摘要
高温超导电缆大都采用带真空多层绝热保护的双层波纹管作为冷却电缆的液氮套管。波纹管内含有超导电缆时液氮的流动压力损失是冷却系统设计的重要参数。对光管、波纹管和含有模拟内芯的波纹管内液氮流动下的压降特性进行实验测量,对相同流量和流速下3种管路的压降和相同雷诺数下流动阻力系数的进行比较。相同流量下,压降最大为带芯波纹管,其次为空心波纹管,最小为光管,并且3种管路的压降都随着流量增大而增大;相同雷诺数下,流动阻力系数最大为空心波纹管,其次为带芯波纹管,最小为光管,并且3种管路流动阻力系数都随着雷诺数增大减小,并趋向定值。在实验研究基础上,提出了空心波纹管和带芯波纹管内液氮压降的无量纲经验关联式。
High temperature superconducting cable mostly uses double-layered bellow with high vacuum andmultilayer insulation as a bushing through which liquid nitrogen (LN2) passes for cable cooling. Pressure drop of LN2flow in bellows with high temperature superconducting cable installed is one of the most important parameters fordesigning the cooling loop system. Experiments are performed to measure the pressure drop in smooth pipe, emptybellow and bellow with an insert core, respectively. The results show that the pressure drop of LN2 in the three kinds ofpipes increases when the flow rate increases. Under the condition of the same flow rates, the pressure drop in bellowwith an insert core is the largest, and the pressure drop in the smooth tube is the lowest. The friction factor of the threekinds of pipes decreases when Reynold number increases and eventually approaches three constants respectively, andthe correlations of the friction factors for empty bellow and bellow with an insert core are developed based on theexperimental investigation.
作者
闫畅迪
黄永华
喻志广
汤涛
YAN Chang-di;HUANG Yong-hua;YU Zhi-guang;TANG Tao(Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240, China;Shanghai Electric Cable Research Institute, Shanghai 200093, China)
出处
《制冷技术》
2016年第3期1-5,共5页
Chinese Journal of Refrigeration Technology
关键词
波纹管
内芯
液氮
流动阻力系数
实验测量
Bellows
Insert core
Liquid nitrogen
Friction factor
Experimental measurement
