cooling. The Chinese patent document with the publication number CN216659606U discloses a liquid-cooled charging pile. In its cooling circulation loop, the first coolant uses oil, water, air, propylene glycol or ethylene glycol, etc., and the first driving source uses a pump body. The Chinese patent document with the publication number CN216817914U discloses a new type of liquid-cooled charging pile cable, and the method adopted by it is cold plate liquid cooling. The Chinese patent documents with the publication numbers CN114596991A and CN113539550A adopt the same method of cold plate liquid cooling. The existing charging pile coolants all adopt non-insulating coolants, and the cooling method mostly adopts cold plate liquid cooling. Cold plate liquid cooling transfers heat through heat conduction, and has the disadvantages of slow cooling response, low cooling efficiency and high working energy consumption. Summary of the Invention

[0005] The present invention provides a mineral oil-based charging pile coolant, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problems of slow cooling response, low cooling efficiency and poor thermal stability of the existing charging pile coolant.

[0006] One of the technical solutions of the present invention is achieved by the following measures: A mineral oil-based charging pile coolant, in which, per one hundred parts by mass of raw materials, includes: 98.9 parts to 99.78 parts of mineral-based base oil, 0.2 parts to 1.0 part of antioxidant, and 0.02 parts to 0.1 part of heat stabilizer. The mineral-based base oil is prepared by a process including hydrotreating, dewaxing and finishing of petroleum fractions.

[0007] The following is a further optimization and / or improvement of the above-mentioned invention technical solution: The above-mentioned mineral oil-based charging pile coolant is prepared by the following method: Mix the required amount of mineral-based base oil, antioxidant and heat stabilizer, heat to 50°C to 60°C, stir until clear and transparent, then cool to room temperature, and filter to obtain the mineral oil-based charging pile coolant.

[0008] The process conditions of the above-mentioned hydrotreating are: reaction temperature 240°C to 410°C, reaction pressure 15.0 MPa to 17.0 MPa, volume space velocity 0.4 h -1 to 1.7 h -1 , and the hydrogen-oil ratio is 500 to 1000 (V / V).

[0009] The process conditions of the above-mentioned dewaxing are: reaction temperature 220°C to 400°C, reaction pressure 15.0 MPa to 17.0 MPa, volume space velocity 0.5 h -1 to 1.5 h -1 , and the hydrogen-oil ratio is 500 to 1000 (V / V).

[0010] The process conditions of the above-mentioned finishing are: reaction temperature 220°C to 330°C, reaction pressure 10.0 MPa to 20.0 MPa, volume space velocity 0.4 h -1 to 2.0 h -1 , and the hydrogen-oil ratio is 400 to 600 (V / V).

[0011] The above-mentioned mineral-based base oil is one or more of mineral-based base oils A, B, and C. Among them, the distillation range of mineral-based base oil A is 280°C to 460°C, the distillation range of mineral-based base oil B is 320°C to 460°C, and the distillation range of mineral-based base oil C is 320°C to 480°C.

[0012] The above-mentioned antioxidant is one or more of 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol and alkyl diphenylamine.

[0013] The above heat stabilizer is one or two of epoxy ester, pentaerythritol and β-diketone.

[0014] The breakdown voltage of the above mineral oil type charging pile coolant is greater than 50 kV.

[0015] The saturated water absorption of the above mineral oil type charging pile coolant is less than 20 mg / kg.

[0016] The kinematic viscosity at 40 °C of the above mineral oil type charging pile coolant is 10 mm 2 / s to 15 mm 2 / s.

[0017] The second technical solution of the present invention is achieved by the following measures: A preparation method of a mineral oil type charging pile coolant is carried out according to the following steps: Mix the required amount of mineral base oil, antioxidant and heat stabilizer, heat to 50 °C to 60 °C, stir until clear and transparent, then cool to room temperature, and filter to obtain the mineral oil type charging pile coolant.

[0018] The present invention provides a mineral oil type charging pile coolant, which has good insulation, antioxidant and thermal stability. The mineral oil type charging pile coolant can be in direct contact with the heating unit, can quickly transfer the heat of the charging gun and the charging cable, has no gap in contact, has the characteristics of fast cooling response, high heat transfer efficiency and good temperature uniformity, can meet the safety requirements of high-power charging piles, ensure the stable performance of the coolant under working conditions, extend the service life of the coolant, and ensure the long-term stable operation of high-power charging piles. Specific Embodiments

[0019] The present invention is not limited by the following embodiments, and the specific implementation manners can be determined according to the technical solutions of the present invention and the actual situation. All chemical reagents and chemical supplies mentioned in the present invention are well-known and commonly used chemical reagents and chemical supplies in the prior art without special instructions; the percentages in the present invention are mass percentages without special instructions; the normal temperature and room temperature in the present invention generally refer to the temperature from 15 °C to 25 °C, and are generally defined as 25 °C.

[0020] The present invention will be further described below in conjunction with embodiments: Embodiment 1: For the mineral oil type charging pile coolant, in every one hundred parts by mass of raw materials, it includes: 98.9 parts to 99.78 parts of mineral base oil, 0.2 parts to 1.0 part of antioxidant, 0.02 parts to 0.1 part of heat stabilizer, and the mineral base oil is prepared by a process of hydrotreating, dewaxing and supplementary refining of petroleum fractions.

[0021] Example 2: As an optimization of the above example, the mineral oil type charging pile coolant is prepared by the following method: Mix the required amount of mineral type base oil, antioxidant and heat stabilizer, heat to 50 °C to 60 °C, stir until clear and transparent, then cool to room temperature, and obtain the mineral oil type charging pile coolant after filtration.

[0022] Example 3: As an optimization of the above example, the process conditions for hydrotreating are: reaction temperature 240 °C to 410 °C, reaction pressure 15.0 MPa to 17.0 MPa, volume space velocity 0.4 h -1 to 1.7 h -1 , and the hydrogen-oil ratio is 500 to 1000 (V / V).

[0023] Example 4: As an optimization of the above example, the process conditions for dewaxing and refining are: reaction temperature 220 °C to 400 °C, reaction pressure 15.0 MPa to 17.0 MPa, volume space velocity 0.5 h -1 to 1.5 h -1 , and the hydrogen-oil ratio is 500 to 1000 (V / V).

[0024] Example 5: As an optimization of the above example, the process conditions for supplementary refining are: reaction temperature 220 °C to 330 °C, reaction pressure 10.0 MPa to 20.0 MPa, volume space velocity 0.4 h -1 to 2.0 h -1 , and the hydrogen-oil ratio is 400 to 600 (V / V).

[0025] Example 6: As an optimization of the above example, the mineral type base oil is one or more of mineral type base oils A, B, and C. Among them, the distillation range of mineral type base oil A is 280 °C to 460 °C, the distillation range of mineral type base oil B is 320 °C to 460 °C, and the distillation range of mineral type base oil C is 320 °C to 480 °C.

[0026] Example 7: As an optimization of the above example, the antioxidant is one or more of 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, and alkyl diphenylamine.

[0027] Example 8: As an optimization of the above example, the heat stabilizer is one or two of epoxy ester, pentaerythritol, and β-diketone.

[0028] Example 9: As an optimization of the above example, the breakdown voltage of the mineral oil type charging pile coolant is greater than 50 kV.

[0029] Example 10: As an optimization of the above example, the saturated water absorption of the mineral oil type charging pile coolant is less than 20 mg / kg.

[0030] Example 11: As an optimization of the above examples, the kinematic viscosity of the mineral oil type charging pile coolant at 40 °C is 10 mm 2 / s to 15 mm 2 / s.

[0031] Example 12: For this mineral oil type charging pile coolant, per 100 parts by mass of the raw materials, it includes: 99.5 parts of mineral type base oil A, 0.4 part of antioxidant 2,6 - di - tert - butyl - p - cresol, and 0.1 part of heat stabilizer epoxidized ester. Mix the mineral type base oil A, 2,6 - di - tert - butyl - p - cresol, and epoxidized ester, heat to 55 °C, stir until clear and transparent, then cool to room temperature, and filter to obtain the mineral oil type charging pile coolant.

[0032] Example 13: For this mineral oil type charging pile coolant, per 100 parts by mass of the raw materials, it includes: 98.95 parts of mineral type base oil A, 0.1 part of antioxidant alkyl diphenylamine, 0.03 part of heat stabilizer pentaerythritol, and 0.02 part of β - diketone. Mix the mineral type base oil A, 2,6 - di - tert - butyl - p - cresol, pentaerythritol, and β - diketone, heat to 55 °C, stir until clear and transparent, then cool to room temperature, and filter to obtain the mineral oil type charging pile coolant.

[0033] Example 14: For this mineral oil type charging pile coolant, per 100 parts by mass of the raw materials, it includes: 19.78 parts of mineral type base oil A, 80.0 parts of mineral type base oil C, 0.1 part of antioxidant 2,6 - di - tert - butyl - p - cresol, 0.1 part of alkyl diphenylamine, 0.01 part of heat stabilizer pentaerythritol, and 0.01 part of β - diketone. Mix the mineral type base oil A, mineral type base oil C, 2,6 - di - tert - butyl - p - cresol, alkyl diphenylamine, pentaerythritol, and β - diketone, heat to 55 °C, stir until clear and transparent, then cool to room temperature, and filter to obtain the mineral oil type charging pile coolant.

[0034] Example 15: For this mineral oil type charging pile coolant, per 100 parts by mass of the raw materials, it includes: 30 parts of mineral type base oil A, 40 parts of mineral type base oil B, 29.7 parts of mineral type base oil C, 0.2 part of antioxidant 2,6 - di - tert - butyl - p - cresol, and 0.1 part of heat stabilizer epoxidized ester. Mix the mineral type base oil A, mineral type base oil B, mineral type base oil C, 2,6 - di - tert - butyl - p - cresol, and epoxidized ester, heat to 60 °C, stir until clear and transparent, then cool to room temperature, and filter to obtain the mineral oil type charging pile coolant.

[0035] Comparative Example: For this mineral oil type charging pile coolant, in every one hundred parts by mass of the raw materials, it includes: 30 parts of mineral base oil A, 40 parts of mineral base oil B, 29.8 parts of mineral base oil C, 0.2 of antioxidant 2,6 - di - tert - butyl - p - cresol, and no heat stabilizer is added. Mix mineral base oil A, mineral base oil B, mineral base oil C and 2,6 - di - tert - butyl - p - cresol, heat to 60 °C, stir until clear and transparent, then cool to room temperature, and filter to obtain the mineral oil type charging pile coolant.

[0036] Test the kinematic viscosity, thermal conductivity, specific heat, flash point, saturated water absorption, thermal stability, breakdown voltage performance indicators of the mineral oil type charging pile coolants of Examples 12 to 15 and the comparative example and the charging pile coolant of the comparative example. The performance comparison is shown in Table 1. It can be seen from Table 1 that the mineral oil type charging pile coolants of Examples 12 to 15 prepared by the scheme of the present invention can achieve good effects in terms of kinematic viscosity, thermal conductivity, specific heat, flash point, saturated water absorption, thermal stability, breakdown voltage and other performance indicators. No heat stabilizer is added in the comparative example, and its thermal stability is slightly lower than that of Example 15, but its thermal stability is still at a relatively high level, which also reflects from the side that the mineral base oil adopted by the present invention has good self - stability. On the basis of this mineral base oil, only a small amount of antioxidant and heat stabilizer need to be added to improve the antioxidant property and thermal stability of the product, and meet the safety requirements for the operation of high - power charging piles.

[0037] In summary, the present invention provides a mineral oil type charging pile coolant. Its mineral base oil is prepared by a hydrotreating - dewaxing refining - supplementary refining process, which has good insulation and stability. By adding a functional additive formulation, the antioxidant property and thermal stability of the product are improved, meeting the safety requirements for the operation of high - power charging piles, ensuring stable performance of the coolant under working conditions, extending the service life of the coolant, and ensuring the long - term stable operation of high - power charging piles.

[0038] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effects. Non - essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A mineral oil type charging pile coolant, characterized in that Per hundred parts by mass, the raw materials include: 98.9 to 99.78 parts of mineral base oil, 0.2 to 1.0 part of antioxidant, and 0.02 to 0.1 part of heat stabilizer. The mineral base oil is prepared by a process of hydrotreating, dewaxing and finishing of petroleum fractions.

2. The mineral oil-based charging pile coolant according to claim 1, characterized in that It is prepared by the following method: Mix the required amounts of mineral base oil, antioxidant and heat stabilizer, heat to 50°C to 60°C, stir until clear and transparent, then cool to room temperature, and filter to obtain the mineral oil type charging pile coolant.

3. The mineral oil-based charging pile coolant according to claim 1 or 2, characterized in that The process conditions for hydrotreating are as follows: reaction temperature is 240°C to 410°C, reaction pressure is 15.0 MPa to 17.0 MPa, volumetric space velocity is 0.4 h -1 to 1.7 h -1 , and the hydrogen-oil ratio is 500 to 1000.

4. The mineral oil type charging pile coolant according to any one of claims 1 to 3, characterized in that The technological conditions for dewaxing and refining are as follows: the reaction temperature is 220°C to 400°C, the reaction pressure is 15.0 MPa to 17.0 MPa, the volumetric space velocity is 0.5 h -1 to 1.5 h -1 , and the hydrogen-oil ratio is 500 to 1000.

5. The mineral oil-based charging pile coolant according to any one of claims 1 to 4, characterized in that The process conditions for supplementary refining are as follows: the reaction temperature is 220°C to 330°C, the reaction pressure is 10.0 MPa to 20.0 MPa, the volumetric space velocity is 0.4 h -1 to 2.0 h -1 , and the hydrogen-oil ratio is 400 to 600.

6. The mineral oil type charging pile coolant according to any one of claims 1 to 5, characterized in that The mineral base oil is one or more of mineral base oils A, B, and C. Among them, the distillation range of mineral base oil A is 280°C to 460°C, the distillation range of mineral base oil B is 320°C to 460°C, and the distillation range of mineral base oil C is 320°C to 480°C.

7. The mineral oil-based charging pile coolant according to any one of claims 1 to 6, characterized in that The antioxidant is one or more of 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol and alkyl diphenylamine; and / or the heat stabilizer is one or two of epoxy ester, pentaerythritol and β-diketone.

8. The mineral oil-based charging pile coolant according to any one of claims 1 to 7, characterized in that The breakdown voltage is greater than 50 kV; and / or the saturated water absorption is less than 20 mg / kg.

9. The mineral oil type charging pile coolant according to any one of claims 1 to 8, characterized in that The kinematic viscosity at 40°C is 10 mm 2 / s to 15 mm 2 / s.

10. A method for preparing a mineral oil-based charging pile coolant according to claim 1 or 3 or 4 or 5 or 6 or 7 or 8 or 9, characterized in that It is carried out according to the following steps: Mix the required amounts of mineral base oil, antioxidant and heat stabilizer, heat to 50°C to 60°C, stir until clear and transparent, then cool to room temperature, and filter to obtain the mineral oil type charging pile coolant.

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