High Efficiency Megawatt Machine Rotating Cryocooler Conceptual Design

Dyson, Rodger W ; Jansen, Ralph H ; Duffy, Kirsten P ; Passe, Paul J

关键词: BRAYTON CYCLE;    CRYOGENIC COOLING;    ELECTRIC MOTORS;    ROTORS;    SUPERCONDUCTIVITY;    TORQUE;    ROTATING SHAFTS;    PROPULSION SYSTEM PERFORMANCE;    PROPULSION SYSTEM CONFIGURATIONS;    ROTATING ENVIRONMENTS;    STIRLING CYCLE;    FLY BY WIRE CONTROL;    THERMAL STABILITY;    TEMPERATURE EFFECTS;   

RP-ID  :  GRC-E-DAA-TN71027

学科分类：航空航天科学

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

Some of the challenges associated with developing electric aircraft propulsion systems include developing powertrain components that are both efficient and light-weight. In particular, electric motors must simultaneously achieve high efficiency by minimizing electrical and mechanical losses while also achieving high specific power by increasing the torque and/or speed. Normally increasing torque or speed will increase electrical and mechanical losses. The High Efficiency Megawatt Machine (HEMM) minimizes electrical losses by incorporating a superconductor to enable increased current on the rotor. And the rotor spins in a vacuum to minimize thermal and mechanical losses. Some organizations have been developing superconducting rotors for similar reasons using either cryogenic fluid transfer systems, fully immersed cryogenic cooling, and in a few cases utilized built-in cryogenic cooling on the rotor using a Brayton or Stirling system but the implementation was too large or inefficient for effective motor integration. Instead, a new approach for cryogenically cooling the superconducting rotor coil with an embedded rotating cryocooler is presented that fits completely within the rotating shaft.