Non-aqueous insulating cooling liquid for cold source end of liquid cooling heat dissipation system and preparation method of non-aqueous insulating cooling liquid

Abstract

The invention relates to non-aqueous insulating cooling liquid for a cold source end of a liquid cooling heat dissipation system and a preparation method of the non-aqueous insulating cooling liquid. The preparation method comprises the following steps: (1) dispersing nano boron nitride particles in absolute ethyl alcohol, adding a silane coupling agent, and uniformly stirring; heating to 30-40 DEG C, stirring and reacting for 2-4 hours, filtering, washing and drying to obtain modified boron nitride; and (2) adding the modified boron nitride into the modified silicone oil, and ultrasonically stirring uniformly to obtain the non-aqueous insulating cooling liquid, wherein the organic functional group of the modified silicone oil is methacrylic acid, and the viscosity at 25 DEG C is 2-10 mm < 2 > / s. According to the non-aqueous insulating cooling liquid prepared by the preparation method disclosed by the invention, the modified boron nitride can be lastingly and stably wrapped in the methacrylic acid modified silicone oil with the spiral structure, and is still not layered after standing for 60 days at 30 DEG C; the pour point is low, and pipelines do not need heat preservation; and even if the insulating liquid is mixed into insulating cooling liquid which is in direct contact with the electronic component, the short circuit of the electronic component can be avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid cooling, and in particular relates to a non-aqueous insulating coolant for a cold source end of a liquid cooling heat dissipation system and a preparation method thereof. Background Art

[0002] In common liquid cooling scenarios, the cold source end of the heat dissipation system is a plate heat exchanger, which uses a coolant such as water, or a mixture of ethylene glycol and water.

[0003] If water is used as the coolant, there are the following disadvantages: 1. When the pipe of the plate heat exchanger is perforated, water enters the liquid cooling liquid circuit through the pipe, and there is a risk of short circuit and burning of the server; 2. The pipe needs to be insulated in winter. If the insulation is not good, the water in the pipe is easy to freeze and the circulation is not smooth, causing the liquid cooling system to shut down due to poor heat dissipation.

[0004] If the coolant is a mixture of ethylene glycol and water, it has the following shortcomings: 1. Although ethylene glycol solution is not corrosive, ethylene glycol will react chemically with dissolved oxygen in water to produce weakly acidic compounds, which will corrode seamless steel pipes, galvanized steel pipes and steel heat exchangers, especially for computer room systems that run for a long time, which will cause safety hazards; 2. Coolant system sewage discharge, water evaporation, etc. will cause the loss of ethylene glycol solution, and ethylene glycol and water will not be lost in equal proportions, causing the concentration of ethylene glycol and water in the coolant system to fluctuate, and the pour point will also fluctuate accordingly. If it is not well controlled, there is still a risk of pipe freezing and cracking in winter, and the water-containing coolant entering the electronic component liquid pool will also cause the electronic components to short-circuit. Summary of the invention

[0005] Based on the above-mentioned shortcomings and deficiencies in the prior art, one of the objects of the present invention is to solve at least one or more of the above-mentioned problems in the prior art. In other words, one of the objects of the present invention is to provide a non-aqueous insulating coolant for the cold source end of a liquid-cooled heat dissipation system and a preparation method thereof that meets one or more of the above-mentioned needs.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0007] A method for preparing a non-aqueous insulating coolant for a cold source end of a liquid cooling system comprises the following steps:

[0008] (1) dispersing nano boron nitride particles in anhydrous ethanol, adding a silane coupling agent, and stirring evenly; heating to 30-40° C. and stirring for reaction for 2-4 hours, filtering, washing, and drying to obtain modified boron nitride;

[0009] (2) adding modified boron nitride to modified silicone oil and stirring the mixture evenly by ultrasonic stirring to obtain a non-aqueous insulating coolant;

[0010] Among them, the organic functional group of the modified silicone oil is methacrylic acid, and the viscosity at 25°C is 2 to 10 mm 2 / s.

[0011] As a preferred embodiment, the mass ratio of the silane coupling agent to the boron nitride particles is (2-8):1.

[0012] As a preferred embodiment, the mass ratio of the silane coupling agent to the boron nitride particles is 5:1.

[0013] As a preferred solution, the model of the silane coupling agent is Shin-Etsu KR-519.

[0014] As a preferred embodiment, the mass ratio of the modified boron nitride to the modified silicone oil is (5-10):100.

[0015] As a preferred embodiment, the mass ratio of the modified boron nitride to the modified silicone oil is 8.6:100.

[0016] As a preferred embodiment, the viscosity of the modified silicone oil at 25°C is 5 mm 2 / s.

[0017] As a preferred solution, the model of the modified silicone oil is Shin-Etsu X-22-2404.

[0018] The present invention also provides a non-aqueous insulating coolant prepared by the preparation method described in any of the above schemes.

[0019] As a preferred solution, the pour point of the non-aqueous insulating coolant is not higher than -50°C and the thermal conductivity is not less than 0.35 W / (m·K).

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The non-aqueous insulating coolant of the present invention has a low pour point and the pipeline does not need to be insulated;

[0022] (2) In the non-aqueous insulating coolant prepared by the preparation method of the present invention, the modified boron nitride can be permanently and stably encapsulated in the helical methacrylic acid modified silicone oil, and no stratification occurs when placed at 30° C. for 60 days;

[0023] (3) The non-aqueous insulating coolant of the present invention has good insulation properties. Even if it is mixed into the insulating coolant in direct contact with electronic components due to defects in the pipeline or the heat exchanger itself, short circuit of the electronic components can be avoided.

[0024] (4) The non-aqueous insulating coolant of the present invention has low viscosity and good heat exchange effect, and the dispersion of nano boron nitride particles in the oil forms a new heat conduction network, thereby improving the thermal conductivity of the entire system. In addition, the Brownian motion of the nanoparticles can promote the transfer of heat in the liquid, and this microscopic heat convection also helps to improve the thermal conductivity;

[0025] (5) The modified silicone oil of the present invention has excellent antioxidant properties and its service life is guaranteed. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further explained below through specific embodiments.

[0027] Embodiment 1:

[0028] The method for preparing the non-aqueous insulating coolant of this embodiment comprises the following steps:

[0029] (1) Preparation of modified boron nitride

[0030] 100 g of nano boron nitride particles (content ≥ 99.5%) were dispersed in 600 mL of anhydrous ethanol solvent, 500 g of silane coupling agent (Shin-Etsu KR-519) was added, and the mass ratio of silane coupling agent to boron nitride particles was 5:1. After stirring evenly, the mixture was heated to 30°C and stirred for 2 hours, and then filtered, washed and dried to obtain modified boron nitride.

[0031] (2) Preparation of non-aqueous insulating coolant

[0032] 100g of modified boron nitride was added to 8.6g of modified silicone oil (Shin-Etsu X-22-2404, organic functional group is methacrylic acid, viscosity 5mm at 25℃) 2 / s), the mass ratio of modified boron nitride to modified silicone oil is 100:8.6, and ultrasonic stirring is performed to obtain a non-aqueous insulating coolant.

[0033] Comparative Example 1:

[0034] The coolant in this comparative example is a conventional 70 vol% ethylene glycol aqueous solution.

[0035] The parameter indicators of the non-aqueous insulating coolant of Example 1 and the coolant of Comparative Example 1 were measured. As shown in Table 1, the pour point of the non-aqueous insulating coolant of Example 1 is as low as -53°C, the thermal conductivity is higher, and the volume resistivity is much higher than that of Comparative Example 1, indicating that the insulation is good.

[0036] Table 1 Parameters of the coolant of Example 1 and Comparative Example 1

[0037] Parameters Comparative Example 1 Example 1 Pour point(℃) -51 -53 Thermal conductivity (W / (m·K)) 25℃ 0.37 0.55 Volume resistivity (Ω·m) <![CDATA[3×10 2 ]]> <![CDATA[1.193×10 12 ]]> <![CDATA[Kinematic viscosity (mm 2 / s) at 25°C]]> 5.9 5

[0038] In addition, this comparative example also measured the parameter indicators of aqueous solutions of ethylene glycol with different concentrations as coolants, as shown in Table 2.

[0039] Table 2 Parameters of different concentrations of ethylene glycol aqueous solutions as coolants

[0040]

[0041] Comparative Example 2:

[0042] The difference between the coolant in this comparative example and that in Example 1 is that:

[0043] The modified silicone oil Shin-Etsu X-22-2404 was replaced with other silicone oils of the same viscosity (the choice of viscosity mainly considers the fluidity of the coolant), and the prepared coolant was left to stand at 30°C for 60 days to observe whether it was stratified to determine the stability of the prepared coolant, as shown in Table 3.

[0044] Table 3 Index parameters of different coolants

[0045]

[0046]

[0047] Comparative Example 3:

[0048] The difference between the coolant in this comparative example and that in Example 1 is that:

[0049] The silane coupling agent KR-519 was replaced with other silane coupling agents of siloxane chain type that can be dissolved in anhydrous ethanol (considering the better compatibility between the organic chain of the silane coupling agent and the modified silicone oil, the silane coupling agent of siloxane chain type was selected to modify the boron nitride), and the prepared coolant was left to stand at 30°C for 60 days to observe whether it was stratified to determine the stability of the prepared coolant; after stratification, the upper layer of liquid was taken to test the performance, and the data obtained are shown in the table below, which are almost the same as the modified silicone oil itself; the specific index parameters are shown in Table 4.

[0050] Table 4 Index parameters of different coolants

[0051]

[0052] In the above embodiment and its alternatives, during the preparation of modified boron nitride, the heating temperature can also be 32°C, 35°C, 36°C, 40°C, etc., and the reaction time can also be 2.5 hours, 3 hours, 3.5 hours, 4 hours, etc.

[0053] In the above embodiment and its alternatives, the organic functional group of the modified silicone oil is methacrylic acid, and the viscosity at 25°C can also be 2 mm 2 / s, 4mm 2 / s, 6mm 2 / s, 9mm 2 / s, 10mm 2 / s, etc.

[0054] In the above embodiment and its alternatives, the mass ratio of the silane coupling agent to the boron nitride particles may also be 2:1, 3:1, 6:1, 8:1, etc.

[0055] In the above embodiment and its alternatives, the mass ratio of modified boron nitride to modified silicone oil can also be 5:100, 6.5:100, 9:100, 10:100, etc.

[0056] In view of the numerous embodiments of the scheme of the present invention, the raw materials and dosage involved can be selected according to actual needs within the limited range, and the experimental data of each embodiment is huge and numerous, which is not suitable for listing and explaining one by one here, but the content required to be verified and the final conclusion obtained in each embodiment are similar. Therefore, the verification content of each embodiment will not be explained one by one here.

[0057] The above description is only a detailed description of the preferred embodiments and principles of the present invention. For ordinary technicians in this field, according to the ideas provided by the present invention, there will be changes in the specific implementation methods, and these changes should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a non-aqueous insulating coolant for a cold source end of a liquid cooling system, characterized in that: The following steps are involved: (1) dispersing nano boron nitride particles in anhydrous ethanol, adding a silane coupling agent, and stirring evenly; heating to 30-40° C. and stirring for reaction for 2-4 hours, filtering, washing, and drying to obtain modified boron nitride; (2) adding modified boron nitride to modified silicone oil, stirring evenly by ultrasonication, and obtaining a non-aqueous insulating coolant; Among them, the organic functional group of the modified silicone oil is methacrylic acid, and the viscosity at 25°C is 2 to 10 mm 2 / s.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the silane coupling agent to the boron nitride particles is (2-8):

1.

3. The preparation method according to claim 2, characterized in that: The mass ratio of the silane coupling agent to the boron nitride particles is 5:

1.

4. The preparation method according to claim 1, 2 or 3, characterized in that: The model of the silane coupling agent is Shin-Etsu KR-519.

5. The preparation method according to claim 1, characterized in that: The mass ratio of the modified boron nitride to the modified silicone oil is (5-10):

100.

6. The preparation method according to claim 5, characterized in that: The mass ratio of the modified boron nitride to the modified silicone oil is 8.6:

100.

7. The preparation method according to claim 1, 5 or 6, characterized in that: The viscosity of the modified silicone oil at 25°C is 5 mm 2 / s.

8. The preparation method according to claim 7, characterized in that: The model of the modified silicone oil is Shin-Etsu X-22-2404.

9. The non-aqueous insulating coolant obtained by the preparation method according to any one of claims 1 to 8.

10. The non-aqueous insulating coolant according to claim 9, characterized in that: The pour point is not higher than -50°C and the thermal conductivity is not less than 0.35W / (m·K).

Images