CN115169267A - A numerical simulation method for the growth of ice-covered ice on the surface of transmission line insulators without overflow - Google Patents
A numerical simulation method for the growth of ice-covered ice on the surface of transmission line insulators without overflow Download PDFInfo
- Publication number
- CN115169267A CN115169267A CN202211098383.1A CN202211098383A CN115169267A CN 115169267 A CN115169267 A CN 115169267A CN 202211098383 A CN202211098383 A CN 202211098383A CN 115169267 A CN115169267 A CN 115169267A
- Authority
- CN
- China
- Prior art keywords
- insulator
- ice
- icing
- growth
- transmission line
- 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.)
- Granted
Links
- 239000012212 insulator Substances 0.000 title claims abstract description 91
- 238000000034 method Methods 0.000 title claims abstract description 73
- 230000012010 growth Effects 0.000 title claims abstract description 42
- 230000005540 biological transmission Effects 0.000 title claims abstract description 30
- 238000004088 simulation Methods 0.000 title claims abstract description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 123
- 239000011248 coating agent Substances 0.000 claims abstract description 27
- 238000000576 coating method Methods 0.000 claims abstract description 27
- 230000008014 freezing Effects 0.000 claims abstract description 19
- 238000007710 freezing Methods 0.000 claims abstract description 19
- 230000033001 locomotion Effects 0.000 claims abstract description 8
- 239000007788 liquid Substances 0.000 claims description 14
- 230000008022 sublimation Effects 0.000 claims description 9
- 238000000859 sublimation Methods 0.000 claims description 9
- 230000008020 evaporation Effects 0.000 claims description 8
- 238000001704 evaporation Methods 0.000 claims description 8
- 239000012530 fluid Substances 0.000 claims description 6
- 230000005855 radiation Effects 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 4
- 230000001133 acceleration Effects 0.000 claims description 3
- 238000004134 energy conservation Methods 0.000 claims description 3
- 238000012546 transfer Methods 0.000 claims description 3
- 230000003116 impacting effect Effects 0.000 claims 2
- 230000004927 fusion Effects 0.000 claims 1
- 229920006395 saturated elastomer Polymers 0.000 claims 1
- 238000009834 vaporization Methods 0.000 claims 1
- 230000008016 vaporization Effects 0.000 claims 1
- 230000005484 gravity Effects 0.000 description 8
- 238000012360 testing method Methods 0.000 description 6
- 238000004364 calculation method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000007773 growth pattern Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 239000002131 composite material Substances 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- 239000000284 extract Substances 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/28—Design optimisation, verification or simulation using fluid dynamics, e.g. using Navier-Stokes equations or computational fluid dynamics [CFD]
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/11—Complex mathematical operations for solving equations, e.g. nonlinear equations, general mathematical optimization problems
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T17/00—Three dimensional [3D] modelling, e.g. data description of 3D objects
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/10—Numerical modelling
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2113/00—Details relating to the application field
- G06F2113/08—Fluids
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Geometry (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Mathematical Physics (AREA)
- Pure & Applied Mathematics (AREA)
- Computational Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Software Systems (AREA)
- Algebra (AREA)
- Data Mining & Analysis (AREA)
- Fluid Mechanics (AREA)
- Computing Systems (AREA)
- Computer Graphics (AREA)
- Operations Research (AREA)
- Databases & Information Systems (AREA)
- Wind Motors (AREA)
- Insulators (AREA)
Abstract
Description
技术领域technical field
一种输电线路绝缘子表面无溢流覆冰增长数值模拟方法,属于输电线路绝缘子覆冰预测技术领域。The invention discloses a numerical simulation method for the growth of ice coating without overflow on the surface of a transmission line insulator, belonging to the technical field of ice coating prediction of transmission line insulators.
背景技术Background technique
随着国民经济的快速发展,为满足日益增长的电力需求,实现我国大范围的电力资源优化配置,国家电网公司建设了多条特高压交、直流输电线路。特高压输电线路在输送容量、电能损耗、经济性等方面有明显优势。但由于输送距离远,不可避免地穿越气候环境复杂的地区,绝缘子作为电力系统中重要的器件,其电气特性对电力系统的安全稳定运行起着决定性的作用。在正常环境下,绝缘子的性能能够满足线路运行的要求。但在低温天气,绝缘子表面的覆冰积雪将严重降低绝缘子的电气及机械强度,导致绝缘子闪络、倒杆倒塔等严重影响电网安全稳定运行的事故发生,故需要针对上述问题提高输电线路绝缘子的设计标准和防灾水平。With the rapid development of the national economy, the State Grid Corporation of China has constructed a number of UHV AC and DC transmission lines in order to meet the growing demand for electricity and realize the optimal allocation of power resources in a wide range of my country. UHV transmission lines have obvious advantages in transmission capacity, power loss and economy. However, due to the long transmission distance, it is inevitable to pass through areas with complex climate and environment. As an important device in the power system, the electrical characteristics of the insulator play a decisive role in the safe and stable operation of the power system. Under normal circumstances, the performance of insulators can meet the requirements of line operation. However, in low temperature weather, the ice and snow on the surface of the insulator will seriously reduce the electrical and mechanical strength of the insulator, resulting in the occurrence of accidents such as insulator flashover, falling poles and towers that seriously affect the safe and stable operation of the power grid. Design standards and disaster prevention levels of insulators.
目前对于输电线路覆冰预测模型的研究大多集中在输电导线方面,由于绝缘子结构复杂,目前尚无较成熟的绝缘子覆冰预测模型。At present, most of the research on the prediction model of icing on transmission lines focuses on the transmission wire. Due to the complex structure of insulators, there is no mature prediction model for icing on insulators.
发明内容SUMMARY OF THE INVENTION
本发明要解决的技术问题是:克服现有技术的不足,提供一种输电线路绝缘子表面无溢流覆冰增长数值模拟方法,用以建立极端环境下输电线路防冰减冰预警机制。The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, and provide a numerical simulation method for the growth of ice-covering without overflow on the surface of transmission line insulators, so as to establish an anti-icing and de-icing early warning mechanism for transmission lines in extreme environments.
本发明解决其技术问题所采用的技术方案是:输电线路绝缘子表面无溢流覆冰增长数值模拟方法,其特征在于:包括以下步骤:The technical solution adopted by the present invention to solve the technical problem is: a numerical simulation method for the growth of ice coating without overflow on the surface of a transmission line insulator, which is characterized by comprising the following steps:
S1建立等比例绝缘子三维几何模型并构建外流场区域;S1 establishes a three-dimensional geometric model of an isometric insulator and constructs an external flow field area;
S2根据实际气象数据设置流场的边界条件,得到绝缘子覆冰连续相空气流场及分散相水滴的运动轨迹;S2 sets the boundary conditions of the flow field according to the actual meteorological data, and obtains the air flow field of the insulator icing continuous phase and the movement trajectory of the dispersed phase water droplets;
S3提取水滴从释放到被绝缘子捕获整个过程的三维坐标、速度大小与方向,通过三角面积投影法获得绝缘子表面局部碰撞系数;S3 extracts the three-dimensional coordinates, velocity and direction of the entire process from release to capture by the insulator, and obtains the local collision coefficient on the surface of the insulator by the triangular area projection method;
S4根据能量守恒原理构建热平衡方程确定绝缘子表面各位置冻结系数,并根据冻结系数值的大小判断覆冰增长类型;S4 constructs a heat balance equation according to the principle of energy conservation to determine the freezing coefficient of each position on the surface of the insulator, and judges the growth type of icing according to the value of the freezing coefficient;
S5确定一个时间步长内的覆冰增长,由“点-线-面-体”建模法对覆冰边界进行重构,得到绝缘子覆冰增长形态的三维模型;S5 determines the icing growth within a time step, reconstructs the icing boundary by the "point-line-surface-body" modeling method, and obtains a three-dimensional model of the insulator icing growth pattern;
S6将三维模型作为下一个时间步长内空气流场的初始条件,重复上述步骤进行覆冰增长的循环迭代,直至获得所需时间内的覆冰形态。S6 takes the three-dimensional model as the initial condition of the air flow field in the next time step, and repeats the above steps to perform the cyclic iteration of icing growth until the icing shape within the required time is obtained.
优选的,S2中的所述边界条件为:Preferably, the boundary conditions in S2 are:
; ;
; ;
其中,为湍流场入口速度,为环境风速,为湍流场出口压力,为湍流强度,为湍流尺度,为计算域的水力直径,为雷诺数。 in, is the inlet velocity of the turbulent field, is the ambient wind speed, is the outlet pressure of the turbulent flow field, is the turbulence intensity, is the turbulence scale, is the hydraulic diameter of the computational domain, is the Reynolds number.
优选的,所述方法还包括,覆冰绝缘子空气外流场视为常温、低速、不可压缩湍流流动,建立湍流模型:Preferably, the method further includes: establishing a turbulent flow model by treating the air outer flow field of the ice-covered insulator as a normal temperature, low speed, incompressible turbulent flow:
; ;
其中,是流场中的速度矢量;是空气的动力粘度;是由于空气湍流额外产 生的动力粘度;是空气密度;为湍流动能;是湍流耗散率;是主应力张量;为体积 力;、分别为和的有效普朗特常数的倒数;、、为湍流模型参数;为 湍流动能源项。 in, is the velocity vector in the flow field; is the dynamic viscosity of air; is the additional dynamic viscosity due to air turbulence; is the air density; is the turbulent kinetic energy; is the turbulent dissipation rate; is the principal stress tensor; is body force; , respectively and the reciprocal of the effective Prandtl's constant; , , are turbulence model parameters; is the turbulent flow energy term.
优选的,所述方法还包括,忽略较小的Saffman 升力、附加质量力、压差力等,可认为过冷却水滴只受到气流曳力及重力的作用,单个水滴拉格朗日运动控制方程为:Preferably, the method further includes, ignoring the small Saffman lift force, additional mass force, pressure differential force, etc., it can be considered that the supercooled water droplet is only affected by the drag force of the airflow and the gravity, and the Lagrangian motion control equation of a single water droplet is: :
其中,等式右侧第一项为水滴的剩余重力,即水滴重力减去空气浮力的剩余部分;和分别是水滴的重量和重力加速度;是水滴密度;等式右侧第二项为水滴受到的 气体曳力;和分别为空气流体相和水滴相瞬时速度;为液滴直径;为空气流体 的动力粘度。 Among them, the first term on the right side of the equation is the residual gravity of the water droplet, that is, the remainder of the water droplet gravity minus the air buoyancy; and are the weight of the droplet and the acceleration of gravity, respectively; is the droplet density; the second term on the right side of the equation is the gas drag force on the droplet; and are the instantaneous velocities of the air fluid phase and the water droplet phase, respectively; is the droplet diameter; is the dynamic viscosity of the air fluid.
优选的,S3中通过三角面积投影法获得绝缘子表面局部碰撞系数的方法如下:Preferably, the method for obtaining the local collision coefficient on the surface of the insulator by the triangular area projection method in S3 is as follows:
; ;
其中,为局部碰撞系数;、、分别为三个过冷却水滴撞击绝缘子表面时 的速度;为三个水滴释放时初速度,三个水滴初速度一致;为三个水滴初始释放位置 组成的三角形的面积;为三个水滴撞击在绝缘子表面后所组成三角形的面积。 in, is the local collision coefficient; , , are the velocities of the three supercooled water droplets hitting the surface of the insulator; is the initial velocity of the three water droplets when they are released, and the initial velocity of the three water droplets is the same; is the area of the triangle formed by the initial release positions of the three water droplets; is the area of the triangle formed by three water droplets hitting the surface of the insulator.
优选的,所述方法还包括,冻结系数基于热平衡方程推导出,绝缘子覆冰过程中的热平衡方程为:Preferably, the method further includes: deriving the freezing coefficient based on a heat balance equation, and the heat balance equation during the insulator icing process is:
; ;
; ;
; ;
; ;
; ;
; ;
; ;
; ;
; ;
; ;
; ;
。 .
其中,为绝缘子表面某控制单元碰撞并捕获水滴的部分由0℃水冻结为0℃冰 过程中释放的潜热;为所取控制单元面积;、、分别为碰撞系数、捕获系数和冻 结系数,捕获系数恒为1;为液态水含量;为环境风速;,为冰的融化 潜热;为气流的摩擦加热;为水滴碰撞动能;为0℃的冰冻结至覆冰绝缘子表面稳 态温度时释放的热量;为冰的比热;为短波辐射所获能量;为对流热损失;是 覆冰表面对流换热系数;为环境温度;为覆冰动态平衡时覆冰表面温度;为液态水 蒸发或冰的升华所带走的热量;为蒸发或升华系数;为温度为时的覆冰表面的水 面或冰面的饱和水汽压;为温度在时的蒸发或升华潜热;为空气 比热;为气压;为大气中的过冷却水滴冻结在绝缘子表面时,由过冷却状态的迅速 上升至0℃过程中过冷却水滴吸收的热量;为液态水的比热;为长波辐射损失的热量;为冰面发射率,为 Stefan-Boltzman 常量;为传导热损失;为热传导法线 方向的温度梯度;为未冻结部分过冷却水滴离开冰面带走的热量。 in, It is the latent heat released in the process of freezing water at 0°C into ice at 0°C when a control unit on the surface of the insulator collides and captures water droplets; is the area of the control unit taken; , , are the collision coefficient, capture coefficient and freezing coefficient, respectively, and the capture coefficient is always 1; is the liquid water content; is the ambient wind speed; , the latent heat of melting ice; Frictional heating of the airflow; is the kinetic energy of the water droplet collision; Freeze from 0°C to the steady-state temperature of the ice-coated insulator surface heat released during is the specific heat of ice; Energy obtained from shortwave radiation; is convective heat loss; is the convective heat transfer coefficient of the ice-covered surface; is the ambient temperature; is the icing surface temperature when icing is in dynamic equilibrium; The heat removed by the evaporation of liquid water or the sublimation of ice; is the evaporation or sublimation coefficient; for the temperature The water surface or the saturated water vapor pressure of the ice surface at the time of the ice-covered surface; for the temperature at the latent heat of evaporation or sublimation; is the specific heat of air; is air pressure; When the supercooled water droplets in the atmosphere freeze on the surface of the insulator, the supercooled state The heat absorbed by the supercooled water droplets during the rapid rise to 0°C; is the specific heat of liquid water; is the heat lost by long-wave radiation; is the ice surface emissivity, is the Stefan-Boltzman constant; is the conduction heat loss; is the temperature gradient in the normal direction of heat conduction; The heat carried away by the supercooled water droplets leaving the ice for the unfrozen part.
优选的,所述方法还包括,冻结系数为:Preferably, the method further comprises: freezing coefficient for:
。 .
优选的,所述方法还包括,湿增长覆冰时,覆冰沿着绝缘子表面法向增长;干增长覆冰时,覆冰沿着液滴碰撞方向增长。Preferably, the method further comprises: when the ice is grown wet, the ice is grown along the normal direction of the surface of the insulator; when the ice is grown dry, the ice is grown along the collision direction of the droplets.
优选的,所述方法还包括,覆冰增长速率为:Preferably, the method further includes that the ice-covering growth rate is:
; ;
其中,为液态水含量;为环境风速;为覆冰密度,计算方式为: in, is the liquid water content; is the ambient wind speed; is the ice-covered density, calculated as:
; ;
其中,,为水滴半径,为覆冰表面温度,为风速。 in, , is the droplet radius, is the icing surface temperature, is wind speed.
优选的,所述方法还包括,覆冰形态的重构通过“点-线-面-体”从低维到高维的建模方法实现。Preferably, the method further includes that the reconstruction of the ice-covered shape is realized by a "point-line-surface-body" modeling method from low-dimensional to high-dimensional.
优选的,所述方法还包括,冰形重构完成后以该形态作为下一时间段空气流场计算初始条件,反复迭代计算直至获得所求时间的覆冰形状和覆冰量。Preferably, the method further includes: after the ice shape reconstruction is completed, the shape is used as the initial condition for calculating the air flow field in the next time period, and the calculation is repeated iteratively until the ice-covered shape and amount of ice-covered at the required time are obtained.
与现有技术相比,本发明所具有的有益效果是:Compared with the prior art, the present invention has the following beneficial effects:
本输电线路绝缘子表面无溢流覆冰增长数值模拟方法不仅可以预测覆冰增长形态,还可以预测绝缘子表面任何位置覆冰增长厚度及覆冰质量,通过迭代空气流场的计算方法实现了较于现有方法更强的精确性,可用于构建极端环境下输电线路覆冰预警机制,具有良好的应用前景。The numerical simulation method for the growth of ice coating on the surface of insulators of transmission lines without overflow can not only predict the growth pattern of ice coating, but also predict the growth thickness and quality of ice coating at any position on the insulator surface. The higher accuracy of the existing method can be used to construct an early warning mechanism for transmission line icing in extreme environments, which has a good application prospect.
附图说明Description of drawings
图1为输电线路绝缘子表面无溢流覆冰增长数值模拟方法的流程图;Fig. 1 is a flow chart of a numerical simulation method for the growth of icing without overflow on the surface of transmission line insulators;
图2是三角面积投影法示意图;Fig. 2 is a schematic diagram of a triangular area projection method;
图3是绝缘子杆径覆冰重构建模法示例图;Figure 3 is an example diagram of an ice-covered reconstruction modeling method for the diameter of an insulator rod;
图4是覆冰一小时内的覆冰形态预测与试验对比示意图;Figure 4 is a schematic diagram showing the comparison between the prediction of the ice coating shape and the test within one hour of ice coating;
图5是绝缘子覆冰长度试验实例与仿真对比;Figure 5 is a comparison between an example of an insulator icing length test and a simulation;
图6是绝缘子覆冰质量试验实例与仿真对比。Figure 6 is a comparison between an example of an insulator icing quality test and a simulation.
具体实施方式Detailed ways
下面结合具体实施例对本发明做进一步说明,然而熟悉本领域的人们应当了解,在这里结合附图给出的详细说明是为了更好的解释,本发明的结构必然超出了有限的这些实施例,而对于一些等同替换方案或常见手段,本文不再做详细叙述,但仍属于本申请的保护范围。The present invention will be further described below in conjunction with specific embodiments, but those familiar with the art should understand that the detailed description given here in conjunction with the accompanying drawings is for better explanation, and the structure of the present invention must exceed these limited embodiments, However, some equivalent alternatives or common means will not be described in detail herein, but still belong to the protection scope of the present application.
图1~6是本发明的最佳实施例,下面结合附图1~6对本发明做进一步说明。1 to 6 are the preferred embodiments of the present invention, and the present invention will be further described below in conjunction with the accompanying
如图1所示:一种输电线路绝缘子表面无溢流覆冰增长数值模拟方法,包括以下步骤:As shown in Figure 1: A numerical simulation method for the growth of ice-covered ice without overflow on the surface of a transmission line insulator, including the following steps:
S1建立等比例绝缘子三维几何模型并构建外流场区域。S1 establishes a three-dimensional geometric model of an isometric insulator and constructs an external flow field area.
S2根据实际气象数据设置流场的边界条件,得到绝缘子覆冰连续相空气流场及分散相水滴的运动轨迹。S2 sets the boundary conditions of the flow field according to the actual meteorological data, and obtains the air flow field of the insulator icing continuous phase and the movement trajectory of the dispersed phase water droplets.
具体的,根据实际气象数据设置流场的边界条件,计算得到绝缘子覆冰连续相空 气流场及分散相水滴的运动轨迹。所需气象数据包括环境温度、大气压强、风速、风向、液态 水含量、过冷却水滴中值直径。气流入口边界设置为速度入口,大小为风速,且方向垂直 于入口截面;选择湍流强度、湍流尺度来表征湍流场的湍流参数,可分别由经验公式和确定,其中为计算域的水力直径;出口为压力出口,设置静压 力为0;对于离散相过冷却水滴,以面入射的形式均匀从计算域入口处入射,水滴初始速度 与自由来流速度相等。覆冰绝缘子空气外流场可视为常温、低速、不可压缩湍流流动。湍流 模型采用模型构建,计算公式为: Specifically, the boundary conditions of the flow field are set according to the actual meteorological data, and the air flow field of the continuous phase of the ice-covered insulator and the movement trajectory of the water droplets of the dispersed phase are calculated. The required meteorological data include ambient temperature, atmospheric pressure, wind speed, wind direction, liquid water content, and median diameter of supercooled water droplets. The airflow inlet boundary is set as the velocity inlet and the size is the wind speed , and the direction is perpendicular to the inlet section; choose the turbulence intensity , turbulence scale to characterize the turbulence parameters of the turbulent field, which can be determined by the empirical formulas and sure, where is the hydraulic diameter of the computational domain; the outlet is the pressure outlet, and the static pressure is set to 0; for the discrete-phase supercooled water droplets, they are uniformly incident from the inlet of the computational domain in the form of surface incidence, and the initial velocity of the water droplets is equal to the free flow velocity. The air flow field outside the ice-coated insulator can be regarded as a normal temperature, low speed, incompressible turbulent flow. The turbulence model uses Model construction, the calculation formula is:
; (1) ; (1)
其中,是流场中的速度矢量;是空气的动力粘度;是由于空气湍流额外产 生的动力粘度;是空气密度;为湍流动能;是湍流耗散率;是主应力张量;为体积 力;、分别为和的有效普朗特常数的倒数;、、为湍流模型参数;为 湍流动能源项。 in, is the velocity vector in the flow field; is the dynamic viscosity of air; is the additional dynamic viscosity due to air turbulence; is the air density; is the turbulent kinetic energy; is the turbulent dissipation rate; is the principal stress tensor; is body force; , respectively and the reciprocal of the effective Prandtl's constant; , , are turbulence model parameters; is the turbulent flow energy term.
过冷却水滴在绝缘子周围运动时,忽略较小的Saffman 升力、附加质量力、压差力等,可认为过冷却水滴只受到气流曳力及重力的作用,单个水滴拉格朗日运动控制方程为:When the supercooled water droplet moves around the insulator, ignoring the small Saffman lift force, additional mass force, pressure difference force, etc., it can be considered that the supercooled water droplet is only affected by the drag force and gravity of the air flow, and the Lagrangian motion control equation of a single water droplet is: :
; (2) ; (2)
其中,等式右侧第一项为水滴的剩余重力,即水滴重力减去空气浮力的剩余部分。和分别是水滴的重量和重力加速度;是水滴密度;等式右侧第二项为水滴受到的 气体曳力。和分别为空气流体相和水滴相瞬时速度;为液滴直径;为空气流体的 动力粘度。Among them, the first term on the right side of the equation is the residual gravity of the water droplet, that is, the remainder of the water droplet gravity minus the air buoyancy. and are the weight of the droplet and the acceleration of gravity, respectively; is the droplet density; the second term on the right side of the equation is the gas drag on the droplet. and are the instantaneous velocities of the air fluid phase and the water droplet phase, respectively; is the droplet diameter; is the dynamic viscosity of the air fluid.
对式(2)的微分方程进行积分,即可获得水滴运动轨迹各点的速度分布,然后再在每个时间步长内对水滴速度进行积分获得水滴运动轨迹,从而获得水滴任意位置的物理参数。Integrate the differential equation of formula (2) to obtain the velocity distribution of each point of the water droplet trajectory, and then integrate the water droplet velocity in each time step to obtain the water droplet trajectory, so as to obtain the physical parameters of any position of the water droplet .
S3提取水滴从释放到被绝缘子捕获整个过程的三维坐标、速度大小与方向,通过 三角面积投影法获得绝缘子表面局部碰撞系数。 S3 extracts the three-dimensional coordinates, velocity and direction of the entire process from release to capture by the insulator, and obtains the local collision coefficient on the surface of the insulator by the triangular area projection method .
具体的,三角面积投影法如图2所示,计算公式为:Specifically, the triangular area projection method is shown in Figure 2, and the calculation formula is:
; (3) ; (3)
其中,为局部碰撞系数;、、分别为三个过冷却水滴撞击绝缘子表面时 的速度;为三个水滴释放时初速度,三个水滴初速度一致;为三个水滴初始释放位置 组成的三角形的面积;为三个水滴撞击在绝缘子表面后所组成三角形的面积。 in, is the local collision coefficient; , , are the velocities of the three supercooled water droplets hitting the surface of the insulator; is the initial velocity of the three water droplets when they are released, and the initial velocity of the three water droplets is the same; is the area of the triangle formed by the initial release positions of the three water droplets; is the area of the triangle formed by three water droplets hitting the surface of the insulator.
S4根据能量守恒原理构建热平衡方程确定绝缘子表面各位置冻结系数,并根 据冻结系数值的大小判断覆冰增长类型。 S4 According to the principle of energy conservation, the heat balance equation is constructed to determine the freezing coefficient of each position on the surface of the insulator , and judge the growth type of icing according to the value of freezing coefficient.
具体的,绝缘子覆冰过程中的热平衡方程为:Specifically, the heat balance equation in the process of insulator icing is:
; (4) ; (4)
其中,为绝缘子表面某控制单元碰撞并捕获水滴的部分由0℃水冻结为0℃冰 过程中释放的潜热: in, It is the latent heat released in the process of freezing water at 0°C into ice at 0°C for the part of a control unit on the surface of the insulator that collides and captures water droplets:
; (5) ; (5)
其中,为所取控制单元面积;、、分别为碰撞系数、捕获系数和冻结系 数,捕获系数恒为1;为液态水含量;为环境风速;,为冰的融化潜 热。 in, is the area of the control unit taken; , , are the collision coefficient, capture coefficient and freezing coefficient, respectively, and the capture coefficient is always 1; is the liquid water content; is the ambient wind speed; , the latent heat of melting ice.
为气流的摩擦加热,空气对于覆冰绝缘子的加热是通过气流对冰表面的摩擦 产生的,由于空气的流速不大,此项可以忽略,即: For the frictional heating of the airflow, the heating of the ice-covered insulator by the air is generated by the friction of the airflow on the ice surface. Since the air velocity is not large, this item can be ignored, namely:
。 (6) . (6)
为水滴碰撞动能: is the kinetic energy of the droplet collision:
。 (7) . (7)
为0℃的冰冻结至覆冰绝缘子表面稳态温度时释放的热量: Freeze from 0°C to the steady-state temperature of the ice-coated insulator surface Heat released when:
; (8) ; (8)
其中,为冰的比热,。 in, is the specific heat of ice, .
为短波辐射所获能量,因为覆冰一般发生在雾天、雨天或阴天,无阳光直射,故 通常忽略该项,即: The energy obtained by shortwave radiation, because icing generally occurs in foggy, rainy or cloudy days without direct sunlight, so this item is usually ignored, namely:
。 (9) . (9)
为对流热损失: For convective heat loss:
; (10) ; (10)
其中,是覆冰表面对流换热系数;为环境温度;为覆冰动态平衡时覆冰表 面温度。 in, is the convective heat transfer coefficient of the ice-covered surface; is the ambient temperature; It is the temperature of the icing surface when the icing is in dynamic equilibrium.
为液态水蒸发或冰的升华所带走的热量: Heat removed by evaporation of liquid water or sublimation of ice:
; (11) ; (11)
其中,为蒸发或升华系数;为温度为时的覆冰表面的水面或冰面的饱和 水汽压;为温度在时的蒸发或升华潜热;为空气比热;为气压。 in, is the evaporation or sublimation coefficient; for the temperature The water surface or the saturated water vapor pressure of the ice surface at the time of the ice-covered surface; for the temperature at the latent heat of evaporation or sublimation; is the specific heat of air; for air pressure.
为大气中的过冷却水滴冻结在绝缘子表面时,由过冷却状态的迅速上升至0 ℃过程中过冷却水滴吸收的热量: When the supercooled water droplets in the atmosphere freeze on the surface of the insulator, the supercooled state Heat absorbed by supercooled water droplets during rapid rise to 0 °C:
; (12) ; (12)
其中,为液态水的比热。 in, is the specific heat of liquid water.
为长波辐射损失的热量: Heat lost for longwave radiation:
; (13) ; (13)
其中,为冰面发射率,,为Stefan-Boltzman常量,。 in, is the ice surface emissivity, , is the Stefan-Boltzman constant, .
为传导热损失: For conduction heat loss:
; (14) ; (14)
其中,为介质的导热系数,为热传导法线方向的温度梯度。 in, is the thermal conductivity of the medium, is the temperature gradient in the normal direction of heat conduction.
为未冻结部分过冷却水滴离开冰面带走的热量: The heat taken away by the unfrozen part of the supercooled water droplets leaving the ice surface:
。 (15) . (15)
冻结系数为: Freeze factor for:
。 (16) . (16)
绝缘子表面无溢流情况下的覆冰类型可通过冻结区域水膜的有无来进行判断,当 冻结系数时为湿增长覆冰,而当时为干增长覆冰。湿增长覆冰时,覆冰沿着绝缘 子表面法向增长,干增长覆冰时,覆冰沿着液滴碰撞方向增长。 The type of ice coating in the case of no overflow on the surface of the insulator can be judged by the presence or absence of water film in the freezing area. When wet grows ice, and when ice for dry growth. During wet growth, the ice grows along the normal direction of the insulator surface, and during dry growth, the ice grows along the direction of droplet collision.
S5确定一个时间步长内的覆冰增长,由“点-线-面-体”建模法对覆冰边界进行重构,得到绝缘子覆冰增长形态的三维模型。S5 determines the growth of icing within a time step, reconstructs the boundary of icing by the "point-line-surface-body" modeling method, and obtains a three-dimensional model of the growth pattern of icing on the insulator.
具体的,根据覆冰增长速率计算公式,计算一个时间步长内的覆冰增长厚度,覆冰增长速率公式为:Specifically, according to the calculation formula of the growth rate of ice coating, the thickness of the growth of ice coating in a time step is calculated, and the formula of the growth rate of ice coating is:
; (17) ; (17)
其中,为液态水含量;为环境风速;为覆冰密度,计算方式为: in, is the liquid water content; is the ambient wind speed; is the ice-covered density, calculated as:
; (18) ; (18)
其中,,为水滴半径,为覆冰表面温度,为风速。 in, , is the droplet radius, is the icing surface temperature, is wind speed.
如图3所示,通过连接碰撞点的相邻点和增长后新形成的点,形成两条曲线,将两条曲线的端点连接在一起,形成二维曲面。通过连接每组曲面的边界来构建三维实体,从而构建出新的覆冰边界。As shown in Figure 3, by connecting the adjacent points of the collision point and the newly formed points after growth, two curves are formed, and the endpoints of the two curves are connected together to form a two-dimensional surface. A new icing boundary is constructed by connecting the boundaries of each set of surfaces to build a 3D solid.
S6将新的覆冰形态作为下一个时间步长内空气流场的初始条件,重复上述步骤进行覆冰增长的循环迭代,直至获得所需时间内的覆冰形态。S6 takes the new icing form as the initial condition of the air flow field in the next time step, and repeats the above steps to perform cyclic iterations of icing growth until the icing form within the required time is obtained.
具体的,当环境温度为-10℃,风速10m/s,液滴中值直径为50,空气中液态水含 量为时,绝缘子一小时内覆冰形态的预测与试验对比如图4所示。 图5为复合绝缘子伞裙边缘及杆径处覆冰增长长度与试验对比,图6为复合绝缘子覆冰质量 与试验对比。 Specifically, when the ambient temperature is -10°C, the wind speed is 10m/s, the median diameter of the droplets is 50 , the liquid water content in the air is hour, Figure 4 shows the comparison between the prediction and the test of the ice-covered shape of the insulator within one hour. Figure 5 shows the comparison of the growth length of the ice coating at the edge of the composite insulator shed and the diameter of the rod with the test, and Figure 6 shows the comparison of the ice coating quality of the composite insulator with the test.
上述输电线路绝缘子表面无溢流覆冰增长数值模拟方法具有预测精度高、方法简单有效、误差小的优点。本发明的技术方案不仅可以应用到本专利所述型号的绝缘子,还可以扩展到任何型号的绝缘子。The above numerical simulation method for the growth of icing without overflow on the surface of the transmission line insulator has the advantages of high prediction accuracy, simple and effective method, and small error. The technical solution of the present invention can not only be applied to insulators of the type described in this patent, but also can be extended to insulators of any type.
以上所述,仅是本发明的较佳实施例而已,并非是对本发明作其它形式的限制,任何熟悉本专业的技术人员可能利用上述揭示的技术内容加以变更或改型为等同变化的等效实施例。但是凡是未脱离本发明技术方案内容,依据本发明的技术实质对以上实施例所作的任何简单修改、等同变化与改型,仍属于本发明技术方案的保护范围。The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any person skilled in the art may use the technical content disclosed above to make changes or modifications to equivalent changes. Example. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention still belong to the protection scope of the technical solutions of the present invention.
Claims (10)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202211098383.1A CN115169267B (en) | 2022-09-09 | 2022-09-09 | Numerical simulation method for overflow-free icing growth on surface of power transmission line insulator |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202211098383.1A CN115169267B (en) | 2022-09-09 | 2022-09-09 | Numerical simulation method for overflow-free icing growth on surface of power transmission line insulator |
Publications (2)
Publication Number | Publication Date |
---|---|
CN115169267A true CN115169267A (en) | 2022-10-11 |
CN115169267B CN115169267B (en) | 2022-11-22 |
Family
ID=83482493
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202211098383.1A Active CN115169267B (en) | 2022-09-09 | 2022-09-09 | Numerical simulation method for overflow-free icing growth on surface of power transmission line insulator |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN115169267B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN116108620A (en) * | 2022-11-25 | 2023-05-12 | 贵州电网有限责任公司 | Insulator electric field characteristic evaluation method based on equivalent growth length model |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101710057A (en) * | 2009-11-11 | 2010-05-19 | 东北电力大学 | Ice-coated test system for transmission line structure |
CN103604419A (en) * | 2013-11-21 | 2014-02-26 | 中国科学院西安光学精密机械研究所 | Three-dimensional reconstruction-based wire icing monitoring method and system |
US20140067271A1 (en) * | 2012-08-30 | 2014-03-06 | International Business Machines Corporation | Predicting ice coating status on transmission lines |
CN104655030A (en) * | 2015-02-16 | 2015-05-27 | 国网安徽省电力公司铜陵供电公司 | Power transmission line icing detecting and early-warning device |
CN104913900A (en) * | 2015-06-03 | 2015-09-16 | 西安工程大学 | Measurement method of power transmission line iced conductor galloping aerodynamic parameters |
US20160169761A1 (en) * | 2014-12-10 | 2016-06-16 | Uchicago Argonne, Llc | Method and system for icing condition detection |
CN106680603A (en) * | 2017-01-17 | 2017-05-17 | 清华大学 | Method for calculation of characteristic lines of three-dimensional ionized field of direct current transmission line |
CN109242159A (en) * | 2018-08-17 | 2019-01-18 | 华北电力大学 | A kind of novel power transmission transmission line icing prediction technique |
CN111967201A (en) * | 2020-07-30 | 2020-11-20 | 华南理工大学 | Method for analyzing critical icing type based on numerical simulation model |
CN112651188A (en) * | 2020-12-02 | 2021-04-13 | 国网重庆市电力公司电力科学研究院 | CFD-based power transmission line icing state simulation method |
CN113591342A (en) * | 2021-06-28 | 2021-11-02 | 国网天津市电力公司电力科学研究院 | 10kV overhead insulated line galloping characteristic analysis method under different wind load and ice coating conditions |
-
2022
- 2022-09-09 CN CN202211098383.1A patent/CN115169267B/en active Active
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101710057A (en) * | 2009-11-11 | 2010-05-19 | 东北电力大学 | Ice-coated test system for transmission line structure |
US20140067271A1 (en) * | 2012-08-30 | 2014-03-06 | International Business Machines Corporation | Predicting ice coating status on transmission lines |
CN103604419A (en) * | 2013-11-21 | 2014-02-26 | 中国科学院西安光学精密机械研究所 | Three-dimensional reconstruction-based wire icing monitoring method and system |
US20160169761A1 (en) * | 2014-12-10 | 2016-06-16 | Uchicago Argonne, Llc | Method and system for icing condition detection |
CN104655030A (en) * | 2015-02-16 | 2015-05-27 | 国网安徽省电力公司铜陵供电公司 | Power transmission line icing detecting and early-warning device |
CN104913900A (en) * | 2015-06-03 | 2015-09-16 | 西安工程大学 | Measurement method of power transmission line iced conductor galloping aerodynamic parameters |
CN106680603A (en) * | 2017-01-17 | 2017-05-17 | 清华大学 | Method for calculation of characteristic lines of three-dimensional ionized field of direct current transmission line |
CN109242159A (en) * | 2018-08-17 | 2019-01-18 | 华北电力大学 | A kind of novel power transmission transmission line icing prediction technique |
CN111967201A (en) * | 2020-07-30 | 2020-11-20 | 华南理工大学 | Method for analyzing critical icing type based on numerical simulation model |
CN112651188A (en) * | 2020-12-02 | 2021-04-13 | 国网重庆市电力公司电力科学研究院 | CFD-based power transmission line icing state simulation method |
CN113591342A (en) * | 2021-06-28 | 2021-11-02 | 国网天津市电力公司电力科学研究院 | 10kV overhead insulated line galloping characteristic analysis method under different wind load and ice coating conditions |
Non-Patent Citations (3)
Title |
---|
BO LI: "Real-time On-line Anti-icing and Ice-melting Power Calculation Method for Transmission Lines Based on Self-ice-melting Conductors", 《2019 IEEE 3RD CONFERENCE ON ENERGY INTERNET AND ENERGY SYSTEM INTEGRATION (EI2)》 * |
杨铭等: "输电线路覆冰原因分析及优化研究", 《电气传动自动化》 * |
蒋兴良等: "绝缘子湿增长动态覆冰模型研究", 《中国电机工程学报》 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN116108620A (en) * | 2022-11-25 | 2023-05-12 | 贵州电网有限责任公司 | Insulator electric field characteristic evaluation method based on equivalent growth length model |
Also Published As
Publication number | Publication date |
---|---|
CN115169267B (en) | 2022-11-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Manatbayev et al. | Numerical simulations on static Vertical Axis Wind Turbine blade icing | |
Shu et al. | Study on small wind turbine icing and its performance | |
Ibrahim et al. | Effects of blade design on ice accretion for horizontal axis wind turbines | |
Makkonen | Models for the growth of rime, glaze, icicles and wet snow on structures | |
Yirtici et al. | Aerodynamic validation studies on the performance analysis of iced wind turbine blades | |
CN103218507A (en) | Two-dimensional numerical simulation method for icing process of power transmission line | |
CN111967201A (en) | Method for analyzing critical icing type based on numerical simulation model | |
CN111967147B (en) | Method for calculating key parameters of icing growth model of overhead transmission line | |
CN114139393B (en) | Part electric heating three-dimensional anti-icing numerical simulation method considering water film flow heat transfer | |
Shu et al. | Numerical and experimental investigation of threshold de-icing heat flux of wind turbine | |
CN111396269A (en) | Multi-time-step unsteady icing calculation method and system and storage medium | |
CN115292806B (en) | Surface temperature calculation method for three-dimensional hot gas anti-icing system considering periodic boundaries | |
Xu et al. | Effects of ambient temperature and wind speed on icing characteristics and anti-icing energy demand of a blade airfoil for wind turbine | |
Han et al. | Analysis of critical condition for dry and wet growth icing on insulators | |
CN115169267B (en) | Numerical simulation method for overflow-free icing growth on surface of power transmission line insulator | |
Jin et al. | A stereoscopic PIV study of the effect of rime ice on the vortex structures in the wake of a wind turbine | |
CN108108533B (en) | Calculation method of ice-covered weight of transmission wire | |
CN111723987A (en) | A method for predicting the thickness of wet snow on composite insulators of transmission lines | |
Bragg et al. | Boundary-layer and heat-transfer measurements on an airfoil with simulated ice roughness | |
Virk et al. | Multiphysics based numerical study of atmospheric ice accretion on a full scale horizontal axis wind turbine blade | |
Homola et al. | Turbine size and temperature dependence of icing on wind turbine blades | |
Caccia et al. | Numerical simulations of a horizontal axis wind turbine in icing conditions with and without electro-thermal ice protection system | |
Virk et al. | Relation between angle of attack and atmospheric ice accretion on large wind turbine's blade | |
Chitransh et al. | Investigation of Single Shot Ice Accretion on Aerofoil of Wind Turbine Blade using ANSYS | |
CN115526078A (en) | A Calculation Method of Water Droplet Freezing Coefficient on Wind Turbine Blades |
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 |