稳态混合磁体装置低温系统过冷槽的设计与优化

Design and optimization of subcooler in cryogenic system for steady high magnetic field facility

40 T稳态混合磁体装置的外超导磁体需要4.5 K、5×105Pa、18 g/s超临界氦迫流冷却,拟采用盘管换热器将从制冷机出来的氦冷却至超临界状态。首先对氦制冷机进行混合模式的热力学分析,确定过冷槽中盘管换热器的进口压力及温度,进而提出阶梯管径理论,根据工程要求设计并优化盘管换热器,得出盘管换热器的盘绕方式及尺寸;最后根据盘管换热器的尺寸以及氦的液化率和抽取时间确定过冷槽的尺寸。

The superconducting outsert of 40 T hybrid magnet of steady high magnetic field facility（SHMFF） is cooled with forced flow of supercritical helium at 4.5 K,5×105Pa and 18 g/s,the spiral-coil heat exchanger was chosen to cool the helium to the supercritical mode.Firstly,the thermodynamic analysis of the refrigeration cycle was carried out to obtain the inlet pressure and temperature of spiral-coil heat exchanger in subcooler,then the hierarchic caliber theory was put forward to design and optimize the subcooler based on project＇s demand,which could obtain the coiled way and dimension of the spiral-coil heat exchanger.Finally,the dimension of the subcooler was obtained according to the dimension of spiral-coil heat exchanger,liquefied fraction and extractive time of helium.