雨凇冰层热导率影响因素的试验分析  

Experimental Analysis on the Influence Factors of Ice's Thermal Conductivity

作　　者：蒋兴良[1] 陈凌[1] 赵阳[1] 肖丹华[1] 巢亚锋[1] 毕茂强[1] 

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030

出　　处：《高电压技术》2011年第8期2032-2037,共6页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2009CB724501/502)~~

摘　　要：冰层的导热率是电网覆冰及融冰机理研究中的一个关键参数,它表征了冰层传热的快慢从而决定了覆冰及融冰的速度。因此,冰层的导热率是预测覆冰增长、合理选定融冰电流及确定融冰时间的基础。在当前的覆冰及融冰研究中,当覆冰密度较小时导热率的选取主要依据Abels、Jason、Devaux、Yoshida等人提出的经验公式,当覆冰密度较大时主要采用纯冰的导热率。但是在不同地区不同时间的覆冰中,冻结温度及冻结水的电导率各不相同,然而目前几乎没有关于冻结温度及冻结水电导率对覆冰导热率影响的研究。为填补此一空白,基于瞬态热针法的导热率测量原理,试验研究了结冰水电导率及冻结温度对冰层的导热率的影响。结果表明:冰层的导热率与结冰水电导率及冻结温度有关,冰层导热率随冻结温度降低而增大,随结冰水电导率增大而降低;冻结温度越高结冰水电导率对冰的导热率影响越大;在自然界雨凇覆冰的导热率受结冰水电导率影响较大。The thermal conductivity of ice is the basis to predict accretionj to choose reasonable lce-memng current and to predict the ice-melting time. Consequently, the thermal conductivity of ice is selected from empirical equa- tions given by Abels, Jason, Devaux and Yoshida when the ice density is low, and it is selected as the pure iceI s thermal conductivity when the ice density is higher. The freezing temperature and freezing Water＇ s electric conduc- tivity are different in icing events occurring at different areas and different time. We experimentally studied the effect of freezing temperature and freezing water＇s electric conductivity on thermal conductivity of ice, on the basis of the transient hot probe method. The results show that the thermal conductivity of ice increases and decreases with the decrease of freezing temperature and increase of freezing water＇s electric conductivity; the higher the freezing tem- perature is, the greater influence of freezing water＇s electric conductivity on thermal conductivity is; the glaze in na- ture is greatly influenced by freezing water＇s electric conductivity.

关 键 词：导热率 覆冰 融冰 瞬态热针法 电导率 冻结温度 

分 类 号：TM75[电气工程—电力系统及自动化]