输电导线冰棱覆冰表面换热系数分析

Analysis of the Surface Convective Heat Transfer Coefficient of Icicle on Transmission Lines

为了研究覆冰输电导线冰棱生长的机理,针对覆冰输电导线冰棱生长的关键因素-表面对流换热系数展开研究,建立了覆冰输电导线多冰棱模型,仿真分析了导线覆冰程度、冰棱间距及冰棱长度对冰棱表面对流换热系数的影响,并设计了专门的装置进行实验验证。结果表明:在所研究的参数范围内,导线覆冰厚度越大,其冰棱表面对流换热系数就越小;冰棱间距越大,其冰棱表面对流换热系数也越小;而冰棱长度的变化对冰棱对流换热系数影响不大。冰棱表面对流换热系数的数值模拟结果与实验结果差值仅为6%~10%,而传统经验公式计算结果与实验结果差值为9%~29%。与传统经验公式计算相比,采用数值模拟的计算结果更精确,有利于深入研究冰棱生长机理。

In order to study the growth mechanism of icicle on ice-covered transmission lines,we studied a key parameter for icing accretion,namely,the surface convective heat transfer coefficient of icicle,and established a multi-icicle model for the ice-covered transmission line.The effects of the ice coverage and the distance between the icicle and the length of the icicle on the heat transfer coefficient were analyzed by means of numerical simulation,and a special device was designed to verify the experiments.The results show that the surface heat transfer coefficient of the icicle decreases with the increase of ice thickness or the distance between the icicle within the studied parameters range,but hardly changes with the change of the icicle length.The results of numerical simulation of convective heat transfer coefficient on icicle are basically consistent with the experimental results,and the difference is 6%~10%,while the difference between the results of the traditional empirical formula and the experimental results is 9%~29%.Compared with the traditional empirical formula,the numerical simulation method has higher accuracy,which is more conducive to the study of icicles growth model.