A type of suspension porcelain insulator

Abstract

This invention relates to the field of ceramic insulator materials, specifically a suspension ceramic insulator, comprising a ceramic body, an iron cap, and a steel foot. The ceramic body includes an alumina matrix and a first coating and a second coating extending outward from the surface of the alumina matrix. The first coating comprises nano-alumina, nano-titanium dioxide, silica powder, and modified water glass. The second coating comprises nano-oxide particles, nano-titanium dioxide, aminated carbon quantum dots, and ATiO3, wherein A is any one or more combinations of Zn, Ca, and Sr. The insulator prepared by this invention exhibits good self-cleaning properties, indicating that dirt is difficult to adhere to the surface of the insulator, thus exhibiting lower ESDD and NSDD values ​​and strong resistance to surface flashover.

Description

Technical Field

[0001] This invention relates to the field of ceramic insulator materials, specifically a suspension ceramic insulator. Background Technology

[0002] Insulators are an essential component of power transmission lines. Their function is mainly reflected in two aspects. First, they connect the conductors at high potential to the towers at low potential, bearing the mechanical forces such as gravity and wind force of the conductors; therefore, they need to meet mechanical performance requirements. Second, they also need to ensure insulation between the two, which is their electrical performance requirement.

[0003] Suspension porcelain insulators, as a type of insulator, have a relatively simple structure, but their importance is no less than that of any other equipment and device that constitutes a power system. In transmission lines, insulators operate in parallel, and a problem with any string of insulators will cause a fault in the transmission line, which can lead to a prolonged power outage in severe cases, causing great harm to the safe operation of the power system and people's daily lives.

[0004] When insulators are placed outdoors for a long time, gaseous, liquid, or solid contaminants will accumulate on their surfaces. Under complex and harsh environmental conditions, dirt often accumulates on the surface of the insulators, forming a conductive film. During the operation of the power grid, the voltage will cause the surface conductivity and leakage current to increase, thereby reducing the electrical strength of the insulator. In severe cases, it may even cause a complete flashover, which may lead to the disconnection of the power grid and cause a large-scale power outage, which will have a great impact on the safe and stable operation of the power grid. Summary of the Invention

[0005] Purpose of the invention: In view of the above-mentioned technical problems, the present invention proposes a suspension porcelain insulator.

[0006] The technical solution adopted is as follows:

[0007] A suspension porcelain insulator includes a porcelain body, an iron cap, and a steel foot. The porcelain body includes an alumina matrix and a first coating and a second coating extending outward from the surface of the alumina matrix.

[0008] The first coating comprises nano-alumina, nano-titanium dioxide, silica powder, and modified water glass;

[0009] The second coating comprises nano-oxide particles, nano-titanium dioxide, aminated carbon quantum dots, and ATiO3, wherein A is any one or more combinations of Zn, Ca, and Sr.

[0010] Furthermore, the mass ratio of nano-alumina, nano-titanium dioxide, and silicon micropowder in the first coating is 5-10:1:0.5-1.

[0011] Furthermore, the preparation method of the modified water glass is as follows:

[0012] The solution obtained by dissolving sodium tetrafluoroborate in water is added dropwise into water glass and stirred until homogeneous.

[0013] Furthermore, the preparation method of the aminated carbon quantum dots is as follows:

[0014] Citric acid and an amination reagent are dissolved in water to obtain a mixed solution. The mixed solution is added to a hydrothermal reactor, heated to 230-250°C and kept at that temperature for 3-5 hours. The mixture is then naturally cooled to room temperature. The resulting reaction solution is filtered through a microfiltration membrane, dialyzed, and then freeze-dried.

[0015] Furthermore, the amination reagent is any one or more combinations of ammonia, ethylenediamine, diethylenetriamine, or polyethyleneimine.

[0016] Furthermore, the mass ratio of the nano-oxide particles, aminated carbon quantum dots, and ATiO3 is 10-20:1-5:1-5.

[0017] Furthermore, the nano-oxide particles are any one or more combinations of nano-chromium oxide, nano-manganese oxide, nano-zinc oxide, and nano-copper oxide.

[0018] Furthermore, the nano-oxide particles are nano-chromium oxide and nano-zinc oxide, with a mass ratio of 1:1.

[0019] Furthermore, A is Sr.

[0020] Furthermore, the preparation method of the above-mentioned suspension porcelain insulator is as follows:

[0021] S1: Mix nano alumina, nano titanium dioxide, silica powder and modified water glass evenly to obtain slurry A. Coat slurry A evenly onto the surface of the alumina substrate, then dry it in an oven at 100-120℃ for 20-40 minutes. After removing it and cooling it to room temperature, perform low-temperature plasma treatment. Repeat the above operation 0-5 times to obtain a semi-finished ceramic body.

[0022] S2: Add nano-oxide particles, aminated carbon quantum dots, and ATiO3 to nano-titanium dioxide sol and mix evenly to obtain slurry B. Coat slurry B evenly onto the surface of the semi-finished ceramic body, then dry it in an oven at 100-120℃ for 20-40 minutes, take it out, cool it to room temperature, and then perform low-temperature plasma treatment. Repeat the above operation 0-5 times to obtain the ceramic body.

[0023] S3: Heat the ceramic body to 1250-1350℃, sinter for 2-4 hours, cool to room temperature, and then anneal for 1-2 hours at a temperature of 600-800℃. Finally, glue the ceramic body to the iron cap and steel foot with adhesive or mechanically clamp them to obtain the suspension porcelain insulator.

[0024] The beneficial effects of this invention are:

[0025] During sintering, due to the difference in thermal expansion coefficients between the coating and the substrate, interphase stress often occurs during cooling, which can easily lead to microcracks within the coating. The suspension porcelain insulator provided by this invention includes an alumina substrate and a first coating and a second coating extending outward from the surface of the alumina substrate. A smooth transition is formed between the alumina substrate and the first and second coatings, and the coating composition changes in a gradient. This ensures good adhesion between the coating and the alumina substrate while effectively reducing deformation caused by thermal stress and minimizing the generation of microcracks. The second coating has a certain effect on improving the electric field distribution on the insulator surface. Low-temperature plasma treatment not only strengthens the bonding performance between the coatings but also introduces interface defects between the second coatings, giving the nano-titanium dioxide in the second coating higher photocatalytic activity and self-cleaning performance, significantly improving the surface contamination condition. Annealing treatment can crystallize some of the grain boundary glass phases, improving the microstructure of the coating and enhancing its mechanical properties. The insulator prepared by this invention exhibits good self-cleaning performance, indicating that contaminants are difficult to adhere to the insulator surface, thus exhibiting lower ESDD and NSDD values ​​and strong resistance to surface flashover. Attached Figure Description

[0026] Figure 1 This is a cross-sectional SEM image of the ceramic body prepared in Example 1 of the present invention. Detailed Implementation

[0027] Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products. Techniques not mentioned in this invention refer to existing technologies.

[0028] Example 1:

[0029] A suspension porcelain insulator includes a porcelain body, an iron cap, and a steel foot, wherein the porcelain body includes an alumina matrix and a first coating and a second coating extending outward along the surface of the alumina matrix.

[0030] The first coating comprises nano-alumina, nano-titanium dioxide, silica powder, and modified water glass;

[0031] The second coating comprises nano-chromium oxide, nano-zinc oxide, nano-titanium dioxide, aminated carbon quantum dots, and SrTiO3.

[0032] The preparation method of modified water glass is as follows:

[0033] Dissolve 100g of sodium tetrafluoroborate in 250mL of water, add the resulting solution dropwise into 800mL of water glass, and stir until homogeneous.

[0034] The preparation method of aminated carbon quantum dots is as follows:

[0035] Dissolve 90g of citric acid and 45g of polyethyleneimine in 100mL of water to obtain a mixed solution. Add the mixed solution to a hydrothermal reactor, heat to 240℃ and keep at that temperature for 4 hours, then allow to cool naturally to room temperature. Filter the resulting reaction solution through a microfiltration membrane (0.2μm) and dialyze it using a dialysis bag with a molecular weight cutoff of 2000. Finally, freeze-dry the solution.

[0036] The preparation method of the above-mentioned suspension porcelain insulator is as follows:

[0037] 100g of nano-alumina, 10g of nano-titanium dioxide, and 10g of silica powder were added to the prepared modified water glass and stirred until homogeneous to obtain slurry A. Slurry A was uniformly coated onto the surface of the alumina substrate, then dried in a 120℃ oven for 30 minutes. After cooling to room temperature, it underwent low-temperature plasma treatment with helium as the dielectric gas and the average current density in the discharge region was adjusted to 5mA / cm². 2 After discharge treatment for 5 minutes, the above operation was repeated once to obtain a semi-finished ceramic body. 40g of nano-chromium oxide, 40g of nano-zinc oxide, 10g of amino-carbon quantum dots, and 10g of SrTiO3 were added to 500mL of nano-titanium dioxide sol and mixed evenly to obtain slurry B. Slurry B was evenly coated onto the surface of the semi-finished ceramic body, and then dried in a 120℃ oven for 30 minutes. After cooling to room temperature, it underwent low-temperature plasma treatment with helium as the dielectric gas. The average current density in the discharge region was adjusted to 5mA / cm². 2 The ceramic body is obtained by discharging for 5 minutes and repeating the above operation once. The ceramic body is heated to 1320°C, sintered for 3 hours, cooled to room temperature, and then annealed for 1.5 hours at a temperature of 750°C. Finally, the ceramic body is glued to the iron cap and steel foot with adhesive or mechanically clamped to obtain the suspension porcelain insulator.

[0038] Flashover performance was tested under ambient temperature of 25.3℃ and humidity of 50.5%. During the test, two copper sheets were bonded to the surface of the suspension porcelain insulator with a spacing of 2cm, and a voltage of 50kV was applied 10 times. No flashover occurred during the test.

[0039] Example 2:

[0040] A suspension porcelain insulator includes a porcelain body, an iron cap, and a steel foot, wherein the porcelain body includes an alumina matrix and a first coating and a second coating extending outward along the surface of the alumina matrix.

[0041] The first coating comprises nano-alumina, nano-titanium dioxide, silica powder, and modified water glass;

[0042] The second coating comprises nano-chromium oxide, nano-zinc oxide, nano-titanium dioxide, aminated carbon quantum dots, and SrTiO3.

[0043] The preparation method of modified water glass is as follows:

[0044] Dissolve 100g of sodium tetrafluoroborate in 250mL of water, add the resulting solution dropwise into 800mL of water glass, and stir until homogeneous.

[0045] The preparation method of aminated carbon quantum dots is as follows:

[0046] Dissolve 90g of citric acid and 45g of polyethyleneimine in 100mL of water to obtain a mixed solution. Add the mixed solution to a hydrothermal reactor, heat to 250℃ and keep at that temperature for 5 hours, then allow to cool naturally to room temperature. Filter the resulting reaction solution through a microfiltration membrane (0.2μm) and dialyze it using a dialysis bag with a molecular weight cutoff of 2000. Finally, freeze-dry the solution.

[0047] The preparation method of the above-mentioned suspension porcelain insulator is as follows:

[0048] 100g of nano-alumina, 10g of nano-titanium dioxide, and 10g of silica powder were added to the prepared modified water glass and stirred until homogeneous to obtain slurry A. Slurry A was uniformly coated onto the surface of the alumina substrate, then dried in a 120℃ oven for 40 minutes. After cooling to room temperature, it underwent low-temperature plasma treatment with helium as the dielectric gas and the average current density in the discharge region was adjusted to 5mA / cm². 2 After discharge treatment for 5 minutes, the above operation was repeated once to obtain a semi-finished ceramic body. 50g of nano-chromium oxide, 50g of nano-zinc oxide, 25g of amino-carbon quantum dots, and 25g of SrTiO3 were added to 500mL of nano-titanium dioxide sol and mixed evenly to obtain slurry B. Slurry B was evenly coated onto the surface of the semi-finished ceramic body, and then dried in a 120℃ oven for 40 minutes. After cooling to room temperature, it underwent low-temperature plasma treatment with helium as the dielectric gas. The average current density in the discharge region was adjusted to 5mA / cm². 2 The ceramic body is subjected to discharge treatment for 5 minutes, and the above operation is repeated once to obtain the ceramic body. The ceramic body is heated to 1350℃, sintered for 4 hours, cooled to room temperature, and then annealed for 2 hours at a temperature of 800℃. Finally, the ceramic body is glued to the iron cap and steel foot with adhesive or mechanically clamped to obtain the suspension porcelain insulator.

[0049] Flashover performance was tested under ambient temperature of 25.3℃ and humidity of 50.5%. During the test, two copper sheets were bonded to the surface of the suspension porcelain insulator with a spacing of 2cm, and a voltage of 50kV was applied 10 times. No flashover occurred during the test.

[0050] Example 3:

[0051] A suspension porcelain insulator includes a porcelain body, an iron cap, and a steel foot, wherein the porcelain body includes an alumina matrix and a first coating and a second coating extending outward along the surface of the alumina matrix.

[0052] The first coating comprises nano-alumina, nano-titanium dioxide, silica powder, and modified water glass;

[0053] The second coating comprises nano-chromium oxide, nano-zinc oxide, nano-titanium dioxide, aminated carbon quantum dots, and SrTiO3.

[0054] The preparation method of modified water glass is as follows:

[0055] Dissolve 100g of sodium tetrafluoroborate in 250mL of water, add the resulting solution dropwise into 800mL of water glass, and stir until homogeneous.

[0056] The preparation method of aminated carbon quantum dots is as follows:

[0057] Dissolve 90g of citric acid and 45g of polyethyleneimine in 100mL of water to obtain a mixed solution. Add the mixed solution to a hydrothermal reactor, heat to 230℃ and keep at that temperature for 3 hours, then allow to cool naturally to room temperature. Filter the resulting reaction solution through a microfiltration membrane (0.2μm) and dialyze it using a dialysis bag with a molecular weight cutoff of 2000. Finally, freeze-dry the solution.

[0058] The preparation method of the above-mentioned suspension porcelain insulator is as follows:

[0059] 50g of nano-alumina, 10g of nano-titanium dioxide, and 5g of silica powder were added to the prepared modified water glass and stirred until homogeneous to obtain slurry A. Slurry A was uniformly coated onto the surface of the alumina substrate, then dried in a 100℃ oven for 20 minutes. After cooling to room temperature, it underwent low-temperature plasma treatment with helium as the dielectric gas and the average current density in the discharge region was adjusted to 5mA / cm². 2After discharge treatment for 5 minutes, the above operation was repeated once to obtain a semi-finished ceramic body. 25g of nano-chromium oxide, 25g of nano-zinc oxide, 5g of amino-carbon quantum dots, and 5g of SrTiO3 were added to 500mL of nano-titanium dioxide sol and mixed evenly to obtain slurry B. Slurry B was evenly coated onto the surface of the semi-finished ceramic body, and then dried in a 100℃ oven for 20 minutes. After cooling to room temperature, it underwent low-temperature plasma treatment with helium as the dielectric gas. The average current density in the discharge region was adjusted to 5mA / cm². 2 The ceramic body is subjected to discharge treatment for 5 minutes, and the above operation is repeated once to obtain the ceramic body. The ceramic body is heated to 1250°C, sintered for 2 hours, cooled to room temperature, and then annealed for 1 hour at a temperature of 600°C. Finally, the ceramic body is glued to the iron cap and steel foot with adhesive or mechanically clamped to obtain the suspension ceramic insulator.

[0060] Flashover performance was tested under ambient temperature of 25.3℃ and humidity of 50.5%. During the test, two copper sheets were bonded to the surface of the suspension porcelain insulator with a spacing of 2cm, and a voltage of 50kV was applied 10 times. No flashover occurred during the test.

[0061] Example 4:

[0062] A suspension porcelain insulator includes a porcelain body, an iron cap, and a steel foot, wherein the porcelain body includes an alumina matrix and a first coating and a second coating extending outward along the surface of the alumina matrix.

[0063] The first coating comprises nano-alumina, nano-titanium dioxide, silica powder, and modified water glass;

[0064] The second coating comprises nano-chromium oxide, nano-zinc oxide, nano-titanium dioxide, aminated carbon quantum dots, and SrTiO3.

[0065] The preparation method of modified water glass is as follows:

[0066] Dissolve 100g of sodium tetrafluoroborate in 250mL of water, add the resulting solution dropwise into 800mL of water glass, and stir until homogeneous.

[0067] The preparation method of aminated carbon quantum dots is as follows:

[0068] Dissolve 90g of citric acid and 45g of polyethyleneimine in 100mL of water to obtain a mixed solution. Add the mixed solution to a hydrothermal reactor, heat to 250℃ and keep at that temperature for 3 hours, then allow to cool naturally to room temperature. Filter the resulting reaction solution through a microfiltration membrane (0.2μm) and dialyze it using a dialysis bag with a molecular weight cutoff of 2000. Finally, freeze-dry the solution.

[0069] The preparation method of the above-mentioned suspension porcelain insulator is as follows:

[0070] 100g of nano-alumina, 10g of nano-titanium dioxide, and 5g of silica powder were added to the prepared modified water glass and stirred until homogeneous to obtain slurry A. Slurry A was uniformly coated onto the surface of the alumina substrate, then dried in a 120℃ oven for 20 minutes. After cooling to room temperature, it underwent low-temperature plasma treatment with helium as the dielectric gas and the average current density in the discharge region was adjusted to 5mA / cm². 2 The ceramic body was subjected to discharge treatment for 5 minutes, and the above operation was repeated once to obtain a semi-finished ceramic body. 50g of nano-chromium oxide, 25g of nano-zinc oxide, 25g of amino-carbon quantum dots, and 5g of SrTiO3 were added to 500mL of nano-titanium dioxide sol and mixed evenly to obtain slurry B. Slurry B was evenly coated onto the surface of the semi-finished ceramic body, and then dried in a 120℃ oven for 20 minutes. After cooling to room temperature, it underwent low-temperature plasma treatment with helium as the dielectric gas and the average current density in the discharge region was adjusted to 5mA / cm². 2 The ceramic body is subjected to discharge treatment for 5 minutes, and the above operation is repeated once to obtain the ceramic body. The ceramic body is heated to 1350°C, sintered for 2 hours, cooled to room temperature, and then annealed for 2 hours at a temperature of 600°C. Finally, the ceramic body is glued to the iron cap and steel foot with adhesive or mechanically clamped to obtain the suspension ceramic insulator.

[0071] Flashover performance was tested under ambient temperature of 25.3℃ and humidity of 50.5%. During the test, two copper sheets were bonded to the surface of the suspension porcelain insulator with a spacing of 2cm, and a voltage of 50kV was applied 10 times. No flashover occurred during the test.

[0072] Example 5:

[0073] A suspension porcelain insulator includes a porcelain body, an iron cap, and a steel foot, wherein the porcelain body includes an alumina matrix and a first coating and a second coating extending outward along the surface of the alumina matrix.

[0074] The first coating comprises nano-alumina, nano-titanium dioxide, silica powder, and modified water glass;

[0075] The second coating comprises nano-chromium oxide, nano-zinc oxide, nano-titanium dioxide, aminated carbon quantum dots, and SrTiO3.

[0076] The preparation method of modified water glass is as follows:

[0077] Dissolve 100g of sodium tetrafluoroborate in 250mL of water, add the resulting solution dropwise into 800mL of water glass, and stir until homogeneous.

[0078] The preparation method of aminated carbon quantum dots is as follows:

[0079] Dissolve 90g of citric acid and 45g of polyethyleneimine in 100mL of water to obtain a mixed solution. Add the mixed solution to a hydrothermal reactor, heat to 230℃ and keep it at that temperature for 5 hours, then allow it to cool naturally to room temperature. Filter the resulting reaction solution through a microfiltration membrane (0.2μm) and dialyze it using a dialysis bag with a molecular weight cutoff of 2000. Finally, freeze-dry the solution.

[0080] The preparation method of the above-mentioned suspension porcelain insulator is as follows:

[0081] 50g of nano-alumina, 10g of nano-titanium dioxide, and 10g of silica powder were added to the prepared modified water glass and stirred until homogeneous to obtain slurry A. Slurry A was uniformly coated onto the surface of the alumina substrate, then dried in a 100℃ oven for 40 minutes. After cooling to room temperature, it underwent low-temperature plasma treatment with helium as the dielectric gas and the average current density in the discharge region was adjusted to 5mA / cm². 2 After discharge treatment for 5 minutes, the above operation was repeated once to obtain a semi-finished ceramic body. 25g of nano-chromium oxide, 50g of nano-zinc oxide, 5g of amino-carbon quantum dots, and 25g of SrTiO3 were added to 500mL of nano-titanium dioxide sol and mixed evenly to obtain slurry B. Slurry B was evenly coated onto the surface of the semi-finished ceramic body, and then dried in a 100℃ oven for 40 minutes. After cooling to room temperature, it underwent low-temperature plasma treatment with helium as the dielectric gas. The average current density in the discharge region was adjusted to 5mA / cm². 2 The ceramic body is subjected to discharge treatment for 5 minutes, and the above operation is repeated once to obtain the ceramic body. The ceramic body is heated to 1250°C, sintered for 4 hours, cooled to room temperature, and then annealed for 1 hour at a temperature of 800°C. Finally, the ceramic body is glued to the iron cap and steel foot with adhesive or mechanically clamped to obtain the suspension porcelain insulator.

[0082] Flashover performance was tested under ambient temperature of 25.3℃ and humidity of 50.5%. During the test, two copper sheets were bonded to the surface of the suspension porcelain insulator with a spacing of 2cm, and a voltage of 50kV was applied 10 times. No flashover occurred during the test.

[0083] Comparative Example 1:

[0084] It is basically the same as Example 1, except that no nano-chromium oxide is added to the second coating.

[0085] Flashover performance was tested under ambient temperature of 25.3℃ and humidity of 50.5%. During the test, two copper sheets were bonded to the surface of the suspension porcelain insulator with a spacing of 2cm, and a voltage of 50kV was applied 10 times. Flashover occurred during the test.

[0086] Comparative Example 2:

[0087] It is basically the same as Example 1, except that no nano zinc oxide is added to the second coating.

[0088] Flashover performance was tested under ambient temperature of 25.3℃ and humidity of 50.5%. During the test, two copper sheets were bonded to the surface of the suspension porcelain insulator with a spacing of 2cm, and a voltage of 50kV was applied 10 times. During the test, multiple arcs were observed, but no flashover occurred.

[0089] Comparative Example 3:

[0090] It is basically the same as Example 1, except that no aminated carbon quantum dots are added to the second coating.

[0091] Flashover performance was tested under ambient temperature of 25.3℃ and humidity of 50.5%. During the test, two copper sheets were bonded to the surface of the suspension porcelain insulator with a spacing of 2cm, and a voltage of 50kV was applied 10 times. During the test, multiple arcs were observed, but no flashover occurred.

[0092] Comparative Example 4:

[0093] It is basically the same as Example 1, except that SrTiO3 is not added to the second coating.

[0094] Flashover performance was tested under ambient temperature of 25.3℃ and humidity of 50.5%. During the test, two copper sheets were bonded to the surface of the suspension porcelain insulator with a spacing of 2cm, and a voltage of 50kV was applied 10 times. Flashover occurred during the test.

[0095] Performance testing:

[0096] The insulators and alumina substrates prepared in Examples 1-5 and Comparative Examples 1-4 were used as samples and suspended in the same environment. High-pressure mercury lamps were used to simulate sunlight. During the test, a 5% oleic acid-acetone solution was used as simulated organic pollutant. A pollutant solution composed of deionized water, kaolin, and NaCl in a mass ratio of 200:10:1 was used. The test was conducted for 30 days. During this period, organic pollutant and pollutant solution were sprayed onto the samples at 10:00 am and 4:00 pm every day, respectively.

[0097] According to the State Grid Corporation of China standard Q / GDW152-2006 "Standard for Pollution Classification and External Insulation Selection in Power Systems", the surface contamination of the above-mentioned samples was measured. The surface contaminants on the ceramic body of the samples were carefully washed off with distilled water. The conductivity of the contaminant solution was measured using a DDS12DW conductivity meter. After conversion, the ESDD value of the sample surface was determined. The contaminant solution was then filtered and dried, and the mass of the filtered material was weighed using an electronic balance to determine the NSDD value of the sample. The test results are shown in Table 1 below.

[0098] Table 1:

[0099]

[0100] Equivalent Salt Deposit Density (ESDD) refers to the amount of NaCl (mg / cm³) equivalent to the amount of conductive material in the contaminant adhering to each square centimeter of the insulator surface. 2 The equivalent salt density characterizes the conductivity of an insulator after the contaminants on its surface have been fully dissolved. An increase in equivalent salt density will significantly reduce the flashover voltage of the insulator.

[0101] Equivalent ash density (NSDD, "Non-Soluble Deposit Density") refers to the mass of insoluble matter adhering to each square centimeter of the insulator surface (mg / cm²). 2 Ash density has a certain impact on the flashover voltage of insulators. As ash density increases, the flashover voltage of insulators tends to decrease, but the effect is much weaker than that of salt density.

[0102] As shown in Table 1 above, the insulators prepared by this invention exhibit good self-cleaning performance in the artificial simulated pollution accumulation test, indicating that dirt is difficult to adhere to the surface of the insulator, thus exhibiting lower ESDD and NSDD values ​​and strong resistance to surface flashover.

[0103] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A suspension porcelain insulator, comprising a porcelain body, an iron cap, and a steel foot, characterized in that, The ceramic body includes an alumina matrix and a first coating and a second coating extending outward from the surface of the alumina matrix; The first coating comprises nano-alumina, nano-titanium dioxide, silica powder, and modified water glass; The second coating comprises nano-oxide particles, nano-titanium dioxide, aminated carbon quantum dots, and SrTiO3; The mass ratio of nano-alumina, nano-titanium dioxide, and silicon micropowder in the first coating is 5-10:1:0.5-1; The modified water glass is prepared as follows: Add the solution obtained by dissolving sodium tetrafluoroborate in water dropwise into water glass and stir until homogeneous. The preparation method of the aminated carbon quantum dots is as follows: Citric acid and an amination reagent are dissolved in water to obtain a mixed solution. The mixed solution is added to a hydrothermal reactor, heated to 230-250°C and kept at that temperature for 3-5 hours. The mixture is then naturally cooled to room temperature. The resulting reaction solution is filtered through a microfiltration membrane, dialyzed, and then freeze-dried. The amination reagent is any one or more combinations of ammonia, ethylenediamine, diethylenetriamine, or polyethyleneimine. The mass ratio of the nano-oxide particles, aminated carbon quantum dots, and SrTiO3 is 10-20:1-5:1-5; The nano-oxide particles are nano-chromium oxide and nano-zinc oxide, with a mass ratio of 1:

1. The preparation method of the above-mentioned suspension porcelain insulator is as follows: S1: Mix nano alumina, nano titanium dioxide, silica powder and modified water glass evenly to obtain slurry A. Coat slurry A evenly onto the surface of the alumina substrate, then dry it in an oven at 100-120℃ for 20-40 minutes. After removing it and cooling it to room temperature, perform low-temperature plasma treatment. Repeat the above operation 0-5 times to obtain a semi-finished ceramic body. S2: Add nano-oxide particles, aminated carbon quantum dots, and SrTiO3 to nano-titanium dioxide sol and mix them evenly to obtain slurry B. Coat slurry B evenly onto the surface of the semi-finished ceramic body, and then dry it in an oven at 100-120℃ for 20-40 minutes. After taking it out and cooling it to room temperature, perform low-temperature plasma treatment. Repeat the above operation 0-5 times to obtain the ceramic body. S3: Heat the ceramic body to 1250-1350℃, sinter for 2-4 hours, cool to room temperature, and then anneal for 1-2 hours at a temperature of 600-800℃. Finally, glue the ceramic body to the iron cap and steel foot with adhesive or mechanically clamp them to obtain the suspension porcelain insulator.

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