A Novel Convection Cooled Cryogenic System for Air Core High-Speed Superconducting Machine

To enhance the integration and power density of superconducting motors, this paper designs a cooling structure applicable to high-speed air-core rotor superconducting motors. By creating cavity within the magnetic support structure of the air-core rotor to facilitate forced convection cooling of the magnets, both support and cooling functions for the superconducting magnets are simultaneously achieved. Based on an analysis of the motor's heat sources and boundary conditions, CFD simulations were conducted on the cooling structure of a single superconducting magnet to verify the feasibility of this structure for cooling air-core rotor superconducting motors. The helium flow vector direction within the helium chamber was further analyzed to optimize the structure. A flow guide structure was introduced, and CFD simulations under the same boundary conditions and heat source analysis were performed to verify the optimization of the temperature and fluid fields. This structure significantly improves the temperature margin and uniformity of temperature distribution for the superconducting magnets in air-core rotor superconducting motors, effectively preventing magnet quenching. Furthermore, for applications requiring high volumetric power density, this structure not only fulfills the cooling function but also greatly enhances the integration and volumetric power density of the air-core rotor superconducting motor.