Refrigeration processes operated with wide-boiling refrigerant mixtures known as cryogenic mixed-refrigerant cycles (CMRC) are an attractive technology for providing cooling capacity in the temperature range between 80 K and 200 K. Due to their simple process design based on components of classical refrigeration technology, they offer a cost-effective and, in comparison to cryocoolers, more scalable cooling technology. Comparatively high process efficiencies are possible by suitable selection of the mixture composition. Hence, mixed-refrigerant cycles have been used in industrial gas liquefication for decades.
In the past, the use of CMRC has also been discussed for cooling of applications in the field of high-temperature superconductivity (HTS). Potential fields of application include cables carrying high currents and current leads for superconducting magnets especially but not limited to accelerator systems. Our research in the field of CMRC covers both, theoretical and numerical investigation of heat exchangers and mixture compositions for CMRC-applications as well as experimental investigations of novel heat exchanger prototypes.