Superconducting motors offer high power-to-weight or -to-volume ratios and are the natural choice for applications such as the electrification of heavy transport. A particular challenge is the cooling of the superconducting rotor coils. While one option is to use a stationary cryocooler and to provide the cooling via a gas circuit on the rotating side – which introduces other technical...
Energy efficiency and reduced power consumption are critical for modern cryogenic systems. Gifford-McMahon (GM) cryocoolers provide an economical, cryogen-free solution across a broad range of temperatures, offering high energy efficiency, reliable long-term performance, and easy maintenance thanks to their simple mechanical design. Compact size and low vibration levels make them especially...
At only about 1% of Carnot, the overall efficiency of 4 K, Gifford-McMahon cryocoolers and Gifford-McMahon type pulse tube refrigerators is not impressive. These refrigerators are most often studied from the perspective of minimizing losses in their regenerators and/or thermal buffer tubes, which are important topics, especially in the real-fluid regime where regenerator losses are very large....
With the further advance of cryogenic technology and high helium cost, more cryogenic environments are designed to be hermetically “sealed”, requiring a detailed understanding and analysis of parasitic heat fluxes crossing into a cryogenic environment. A thermal balance sheet therefore includes operational states but also needs to cover outages.
One of the frequently underestimated heat...
