输电导线粗糙覆冰表面对流换热特性  

Convective Heat Transfer Characteristics of Transmission Lines on Rough Ice Surface

作　　者：黄新波[1] 高华 朱永灿[1] 崔运涛[1] 胡潇文 HUANG Xinbo;GAO Hua;ZHU Yongcan;CUI Yuntao;HU Xiaowen(College of Electronics and Information,Xi＇an Polytechnic University,Xi＇an 710048,China)

机构地区：[1]西安工程大学电子信息学院

出　　处：《高电压技术》2018年第11期3509-3516,共8页High Voltage Engineering

基　　金：国家自然科学基金(51177115);陕西省重点科技创新团队计划(2014KCT-16);陕西省工业科技攻关项目(2016GY-052)~~

摘　　要：对流换热系数是覆冰热平衡中的关键参数,其精确计算对于提高热平衡方程计算精度有很大作用。以往对于覆冰导线的模拟过程中,大都将覆冰导线等效为光滑圆柱处理,但过冷却液滴的冻结会引起覆冰形状差异和覆冰表面粗糙高度的大幅增加,从而能对覆冰导线表面换热特性的计算精度带来很大影响。针对硬雾凇覆冰表面工况,建立了包含表面粗糙高度的覆冰输电导线有限元模型,并采用流体力学数值模拟计算方法分析了覆冰导线表面粗糙高度对其换热特性影响。结果表明：覆冰导线表面粗糙高度将改变边界层内流体流态,加剧流体扰动,换热效果显著增强;在雷诺数为40 000时,与以往光滑覆冰模型相比,粗糙覆冰模型平均对流换热系数分别增长为原来的1.333、1.452、1.667倍;在相同情况下,新月形覆冰结构湍流程度整体略低于圆形覆冰结构,平均对流换热系数也小于圆形覆冰结构。Convective heat transfer coefficient is a key parameter in an ice thermal balance, and its accurate calculation plays an important role in improving the calculation accuracy of the heat balance equation. In the past, the iced conductor was usually treated as a smooth cylinder in the simulation of iced conductor. However, the freezing of supercooled droplets will lead to the difference of icing shape and the increase of roughness height of icing surface, which will greatly affect the calculation accuracy of heat transfer characteristics of icing conductor surface. Consequently, we established a finite element model of ice-coated transmission line with rough surface height for the working condition of hard fog and ice-coated surface. Moreover, we analyzed the influences of rough surface height of ice-coated conductor on its heat transfer characteristics by means of a fluid dynamics numerical simulation method. The results show that the surface roughness height of icing wire will change the fluid flow in the boundary layer, aggravate the fluid disturbance and enhance the heat transfer effect. When Reynolds number is 40 000, compared with the previous smooth icing model, rough icing model average heat transfer coefficients will increase to 1.333, 1.452 and 1.667 times. In the same circumstances, crescent icing turbulent structure is slightly lower than the overall level of circular icing structure, and the average is less than the circular structure on icing flow heat transfer coefficient.

关 键 词：输电导线 覆冰 粗糙高度 对流换热系数 流体力学 边界层 

分 类 号：TM752[电气工程—电力系统及自动化]