CN110489867B - Dirt accumulation characteristic analysis method for wet and snow prevention composite insulator - Google Patents
Dirt accumulation characteristic analysis method for wet and snow prevention composite insulator Download PDFInfo
- Publication number
- CN110489867B CN110489867B CN201910768729.6A CN201910768729A CN110489867B CN 110489867 B CN110489867 B CN 110489867B CN 201910768729 A CN201910768729 A CN 201910768729A CN 110489867 B CN110489867 B CN 110489867B
- Authority
- CN
- China
- Prior art keywords
- insulator
- wet
- flow field
- snow
- composite insulator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Insulators (AREA)
Abstract
The invention relates to a method for analyzing dirt accumulation characteristics of a wet and snow prevention composite insulator, which is technically characterized by comprising the following steps of: using Geometry and Mesh modules of Fluent software to establish a moisture and snow-proof insulator and a surrounding flow field model and divide grids; carrying out fluid mechanics simulation calculation on a flow field model around the insulator by using Fluent, and solving a flow field; repeatedly solving according to the variable modification parameters to obtain the element values of each finite element; the insulator dirt accumulation characteristics of the anti-wet and snow composite insulator under the conditions of distribution of surrounding gas flow fields, different wind speeds and particle sizes are obtained. The invention has reasonable design, and the simulation analysis of the differences of the surrounding flow fields of the wet-snow-proof composite insulator under different umbrella structures and suspension modes can obtain the anti-pollution flashover characteristics of different double-string suspension modes, common type insulators and wet-snow-proof insulators and key influence factors thereof, thereby laying a foundation for the application of the wet-snow-proof composite insulator in key areas.
Description
Technical Field
The invention belongs to the technical field of overhead transmission lines, and particularly relates to a dirt accumulation characteristic analysis method of a wet and snow prevention composite insulator.
Background
The insulator mainly plays an important role in electric insulation and mechanical support in an electric power system, is important electric equipment related to safe and stable operation of the electric power system, and has wide application in overhead lines. In order to maintain the stability of the power system, studies on the susceptibility of insulators to failure are particularly important. In actual operation of the power system, the insulator is often arranged outdoors and is in various types of external environments, even under severe conditions. This results in a large number of contaminants, such as saline alkali, bird droppings, dust, other solid particulates, etc. that deposit and adhere to the insulator surface to form a messy layer. When the weather is dry in sunny days, the electric conductivity of the pollution layer is low, and once the wet weather such as fog, dew, capillary rain, snow melting and the like is met, the pollution on the surface of the insulator can absorb moisture, so that electrolyte contained in the pollution layer begins to be dissolved and ionized, and the electric conductivity of the pollution layer on the surface of the insulator can be increased due to the dissolution and ionization. In addition, the high voltage at the two ends of the insulator can easily cause pollution flashover accidents of the insulator.
At present, the electric power department and related researchers usually carry out antifouling work based on pollution degree measurement, and the pollution accumulation rule of the insulator is researched through the pollution degree measurement, so that the grade of a pollution area is determined according to the pollution degree measurement, and related work such as external insulation design, creepage distance adjustment, line cleaning and the like is guided. The study on the pollution condition of the typical insulator is the basis for guiding the research work of the pollution of the insulator, and the pollution analysis on the insulators with other specific shapes is also indispensable.
In recent years, the electric power department carries out anti-icing (snow) reconstruction on the transmission line in partial ice and snow flashover areas of the power grid, adopts a composite anti-icing insulator with an enlarged umbrella skirt, and keeps the suspension string in a double-string design so as to improve the anti-icing, anti-windage and anti-string dropping capacity of the line. However, the influence of the suspension modes such as II type, V type and inverted V type on the existing external insulation performance is not comprehensively considered, and particularly, the analysis of the dirt accumulation characteristics of the composite wet and snow prevention insulator with the special umbrella skirt is not carried out.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide the dirt accumulation characteristic analysis method of the wet and snow preventing composite insulator, which has reasonable design, is accurate and reliable and can provide basis for the transformation of a power transmission line.
The invention solves the technical problems by adopting the following technical scheme:
a dirt accumulation characteristic analysis method of a wet and snow prevention composite insulator comprises the following steps:
step 1, using Geometry and Mesh modules of Fluent software to establish a moisture and snow-proof insulator and a surrounding flow field model thereof and divide grids;
step 2, performing fluid mechanics simulation calculation on a flow field model around the insulator by using Fluent, and solving a flow field;
and 4, obtaining the distribution of the surrounding gas flow field of the wet and snow preventing composite insulator, the insulator pollution accumulation characteristics under different wind speeds and particle sizes according to the element values obtained in the step 3.
The wet-snow-proof insulator model is used for selecting one large umbrella group and two small umbrella groups in the whole insulator, and simplifying the rod part of the insulator into a cylinder; the size of the flow field area of the flow field model is 2100 multiplied by 2600 multiplied by 2800mm, wherein the left side is an inlet of the air flow field, and the right side is an outlet of the air flow field.
The dividing network adopts a tetrahedral mesh dividing method, and when the meshes are divided, the insulator model is compressed to obtain a complete insulator surface boundary surface, so that static pressure distribution display of the insulator wall surface, vector direction display of an air flow field and dirt particle capture are ensured to be completed in a fluid experiment.
The specific implementation method of the step 2 is as follows: setting four boundary surfaces of a flow field inlet, a flow field outlet, a flow field boundary and an insulator surface in a flow field model around an insulator: the flow field inlet is set as a speed inlet and is responsible for entering air flow with a certain speed, water with a certain humidity proportion and dirt particle flow with a discrete phase; the outlet of the flow field is set as a pressure outlet and is used for air fluid and liquid phase flow fluid model characterizing humidity; when the Mesh module is processed, the flow field boundary is named as a wall surface, and the entering Fluent fluid calculation module is automatically defined as the wall surface; the insulator surface is set as a wall surface, can receive the influence of the pressure of an external flow field and discrete phase-dirt particles, and is used as an insulator to participate in the formation of a flow field model; and then adopting a simple algorithm to carry out fluid mechanics simulation calculation.
The step 3 obtains the collision rate, the capture rate and the fouling performance by solving, wherein
The collision rate is expressed as:
the capture rate is expressed as:
the fouling performance is expressed as:
J k ＝c k Q k
in the above formula, the meaning of each parameter is: p is p k Is the k-th finite element surface collision rate; q (Q) k The total amount of particles impacted for the kth finite element; ρ k An average concentration of particles impacted by the kth finite element; s is S k Is the kth finite element surface area; v k An average velocity of particles impacted for the kth finite element table; t is the calculation time; c k Is the k finite element capture rate; f (f) i Reaction force of the ith particle; f (F) surface Is surface adhesion (constant); j (J) k Is the k-th finite element fouling performance.
And 4, obtaining the dirt accumulation characteristic of the wet and snow preventing composite insulator according to the following steps:
J max ＝max(J k )
in the above formula, J is dirt accumulation property.
The invention has the advantages and positive effects that:
the invention has reasonable design, and according to the typical pollution characteristics of the wet and snow prevention composite insulator, the influence rules of the suspension distance of the II strings of the wet and snow prevention composite insulator and the suspension angle of the V strings and the inverted V strings on the surface pollution accumulation characteristic of the insulator are analyzed in a simulation mode, and compared with the common composite insulator, the differences of flow fields around the wet and snow prevention composite insulator under different umbrella structures and suspension modes are simulated and analyzed, so that the anti-pollution flashover characteristics of different double-string suspension modes, common and wet and snow prevention insulators and key influence factors thereof are obtained, and a foundation is laid for the application of the wet and snow prevention composite insulator in key areas.
Drawings
FIG. 1 is a simulation flow diagram of the present invention;
FIG. 2 is a diagram of an insulator model;
FIG. 3 is a meshing effect diagram;
FIG. 4 is a simple algorithm flow chart;
FIG. 5a is a static pressure cloud chart (flow field air pressure distribution in the x-y direction) of the surface of a 500kV wet and snow prevention composite insulator;
FIG. 5b is a static pressure cloud chart (flow field air pressure distribution in the x-z direction) of the surface of a 500kV wet and snow prevention composite insulator;
FIG. 6 is a graph of insulator pressure change on the windward side and leeward side at different wind speeds;
FIG. 7 is a vector diagram of the velocity distribution between the sheds at 10 m/s;
FIG. 8a is a graph of velocity vector distribution around an insulator (X-Y plane velocity vector) at different angles;
fig. 8b is a graph of velocity vector distribution (X-Z plane velocity vector) around the insulator at different angles.
Detailed Description
Embodiments of the invention are described in further detail below with reference to the attached drawing figures:
the design idea of the invention is as follows:
from the analysis it is known that: the accumulated dirt on the insulator is mostly from dirt particles in the air around the insulator, and the dirt particles are mostly contacted and attached with the surface of the insulator under the influence of gravity, wind force and other acting forces through the flow of the air. By researching the distribution condition of the air flow field around the insulator, the running track of dirt particles in the air and the dirt accumulation process of the insulator can be better known. Therefore, aiming at the typical pollution characteristics of partial areas, the influence rule of the suspension distance of the wet and snow prevention composite insulator II string and the suspension angle of the V string and the inverted V string on the surface pollution characteristic of the insulator is researched through simulation calculation. And then comparing the composite insulator with a common composite insulator, and performing simulation analysis on differences of flow fields around the wet and snow preventing composite insulator under different umbrella structures and suspension modes to obtain the anti-pollution flashover characteristics and key influence factors of different double-string suspension modes, common and wet and snow preventing insulators.
Based on the design thought, the patent utilizes fluid mechanics simulation experiments to research the air flow field around the insulator and the movement condition of the pollution particles through Fluent software. The specific method comprises the following steps:
step 1, utilizing Geometry and Mesh modules of Fluent software to establish a moisture and snow-proof insulator and a surrounding flow field model thereof and divide grids.
The simulation experiment of the pollution characteristic of the insulator is based on researching the motion trail of pollution particles in the air contacting the surface of the insulator, and the motion trail of the pollution particles in the air is researched according to the principle of fluid mechanics in a flow field. The principle of fluid mechanics is based on three basic equations: conservation of mass equation, conservation of momentum equation, conservation of energy equation. In the experiment, the factors such as temperature and the like are not considered, and an energy conservation equation is not added. Wherein the mass conservation equation represents a balance between the net mass flowing through any one voxel in a unit time and the increase in the volume voxel mass expressed as:
in equation 1, u represents a velocity vector, t represents time, and ρ is a fluid density. The formula is applicable to a transient compressible fluid model, so that the fluid field around the insulator, namely air, in the experiment is satisfied.
For the law of conservation of momentum, the meaning is: the change rate of the momentum of the micro-element body along with time is equal to the resultant force of external acting force on the micro-element body. From this, the momentum conservation equation in the Cartesian coordinate system can be obtained as:
wherein p is the pressure on the fluid microcell; τ xx 、τ xy 、τ xz The components of the viscous force tau generated on the surface of the micro-element body due to the viscous action among molecules in all directions are equal; fx, fy, fz are the volumetric forces in three coordinate directions of the infinitesimal.
The model of the fouling characteristic of the insulator also comprises a turbulence characteristic equation, and because the insulator has a complex surface structure with multiple umbrella skirts, the air flow field nearby the insulator belongs to typical turbulence flow. The wet-snow-proof composite insulator has a unique umbrella skirt structure subsection, and ice and snow are prevented from accumulating on the insulator through the shielding effect of the large umbrella skirt and the 'dumping' effect of the deformation of special materials. The insulator model is built according to the insulator model parameters shown in fig. 2, 1:1.
The design of the umbrella skirt of the wet-snow-proof composite insulator is characterized in that an enlarged umbrella skirt with the diameter larger than that of a common umbrella skirt is arranged and is used for shielding dirt and cleaning the dirt through deformation. Compared with other insulators, the ratio of the rod diameter to the umbrella skirt diameter of the wet and snow preventing composite insulator is small, so that the flow field distribution of the insulator has the characteristic of unobvious back air flow of lee surface and the like.
In order to simplify the calculation amount, the model selects one large umbrella group in the whole insulator, adds two small umbrella groups, and simplifies the rod part of the insulator into a cylinder. To fit the actual situation. The edge and the surface of the umbrella skirt of the insulator model are designed with radians according to actual data, so that the requirements of calculation precision and accuracy can be met. A specific model is shown in fig. 2.
The adopted grid dividing tool is as follows: the grid division of Fluent adopts a tetrahedral grid division method, the types of grid division are quite comprehensive, the division of discontinuous grids, mixed grids, deformed grids, sliding grids and other grid types of interfaces can be realized, and the self-adaption capability of the grids according to the model surface is good. The edge of the umbrella skirt of the insulator model has the characteristic of drastic curvature change, has high requirements on the self-adaptive capacity of grids, and can ensure the accuracy of flow field calculation by the grid quality of Fluent software.
Because the umbrella skirt structure of the insulator is complex, the requirement on grid cutting precision is high, and the boundary between the surface of the insulator and air is easy to break when the insulator is divided into grids, the insulator model is compressed when the grids are divided in the experiment, namely the insulator model is not subjected to grid processing. The method can obtain a complete insulator surface boundary surface, can ensure that experimental tasks such as static pressure distribution display, air flow field vector direction display, dirt particle capture and the like of the insulator wall surface are completed in the following fluid experiment, and the experimental meshing effect is shown in figure 3.
And 2, performing fluid mechanics simulation calculation on a flow field model around the insulator by using Fluent, and solving the flow field.
As shown in FIG. 4, the fluid mechanics simulation calculation is performed by using a simple algorithm (Semi-implicit method for solving the pressure coupling equation set). After the model building and meshing work is completed, the setting of the properties of the respective boundary surfaces is required. The experimental insulator and the model of the surrounding flow field thereof comprise four boundary surfaces of a flow field inlet, a flow field outlet, a flow field boundary and an insulator surface. The flow field inlet is set as a velocity inlet (velocity-inlet) and is responsible for entering air flow with a certain velocity, water with a certain humidity proportion and dirt particle flow with a discrete phase. The outlet of the flow field is set as a pressure outlet (pressure-outlet) for the air fluid and the liquid phase flow characterizing the humidity flow model.
The boundary of the flow field is named as wells when the Mesh module processes, and the entering Fluent computing module is automatically defined as a wall (wall). The surface treatment of the insulator is the key for researching the pollution characteristic of the insulator, and the static pressure distribution of the surface and the collision condition of pollution particles and the surface are required to be obtained on the surface of the insulator, so that when the surface of the insulator is obtained, the insulator is subjected to compression treatment in the grid dividing step, and the complete surface of the insulator is obtained. The insulator surface needs to be a wall surface (wall), namely the insulator surface can receive the influence of the pressure and discrete phase-dirt particles of an external flow field and is used as the insulator to participate in the formation of a flow field model, but the boundary attribute of the insulator surface does not influence the generated flow field condition. In order to capture the collision condition of discrete phase-dirt particles, when the dirt particles collide with the surface of the insulator, the dirt particles are considered to be captured by the surface of the insulator.
(1) collision Rate
(2) Capture rate
(3) Dirt accumulation property (dirt accumulation amount)
J k ＝c k Q k (5)
In the above formula, the meaning of each parameter is: p is p k Is the k-th finite element surface collision rate; q (Q) k The total amount of particles impacted for the kth finite element; ρ k An average concentration of particles impacted by the kth finite element; s is S k Is the kth finite element surface area; v k An average velocity of particles impacted for the kth finite element table; t is the calculation time; c k Is the k finite element capture rate; f (f) i Reaction force of the ith particle; f (F) surface Is surface adhesion (constant); . J (J) k Is the k-th finite element fouling performance (fouling amount).
And step 4, obtaining the insulator dirt accumulation characteristics of the anti-wet and snow composite insulator under the conditions of distribution of surrounding gas flow fields, different wind speeds and particle sizes of the anti-wet and snow composite insulator according to the element values solved in the step 3.
The dirt accumulation characteristic of the wet and snow prevention composite insulator refers to dirt accumulation amount in each finite element analysis result on the surface, and the largest value of the dirt accumulation amount is found, namely the position most prone to dirt accumulation. Can obtain the dirt accumulation characteristic J of the wet and snow prevention composite insulator k Is a profile of (a).
J max ＝max(J k ) (6)
In the above, J is the dirt accumulation property (maximum dirt accumulation amount)
The distribution of the gas flow field around the insulator, the different wind speeds and the insulator pollution accumulation characteristics under the particle sizes are described below:
as shown in fig. 1, fluent software is applied to perform hydrodynamic simulation, air around an insulator is set as a continuous phase to perform transient turbulent fluid simulation calculation, then dirt particles are added as a discrete phase, and steady state calculation of coupling with air fluid is performed, so that the 'collision rate' describing dirt accumulation characteristics is obtained. In the hydrodynamic simulation, the distribution of the gas flow field around the insulator, different wind speeds and the insulator pollution accumulation characteristic under the particle size are obtained. And the results are analyzed using the quantized data curves.
1. Analysis of insulator ambient gas flow field
The gas flow field distribution of the air around the insulator is researched, so that the movement track of dirt particles in the flow field is favorably researched, and the method is greatly helpful for analyzing the dirt process of the insulator. The flow field distribution of the wet and snow prevention composite insulator in the fluid simulation experiment is analyzed, and the static pressure distribution on the surface of the insulator and the speed distribution in the air flow field are obtained under the unique umbrella skirt structure of the insulator, as shown in fig. 5a and 5 b.
2. Static pressure distribution of insulator in flow field
Static pressure is a physical parameter that characterizes the pressure generated by an air fluid impacting an object and may also represent the amount of energy carried per unit volume of air. The static pressure distribution near the surface of the insulator can be obtained through simulation experiments and is shown by using a cloud chart, which is helpful for describing the collision condition of dirt particles and the surface of the insulator. The static pressure cloud chart of the whole surface of the insulator is shown in fig. 6.
A place with a large static pressure indicates that air molecules collide with the insulator more easily, whereas a smaller static pressure indicates that air molecules bypass the insulator more easily than collide. Meanwhile, dirt particles with small particle sizes in the air are easy to move along with air flow due to small volume, weight and inertia. Therefore, the places with large static pressure in the simulation cloud pictures are easy to be impacted by dirt particles with small particle sizes, and the dirt of the small particles in the places with small static pressure is easy to avoid impacting the surface of the insulator due to the following air bypass. However, when the particle size of the polluted particles is large, the real collision rate is affected by the mass and inertia of the polluted particles, and discrete simulation analysis is required.
The static pressure distribution of the windward side and the leeward side of the insulator is very different. The static pressure of the windward side of the insulator is larger and is positive, the static pressure of the leeward side of the insulator is smaller, and negative pressure can occur locally. The static pressure distribution of the windward side is larger and uneven, the static pressure is lower in the air field around the insulator closer to the surface of the insulator, and a concave distribution cloud picture is formed between two large umbrella skirts according to the umbrella shape of the insulator. And the maximum static pressure on the surface of the windward insulator occurs at the edge of the umbrella skirt closest to the air inlet.
The static pressure distribution of the leeward side of the insulator is average, the minimum static pressure distribution is formed at the positions of the rods at the two ends of the insulator, the static pressure of the distribution part of the small shed in the middle of the two large sheds is larger than that at the two ends, in addition, the static pressure distribution of the leeward side has negative pressure, and the static pressure of the leeward side is generally lower, so that dirt particles are easily sucked into the leeward side area through air flow formed by pressure difference, and meanwhile, vortex phenomenon exists in the air flow in the sheds of the leeward side of the insulator, so that the dirt particles possibly collide with the insulator on the leeward side along with vortex so as to accumulate and precipitate on the surface. And considering that the leeward wind force is smaller, dirt is easy to deposit on the surface and is difficult to clean by larger wind force after accumulating on the surface of the insulator, so that a dirt layer is usually formed on the leeward surface of the insulator. The static pressure distribution of the side wind surface of the insulator is similar to that of the lee wind surface, the static pressure distribution is uniform, the minimum static pressure can appear at two ends, and the static pressure in the middle is higher than that at two ends.
The static pressure distribution of the windward side and the leeward side of the insulator is very different. The static pressure of the windward side of the insulator is larger and is positive, the static pressure of the leeward side of the insulator is smaller, and negative pressure can occur locally. The static pressure distribution of the windward side is larger and uneven, the static pressure is lower in the air field around the insulator closer to the surface of the insulator, and a concave distribution cloud picture is formed between two large umbrella skirts according to the umbrella shape of the insulator. And the maximum static pressure on the surface of the windward insulator occurs at the edge of the umbrella skirt closest to the air inlet.
The static pressure distribution of the leeward side of the insulator is average, the minimum static pressure distribution is formed at the positions of the rods at the two ends of the insulator, the static pressure of the distribution part of the small shed in the middle of the two large sheds is larger than that at the two ends, in addition, the static pressure distribution of the leeward side has negative pressure, and the static pressure of the leeward side is generally lower, so that dirt particles are easily sucked into the leeward side area through air flow formed by pressure difference, and meanwhile, vortex phenomenon exists in the air flow in the sheds of the leeward side of the insulator, so that the dirt particles possibly collide with the insulator on the leeward side along with vortex so as to accumulate and precipitate on the surface. And considering that the leeward wind force is smaller, dirt is easy to deposit on the surface and is difficult to clean by larger wind force after accumulating on the surface of the insulator, so that a dirt layer is usually formed on the leeward surface of the insulator.
Through carrying out hydrodynamic simulation on the wet and snow prevention composite insulator, static pressure distribution conditions of wind speeds of 1m/s, 2m/s, 3m/s, 4m/s, 5m/s and 10m/s are obtained, and the static pressure distribution conditions of the insulator at different wind speeds are found to be similar through comparing cloud patterns. The maximum value of static pressure varies greatly at different wind speeds. The variation rule of the maximum static pressure and the minimum static pressure increases with the increase of wind speed, namely the difference between the maximum static pressure and the minimum static pressure increases. Wherein the maximum static pressure is obviously increased along with the wind speed; the minimum static pressure is negative, the value is small, and the variation amplitude is small. The method is characterized in that the rod diameter of the wet-snow-preventing composite insulator is smaller, so that the static pressure value of the negative value of the leeward side of the insulator is smaller, the influence of wind force on the negative pressure of the leeward side is small, and the phenomena of gas vortex and backflow of the leeward side of the wet-snow-preventing composite insulator are not obvious.
3. Velocity profile of air flow field
The speed of the air flow field around the insulator, namely the airflow speed, is an important factor for analyzing the aggregation and accumulation process of the dirt particles, and in a place with high airflow speed, the dirt particles are harder to stay on the surface of the insulator after contacting with the surface of the insulator because of higher airflow speed, and conversely, the smaller airflow speed is one of good conditions for dirt accumulation. The velocity vector diagram (shown in fig. 7) at 10m/s was obtained by simulation, and the velocity distribution in the air flow field was studied.
The velocity distribution vectors are similar in the velocity distribution in the insulator air flow field at different wind speeds, and the windward side and the crosswind side are greatly different, as shown in fig. 8a and 8 b.
The maximum speed of air flow in the surrounding air flow field of the insulator appears on two sides of the insulator, and the air flow speeds of the side air surface and the windward surface of the insulator are generally higher, namely that dirt particles are harder to stay on the surface after contacting with the surface of the insulator. In addition, the upward vortex exists in the air flow field near the surface of the insulator, so that dirt particles with smaller particle sizes can collide with the lower surface of the umbrella skirt of the insulator through the upward vortex, which also explains that the dirt particles are removed and settled on the upper surface of the insulator due to gravity, and partial dirt deposits are also formed on the lower surface of the insulator.
On the lee side of the insulator, the flow field speed distribution is smaller, and the air vortex phenomenon between insulator sheds also occurs in a vector diagram of the flow field speed. Because the air flow speed of the leeward side is smaller, dirt particles are more easily adhered to the surface of the insulator on the leeward side, and then the result is combined with the analysis of static pressure distribution on the surface of the insulator, and under the driving action of air flow formed by static pressure difference, part of dirt particles are pulled to the leeward side area, so that the dirt layer is also easily formed on the leeward side of the insulator.
The invention is applicable to the prior art where it is not described.
It should be emphasized that the examples described herein are illustrative rather than limiting, and therefore the invention includes, but is not limited to, the examples described in the detailed description, as other embodiments derived from the technical solutions of the invention by a person skilled in the art are equally within the scope of the invention.
Claims (1)
1. A dirt accumulation characteristic analysis method of a wet and snow prevention composite insulator is characterized by comprising the following steps of:
step 1, using Geometry and Mesh modules of Fluent software to establish a wet-snow-proof composite insulator and a surrounding air flow field model and divide grids;
step 2, performing fluid mechanics simulation calculation on an air flow field model around the wet and snow preventing composite insulator by utilizing Fluent, and solving a flow field;
step 3, repeatedly solving according to the variable modification parameters to obtain the element values of each finite element;
step 4, obtaining the distribution of the air flow field around the wet-snow-proof composite insulator, the wet-snow-proof composite insulator pollution accumulation characteristics under different wind speeds and particle sizes according to the element values obtained in the step 3;
the wet-snow-proof composite insulator model is used for selecting one large umbrella group and two small umbrella groups in the whole wet-snow-proof composite insulator, and simplifying the rod part of the wet-snow-proof composite insulator into a cylinder; the size of a flow field area of the air flow field model is 2100 multiplied by 2600 multiplied by 2800mm, wherein the left side is an inlet of the air flow field, and the right side is an outlet of the air flow field;
the dividing network adopts a tetrahedral mesh dividing method, and when the mesh is divided, the wet and snow preventing composite insulator model is compressed to obtain a complete wet and snow preventing composite insulator surface boundary surface, so that static pressure distribution display, air flow field vector direction display and dirt particle capture of the wet and snow preventing composite insulator wall surface are ensured to be completed in a fluid experiment;
the specific implementation method of the step 2 is as follows: the method comprises the following steps of setting four boundary surfaces of a flow field inlet, a flow field outlet, a flow field boundary and a surface of a wet and snow preventing composite insulator in an air flow field model around the wet and snow preventing composite insulator: the flow field inlet is set as a speed inlet and is responsible for entering air flow with a certain speed, water with a certain humidity proportion and dirt particle flow with a discrete phase; the outlet of the flow field is set as a pressure outlet and is used for outputting an air fluid and a liquid phase flow representing humidity characteristics out of an air flow field model; when the Mesh module is processed, the flow field boundary is named as a wall surface, and the entering Fluent fluid calculation module is automatically defined as the wall surface; the surface of the wet-snow-proof composite insulator is set as a wall surface, receives the influence of the pressure and discrete phase-dirt particles of an external flow field, and is used as the wet-snow-proof composite insulator to participate in the formation of an air flow field model; then adopting a simple algorithm to carry out fluid mechanics simulation calculation;
the step 3 obtains the collision rate, the capture rate and the fouling performance by solving, wherein
The collision rate is expressed as:
the capture rate is expressed as:
the fouling performance is expressed as:
J k ＝c k Q k
in the above formula, the meaning of each parameter is: p is p k Is the k-th finite element surface collision rate; q (Q) k The total amount of particles impacted for the kth finite element; ρ k An average concentration of particles impacted by the kth finite element; s is S k Is the kth finite element surface area; v k An average velocity of particles impacted by the kth finite element; t is the calculation time; c k Is the k finite element capture rate; f (f) i Reaction force of the ith particle; f (F) surface Is the surface adhesion constant; j (J) k The k-th finite element dirt accumulation performance;
and 4, obtaining the dirt accumulation characteristic of the wet and snow preventing composite insulator according to the following steps:
J max ＝max(J k )
in the above formula, J is dirt accumulation property.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910768729.6A CN110489867B (en) | 2019-08-20 | 2019-08-20 | Dirt accumulation characteristic analysis method for wet and snow prevention composite insulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910768729.6A CN110489867B (en) | 2019-08-20 | 2019-08-20 | Dirt accumulation characteristic analysis method for wet and snow prevention composite insulator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110489867A CN110489867A (en) | 2019-11-22 |
| CN110489867B true CN110489867B (en) | 2023-05-26 |
Family
ID=68552258
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910768729.6A Active CN110489867B (en) | 2019-08-20 | 2019-08-20 | Dirt accumulation characteristic analysis method for wet and snow prevention composite insulator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110489867B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111324994B (en) * | 2020-02-29 | 2021-02-09 | 西南交通大学 | Simulation calculation method for simulating hard phase particle matrix surface distribution condition based on FLUENT |
| CN113947040B (en) * | 2021-10-12 | 2024-06-25 | 中铁第一勘察设计院集团有限公司 | Method for analyzing uneven dirt accumulation on upper and lower surfaces of insulator based on volume distribution coefficient |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109583066A (en) * | 2018-11-22 | 2019-04-05 | 南京工程学院 | A kind of direct current overhead transmission line insulator surface filth deposition analogy method |
| CN109598065A (en) * | 2018-12-05 | 2019-04-09 | 西南交通大学 | The acquisition methods of insulator charged contamination distribution under a kind of flow fields environment |
-
2019
- 2019-08-20 CN CN201910768729.6A patent/CN110489867B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109583066A (en) * | 2018-11-22 | 2019-04-05 | 南京工程学院 | A kind of direct current overhead transmission line insulator surface filth deposition analogy method |
| CN109598065A (en) * | 2018-12-05 | 2019-04-09 | 西南交通大学 | The acquisition methods of insulator charged contamination distribution under a kind of flow fields environment |
Non-Patent Citations (4)
| Title |
|---|
| 低风速下瓷三伞绝缘子积污特性数值模拟研究;吕玉坤等;《华北电力大学学报(自然科学版)》;20160930(第05期);全文 * |
| 动车组支柱绝缘子伞裙不同部位积污特性的仿真研究;律方成等;《高压电器》;20161116(第11期);全文 * |
| 复合绝缘子表面湿润积污过程的数值模拟方法;江云志等;《华中电力》;20100220(第01期);全文 * |
| 浙江输电线路不同伞形绝缘子积污特性试验研究;李特等;《绝缘材料》;20161231(第09期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110489867A (en) | 2019-11-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Kataoka et al. | Numerical flow computation around aeroelastic 3D square cylinder using inflow turbulence | |
| Jin et al. | Darrieus vertical axis wind turbine: Basic research methods | |
| CN110489867B (en) | Dirt accumulation characteristic analysis method for wet and snow prevention composite insulator | |
| CN110728018A (en) | Method for analyzing dirt accumulation characteristics of large umbrella skirt composite insulator under different air humidity | |
| Wu et al. | Effects of rain on vertical axis wind turbine performance | |
| CN110489864B (en) | Method for analyzing antifouling property of wet and snow preventing insulator by considering wind speed, pollution and particle size | |
| Szilder | Theoretical and experimental study of ice accretion due to freezing rain on an inclined cylinder | |
| Zare et al. | NREL Phase VI wind turbine in the dusty environment | |
| Zidane et al. | Computational fluid dynamics study of dusty air flow over NACA 63415 airfoil for wind turbine applications | |
| Deng et al. | A turbulent crosswind simulation method at high-speed railway tunnel entrance: Based on field test and geometric turbulence generator | |
| Utnes et al. | Turbulent flows over mountainous terrain modelled by the Reynolds equations | |
| Palaszewski et al. | A three-dimensional air-vapor-droplet local interaction model for spray units | |
| Bodavula et al. | Numerical investigation of the unsteady aerodynamics of NACA 0012 with suction surface protrusion | |
| Longji et al. | Pollution characteristics analysis of II-strings anti-wet snow composite insulators in transmission lines | |
| Poots et al. | Simulation of wet-snow accretion by axial growth on a transmission line conductor | |
| Bernardoni et al. | Implications of complex terrain topography on the performance of a real wind farm | |
| Baker et al. | Ice accretion on cables of various cross-sections | |
| Jurij et al. | Development and testing of open-jet wind tunnel for quadrotor flight testing | |
| Wang et al. | Simulation and verification of indirect modeling method for urban wind environment | |
| CN110516351A (en) | A kind of double insulator string suspension angles optimization method based on insulator contamination accumulation characteristics | |
| Zong et al. | Three‐Dimensional Numerical Simulation of Rime Ice Accretion on Polymeric Insulator Based on Computational Fluid Dynamics and its Experimental Verification | |
| Sharma et al. | A CFD Analysis of the Effect of Ice and Snow Accretion on the Aerodynamic Behavior of Bridge Cables | |
| Li et al. | Analysis of water film distribution and aerodynamic characteristics of high-speed train under rainfall environment | |
| Tamura et al. | BCM-LES for moving cIBM on aeroelastic stability of a tall building with various modes | |
| Wada et al. | Evaluation of aerodynamic performance of airfoil using the e-mps method after icing |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |