超临界氦循环泵在EAST中的应用研究

Study on the using of supercritical helium circulating pump

EAST超导托卡马克装置的极向场和纵场线圈的超导磁体均采用迫流冷却的CICC(Cable in Conduit Conduc- tor)导体,极向场线圈的冷却介质直接由制冷机节流路来提供,而纵场线圈和线圈盒由氦循环泵来提供。文中概述了氦循环泵在超导装置中的使用情况,分析了超导磁体的迫流冷却特性以及EAST超导磁体的迫流冷却回路,揭示了氦循环泵的应用优点。比较两种冷却方式,得出热效率比较图,证明了氦循环泵的有效性,为氦循环泵的使用范围及选型提供了理论依据。

The toroidal field （TF） magnets and poloidal field （PF） magnets of EAST are all made of forced--flow cooled cable in conduit conductor （CICC） with a large of mass flow rate of supereritieal helium （SHe）. The SHe of PF magnets is directly provided by helium refrigerator through the Joule Thomson valve while that of TF and ease magnets is provided by helium circulating pump. This paper summarizes the using of helium circulating pumps in superconducting devices all over the world. The forced flow cooling loops of PF and TF magnets are presented. A thermodynamic study shows some merits for the method of using helium circulating pump compared with that of using J--T stream. It is proved that the pump is reasonable and effective to achieve a large of mass flow rate of SHe for superconducting magnets of EAST.