Present status and one upgrading method with a cold compressor of the EAST sub-cooling helium cryogenic system

作     者：朱志刚 张启勇 宋云涛 庄明 周芷伟 成安义 朱平 

作者机构：Institute of Plasma PhysicsChinese Academy of SciencesHefei 230031People's Republic of China University of Science and Technology of ChinaHefei 230026People's Republic of China 

出 版 物：《Plasma Science and Technology》 (等离子体科学和技术（英文版）)

年 卷 期：2017年第19卷第5期

页      面：102-108页

核心收录：

学科分类：08[工学] 0827[工学-核科学与技术] 082701[工学-核能科学与工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by National Natural Science Foundation of China(No.11505237) 

主　　题：EAST cryogenic system helium refrigerator sub cooling helium cold compressor 

摘      要：Since 2006, the superconducting toroidal field（TF） coils of the Experimental Advanced Superconducting Tokomak（EAST） have been successfully cooled by supercritical helium at a temperature of 4.5 K and a pressure of 4 bara in eleven experiments. To obtain higher operating currents and magnetic fields it is necessary to lower the operating temperature of the TF coils.The EAST sub-cooling helium cryogenic system, with a warm oil ring pump（ORP）, was tested twice in cool-down experiments, which made the TF coils operate at 3.8 K. However, the long term operational stability of the sub-cooling system cannot be guaranteed because of the ORP＇s poor mechanical and control performance. In this paper, the present status of the EAST subcooling helium cryogenic system is described, and then several cooling methods below 4.2 K and their merits are presented and analyzed. Finally, an upgrading method with a cold compressor for an EAST sub-cooling helium cryogenic system is proposed. The new process flow and thermodynamic calculation of the sub-cooling helium system, and the main parameters of the cold compressor, are also presented in detail. This work will provide a reference for the future upgrading of the sub-cooling helium system for higher operation parameters of the EAST device.