The cold-compressor systems for the LHC cryoplants at CERN

Publisher Summary CERN, the European Laboratory for Particle Physics, is currently engaged in the construction of the Large Hadron Collider (LHC). This LHC will make use of high field super-conducting magnets operating in super-fluid helium and thus will require a huge refrigeration capacity at several temperature levels. The refrigeration capacity will be generated and distributed by eight refrigerator stations located along the colliders tunnel. The IHI-Linde Consortium is reviewing the successfully completed tests of the cold-compressor prototype plant at CERN and looks forward to the commissioning of the serial plants. The paper informs on experiences and conclusions for future cold-compressor applications. With the successful commissioning of a four stage cold compressor application for LHC, the state of prototypes is left. A lot of know-how is gathered concerning machinery as well as concerning process arrangement and speed control. The cold compressing systems have reached the state of marketable products. But their market, particularly the market for refrigerators with super-fluid helium in the capacity range of several Kilowatt, is small. Further investigations are required to design smaller cold compressor units which are applicable for a lower capacity range. The target is a flow of 5 g/s at 1.5 kPa.