A porcelain insulator reliability comprehensive evaluation method

Abstract

The application discloses a reliability comprehensive evaluation method for porcelain insulators, and provides a reliability evaluation method for porcelain insulators and application of the reliability evaluation method in quality evaluation of the porcelain insulators. The application discloses a reliability comprehensive evaluation method for porcelain insulators, and provides a reliability evaluation method for porcelain insulators and application of the reliability evaluation method in quality evaluation of the porcelain insulators. The application discloses a reliability comprehensive evaluation method for porcelain insulators, and provides a reliability evaluation method for porcelain insulators and application of the reliability evaluation method in quality evaluation of the porcelain insulators.

Description

Technical Field

[0001] This invention relates to the reliability evaluation of porcelain insulators, and in particular to a comprehensive evaluation method for different types of porcelain insulators. Background Technology

[0002] Porcelain insulators are critical components in power grids / railway contact networks, providing insulation and mechanical support, and are crucial to the safe and stable operation of the power grid. During the insulator manufacturing process, fluctuations in porcelain insulator quality can occur due to factors such as the stability of raw material sources and production control, especially the firing process. Previously, a series of tests were conducted on porcelain insulator supports, hollow insulators, and suspension porcelain insulator strings using large equipment. This resulted in diverse testing equipment, long testing cycles, high costs, high labor intensity, and significant screening difficulties, while also failing to identify the root causes of problems.

[0003] Therefore, this invention discloses a comprehensive evaluation method for the reliability of porcelain insulators, which achieves the purpose of universal testing of various porcelain insulators through comprehensive analysis of chemical composition, phase composition, pores and crystal structure. Summary of the Invention

[0004] The main objective of this invention is to provide a comprehensive evaluation method for the reliability of porcelain insulators. Through comprehensive analysis of chemical composition, phase composition, porosity, and crystal structure, it achieves the goal of universal testing of various porcelain insulators, thus solving the problems of diverse testing equipment, long testing cycles, high costs, high labor intensity, and high screening difficulty, while failing to discover the root causes of problems.

[0005] To achieve the above objectives, this invention provides a method for evaluating the reliability of porcelain insulators and its application in the quality evaluation of porcelain insulators. It includes a sample preparation method, a testing method, and a comprehensive data processing method for analyzing the chemical composition, phase composition, porosity, and crystal structure of porcelain insulators.

[0006] The principle of comprehensively analyzing and evaluating the reliability of porcelain insulators through chemical composition, phase composition, porosity, and crystal structure is as follows: First, unstable raw materials for porcelain insulators will lead to changes in the chemical composition of the porcelain, resulting in variations in the forming process and firing temperature. Under constant production process parameters, this can lead to under-firing or over-firing of the porcelain insulators. Under-firing results in decreased density and increased porosity; over-firing leads to an increase in the glassy phase and the merging of pores into large pores. Second, instability in the firing process will also lead to under-firing or over-firing. Third, the thickest areas of the insulator blank, due to their large thickness and slow heat transfer, often experience under-firing; especially at the ends, which are often placed on or encased by the kiln furniture. The energy required for firing is absorbed by the kiln furniture, or the encasing furniture prevents sufficient heat exchange, making under-firing more likely. Fourth, poor control during the ball milling process can result in insufficient grinding of hard particles, producing large particles that manifest as residual quartz particles or feldspar remnants in the porcelain. Therefore, based on the above-mentioned unstable raw materials, unstable molding and firing processes, etc., changes in chemical composition, phase composition, pores and crystal structure can be caused. This invention, through comprehensive analysis of chemical composition, phase composition, pores and crystal structure, can serve as a basis for evaluating the reliability of porcelain insulators.

[0007] The porcelain insulators of different tonnages and applications, including porcelain insulators of different voltage levels currently in use, are made of silica porcelain and alumina porcelain, as well as alumina porcelain and bauxite porcelain in alumina porcelain, and are in various forms such as suspension, post, or hollow insulators. All of them can be evaluated by the method provided by this invention.

[0008] The chemical composition analysis and sample preparation method for the porcelain insulators utilizes X-ray fluorescence spectrometry, which offers advantages such as small sample volume, fast detection speed, and reliable results. The X-ray fluorescence spectrometry sample preparation method employs a zirconia mortar and pestle for powder preparation. The zirconia mortar and pestle possess advantages such as high strength, high hardness, and high toughness, resulting in minimal wear during porcelain powder processing and the introduction of few impurities. Furthermore, since existing porcelain insulator material systems do not contain zirconium, any introduced zirconium oxide impurities will not affect the porcelain powder test results. The processed porcelain powder passes through a sieve of 200 mesh or finer.

[0009] The phase composition measurement method employs X-ray diffraction and Raman spectroscopy analysis, and the sample preparation method uses a zirconia mortar and pestle to grind and crush the powder. X-ray diffraction can determine the relative contents of corundum, quartz, mullite, and glass phases, and can detect situations where the iron impurity content is high; Raman spectroscopy can obtain information on iron and titanium impurities that affect the electrical performance of porcelain insulators and the occurrence morphology of iron and titanium impurities in porcelain insulators.

[0010] The method for testing the porosity and crystal phase composition is characterized by the use of scanning electron microscopy (SEM). The porosity observation sample preparation method involves cutting with a double-bladed diamond blade, followed by polishing, cleaning, and drying, and then observing the porosity morphology using an SEM. The crystal phase observation sample preparation method involves cutting with a double-bladed diamond blade, followed by polishing and cleaning, etching with a 20% hydrofluoric acid solution for 2 minutes, rinsing the surface with deionized water, drying, and then observing the crystal phase morphology using an SEM. The data analysis method uses particle size measurement and statistical software to measure and statistically analyze the size and distribution of the obtained porosity and crystal phase SEM images.

[0011] The comprehensive data processing method is characterized by comprehensively analyzing the influence of key data such as alumina content, iron and titanium impurities, and potassium / sodium ratio in different chemical compositions of siliceous ceramics and alumina ceramics (bauxite ceramics and alumina ceramics), as well as data on pore morphology, size and distribution in ceramic parts, and the content, grain size and distribution of corundum phase, quartz phase, and mullite phase in the glass phase. This analysis further evaluates the reliability of ceramic insulators by comprehensively analyzing the influence of main chemical composition, impurity elements, pore size, pore distribution, irregular pores, residual quartz size, and corundum and quartz size on the mechanical / electrical properties of ceramic insulators.

[0012] The beneficial effects of this invention are as follows: This invention provides a comprehensive evaluation method for the reliability of porcelain insulators. This method is based on the instability of the porcelain insulator material system, raw materials, and processes, which leads to changes in its chemical composition, phase composition, porosity, and crystal structure. The comprehensive analysis of the chemical composition, phase composition, porosity, and crystal structure of porcelain insulators can accurately reflect the quality of porcelain components. It has the advantages of convenient, low-cost, and reliable evaluation for both porcelain insulator manufacturers and power grid operators, and can effectively ensure the safe and stable operation of the power grid.

[0013] Compared with existing technologies, the evaluation method provided by this invention can be directly applied to the field testing of porcelain insulators. It is flexible, easy to control, highly practical, and provides reliable data, thus offering good economic benefits and application prospects. Attached Figure Description

[0014] Figure 1 Phase analysis spectra from various manufacturers; Figure 2 Pore ​​morphology of insulators from different manufacturers (A, B, C, D from top to bottom); Figure 3 Crystal phase morphology of insulators after corrosion; Figure 4 Crystal phase morphology of porcelain insulators after corrosion; Figure 5 Crystal phase morphology of porcelain insulators after corrosion; Figure 6Crystal morphology of porcelain insulators after corrosion. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. The described embodiments are only a part of the present invention and do not include all embodiments, all of which are within the scope of protection.

[0016] Example The method provided in this invention was used to analyze and evaluate the performance and reliability of five suspension porcelain insulators from domestic and international manufacturers. Their chemical analysis, phase analysis, porosity, and crystal structure are as follows. Through comparative analysis, insulator A, with its low alumina content, achieves good mechanical properties; its low iron and titanium impurity content ensures excellent electrical performance; and its near-spherical and uniformly distributed pore structure, fully developed mullite crystals, regularly shaped and uniformly distributed alumina grains, and relatively uniformly sized residual quartz particles with rounded corners all ensure the stability of the porcelain insulator, making it the best among the four insulators. Insulator B has a relatively high iron content, numerous small and unevenly distributed pores, many chain-like pore groups and elongated pores, and angular residual quartz, resulting in relatively low quality. Manufacturer C has a slightly higher iron impurity content, more pores, and also elongated pores and angular quartz; its shortcomings are compensated for by a higher alumina content. Manufacturer D's sodium content is relatively high, the pores are nearly spherical and evenly distributed, and the quartz has certain rounded corners, similar to manufacturer A. Its high sodium content is the key factor affecting its quality.

[0017] Table 1. Chemical composition analysis results of insulators from different manufacturers Table 2. Phase content results (%) for each manufacturer Table 3. Statistics on the pore size and number of air pores in insulators under 200x magnification. Table 4. Statistical table of residual quartz particle size and quantity at 500x magnification.

Claims

1. A comprehensive evaluation method for the reliability of porcelain insulators, characterized in that: The reliability evaluation of porcelain insulators for different tonnages and applications includes the following steps: S1 uses porcelain insulators to prepare samples for chemical composition analysis; and performs chemical composition analysis. S2 uses ceramic insulators to prepare samples for phase composition analysis; and performs phase composition analysis. S3 uses ceramic insulators to prepare samples for porosity analysis; and performs porosity analysis. S4 uses ceramic insulators to prepare samples for crystal phase composition and structure analysis; and performs crystal phase composition and structure analysis. S5 collects and analyzes data and performs comprehensive data processing.

2. The comprehensive reliability evaluation method for porcelain insulators as described in claim 1, characterized in that: The porcelain insulators of different tonnages and for different applications include silica porcelain and alumina porcelain, alumina porcelain and bauxite porcelain, and suspension, post, or hollow insulators.

3. The comprehensive reliability evaluation method for porcelain insulators as described in claim 1, characterized in that: S1 includes the step of grinding and pressing powder using a zirconium oxide mortar and pestle; The chemical composition analysis described in S1 includes the step of analyzing the chemical composition of porcelain insulators using X-ray fluorescence spectroscopy.

4. The comprehensive reliability evaluation method for porcelain insulators as described in claim 1, characterized in that: The phase composition analysis described in S2 includes the steps of analyzing the test sample using X-ray diffraction and Raman spectroscopy.

5. The comprehensive reliability evaluation method for porcelain insulators as described in claim 1, characterized in that: S3 includes the steps of cutting porcelain insulators with double-blade diamond blades, polishing, cleaning and drying, and then observing the pore morphology with a scanning electron microscope. The stomatal analysis described in S3 includes the step of analysis using a scanning electron microscope.

6. The comprehensive reliability evaluation method for porcelain insulators as described in claim 1, characterized in that: The analysis of the crystal phase composition and structure described in S4 includes the step of analysis using a scanning electron microscope; S3 involves cutting with a double-blade diamond blade, polishing and cleaning, etching with a 20% hydrofluoric acid solution for 2 minutes, rinsing the surface with deionized water, drying, and then observing the crystal morphology using a scanning electron microscope.

7. The comprehensive reliability evaluation method for porcelain insulators as described in claim 1, characterized in that: The comprehensive processing includes the steps of measuring and statistically analyzing the size and distribution of pores and grains in the obtained electron microscope images of pores and crystal phases using particle size measurement and statistical software.

8. The comprehensive reliability evaluation method for porcelain insulators as described in claim 1, characterized in that: The comprehensive processing, based on key data such as alumina content, iron-titanium impurities, and potassium / sodium ratio in different chemical compositions of silica and alumina ceramics, as well as data on pore morphology, size, and distribution in ceramic parts, and the content, grain size, and distribution of corundum, quartz, and mullite phases in the glass phase, comprehensively analyzes the influence of main chemical composition, impurity elements, pore size, pore distribution, irregular pores, residual quartz size, and corundum and quartz size on the mechanical and / or electrical properties of ceramic insulators, and further evaluates the reliability of ceramic insulators.

9. The comprehensive reliability evaluation method for porcelain insulators as described in claim 8, characterized in that: The alumina ceramics include bauxite ceramics and / or alumina ceramics.

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