回填土高热阻系数下电缆集群敷设载流量的解析计算
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摘要
IEC60287标准给出了土壤热阻系数一致时电缆集群敷设恒定负荷载流量的解析计算方法,并给出了计及回填土与母土热阻系数差异的载流量修正计算方法.载流量数值计算结果表明该修正计算方法仅适用于回填土相对于母土为良导热介质的情况.寒冷地区为防止四季温差造成地面下沉,回填土通常会选择细沙.细沙中水分较易流失,干燥的细沙热阻系数大于母土热阻系数.以有限元法计算的电缆载流量为基准,深入分析回填土热阻系数较大时,IEC解析计算方法产生误差的原因,并修正了相应的解析计算方法,显著地提高了回填土高热阻下电缆集群敷设载流量解析方法的计算精度.
IEC 60287 standard gives the calculation method of steady state carrying capacity of cable cluster laying in homogeneous soil,and gives the amending calculation method of carrying capacity of cable cluster laying with backfill.The numerical calculation of temperature field and carrying capacity of cable cluster laying shows that the amending calculation method of this ampacity is only applicable to the case that the thermal resistance coefficient of backfill is less than that of the parent soil.Considering the ground subsidence caused by the great temperature difference in Northeast China,the cable engineering designers chose the backfill that has larger thermal resistance coefficient than the surrounding fine sand.the cable cluster calculated in this paper using the finite element method,the load flow as a benchmark,in-depth analysis when the back fill of the resistance coefficient is larger,the reason why IEC simplified calculation method causes calculation error,and gives the corresponding simplified calculation method,improves the accuracy of analytic method to calculate the ampacity of cable in cluster laying obviously.
IEC 60287 standard gives the calculation method of steady state carrying capacity of cable cluster laying in homogeneous soil,and gives the amending calculation method of carrying capacity of cable cluster laying with backfill.The numerical calculation of temperature field and carrying capacity of cable cluster laying shows that the amending calculation method of this ampacity is only applicable to the case that the thermal resistance coefficient of backfill is less than that of the parent soil.Considering the ground subsidence caused by the great temperature difference in Northeast China,the cable engineering designers chose the backfill that has larger thermal resistance coefficient than the surrounding fine sand.the cable cluster calculated in this paper using the finite element method,the load flow as a benchmark,in-depth analysis when the back fill of the resistance coefficient is larger,the reason why IEC simplified calculation method causes calculation error,and gives the corresponding simplified calculation method,improves the accuracy of analytic method to calculate the ampacity of cable in cluster laying obviously.
引文
[1] 梁永春.高压电力电缆温度场和载流量评估研究动态[J].高电压技术,2016,42(4):1142-1150.
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[4] 林国新.高压输电线路跨海通道建设方案比选研究[J].东北电力大学学报,2017,37(4):86-93.
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[7] 鲁志伟,张航,敖明,等.电缆载流量试验热稳定判据及试验误差的研究[J].东北电力大学学报,2016,36(5):25-31.
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[11] 李文祥,刘刚,王振华,等.XLPE三芯电缆稳态并联热路模型及实验验证[J].南方电网技术,2015,9(3):57-62.
[12] 郑雁翎.电缆线路的电缆群载流量优化数值计算模型研究[J].高电压技术,2015,41(11):3760-3765.
[13] 刘畅,徐政,宣耀伟,等.基于等效导热系数的直流电缆稳态载流量简化有限元算法[J].高压电器,2016,52(5):7-13.
[14] 李萌,牛胜锁,刘玉芹,等.基于多场耦合模型的海底电缆载流量和温度场计算研究[J].电测与仪表,2018,55(8):12-16,23.
[15] 吴文克,鲁志伟,张航,等.直埋电力电缆动态增容和双线增容策略研究[J].东北电力大学学报,2016,36(5):7-12.
[16] 赵继光,牛海清,陈诚,等.直埋集群敷设配电缆的载流量多回路修正系数校核[J].南方电网技术,2014,8(1):89-93.
[17] 马国栋.电线电缆载流量[M].2版.北京:中国电力出版社,2013:38-135.
[18] 周凡.电力电缆暂态热路模型的优化分析[D].广州:华南理工大学,2014.
[2] 杜伯学,马宗乐,霍振星,等.电力电缆技术的发展与研究动向[J].高压电器,2010,46(7):100-104.
[3] 鲁志伟,于建立,郑良华,等.交联电缆集群敷设载流量的数值计算[J].高电压技术,2010,36(2):481-487.
[4] 林国新.高压输电线路跨海通道建设方案比选研究[J].东北电力大学学报,2017,37(4):86-93.
[5] 焦阳.电力电缆温度场仿真及在线监测系统研究[D].重庆:重庆大学,2016.
[6] 周文斌,王新颖,白俊峰,等.35kV新旧导线载流量与温升对比分析[J].南方电网技术,2014,8(2)92-95.
[7] 鲁志伟,张航,敖明,等.电缆载流量试验热稳定判据及试验误差的研究[J].东北电力大学学报,2016,36(5):25-31.
[8] International Electrotechnical Commission.IEC60287-1 Calculation of the current rating-part 1:current rating equations (100 % load factor) and calculation of losses[S].Geneva,Switzerland:IEC,2006.
[9] 梁永春,李延沐,李彦明,等.利用模拟热荷法计算地下电缆稳态温度场[J].中国电机工程学报,2008,28(16):129-134.
[10] 于建立,隋琳琳,田际平,等.预埋管电缆载流量的有限容积法计算和分析[J].东北电力大学学报,2013,33(3):43-46.
[11] 李文祥,刘刚,王振华,等.XLPE三芯电缆稳态并联热路模型及实验验证[J].南方电网技术,2015,9(3):57-62.
[12] 郑雁翎.电缆线路的电缆群载流量优化数值计算模型研究[J].高电压技术,2015,41(11):3760-3765.
[13] 刘畅,徐政,宣耀伟,等.基于等效导热系数的直流电缆稳态载流量简化有限元算法[J].高压电器,2016,52(5):7-13.
[14] 李萌,牛胜锁,刘玉芹,等.基于多场耦合模型的海底电缆载流量和温度场计算研究[J].电测与仪表,2018,55(8):12-16,23.
[15] 吴文克,鲁志伟,张航,等.直埋电力电缆动态增容和双线增容策略研究[J].东北电力大学学报,2016,36(5):7-12.
[16] 赵继光,牛海清,陈诚,等.直埋集群敷设配电缆的载流量多回路修正系数校核[J].南方电网技术,2014,8(1):89-93.
[17] 马国栋.电线电缆载流量[M].2版.北京:中国电力出版社,2013:38-135.
[18] 周凡.电力电缆暂态热路模型的优化分析[D].广州:华南理工大学,2014.