Design of cold compressor systems in terms of operational and economical aspects

Abstract

In the past, cooling at 2 K used to be an exotic application in large scale cryogenics. The required sub-atmospheric helium bath was established with the help of one of the following two technical approaches - rough vacuum pumping at ambient temperature or turbo compression at cryogenic temperature - or a combination of both. The aforementioned approaches are still being applied, but the optimum distribution between warm and cold stages is not always obvious. In the last few years, 2 K cooling became a new state-of-the-art in the fields of experimental and applied physics. Standardisation of the machinery and its control significantly reduced commissioning time which has clearly been demonstrated during start-up of refrigeration plants such as Fermilab and DESY. Thus, the technological readiness of cold compressors has successfully been proven. This paper presents criteria for the optimisation of a cold compressor system under operational and economical aspects depending on the required 2 K cooling capacity.