Quasi-3D thermal-hydraulic analysis of the cool-down for CFETR CSMC

The cool-down of large Cable-in-Conduit Conductor (CICC) superconducting magnets presents significant complexity, necessitating careful management to ensure operational safety. This study proposes a quasi-threedimensional thermal-hydraulic analysis model, developed using COMSOL Multiphysics, specifically designed for large CICC superconducting magnets. The model facilitates an in-depth analysis of the 300 K-80 K cool-down for the Central Solenoid Model Coil (CSMC) of China Fusion Engineering Test Reactor (CFETR). The proposed numerical model is capable of successfully constraining the maximum temperature difference among the various components of the magnet while providing an accurate depiction of the temperature distribution throughout the cool-down. Furthermore, it incorporates the inter-turn heat transfer within the coils. This article discusses improvement suggestions for the cool-down of the CSMC and presents the results after these enhancements. This study also investigates the effects of varying inlet pressures and maximum temperature differences on the cool- down of the magnet. The results offer valuable theoretical insights for future cool-down experiments, thereby helping to mitigate the risk of damage to the magnet due to inappropriate cool-down parameters.