An integrated mixed refrigeration cycle for pre-cooling of refrigeration below 25 K

27th International Cryogenics Engineering Conference and International Cryogenic Materials Conference 2018

Kloeppel, S.^1 ; Quack, H.^1 ; Haberstroh, C.^1

TU Dresden, Bitzer of Refrigeration, Cryogenics and Compressor Technology, Dresden, Germany^1

关键词: Conventional superconductors;    Helium mixtures;    Increasing capacities;    Pre-cooling;    Refrigeration cycles;    Screw compressors;    Temperature level;    Turbo compressors;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/502/1/012149/pdf
DOI  :  10.1088/1757-899X/502/1/012149

来源: IOP

【 摘 要 】

Two trends can be found in current large-scale cryogenic projects. The first is the ever-increasing capacity requirements, while also a shift towards cooling demands at higher temperatures is observed. Conventional helium cycles require the use of oil flooded screw compressors, which are limited in efficiency, capacity, and reliability. Reverse-Brayton cycles with neon-helium mixtures deliver efficient refrigeration at a temperature above the dew point of neon, but cannot be applied to the cooling of conventional superconductors. This paper describes an approach where oxygen as a heavier gas allows the use of turbo-compressors viable. The oxygen is separated and used for providing refrigeration at higher temperature levels.