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.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2009年第11期2826-2831,共6页
High Voltage Engineering
关键词
电缆
有限差分法
预埋管
导热介质
温度场
载流量
cables
finite difference method
ducts
heat-conducting material
temperature field
ampacity
