Analysis on the Characteristics of the Decompression Cooling System Used in the Superconducting Motor

Liquid nitrogen decompression cooling systems are widely used in superconducting devices to reduce cooling temperature and improve performance. This paper constructs a simple schematic of a lightweight liquid nitrogen decompression cooling system for a superconducting motor used in electric aircraft propulsion. A corresponding mathematical model is established to comprehensively consider the AC loss characteristic, the flow boiling heat transfer characteristic, and the suction rate characteristic. The coupling characteristics between the decompression cooling system and the superconducting motor are examined. The result shows that both reducing the pressure in liquid nitrogen tank and improving the flow boiling heat transfer significantly extend the safe operating range of the superconducting motor.