高温超导磁体试验装置设计

Design of high temperature superconduting magnet test equipment

在高温超导磁体试验装置设计中,冷却方式有制冷机传导冷却和液氮浸泡冷却两种。制冷机传导冷却是将磁体通过一种热导率高的材料与制冷机冷头相连。该方式为保证绝缘、冷量传递、温场均匀性等指标,对磁体的结构设计要求较高;液氮浸泡冷却是将高温超导磁体浸泡在液氮中,该方式虽然对磁体结构设计要求有所降低,但在试验过程中需定期补充蒸发掉的液氮,试验过程较繁琐。有鉴于此,我们设计了一套利用热虹吸原理的零蒸发液氮浸泡冷却高温超导磁体试验装置,超导磁体吊装在杜瓦上盖板法兰下,液氮浸泡超导磁体,带GM制冷机的液氮再冷凝杜瓦与超导磁体分开,用一根真空绝热管道将两者连接起来,利用热虹吸原理构成自循环系统。

In the design of test equipment of HTS magnet, there are two cooling methods which one is refrigerator conduction cooling and the other is liquid nitrogen immersion cooling. The refrigerator conduction cooling means that the magnet is connected to the cold head through one of conductors which has high thermal conductivity . To ensure the indexes such as the high - voltage insulation, cooling capacity conduction and temperature field uniformity, the structure design of magnet is highly required. Liquid nitrogen immersion cooling means that the magnet is immersed in the liquid nitrogen. Although the same requirement on the structure design does not need to be reached compared to the refrigerator conduction cooling, technical staff must add liquid nitrogen regularly in the course of the experiments. In order to solve the problem above, we designed a set of test equipment of zero evapo- rative liquid nitrogen immersion cooling HTS magnet using thermosiphon principle. Superconducting magnets were lifted under the dewar cover flange. Liquid nitrogen recondensered dewar with G - M refrigerator was connected to superconducting magnet by an vacuum insulation pipeline. Then the system will have a natural circulation in the role of thermosiphon principle.