铌三锡管内电缆导体分流温度和刚度分析研究

Research of Current Sharing Temperature and Stiffness for Nb_3Sn-based Cable-in-conduit Conductor

低温下,导体的分流温度和刚度是管内电缆导体(cable-in-conduit conductor,CICC)稳定运行的重要因素,为克服铌钛(NbTi)的不足,应对10 T以上的磁场冲击,国际热核聚变反应堆(international thermal-nuclear experimentalreactor,ITER)装置上环向磁场(toroidal field,TF)和中心螺管(central solenoid,CS)磁体系统中的导体已采用铌三锡(Nb3Sn)材料,但缺乏应变效应对分流温度和导体刚度影响的研究。为此,该文利用模拟应变效应的横向载荷周期,对TF和CS样品的分流温度和弹性模量进行测试,分析获得扭距、空隙率和子缆级数等综合作用使分流温度和刚度随模拟应变载荷周期退化的结果,同时由接触面和股线接触角决定的电缆刚度以及股线的侧向支撑强烈影响导体的变形程度。

Under the condition of low temperature, the current sharing temperature and the stiffness are the key factors for the steady operation of cable-in-conduit conductor （CICC）. In order to overcome the insufficiency of titanium niobium （NbTi） and in response to impact of magnet field above 10 T （Tesla）, a Nb3Sn-based CICC has been applied to the toroidal field （TF） and the central solenoid （CS） of international thermal-nuclear experimental reactor （ITER）. However, the current sharing temperature and the stiffness of Nb3Sn-based conductor with strain have not been explored. In this paper, by using simulation strain effect with transverse load cycle, the measured data on the current sharing temperature and the stiffness of the toroidal field and the central solenoid sample is analysed. The results show that the comprehensive effect of torque, void fraction and sub-cable levels leads to degradation of the current sharing temperature and the stiffness with simulation strain load cycle. At the same time, the cable stiffness which resulted from the contact area and contact angle, as well as strand lateral support will strongly influence the deformation of conductor.