A new type of hybrid insulator for coastal operating environment and its preparation method

Abstract

The application discloses a novel hybrid insulator for a coastal operation environment and a preparation method thereof, and relates to the field of insulators. The preparation method comprises the following steps: preparing a mold, controlling the thickness of a surface layer of silicone rubber to be 1-8 mm, and the insulator being a porcelain or glass insulator; adopting a plasma jet technology to perform surface treatment on the insulator; and placing the insulator in the mold, injecting high-temperature vulcanized silicone rubber into the mold, and obtaining the insulator after solidification and demolding. In the application, a high-temperature silicone rubber with a breakdown resistance effect is vulcanized on the surface of the porcelain / glass insulator, the hydrophobicity is improved, the surface creepage density is reduced, and the electrochemical corrosion is reduced, so that the anti-pollution flashover performance of the composite insulator is combined, meanwhile, the excellent mechanical performance of the porcelain / glass insulator is retained, and the operation requirements of the insulator in the coastal area can be met.

Description

Technical Field

[0001] This invention relates to the field of insulators, and more particularly to a novel hybrid insulator for coastal operating environments and its preparation method. Background Technology

[0002] With the rapid development of my country's economy, power grid construction has also entered an unprecedented period of development, and its overall scale has now jumped to the forefront of the world. Power grids are divided into transmission lines and distribution lines according to voltage levels. In my country, transmission lines specifically refer to lines with voltage levels of 35kV and above, which are the main arteries of the power grid. As an important carrier in the operation of the power grid, transmission lines cover a wide area, have long distances, and pass through regions with complex and varied geographical conditions. The safety and stability of the power grid are related to the overall economic and social development and the vital interests of the people. Insulators, as special insulating components, are an important part of transmission lines, playing a role in mechanical connection and electrical insulation in overhead transmission lines. Therefore, the operating condition of insulators has an extremely important impact on the safe operation of the power grid.

[0003] Currently, there are three main types of insulators for transmission lines: porcelain insulators, glass insulators, and composite insulators. Because porcelain insulators require zero-value testing and involve significant maintenance, composite and glass insulators are currently the primary types used. However, composite and glass insulators have experienced frequent safety issues in recent years, exposing shortcomings in their overall performance. Composite insulators offer excellent anti-pollution flashover performance, but aging issues are prominent, with frequent occurrences of large-area overheating, breakdown, and even string breakage. Porcelain / glass insulators have reliable lifespans but poor anti-pollution performance. In coastal areas, they frequently experience creepage defects and a high risk of pollution flashover. Furthermore, steel foot corrosion and even string breakage can occur. This is because the surface of porcelain / glass insulators is hydrophilic; when soluble salts deposit on their surface, a conductive film forms, reducing the effective creepage distance and leading to creepage defects. Summary of the Invention

[0004] This invention provides a novel hybrid insulator for coastal operating environments and its preparation method, in order to solve the technical problems of flashover and steel foot corrosion that are common in current porcelain / glass insulators. This application improves the surface hydrophobicity of porcelain / glass insulators and reduces surface creepage, resulting in superior anti-flashover and anti-electrochemical corrosion performance of porcelain / glass insulators.

[0005] To address the aforementioned technical problems, one objective of this invention is to provide a method for preparing a novel hybrid insulator for coastal operating environments, comprising the following steps:

[0006] (1) The insulator is scanned by a laser scanning device to obtain the size information of the insulator. Then, the mold is made according to the size information. The thickness of the surface silicone rubber is controlled to be 1-8mm. The insulator is a porcelain insulator or a glass insulator.

[0007] (2) The surface of the insulator is treated using plasma jet technology;

[0008] (3) Place the surface-treated insulator in the mold, inject the high-temperature vulcanized silicone rubber compound into the mold, and obtain the product after curing and demolding.

[0009] The high-temperature vulcanized silicone rubber compound comprises the following components in parts by weight:

[0010] Vinyl-terminated polymethylvinylsiloxane; 100-150 parts;

[0011] Aluminum hydroxide; 60-90 parts;

[0012] Nano-silica; 20-30 parts;

[0013] Silane coupling agent; 4-6 parts;

[0014] Methyl silicone oil; 1-4 parts;

[0015] Vinyl silicone oil; 1-4 parts;

[0016] Hydroxy silicone oil; 1-4 parts;

[0017] Vulcanizing agent: 1-5 parts.

[0018] By adopting the above technical solution, this application vulcanizes a layer of silicone rubber on the surface of the porcelain / glass insulator. This is because when the insulator is operating in coastal areas, soluble salts are deposited on the surface due to its hydrophilicity, forming a conductive film that reduces the effective creepage distance of the insulator. The surface-vulcanized silicone rubber layer improves the surface hydrophobicity of the porcelain / glass insulator, which can reduce surface creepage and electrochemical corrosion. The new hybrid insulator combines the advantages of both glass insulators and composite insulators. While retaining the excellent mechanical properties of glass insulators, it also has the anti-pollution flashover performance of composite insulators, which can meet the requirements of hydrophobic insulation and mechanical performance of insulators used in coastal areas.

[0019] As a preferred embodiment, the molecular weight of the terminal vinyl polymethyl vinyl siloxane is 1000-10000 g / mol. The molecular weight affects the flowability after mixing. The molecular weight of the terminal vinyl polymethyl vinyl siloxane in this application helps to improve the flowability of the silicone rubber compound, which is beneficial for it to form a surface coating on the insulator in the mold.

[0020] As a preferred embodiment, the high-temperature vulcanized silicone rubber compound further includes inorganic fillers, wherein the mass ratio of the inorganic fillers to the vinyl-terminated polymethyl vinyl siloxane is (1-2):50, and the inorganic fillers are color masterbatch and / or boehmite.

[0021] As a preferred embodiment, the inorganic filler has a mesh size of 500-5000 mesh, the aluminum hydroxide has a mesh size of 500-5000 mesh, and the nano-carbon black has a particle size of 7-40 nm.

[0022] As a preferred embodiment, the aluminum hydroxide comprises 500 mesh, 1250 mesh and 5000 mesh aluminum hydroxide in a mass ratio of 1:2:1.

[0023] As a preferred embodiment, the preparation method of the high-temperature vulcanized silicone rubber internal mixer includes the following steps: adding the terminal vinyl polymethyl vinyl siloxane into an internal mixer, and then sequentially adding aluminum hydroxide, inorganic filler, silane coupling agent, methyl silicone oil, vinyl silicone oil, hydroxyl silicone oil, and nano-silicone black. After mixing and stirring, the mixture is cooled to room temperature and placed in a double-roll open mill for open milling. A vulcanizing agent is added during the open milling process to obtain the high-temperature vulcanized silicone rubber internal mixer.

[0024] As a preferred embodiment, in the preparation method of the high-temperature vulcanized silicone rubber internal mixer, the mixing temperature is 40-60℃, the stirring time is 8-10h, and the rotation speed is 400-800r / min.

[0025] As a preferred embodiment, in step (2), the voltage of the plasma jet is 10-15kV, the frequency is 1-5kHz, and the air velocity is 40-50m / s.

[0026] As a preferred embodiment, the vulcanizing agent is an organic peroxide.

[0027] As a preferred embodiment, the vulcanizing agent is at least one of 2,5-dimethyl-2,5-di-tert-butylperoxide, dicumyl peroxide, and di-tert-butyl peroxide.

[0028] To address the aforementioned technical problems, a second objective of this invention is to provide a novel hybrid insulator for coastal operating environments prepared using the aforementioned method for preparing a novel hybrid insulator for coastal operating environments.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. This application involves vulcanizing a layer of high-temperature silicone rubber with breakdown resistance on the surface of a porcelain / glass insulator. This can change the hydrophilicity of the insulator surface to hydrophobicity, preventing the formation of a conductive film composed of soluble salts on the surface. This reduces surface creepage density, provides anti-flashover protection, and reduces electrochemical corrosion. In other words, it combines the anti-flashover performance of composite insulators with the excellent mechanical properties of porcelain / glass insulators, which can meet the operational requirements of insulators in coastal areas.

[0031] 2. This application utilizes plasma jet technology to pre-etch and generate free radicals on the surface of porcelain / glass insulators, thereby increasing the base area and interfacial adhesion between the silicone rubber material and the insulator surface, improving the bonding strength, preventing detachment during operation, and enhancing operational stability. Attached Figure Description

[0032] Figure 1 The results show the maximum electric field strength and hydrophobicity of the steel feet of the insulators prepared in Examples 1-5 and Comparative Example 3 of this invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Preparation Example 1

[0035] A high-temperature vulcanized silicone rubber compound comprises 110 kg of vinyl-terminated polymethyl vinyl siloxane (Vi-PMVS), 80 kg of aluminum hydroxide, 25 kg of nano-silicone black, 5 kg of silane coupling agent, 2 kg of methyl silicone oil, 2 kg of vinyl silicone oil, 2 kg of hydroxyl silicone oil, and 2 kg of vulcanizing agent. The aluminum hydroxide comprises 500 mesh, 1250 mesh, and 5000 mesh aluminum hydroxide in a mass ratio of 1:2:1. The molecular weight of the vinyl-terminated polymethyl vinyl siloxane is 8000 g / mol. The vulcanizing agent is dicumyl peroxide, and the nano-silicone black has a particle size of 20 nm.

[0036] Preparation Example 2

[0037] A high-temperature vulcanized silicone rubber compound comprises 110 kg of vinyl-terminated polymethyl vinyl siloxane (Vi-PMVS), 80 kg of aluminum hydroxide, 25 kg of nano-silicone black, 5 kg of silane coupling agent, 2 kg of methyl silicone oil, 2 kg of vinyl silicone oil, 2 kg of hydroxyl silicone oil, 3 kg of 2000-mesh masterbatch inorganic filler, and 2 kg of vulcanizing agent. The aluminum hydroxide comprises 500-mesh, 1250-mesh, and 5000-mesh aluminum hydroxide in a mass ratio of 1:2:1. The molecular weight of the vinyl-terminated polymethyl vinyl siloxane is 8000 g / mol. The vulcanizing agent is dicumyl peroxide, and the nano-silicone black has a particle size of 20 nm.

[0038] Preparation Example 3

[0039] A high-temperature vulcanized silicone rubber compound comprises 110 kg of vinyl-terminated polymethyl vinyl siloxane (Vi-PMVS), 80 kg of aluminum hydroxide, 25 kg of nano-silicone, 5 kg of silane coupling agent, 2 kg of methyl silicone oil, 2 kg of vinyl silicone oil, 2 kg of hydroxyl silicone oil, 3 kg of 2000-mesh boehmite inorganic filler, and 2 kg of vulcanizing agent. The aluminum hydroxide comprises 500-mesh, 1250-mesh, and 5000-mesh aluminum hydroxide in a mass ratio of 1:2:1. The molecular weight of the vinyl-terminated polymethyl vinyl siloxane is 8000 g / mol. The vulcanizing agent is dicumyl peroxide, and the nano-silicone has a particle size of 20 nm.

[0040] Preparation Example 4

[0041] A high-temperature vulcanized silicone rubber compound comprises 110 kg of vinyl-terminated polymethyl vinyl siloxane (Vi-PMVS), 80 kg of aluminum hydroxide, 25 kg of nano-silicone black, 5 kg of silane coupling agent, 2 kg of methyl silicone oil, 2 kg of vinyl silicone oil, 2 kg of hydroxyl silicone oil, 3 kg of 2000-mesh silica inorganic filler, and 2 kg of vulcanizing agent. The aluminum hydroxide comprises 500-mesh, 1250-mesh, and 5000-mesh aluminum hydroxide in a mass ratio of 1:2:1. The molecular weight of the vinyl-terminated polymethyl vinyl siloxane is 8000 g / mol. The vulcanizing agent is dicumyl peroxide, and the particle size of the nano-silicone black is 20 nm.

[0042] Preparation Example 5

[0043] A high-temperature vulcanized silicone rubber compound is prepared in the same way as the preparation example 1, except that the aluminum hydroxide used is 5000 mesh aluminum hydroxide.

[0044] Preparation Example 6

[0045] A high-temperature vulcanized silicone rubber compound is prepared in the same way as the preparation example 1, except that the aluminum hydroxide used is 500 mesh aluminum hydroxide.

[0046] The above-mentioned method for preparing a high-temperature vulcanized silicone rubber compound includes the following steps:

[0047] Vinyl-terminated polymethyl vinyl siloxane was added to a mixer, followed by aluminum hydroxide, inorganic filler, silane coupling agent, methyl silicone oil, vinyl silicone oil, hydroxyl silicone oil, and nano-silicone. The mixer door was closed, and the mixture was stirred at 50°C for 10 hours at a speed of 600 r / min. After stirring, the mixture was cooled to room temperature and placed in a double-roll open mill. A vulcanizing agent was added during the open milling process to obtain a high-temperature vulcanized silicone rubber mixer.

[0048] Example 1

[0049] A method for preparing a novel hybrid insulator for coastal operating environments includes the following steps:

[0050] (1) Use a laser scanner to scan the glass insulator to obtain the size information of the glass insulator, and then make a mold according to the size information to control the thickness of the surface silicone rubber to 1mm;

[0051] (2) The glass insulator was surface treated for 5 minutes using plasma jet technology. The plasma jet voltage was 12.5kV, the frequency was 4kHz, and the air velocity was 46m / s.

[0052] (3) Place the surface-treated glass insulator in the mold, inject the high-temperature vulcanized silicone rubber compound of Preparation Example 1 into the mold, cure it at 110°C and 15MPa for 10 minutes, and then demold it to obtain the product.

[0053] Example 2

[0054] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as in Example 1. The difference is that in step (1), the thickness of the surface silicone rubber is controlled to be 2 mm.

[0055] Example 3

[0056] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as in Example 1. The difference is that in step (1), the thickness of the surface silicone rubber is controlled to be 3 mm.

[0057] Example 4

[0058] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as in Example 1. The difference is that in step (1), the thickness of the surface silicone rubber is controlled to be 4 mm.

[0059] Example 5

[0060] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as in Example 1. The difference is that in step (1), the thickness of the surface silicone rubber is controlled to be 5 mm.

[0061] Example 6

[0062] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as those in Example 2. The difference is that in step (3), the high-temperature vulcanized silicone rubber compound prepared in Example 2 is used.

[0063] Example 7

[0064] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as those in Example 2. The difference is that in step (3), the high-temperature vulcanized silicone rubber compound of Example 3 is used.

[0065] Example 8

[0066] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as those in Example 2. The difference is that in step (3), the high-temperature vulcanized silicone rubber compound prepared in Example 4 is used.

[0067] Example 9

[0068] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as those in Example 2. The difference is that in step (3), the high-temperature vulcanized silicone rubber compound of Example 5 is used.

[0069] Example 10

[0070] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as in Example 2. The difference is that in step (3), the high-temperature vulcanized silicone rubber compound prepared in Example 6 is used.

[0071] Comparative Preparation Example 1

[0072] A high-temperature vulcanized silicone rubber compound is prepared in the same way as the preparation example 1, except that methyl silicone oil is replaced by an equal amount of ethyl silicone oil.

[0073] Comparative Preparation Example 2

[0074] A high-temperature vulcanized silicone rubber compound is prepared in the same way as the preparation example 1, with the same steps, reagents and process parameters. The difference is that hydroxyl silicone oil is replaced by an equal amount of ethyl silicone oil.

[0075] Comparative Example 1

[0076] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as those in Example 2. The difference is that in step (3), the high-temperature vulcanized silicone rubber compound of Comparative Preparation Example 1 is used.

[0077] Comparative Example 2

[0078] A method for preparing a novel hybrid insulator for coastal operating environments. The steps and reagents and process parameters used in each step are the same as those in Example 2. The difference is that in step (3), the high-temperature vulcanized silicone rubber compound of Comparative Preparation Example 2 is used.

[0079] Comparative Example 3

[0080] A method for manufacturing an insulator for use in coastal operating environments includes the following steps:

[0081] (1) Use a laser scanner to scan the glass insulator to obtain the size information of the glass insulator, and then make a mold according to the size information to control the thickness of the surface silicone rubber to 1mm;

[0082] (2) The glass insulator was surface treated for 5 minutes using plasma jet technology. The plasma jet voltage was 12.5kV, the frequency was 4kHz, and the air velocity was 46m / s. The insulator was then obtained.

[0083] Comparative Example 4

[0084] A method for preparing a novel hybrid insulator for coastal operating environments includes the following steps:

[0085] (1) Use a laser scanner to scan the glass insulator to obtain the size information of the glass insulator, and then make a mold according to the size information, and control the thickness of the surface silicone rubber to 2mm;

[0086] (2) Place the glass insulator in the mold, inject the high-temperature vulcanized silicone rubber compound of Preparation Example 1 into the mold, cure it at 110°C and 15MPa for 10 minutes, and then demold it to obtain the product.

[0087] Performance testing

[0088] 1. Adhesion test: The adhesion of the insulators in the examples and comparative examples was tested using the circle-crossing method standard in GB / T 1720. The test results are shown in Table 2 below.

[0089] 2. Dielectric Loss Factor: The dielectric loss factor of the insulators in the examples and comparative examples was determined in accordance with GB / T1409-2006 standard. The specific details are as follows: A circular silicone rubber test piece with a thickness of 1.5 mm and a diameter of 100 mm was prepared. A dielectric loss test at a power frequency of 50 Hz was conducted using a plate-to-plate electrode system test platform. After adjusting the power frequency voltage and waiting for the data to stabilize, the dielectric loss tangent value tanδ was read. The test results are shown in Table 2 below.

[0090] 3. Maximum electric field strength of the steel foot: After modeling, the maximum electric field strength of the steel foot of the insulator in the embodiments or comparative examples was obtained by simulation using COMSOL software. The results are shown in Table 2 below. The results of Embodiments 1-5 and Comparative Example 3 are as follows: Figure 1 As shown.

[0091] 4. Hydrophobicity: The hydrophobicity of the insulator surface in the examples or comparative examples was tested according to the water spray classification method standard in GB / T24622-2022. HC1 corresponds to the hydrophobic state and HC7 corresponds to the hydrophilic state. The different grade standards are shown in Table 1 below, and the test results are shown in Table 2 below.

[0092] Table 1 - Standards for Different Grades of Hydrophobicity

[0093]

[0094] Table 2 - Performance test results of insulators obtained from embodiments and comparative examples of this application

[0095]

[0096]

[0097] Combine Table 2 and Figure 1 A comparison of the performance test results of Examples 1-5 and Comparative Example 3 shows that the corrosion of the steel feet of the glass insulator is closely related to its surface creepage. If surface creepage occurs, the leakage current increases and the resulting electrochemical corrosion is more obvious. In this application, a layer of compounded silicone rubber is vulcanized on the surface of the glass insulator using a mold, which changes its surface properties from hydrophilic to hydrophobic, so that no conductive water film is formed on its surface. This can reduce surface creepage, thereby reducing the leakage current of the insulator. The maximum electric field strength at the steel feet is reduced, thus improving resistance to electrochemical corrosion.

[0098] A comparison of the performance test results of Example 2 and Comparative Examples 1-2 in Table 2 shows that the methyl silicone oil and hydroxyl silicone oil added to the high-temperature vulcanized silicone rubber of this application can improve the adsorption and hydrogen bonding between the filler and the siloxane, enhance the breakdown resistance of the silicone rubber and the insulator, and at the same time ensure that the hydrophobic effect of the silicone rubber meets a high level.

[0099] By comparing the performance test results of Example 2 and Comparative Example 4 in Table 2, it can be seen that the plasma jet technology used in this application to treat the surface of the glass insulator can clean the surface of the glass insulator, while generating etching and free radicals, further increasing the contact area and interfacial adhesion, improving the adhesion of silicone rubber to the glass insulator, and preventing detachment during operation that would affect the hydrophobic effect.

[0100] A comparison of the performance test results of Examples 2 and 6-8 in Table 2 shows that, by adding color masterbatch or boehmite to high-temperature vulcanized silicone rubber, this application can further improve the dielectric properties of insulators compared to other inorganic fillers such as silica.

[0101] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method for preparing a novel hybrid insulator for coastal operating environments, characterized in that, Includes the following steps: (1) The insulator is scanned by a laser scanning device to obtain the size information of the insulator. Then, the mold is made according to the size information. The thickness of the surface silicone rubber is controlled to be 1-8 mm. The insulator is a porcelain insulator or a glass insulator. (2) Plasma jet technology is used to treat the surface of the insulator; (3) Place the surface-treated insulator in the mold, inject the high-temperature vulcanized silicone rubber compound into the mold, and obtain the product after curing and demolding. The high-temperature vulcanized silicone rubber compound comprises the following components in parts by weight: Vinyl-terminated polymethylvinylsiloxane; 100-150 parts; Aluminum hydroxide; 60-90 parts; Nano-silica; 20-30 parts; Silane coupling agent; 4-6 parts; Methyl silicone oil; 1-4 parts; Vinyl silicone oil; 1-4 parts; Hydroxy silicone oil; 1-4 parts; Vulcanizing agent: 1-5 parts; The high-temperature vulcanized silicone rubber also includes inorganic fillers, wherein the mass ratio of the inorganic filler to the vinyl-terminated polymethyl vinyl siloxane is (1-2):50, and the inorganic filler is a color masterbatch; the aluminum hydroxide includes 500 mesh, 1250 mesh and 5000 mesh aluminum hydroxide in a mass ratio of 1:2:

1. In step (2), the voltage of the plasma jet is 10-15 kV, the frequency is 1-5 kHz, and the air velocity is 40-50 m / s.

2. The method for preparing a novel hybrid insulator for coastal operating environments as described in claim 1, characterized in that, The molecular weight of the terminal vinyl polymethylvinylsiloxane is 1000-10000 g / mol.

3. The method for preparing a novel hybrid insulator for coastal operating environments as described in claim 1, characterized in that, The inorganic filler has a mesh size of 500-5000 mesh, and the nano-silica has a particle size of 7-40 nm.

4. The method for preparing a novel hybrid insulator for coastal operating environments as described in claim 1, characterized in that, The preparation method of the high-temperature vulcanized silicone rubber internal mixer includes the following steps: adding the terminal vinyl polymethyl vinyl siloxane into the internal mixer, and then sequentially adding aluminum hydroxide, inorganic filler, silane coupling agent, methyl silicone oil, vinyl silicone oil, hydroxyl silicone oil, and nano-silicone black. After mixing and stirring, the mixture is cooled to room temperature and placed in a double-roll open mill for open milling. A vulcanizing agent is added during the open milling process to obtain the high-temperature vulcanized silicone rubber internal mixer.

5. The method for preparing a novel hybrid insulator for coastal operating environments as described in claim 4, characterized in that, In the preparation method of the high-temperature vulcanized silicone rubber internal mixer, the mixing temperature is 40-60 ℃ and the stirring time is 8-10 h.

6. The method for preparing a novel hybrid insulator for coastal operating environments as described in claim 1, characterized in that, The vulcanizing agent is an organic peroxide.

7. A novel hybrid insulator for coastal operating environments prepared by a method according to any one of claims 1-6.

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