管道内填充导热介质提高电缆载流量  

Increasing Cable Ampacity by Pumping Heat-conducting Material into Ducts

作　　者：鲁志伟[1] 于建立[1] 葛丽婷[1] 展鹏[2] 

机构地区：[1]东北电力大学输变电技术学院,吉林132012 [2]华东理工大学材料科学与工程学院,上海200237

出　　处：《高电压技术》2009年第11期2826-2831,共6页High Voltage Engineering

摘　　要：电力电缆排管敷设时,因预埋管中空气热阻较大,使其载流量比直埋方式的载流量有显著下降。为提高预埋管敷设方式下电缆输送能力,可向管道内填充导热介质以改善管道的散热状况。采用基于坐标组合的有限差分法,编制了电缆排管敷设温度场和载流量通用计算程序。程序计算结果与模拟试验及现场试验结果相符。计算结果表明,单回路电缆填充导热介质可提高载流量约5.6%,降低缆芯温度约7°C。多回路电缆由于电缆间的互热效应,填充导热介质对提高载流量的作用显著减小。管道内填充导热介质,可降低电缆运行温度,提高电缆输送能力。Because the air thermal resistance is high, the ampacity of underground cables in ducts is much lower than the ampacity of direct buried cables. In order to improve the cable current carrying capacity, the heat-conducting material was pumped into ducts to improve the situation of duct heat output. Based on the combinatorial coordinates, a complex computer program employing the finite difference method was developed to calculate the temperature field distributions and ampacity of underground cables in ducts. The calculated results are consistent with results obtained by simulation test and field test. Ampacity influenced by pumping heat-conducting material into ducts from three single conductors to eighteen single conductors is studied. The results reveal that the ampacity of three single conductors can be improved by about 5.6 % or the temperature of cable cores can be reduced by about 7℃for the same circulating current by pumping heat-conducting material into ducts. When six or more cables are laid one another, their current carrying capacity improved by pumping heat-conducting material into ducts is obviously reduced by the mutual heating effect. The cable current carrying capacity can he improved and operation temperature of cable cores can be reduced by pumping the heat-conducting material into ducts.

关 键 词：电缆 有限差分法 预埋管 导热介质 温度场 载流量 

分 类 号：TM247[一般工业技术—材料科学与工程]