基于微通道液氮换热的脉冲磁体快速冷却方法研究  

Investigation on fast cooling method for pulsed magnet based on heat transfer of flowing liquid nitrogen in micro-channels

作　　者：何勇[1] 孟昭男 张鹏[2] 孙衢骎 周星健[1] He Yong;Meng Zhaonan;Zhang Peng;Sun Quqin;Zhou Xingjian(Institute of Fluid Physics,CAEP,Mianyang 621900,China;Institute of Refrigeration and Cryogenics,Shanghai Jiao Tong University,Shanghai 200240,China;Wuhan Second Ship Design and Research Institute,Wuhan 430205,China)

机构地区：[1]中国工程物理研究院流体物理研究所,四川绵阳621900 [2]上海交通大学制冷与低温工程研究所,上海200240 [3]武汉第二舰船设计研究院,武汉430205

出　　处：《强激光与粒子束》2022年第11期107-112,共6页High Power Laser and Particle Beams

摘　　要：影响脉冲磁体重频运行能力的关键因素是磁体的冷却速度。提出了一种脉冲磁体快速冷却方法:在磁体导体内开微小通道,在通道内注入液氮,通过增大导体与液氮之间的直接接触面积(换热面积)、液氮单相流动换热、液氮流动沸腾换热这三个途径来大幅提高导体的冷却速度,与此同时尽可能减小对脉冲磁体性能(磁场强度、脉宽和内直径)的影响。阐述了基于微通道内液氮流动、沸腾换热的脉冲磁体快速冷却方法的原理,开展了数值模拟和验证性试验,结果表明,对于25 T的20 mm口径脉冲磁体,采用快速冷却方法,30 s即可冷却至初始温度,为磁体仅浸泡在液氮中的冷却时间(600 s)的5%,冷却速度提高了19倍。The cooling-down time limits the capability of repetitive operation of the pulsed magnet.A fast cooling method for the pulsed magnet based on heat transfer of flowing liquid nitrogen(LN_(2))in micro-channels formed inside the conductors of the pulsed magnet is presented.The large amount of heat produced during discharging of the pulsed magnet can be quickly dissipated by LN_(2) inside the micro-channels through the enlarged contact areas between LN_(2) and conductors,by single-phase LN_(2) flow and/or flow boiling.Furthermore,the impacts of the microchannels on the performances(strengthening of the magnetic field,pulse duration and diameter of inner bore)can be tolerable.The principles of fast cooling method based on single-phase LN_(2) flow or flow boiling are elucidated.Numerical simulations and validation experiments of the fast cooling method indicate that pulsed magnet with inner bore diameter of 20 mm and magnetic field of 25 T can be cooled down in 30 s.The cooling speed of the pulsed magnet of the fast cooling method is increased by about 19 times compared with the conventional cooling method(600 s)where the pulsed magnet is simply immersed in LN_(2).

关 键 词：脉冲磁体 重频运行能力 微通道 沸腾换热 对流换热 

分 类 号：TL331[核科学技术—核技术及应用]