A dirt-proof train roof insulator structure

Abstract

This invention provides a structure for an anti-pollution train roof insulator, relating to the field of high-speed train technology. It includes multiple core rods and multiple sheds, with the sheds fixed to both ends of the core rods. The upward and downward tilt angles of the sheds are adjustable. This invention considers the wind effect, improving the pressure on the leeward side of the insulator by changing the upward and downward tilt angles of the sheds and the height of the core rods. This alters the airflow on the insulator surface, optimizing pollution accumulation and effectively reducing the probability of flashover accidents on the train roof insulator.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-speed trains, in particular to a train roof insulator structure capable of preventing dirt accumulation. BACKGROUND

[0002] Currently, there are three main methods to improve the anti-flashover capability of the roof insulator: one is to increase the creepage distance of the roof insulator, which can improve the flashover voltage of the insulator to a certain extent, but the creepage distance of the roof insulator is limited to a certain size due to the limitations of the insulator structure size and production process; two is to manually clean the surface of the roof insulator at regular intervals, which is the most widely used method at present, but for the composite material commonly used in the roof insulator, the surface of the composite material will be damaged due to the friction of the cleaning material, resulting in a decrease in the self-cleaning performance of the composite material on the surface of the roof insulator; three is to spray a dirt-resistant coating on the surface of the roof insulator, which has good dirt-resistant effect, but the dirt-resistant coating is expensive and has a short effective period. Therefore, it is necessary to find an insulator structure that can effectively improve the anti-dirt accumulation performance of the roof insulator. SUMMARY

[0003] The present application relates to the technical field of high-speed trains, in particular to a train roof insulator structure capable of preventing dirt accumulation.

[0004] In a first aspect, the present application provides a train roof insulator structure capable of preventing dirt accumulation, which comprises a plurality of core rods and a plurality of sheds, the sheds being fixed at both ends of the core rods, and the up and down angles of the plurality of sheds being adjustable.

[0005] Further, the sheds comprise large sheds and small sheds, the diameter of the large sheds being larger than that of the small sheds, each core rod having the large and small sheds fixed at both ends thereof, the large sheds being arranged in parallel and at equal intervals, and the small sheds being arranged in parallel and at equal intervals.

[0006] Further, the up and down angles of the large and small sheds range from 0° to 10°.

[0007] Further, the up and down angles of the large and small sheds range from 0° to 5°.

[0008] Further, the height of the core rod ranges from 20 mm to 60 mm.

[0009] Further, the diameter of the large sheds is 182 mm, and the diameter of the small sheds is 152 mm.

[0010] Further, the diameter of the core rod is 70mm. In a second aspect, the application also provides a method for determining a dirt-accumulation-preventing train roof insulator structure, comprising:

[0011] constructing a three-dimensional model of the insulator structure, the insulator structure comprising a plurality of core rods and a plurality of sheds, the plurality of sheds comprising large sheds and small sheds, the diameter of the large sheds being greater than the diameter of the small sheds;

[0012] importing the three-dimensional model into a fluid dynamics-based software for meshing to obtain a plurality of target mesh units;

[0013] inputting boundary conditions into the fluid dynamics-based software and performing dirt-accumulation simulation of the insulator based on a preset discrete phase model in the fluid dynamics-based software to obtain a plurality of insulator simulation results, the insulator simulation results being obtained by weighted summation of simulation results corresponding to each target mesh unit;

[0014] determining an optimal simulation result and corresponding boundary parameters from the plurality of insulator simulation results, the optimal simulation result being used to represent a simulation result in which the corresponding pollution volume fraction of the three-dimensional model in the dirt-accumulation simulation is the smallest, and the boundary parameters comprising the height of the core rod, the up-inclination angle of the shed, and the down-inclination angle of the shed;

[0015] setting the insulator structure based on the boundary parameters and fixing the insulator structure on the train roof.

[0016] The application has the following beneficial effects:

[0017] The application considers the wind blowing effect, changes the up-inclination and down-inclination angles of the sheds and the height of the core rod, thereby improving the pressure condition on the leeward side of the insulator, changing the airflow condition on the surface of the insulator, and achieving the purpose of optimizing the dirt accumulation on the surface of the insulator, thereby effectively reducing the probability of pollution flashover accidents of the train roof insulator.

[0018] Other features and advantages of the application will be described in the following description, and some will become apparent from the description, or will be understood from the practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0020] Figure 1 The figure is a schematic diagram of the dirt-accumulation-preventing train roof insulator structure described in the embodiments of the application.

[0021] Figure 2 A method flow chart for determining the anti-fouling train roof insulator structure described in the embodiments of the present application is shown in the figure.

[0022] Figure 3 The corresponding fouling and flow field conditions of the initial insulator in the fluid dynamics software simulation described in the embodiments of the present application are shown in the figure.

[0023] Figure 4 The corresponding fouling and flow field conditions of the optimal simulation result in the fluid dynamics software simulation described in the embodiments of the present application are shown in the figure.

[0024] Figure 5 The insulator leeward side pressure numerical comparison chart described in the embodiments of the present application is shown in the figure.

[0025] Figure 6 A train roof insulator group flow field condition schematic diagram described in the embodiments of the present application is shown in the figure.

[0026] Figure 7 Another train roof insulator group flow field condition schematic diagram described in the embodiments of the present application is shown in the figure.

[0027] Marked in the figure: 1, core rod; 2, large umbrella skirt; 3, small umbrella skirt. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0029] It should be noted that: similar labels and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0030] Embodiment 1:

[0031] Referring to Figure 1 The present embodiment provides an anti-fouling train roof insulator structure, comprising:

[0032] The plurality of core rods 1 and the plurality of umbrella skirts are fixed at both ends of the core rod 1, and the up inclination and the down inclination of the plurality of umbrella skirts are adjustable;

[0033] Specifically, considering that there are two main reasons for the surface contamination of the insulator: one is that when the dirt flows through the roof insulator, it is affected by the negative pressure area formed by the reduced flow rate on the leeward side, and the airflow forms a turbulent flow on the leeward side of the insulator. When the total force acting on the dirt is zero, the dirt will deposit on the surface of the insulator; the second is that the dirt accumulated on the windward side and the side of the insulator will slide along the surface of the insulator under the action of wind blowing effect, and part of the dirt will slide to the leeward side of the insulator, resulting in increased contamination.

[0034] Therefore, the application considers adjusting the up and down inclination of the umbrella skirt of the insulator and the height of the core rod 1, thereby affecting the airflow flowing through the insulator, selecting appropriate umbrella skirt inclination and core rod 1 height to optimize the flow field of the insulator, thereby reducing the surface contamination of the insulator.

[0035] The umbrella skirt includes large umbrella skirts 2 and small umbrella skirts 3, the diameter of the large umbrella skirt 2 is larger than that of the small umbrella skirt 3, each core rod 1 is fixed with a large umbrella skirt 2 and a small umbrella skirt 3 at both ends, the large umbrella skirts 2 are parallel to each other and arranged at equal intervals, and the small umbrella skirts 3 are parallel to each other and arranged at equal intervals; the large umbrella skirts 2 and the small umbrella skirts 3 are arranged at intervals, the large umbrella skirts 2 can provide a larger coverage range, effectively change the airflow path, reduce the negative pressure area and turbulent flow on the leeward side, and thereby reduce the possibility of dirt deposition; the small umbrella skirts 3 supplement protection and further optimize the uniformity of the airflow.

[0036] The up inclination of the large umbrella skirt 2 and the small umbrella skirt 3 is in the range of 0°-10°, the down inclination of the large umbrella skirt 2 and the small umbrella skirt 3 is in the range of 0°-5°, the height of the core rod 1 is in the range of 20mm-60mm, the diameter of the large umbrella skirt 2 is 182mm, the diameter of the small umbrella skirt 3 is 152mm, and the diameter of the core rod 1 is 70mm. In the application, only the up and down inclination of the large umbrella skirt 2 and the small umbrella skirt 1 is adjusted and the height of the core rod 1 is adjusted under the condition that the diameters of the large umbrella skirt 2, the small umbrella skirt 3 and the core rod 1 are fixed, thereby achieving the purpose of optimizing the airflow distribution, improving the airflow dynamics on the surface of the insulator, and reducing the surface contamination of the insulator.

[0037] Example 2:

[0038] The model of the insulator is constructed by using SolidWorks software, and a plurality of insulator models after changing the upper and lower inclination angles of the shed of the insulator and the height of the core rod 1 are simulated to obtain the flow field and the dirt accumulation of the insulator under different insulator structure parameters. The optimal insulator structure parameters are obtained by comparing the dirt accumulation of the insulator. The flow field distribution corresponding to the optimal insulator structure parameters is determined to determine the mechanism for improving the dirt accumulation of the roof insulator.

[0039] The specific implementation steps are as shown in Figure 2 The embodiment provides a train roof insulator structure determination method for preventing dirt accumulation. The method includes steps S10, S20, S30, S40 and S50 as shown in the figure:

[0040] Step S10. Construct a three-dimensional model of the insulator structure, which includes a plurality of core rods 1 and a plurality of sheds, and the plurality of sheds include large sheds 2 and small sheds 3. The diameter of the large shed 2 is greater than that of the small shed 3.

[0041] Step S20. Import the three-dimensional model into a fluid dynamics software for mesh division to obtain a plurality of target mesh units.

[0042] Specifically, step S20 specifically includes steps S21 and S22:

[0043] Step S21. Divide the three-dimensional model into a plurality of initial mesh units based on the fluid dynamics software, wherein the surface area of the insulator is subjected to refined mesh division, and the rest is subjected to conventional mesh division.

[0044] Step S22. Set a boundary layer for the surface area of the insulator and correspondingly set the number of boundary layer layers, the stretching factor and the thickness adjustment factor to obtain a plurality of target mesh units. The number of boundary layer layers is used to represent the number of mesh units in the boundary layer, the stretching factor is used to represent the size ratio change of adjacent mesh units in the boundary layer, and the thickness adjustment factor is used to control the overall thickness of the boundary layer.

[0045] Specifically, in the fluid dynamics software simulation, the surface of the roof insulator is subjected to mesh refinement processing, the rest is subjected to mesh conventional processing, and the boundary layer is set for the roof insulator. The number of boundary layer layers is usually 1 layer, the stretching factor is 1.1, and the thickness adjustment factor is 1.1. Therefore, the complete mesh of the roof insulator includes 831072 units.

[0046] Step S30. Input the boundary conditions into the fluid dynamics software, and perform dirt accumulation simulation of the insulator based on the preset discrete phase model in the fluid dynamics software to obtain a plurality of insulator simulation results. The insulator simulation result is obtained by weighting and summing the simulation results corresponding to each target unit mesh.

[0047] Specifically, in order to obtain the pollution and flow field of the roof insulator, COMSOL software is used for simulation calculation, and the boundary conditions required for simulation calculation are shown in Table 1:

[0048] Table 1

[0049]

[0050] In the fluid dynamics software simulation, the physical field is set as "mixture model", "k-ε turbulence model based on RANS" and "global ordinary differential equation", which is used to simulate the interaction between airflow and pollution particles. The continuous phase is air, and the discrete phase, i.e. pollution, is calcium carbonate particles with a diameter of 10 μm. The distribution of pollution in air accounts for 15%. The calculation domain is set as a cylinder with a radius of 0.5 m and a length of 2 m. The turbulence model and mixture model can accurately simulate the pushing, sliding and deposition of airflow on pollution particles, so as to more accurately predict the deposition of pollution particles on the surface of the insulator, determine which area is more prone to pollution, and provide direction for the optimization of the structure of the insulator.

[0051] Step S40. Determine the optimal simulation result and the corresponding boundary parameter from the simulation results of the plurality of insulators. The optimal simulation result is used to represent the simulation result with the smallest pollution volume fraction of the three-dimensional model in the pollution simulation simulation. The boundary parameters include the height of the core rod 1, the up inclination angle of the shed and the down inclination angle of the shed.

[0052] Specifically, in the fluid dynamics software simulation, in order to more intuitively represent the pollution condition of the insulator surface in high-speed airflow, the amount of pollution is usually represented by the pollution volume fraction. The calculation formula of the pollution volume fraction is:

[0053]

[0054] Wherein, ρ is the pollution volume fraction dimensionless; V p is the pollution volume; V g is the air volume.

[0055] The above pollution volume and air volume need to be calculated under the same temperature and pressure.

[0056] The analysis of the flow field and the pollution of the roof insulator in the fluid dynamics software simulation is also displayed by images. Firstly, the cross-section pressure and the pressure value of the leeward surface of the roof insulator are extracted. The cross-section pressure graph of the insulator is obtained by simulating the cross-section of the insulator. Meanwhile, the pressure value of the leeward surface of the insulator is extracted and introduced into the origin drawing software to construct the along-surface pressure value curve of the leeward surface. The cross-section pressure graph and the along-surface pressure curve of the roof insulator corresponding to the initial simulation result and the optimal simulation result are compared, so as to provide an optimization direction for improving the pollution of the roof insulator.

[0057] As shown in Figure 3 , it is the pollution and flow field of the initial insulator corresponding to the fluid dynamics software simulation. It can be seen that the pollution on the leeward surface of the insulator is very serious. Figure 4 As shown in Figure 3 , it is the fluid dynamics software simulation result of the insulator structure parameter corresponding to the optimal simulation result. It can be seen that the pollution on the windward surface of the insulator has no great change compared with

[0058] As shown in Figure 5 , the graph collects the pressure value of the leeward side of the roof insulator. As can be seen from the graph, the along-surface pressure of the leeward side corresponding to the optimal simulation result is obviously greater than that of the initial insulator. The comparison of the pressure of the leeward side of the insulator is displayed in the numerical value.

[0059] Step S50. Set the insulator structure based on the boundary parameter, and fix the insulator structure on the roof of the train.

[0060] Specifically, the flow field corresponding to different installation modes of the roof insulator group is further explored in the present application. The structure of the roof insulator group of the high-speed train is simplified, and only the insulator group is retained, and other auxiliary structures are removed.

[0061] The initial installation mode of the insulator group is that the distance between the front and rear roof insulators is 2.5 m, the distance between the left and right roof insulators is 2 m, and the distance between the left and right roof insulators and the rear roof insulator is 1 m. Under the premise of ensuring the insulation distance, the variable distance between the left and right roof insulators is 1 m to 2.5 m, and the variable distance between the front and rear roof insulators is 2 m to 3 m. By simulating and analyzing the roof insulators in different installation modes, the current-carrying condition of each insulator under different installation modes is explored.

[0062] As shown in Figure 6 and Figure 7As shown in the two figures, the flow field of the roof insulator group at different installation positions can be effectively reduced by shortening the roof insulators at the left and right ends. Meanwhile, the negative pressure area of ​​the remaining roof insulators will not change much. The reduction of the negative pressure area effectively reduces turbulence, thereby greatly reducing the accumulation of dirt.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. 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.

[0064] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for determining the structure of an anti-pollution train roof insulator, characterized in that, The insulator structure includes multiple core rods (1) and multiple sheds, the sheds being fixed at both ends of the core rods (1), and the upward and downward tilt angles of the multiple sheds being adjustable; The umbrella skirt includes a large umbrella skirt (2) and a small umbrella skirt (3). The diameter of the large umbrella skirt (2) is larger than the diameter of the small umbrella skirt (3). The large umbrella skirt (2) and the small umbrella skirt (3) are fixed at both ends of each core rod (1). The large umbrella skirts (2) are parallel to each other and are equally spaced. The small umbrella skirts (3) are parallel to each other and are equally spaced. The method for determining the structure of the roof insulators for trains designed to prevent pollution accumulation includes: A three-dimensional model of an insulator structure is constructed. The insulator structure includes multiple core rods (1) and multiple skirts. The multiple skirts include a large skirt (2) and a small skirt (3). The diameter of the large skirt (2) is larger than the diameter of the small skirt (3). The three-dimensional model was imported into fluid dynamics software for mesh generation to obtain multiple target mesh elements. For the surface region of the insulator, a refined mesh was used and a boundary layer was set, while for the surface region of the insulator, a conventional mesh was used. The boundary conditions are input into the fluid dynamics software to extract the cross-sectional pressure and leeward pressure values ​​of the roof insulator. At the same time, the pollution accumulation simulation of the insulator is performed based on the preset discrete phase model in the fluid dynamics software to obtain multiple insulator simulation results. The insulator simulation results are obtained by weighted summation of the simulation results corresponding to each target cell grid. The optimal simulation result and corresponding boundary parameters are determined from multiple insulator simulation results. The optimal simulation result is used to characterize the simulation result with the smallest pollution volume fraction corresponding to the three-dimensional model in the pollution accumulation simulation. The boundary parameters include the height of the core rod (1), the upward tilt angle of the umbrella skirt, and the downward tilt angle of the umbrella skirt. The insulator structure is set according to the boundary parameters and fixed to the roof of the train.

2. The method for determining the structure of the anti-pollution train roof insulator according to claim 1, characterized in that... The upward tilt angle of the large umbrella skirt (2) and the small umbrella skirt (3) ranges from 0° to 10°.

3. The method for determining the structure of the anti-pollution train roof insulator according to claim 1, characterized in that... The downward tilt angle of the large umbrella skirt (2) and the small umbrella skirt (3) ranges from 0° to 5°.

4. The method for determining the structure of the anti-pollution train roof insulator according to claim 1, characterized in that... The height of the mandrel (1) ranges from 20mm to 60mm.

5. The method for determining the structure of the anti-pollution train roof insulator according to claim 1, characterized in that... The diameter of the large umbrella skirt (2) is 182mm, and the diameter of the small umbrella skirt (3) is 152mm.

6. The method for determining the structure of the anti-pollution train roof insulator according to claim 4, characterized in that... The diameter of the mandrel (1) is 70 mm.

7. The method for determining the structure of the anti-pollution train roof insulator according to claim 1, characterized in that... The three-dimensional model is imported into fluid dynamics software for mesh generation to obtain multiple target mesh elements, including: meshing the three-dimensional model based on the fluid dynamics software to obtain multiple initial mesh elements, wherein a refined mesh generation is used for the insulator surface area, and a conventional mesh generation is used for the insulator surface area; A boundary layer is set on the surface region of the insulator, and the number of boundary layer layers, stretching factor and thickness adjustment factor are set accordingly to obtain multiple target mesh cells. The number of boundary layer layers is used to characterize the number of mesh cell layers in the boundary layer, the stretching factor is used to characterize the size ratio change of adjacent mesh cells in the boundary layer, and the thickness adjustment factor is used to control the overall thickness of the boundary layer.

8. The method for determining the structure of the anti-pollution train roof insulator according to claim 1, characterized in that... The formula for calculating the volume fraction of contaminants is as follows: in, It represents the volume fraction of dirt; For the volume of filth; This represents the volume of air.

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