应变下Nb_3Sn基CICC温度分布变化模型

摘要

The current sharing temperature and temperature margin are key factors to effect the steady operation of cable-in-conduit conductor （CICC）. In response to impact of magnet fields above 10T, the NbaSn-based CICC has been applied to the central solenoid and toroidal field of international thermal-nuclear experimental reactor. However, the current sharing temperature and temperature margin of Nb3Sn-based conductor with strain ate not been explored. According to the measured data of the current sharing temperature and temperature margin of toroidal field sample in SULTAN, the CICC stability increase caused by improvement of the current sharing temperature and temperature margin is analyzed without strain. Then, with the periodic load to simulate strain, the deterioration of the current sharing temperature and temperature margin is obtained after 600 cycles and 1000 cycles. Finally, based on assumptions and reasoning, the evolution model of current sharing temperature and temperature margin is built with double logarithm, which can well describe the performance degradation of the Chinese toroidal field sample （TFCN） resulted from bending strain by the periodic load.%分流温度和温度裕度是管内电缆导体（CICC）稳定运行的关键因素,为应对10T以上的磁场冲击,国际热核聚变反应堆ITER装置上的CS和TF等已采用铌三锡（Nb3Sn）导体,但缺乏应变效应对分流温度和温度裕度分布影响的研究。本文根据在SULTAN对TF样品分流温度和温度裕度的测量数据,首先在无应变下,对由分流温度和温度裕度的改善使得TFCN导体的稳定性得到提高进行分析。然后用周期载荷模拟应变,在600周期和1000周期时,分析CICC分流温度和温度裕度的恶化情况。最后由假设条件,推理并获得分流温度随周期载荷变化的双对数分布模型,该模型能很好描述TFCN导体样品中由周期载荷导致的弯曲应变所产生的性能降级情况。