阅读说明：本技术 一种纳米SiC改性的高导热率玉米绝缘油及其制备方法 (Nano SiC-modified high-thermal-conductivity corn insulating oil and preparation method thereof ) 是由 张镱议 刘捷丰 刘楚英 张恒 于 2021-06-09 设计创作，主要内容包括：本发明涉及高电压与绝缘技术领域,具体公开了一种纳米SiC改性的高导热率玉米绝缘油及其制备方法。该方法步骤包括：(1)将纳米硅酸钠及SiC纳米粒子加热升温进行混合球磨；(2)在混合球磨的混合物中加入油酸,继续升温并进行机械搅拌,然后超声；(3)对步骤(2)中超声震荡后的混合物进行过滤,乙醇洗涤,干燥,得到改性纳米SiC颗粒；(4)将改性纳米SiC颗粒与氢氧化钠、偶联剂和水混合后超声振荡均匀,形成混合液；(5)进行玉米绝缘油室温条件下真空过滤；(6)将步骤(4)中得到的混合液加入玉米绝缘油中,超声振荡,真空干燥,得到纳米SiC改性玉米绝缘油。本发明的纳米SiC改性的高导热率玉米绝缘油不仅具有较高的导热系数,而且具备较高体积电阻率。(The invention relates to the technical field of high voltage and insulation, and particularly discloses nano SiC modified high-thermal-conductivity corn insulating oil and a preparation method thereof. The method comprises the following steps: (1) heating nano sodium silicate and SiC nano particles, heating, mixing and ball-milling; (2) adding oleic acid into the mixture subjected to the mixed ball milling, continuously heating, mechanically stirring, and then performing ultrasonic treatment; (3) filtering the mixture subjected to ultrasonic oscillation in the step (2), washing with ethanol, and drying to obtain modified nano SiC particles; (4) mixing the modified nano SiC particles with sodium hydroxide, a coupling agent and water, and then uniformly oscillating by ultrasound to form a mixed solution; (5) carrying out vacuum filtration under the temperature condition of the corn insulating oil chamber; (6) and (4) adding the mixed solution obtained in the step (4) into the corn insulating oil, performing ultrasonic oscillation, and performing vacuum drying to obtain the nano SiC modified corn insulating oil. The nano SiC modified high-thermal-conductivity corn insulating oil disclosed by the invention not only has a higher thermal conductivity coefficient, but also has a higher volume resistivity.)

1. A preparation method of nano SiC modified high-thermal conductivity corn insulating oil is characterized by comprising the following steps:

(1) mixing nano sodium silicate and SiC nano particles, heating the mixture to a set temperature, and then carrying out mixing ball milling;

(2) adding oleic acid into the mixture obtained in the step (1), heating to another set temperature, mechanically stirring the mixture, and then ultrasonically oscillating;

(3) filtering the mixture subjected to ultrasonic oscillation in the step (2), washing with ethanol, and drying to obtain modified nano SiC particles;

(4) mixing the modified nano SiC particles with sodium hydroxide, a coupling agent and water, and then uniformly oscillating by ultrasound to form a mixed solution;

(5) carrying out vacuum filtration on the corn insulating oil;

(6) and (4) adding the mixed solution obtained in the step (4) into the corn insulating oil, performing ultrasonic oscillation, and performing vacuum drying to obtain the nano SiC modified corn insulating oil.

2. The preparation method of the nano SiC-modified high thermal conductivity corn insulating oil as claimed in claim 1, wherein the particle size of the SiC nano particles in the step (1) is 10-100 nm.

3. The method for preparing the nano SiC-modified high-thermal-conductivity corn insulating oil as claimed in claim 1, wherein in the step (1), the particle size of the sodium silicate nano particles is 24-31 nm.

4. The preparation method of the nano SiC-modified high-thermal-conductivity corn insulating oil as claimed in claim 1, wherein in the step (1), the heating temperature is 40-50 ℃, and the mixing and ball-milling time is 1-3 h.

5. The method for preparing the nano SiC-modified high thermal conductivity corn insulating oil as claimed in claim 1, wherein in the step (2), the ratio of the amount of oleic acid to the amount of SiC nano particles is 40ml:1 g.

6. The method for preparing the nano SiC modified high thermal conductivity corn insulating oil as claimed in claim 1, wherein in the step (2), the other set temperature is 80-90 ℃, and the mechanical stirring is as follows: stirring for 20-25 min at the rotating speed of 2000r/min, and performing ultrasonic oscillation as follows: and (3) performing ultrasonic treatment for 20-30 min under the condition of 1000W of power.

7. The preparation method of the nano SiC-modified high-thermal-conductivity corn insulating oil as claimed in claim 1, wherein in the step (4), the ultrasonic oscillation time is 9-10 min.

8. The method for preparing the nano SiC-modified high-thermal-conductivity corn insulating oil as claimed in claim 1, wherein the mass ratio of the modified nano SiC particles, the sodium hydroxide, the coupling agent and the water in the step (4) is (1-3): (2-5): 10.

9. The preparation method of the nano SiC-modified high-thermal-conductivity corn insulating oil as claimed in claim 1, wherein the ultrasonic oscillation in the step (6) is ultrasonic for 10-13 min under the power condition of 800W, and the vacuum drying is drying in a vacuum drying oven for 6-8 h.

10. The nano SiC-modified high-thermal-conductivity corn insulating oil prepared by the preparation method of the nano SiC-modified high-thermal-conductivity corn insulating oil as claimed in any one of claims 1 to 9, wherein the modified nano SiC is contained in the nano SiC-modified high-thermal-conductivity corn insulating oil by mass in a range of 2% to 6%.

Technical Field

The invention relates to the technical field of high voltage and insulation, in particular to nano SiC modified high-thermal-conductivity corn insulating oil and a preparation method thereof.

Background

Oil-filled power transformers are critical devices in the safe operation of power grids, and the failure of the oil-filled power transformers interrupts the power supply. The insulation performance of oil-filled transformers is mainly determined by the internal insulation consisting of insulating oil and insulating paper. The insulating oil plays roles of insulation, heat dissipation and cooling, and the guarantee of good operation characteristics of the insulating oil is very important for safe operation of the transformer. Corn oil is used as a novel breakdown-resistant, high-ignition-point and environment-friendly liquid dielectric medium and is used as transformer insulating oil. However, the corn insulating oil has high viscosity and low fluidity, and is not beneficial to heat dissipation inside the transformer, so that the application of the corn insulating oil in a large power transformer is limited. Therefore, the development of the high-thermal conductivity corn insulating oil has important practical value.

Disclosure of Invention

Aiming at the problem of low heat dissipation performance of the corn insulating oil, the invention aims to provide the nano SiC modified high-thermal-conductivity corn insulating oil and the preparation method thereof.

In order to achieve the aim, the invention provides a preparation method of nano SiC modified high-thermal conductivity corn insulating oil, which is characterized by comprising the following steps:

(1) adding nano sodium silicate and SiC nano particles into a ball mill for mixing, heating the mixture to a set temperature, and then carrying out mixing ball milling; the mixing mass ratio of the nano sodium silicate to the SiC nano particles is 1: 1-8: 3;

(2) adding oleic acid into the mixture subjected to the mixed ball milling, continuously heating the mixture to another set temperature, mechanically stirring the mixture, and then ultrasonically oscillating;

(3) washing the mixture subjected to ultrasonic oscillation in the step (2) with ethanol, filtering and drying to obtain modified nano SiC particles;

(4) mixing the modified nano SiC particles with sodium hydroxide, a coupling agent and water, and then uniformly oscillating by ultrasound to form a mixed solution;

(5) carrying out vacuum filtration under the temperature condition of the corn insulating oil chamber;

(6) and (4) adding the mixed solution obtained in the step (4) into the corn insulating oil, performing ultrasonic oscillation, and performing vacuum drying to obtain the nano SiC modified corn insulating oil.

Preferably, in the above technical solution, the particle size of the SiC nanoparticle in step (1) is 10-100 nm.

Preferably, in the above technical scheme, the particle size of the sodium silicate nanoparticles in step (1) is 24-31 nm.

Preferably, in the above technical scheme, the set temperature in the step (1) is 40-50 ℃, and the mixing and ball-milling time is 1-3 h.

Preferably, in the above technical solution, the ratio of the amount of the oleic acid used in the step (2) to the amount of the SiC nanoparticles used in the step (1) is 40ml to 1 g.

Preferably, in the above technical scheme, the other set temperature in the step (2) is 80-90 ℃, the machine stirring is carried out for 20-25 min at a rotating speed of 2000r/min, and the ultrasonic oscillation is carried out for 20-30 min at a power of 1000W.

Preferably, in the above technical scheme, the ultrasonic oscillation time in the step (4) is 9-10 min.

Preferably, in the above technical scheme, the mixing mass ratio of the modified nano SiC particles, the sodium hydroxide, the coupling agent and the water in the step (4) is (1-3): (2-5): 10.

Preferably, in the above technical scheme, in the step (6), the ultrasonic oscillation is performed for 10-13 min under the power of 800W, and the vacuum drying is drying in a vacuum drying oven for 6-8 h.

Further, the invention also provides the nano SiC modified high-thermal-conductivity corn insulating oil prepared according to the technical scheme, wherein the mass content of modified nano SiC in the nano SiC modified high-thermal-conductivity corn insulating oil is 2-6%.

The invention has the following beneficial effects:

the modified high-thermal-conductivity corn insulating oil is obtained by adding the modified nano SiC material into the corn insulating oil, and the high-thermal-conductivity corn insulating oil is simple in preparation method, low in material cost and easy to popularize; in the process of preparing the modified high-thermal-conductivity corn insulating oil, the invention improves the agglomeration phenomenon of the modified SiC nano particles and ensures that the modified nano SiC is uniformly dispersed in the corn insulating oil; the modified corn insulating oil disclosed by the invention not only has good heat-conducting property, but also has higher volume resistivity and good long-term stability.

Drawings

FIG. 1 is a schematic flow diagram of a process for preparing nano SiC modified high thermal conductivity corn insulating oil in accordance with an embodiment of the present invention;

FIG. 2 is a graph comparing the effect of modified nano SiC content on the thermal conductivity of corn insulating oil according to an embodiment of the present invention;

FIG. 3 is a graph comparing the effect of modified nano-SiC content on corn insulating oil volume resistivity for examples of the invention.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the scope of the present invention will be more clearly and clearly defined.

The preparation flow of the nano SiC modified high-thermal conductivity corn insulating oil is shown in figure 1 and is specifically implemented in the following examples

Example 1

Preparing the nano SiC modified high-thermal conductivity corn insulating oil:

(1) adding nano sodium silicate with the particle size of 24-31nm and SiC nano particles with the particle size of 10-100nm into a ball mill, mixing, and carrying out ball milling for 3h after heating the mixture to 40 ℃; the mixing mass ratio of the nano sodium silicate to the SiC nano particles is 1:1;

(2) adding oleic acid into the mixture subjected to mixing and ball milling, then continuously heating the mixture to 80 ℃, stirring the mixture by a machine for 20min at the rotating speed of 2000r/min, and then ultrasonically oscillating for 20min at the power of 1000W; the ratio of the using amount of the oleic acid to the using amount of the SiC nano particles is 40ml to 1 g;

(3) filtering the mixture subjected to ultrasonic oscillation in the step (2), washing with ethanol, and drying to obtain modified nano SiC particles;

(4) mixing the modified nano SiC particles with sodium hydroxide, a coupling agent KH-570 and water, and then carrying out ultrasonic oscillation for 9min to form a mixed solution; the mixing mass ratio of the modified nano SiC particles to the sodium hydroxide to the coupling agent to the water is 1:2:2: 10;

(5) carrying out vacuum filtration under the temperature condition of the corn insulating oil chamber;

(6) adding the mixed solution obtained in the step (4) into corn insulating oil, performing ultrasonic oscillation, and drying in a vacuum drying oven for 6 hours to obtain nano SiC modified corn insulating oil, wherein the mass content of modified nano SiC in the nano SiC modified corn insulating oil is 2%; the ultrasonic vibration is ultrasonic 10 under the condition of 800W power.

Example 2

Preparing the nano SiC modified high-thermal conductivity corn insulating oil:

(1) adding nano sodium silicate with the particle size of 24-31nm and SiC nano particles with the particle size of 10-100nm into a ball mill, mixing, and carrying out ball milling for 1h after heating the mixture to 50 ℃; the mixing mass ratio of the nano sodium silicate to the SiC nano particles is 8:3;

(2) adding oleic acid into the mixture subjected to mixing and ball milling, then continuously heating the mixture to 90 ℃, stirring the mixture by a machine at a rotating speed of 2000r/min for 25min, and then ultrasonically oscillating the mixture for 30min under a power condition of 1000W; the ratio of the using amount of the oleic acid to the using amount of the SiC nano particles is 40ml to 1 g;

(3) filtering the mixture subjected to ultrasonic oscillation in the step (2), washing with ethanol, and drying to obtain modified nano SiC particles;

(4) mixing the modified nano SiC particles with sodium hydroxide, a coupling agent KH-570 and water, and then carrying out ultrasonic oscillation for 10min to form a mixed solution; the mixing mass ratio of the modified nano SiC particles to the sodium hydroxide to the coupling agent to the water is 3:5:5: 10;

(5) carrying out vacuum filtration under the temperature condition of the corn insulating oil chamber;

(6) adding the mixed solution obtained in the step (4) into corn insulating oil, performing ultrasonic oscillation, and drying in a vacuum drying oven for 8 hours to obtain nano SiC modified corn insulating oil, wherein the mass content of modified nano SiC in the nano SiC modified corn insulating oil is 3%; and (4) carrying out ultrasonic treatment for 13min under the condition of the ultrasonic oscillation of 800W power.

Example 3

Preparing the nano SiC modified high-thermal conductivity corn insulating oil:

(1) adding nano sodium silicate with the particle size of 24-31nm and SiC nano particles with the particle size of 10-100nm into a ball mill, mixing, and carrying out ball milling for 2 hours after heating the mixture to 45 ℃; the mixing mass ratio of the nano sodium silicate to the SiC nano particles is 4:3;

(2) adding oleic acid into the mixture subjected to mixing and ball milling, then continuously heating the mixture to 85 ℃, stirring the mixture by a machine for 23min at the rotating speed of 2000r/min, and then ultrasonically oscillating for 25min at the power of 1000W; the ratio of the using amount of the oleic acid to the using amount of the SiC nano particles is 40ml to 1 g;

(3) filtering the mixture subjected to ultrasonic oscillation in the step (2), washing with ethanol, and drying to obtain modified nano SiC particles;

(4) mixing the modified nano SiC particles with sodium hydroxide, a coupling agent KH-570 and water, and then carrying out ultrasonic oscillation for 10min to form a mixed solution; the mixing mass ratio of the modified nano SiC particles to the sodium hydroxide to the coupling agent to the water is 2:4:4: 10;

(5) carrying out vacuum filtration under the temperature condition of the corn insulating oil chamber;

(6) adding the mixed solution obtained in the step (4) into corn insulating oil, performing ultrasonic oscillation, and drying in a vacuum drying oven for 7 hours to obtain nano SiC modified corn insulating oil, wherein the mass content of modified nano SiC in the nano SiC modified corn insulating oil is 4%; and (5) carrying out ultrasonic treatment for 12min under the condition of the ultrasonic oscillation of 800W power.

Example 4

Preparing the nano SiC modified high-thermal conductivity corn insulating oil:

(1) adding nano sodium silicate with the average particle size of 24-31nm and SiC nano particles with the particle size of 10-100nm into a ball mill, mixing, and carrying out ball milling for 1.5h after heating the mixture to 47 ℃;

(2) adding oleic acid into the mixture subjected to mixing and ball milling, then continuously heating the mixture to 86 ℃, stirring the mixture by a machine for 22min at the rotating speed of 2000r/min, and then ultrasonically oscillating for 27min at the power of 1000W; the ratio of the using amount of the oleic acid to the using amount of the SiC nano particles is 40ml to 1 g;

(3) filtering the mixture subjected to ultrasonic oscillation in the step (2), washing with ethanol, and drying to obtain modified nano SiC particles;

(4) mixing the modified nano SiC particles with sodium hydroxide, a coupling agent KH-570 and water, and then carrying out ultrasonic oscillation for 10min to form a mixed solution; the mixing mass ratio of the modified nano SiC particles to the sodium hydroxide to the coupling agent to the water is 2:4:5: 10;

(5) carrying out vacuum filtration under the temperature condition of the corn insulating oil chamber;

(6) adding the mixed solution obtained in the step (4) into corn insulating oil, performing ultrasonic oscillation, and drying in a vacuum drying oven for 7 hours to obtain nano SiC modified corn insulating oil, wherein the mass content of modified nano SiC in the nano SiC modified corn insulating oil is 5%; and (5) carrying out ultrasonic treatment for 11min under the condition of the ultrasonic oscillation of 800W power.

Example 5

Preparing the nano SiC modified high-thermal conductivity corn insulating oil:

(1) adding nano sodium silicate with the particle size of 24-31nm and SiC nano particles with the particle size of 10-100nm into a ball mill, mixing, and carrying out ball milling for 1h after heating the mixture to 50 ℃; the mixing mass ratio of the nano sodium silicate to the SiC nano particles is 6:3;

(2) adding oleic acid into the mixture subjected to mixing and ball milling, then continuously heating the mixture to 90 ℃, stirring the mixture by a machine at a rotating speed of 2000r/min for 25min, and then ultrasonically oscillating the mixture for 30min under a power condition of 1000W; the ratio of the using amount of the oleic acid to the using amount of the SiC nano particles is 40ml to 1 g;

(3) filtering the mixture subjected to ultrasonic oscillation in the step (2), washing with ethanol, and drying to obtain modified nano SiC particles;

(4) mixing the modified nano SiC particles with sodium hydroxide, a coupling agent KH-570 and water, and then carrying out ultrasonic oscillation for 10min to form a mixed solution; the mixing mass ratio of the modified nano SiC particles to the sodium hydroxide to the coupling agent to the water is 2:4:4: 10;

(5) carrying out vacuum filtration under the temperature condition of the corn insulating oil chamber;

(6) adding the mixed solution obtained in the step (4) into corn insulating oil, performing ultrasonic oscillation, and drying in a vacuum drying oven for 8 hours to obtain nano SiC modified corn insulating oil, wherein the mass content of modified nano SiC in the nano SiC modified corn insulating oil is 6%; and (4) carrying out ultrasonic treatment for 13min under the condition of the ultrasonic oscillation of 800W power.

The results of the tests on the nano SiC-modified corn insulating oils obtained in examples 1, 3 and 5 are shown in fig. 2 and 3, and it can be seen from fig. 2 that the heat conductivity of the corn insulating oil with 4% by mass of modified nano SiC is higher than the heat conductivity of the corn insulating oil with 6% by mass of modified nano SiC, 2% by mass of modified nano SiC and without modified nano SiC at the same temperature, the heat conductivity of the corn insulating oil with 6% by mass of modified nano SiC and 2% by mass of modified nano SiC is higher than the heat conductivity of the corn insulating oil without modified nano SiC, the heat conductivity of the corn insulating oil with different contents of modified nano SiC is reduced to different degrees with the temperature rise, the insulating oil is raised at 30 to 90 ℃, and particularly, the heat conductivity of the corn insulating oil with 4% by mass of modified nano SiC within the temperature range of 30 to 50 ℃ is minimized with the temperature rise, the heat-conducting property is stable. Fig. 3 shows that the volume resistivity of the corn insulating oil with the added modified nano SiC is greater than that of the corn insulating oil without the added modified nano SiC, and particularly, the volume resistivity of the corn insulating oil with the modified nano SiC content of 4% is greater than that of the corn insulating oil with other content or without the added modified nano SiC, so that the insulating property is outstanding.

The nano SiC modified high-thermal-conductivity corn insulating oil prepared by the invention has the advantages of high thermal conductivity coefficient, reliable insulating property, simple preparation method, low material cost and easy popularization.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.