高电压技术
高電壓技術
고전압기술
HIGH VOLTAGE ENGINEERING
2012年
5期
1225-1232
,共8页
导线覆冰%防冰%临界电流%传热%集肤效应%几何外形
導線覆冰%防冰%臨界電流%傳熱%集膚效應%幾何外形
도선복빙%방빙%림계전류%전열%집부효응%궤하외형
conductor icing%anti-icing%critical current%heat transfer%skin effect%geometric shapes
导线覆冰是影响输电线路安全运行的主要问题之一,基于焦耳热效应的临界电流防冰方法可行且有效。为此,基于焦耳热效应和导线在临界覆冰状态下的传热过程,并考虑了集肤效应、导线几何外形及其表面水膜对传热过程的影响,建立了临界防冰电流模型,其计算结果与人工气候室试验结果符合。另外,还研究了在覆冰环境下,导线直径及几何外形、环境温度、风速、液态水含量(LWC)、中值体积直径(MVD)对输电线路临界防冰电流的影响。仿真结果表明,临界防冰电流随温度的降低或风速的增加而迅速增大,随LWC的增大或MVD在0~100μm区间增大而缓慢增大,而当MVD〉100μm时,临界防冰电流无明显变化。
導線覆冰是影響輸電線路安全運行的主要問題之一,基于焦耳熱效應的臨界電流防冰方法可行且有效。為此,基于焦耳熱效應和導線在臨界覆冰狀態下的傳熱過程,併攷慮瞭集膚效應、導線幾何外形及其錶麵水膜對傳熱過程的影響,建立瞭臨界防冰電流模型,其計算結果與人工氣候室試驗結果符閤。另外,還研究瞭在覆冰環境下,導線直徑及幾何外形、環境溫度、風速、液態水含量(LWC)、中值體積直徑(MVD)對輸電線路臨界防冰電流的影響。倣真結果錶明,臨界防冰電流隨溫度的降低或風速的增加而迅速增大,隨LWC的增大或MVD在0~100μm區間增大而緩慢增大,而噹MVD〉100μm時,臨界防冰電流無明顯變化。
도선복빙시영향수전선로안전운행적주요문제지일,기우초이열효응적림계전류방빙방법가행차유효。위차,기우초이열효응화도선재림계복빙상태하적전열과정,병고필료집부효응、도선궤하외형급기표면수막대전열과정적영향,건립료림계방빙전류모형,기계산결과여인공기후실시험결과부합。령외,환연구료재복빙배경하,도선직경급궤하외형、배경온도、풍속、액태수함량(LWC)、중치체적직경(MVD)대수전선로림계방빙전류적영향。방진결과표명,림계방빙전류수온도적강저혹풍속적증가이신속증대,수LWC적증대혹MVD재0~100μm구간증대이완만증대,이당MVD〉100μm시,림계방빙전류무명현변화。
Conductor icing is one of major factors which affect the safe operation of the transmission line, and the anti-icing method based on the Joule heating effect is feasible and effective. Taking the skin effect, the effect of geometric shapes, and water film covering conductors on heat transfer process into consideration, we established a mathematical model of critical anti-icing current on the basis of Joule heating effect and the heat transfer process of conductor under critical icing condition, and its calculations were consistent with the test results in artificial climate chamber. The proposed model is more accurate compared with other current models. We also studied the effects of the geometrical parameters of conductor, environment temperature, wind velocity, liquid water content (LWC), and median volume diameter(MVD) on critical anti-icing current of conductor. The simulation results show that the critical current increases rapidly with decreasing temperature, and increases rapidly with increasing wind velocity. The critical current slowly increases with increasing LWC, and increases slowly with increasing MVD when MVD is in the range of 0-100 μm.