用于CEPC探测器超导磁体的液氮虹吸实验研究

The LN_2 thermosiphon experimental study for the superconducting magnet of the CEPC

概括了环形正负电子对撞机(CEPC)探测器超导磁体拟采用的虹吸冷却低温系统的研制背景,重点介绍了液氮虹吸实验平台的设计、组装及检漏。分别以氮气液化后的液氮填充相分离器的1/5和1/3体积的要求进行了两次实验,其常温常压下的体积分别为0.32m^3和0.47m^3。实验发现当充装量为0.32m^3时,蒸发侧加热功率达到10W后发生了烧干现象;充装量为0.47m^3时,蒸发侧加热功率达到20W后液氮回路仍循环良好,管路最大温差不到1K,管路温度分布均匀,未发生烧干现象。实验结果表明,氮气的充装量以及蒸发侧的加热功率是影响虹吸冷却效果的两个重要因素。

The cryogenic siphon cooling system used in the Circular Electron Positron Collider（CEPC） detector supercon- ducting magnet was introduced. This paper mainly discussed the experiment on the liquid nitrogen siphon system, including the design of the experimental device, the assembly, the leakage detection and the detailed experiment procedures. The nitrogen at room temperature and normal atmospheric pressure was filled into the siphon system with two different volumes of 0.32m3 and 0. 47m3 ,which was calculated that the condensed liquid nitrogen could be filled in 1/5 and 1/3 of the volume of the phase separa- tor, respectively. The pipe at the evaporation side boiled away at the heat power of 10W when the filling amount of nitrogen was 0.32m3. But when the filling amount was set to be 0.47m3 , the siphon cooling system could work well at the heat power of 20W with the maximum temperature difference of below 1K. The experimental results indicate that the filling amount of the nitrogen and the heat power are the two main factors which can influence the siphon cooling effect.