Theoretical study on the efficacy of the cold compressor based cryogenic cycles

Abstract

Cold compressor based cycles have emerged as practical necessity for sub 4.5K (sub atmospheric) large scale cryogenic systems as used in most modern high energy accelerators and tokamaks. The concept of cold compressor can be applied in a generalized way for even atmospheric (high pressure) cycles, if justified. A rise in temperature is exhibited at the exit of the cold compressor due to pressurization and the inefficiency involved in the process. This rise in temperature results in gain of sensible heat, and acts like a refrigeration load at that temperature. This loss can only be acceptable if other advantages of cold compressors are substantial. In the present work, it is tried to explore the possibility of using the emerged cold compressor technology for medium scale cryogenics. One of the objectives of the study is to develop a cold compressor based refrigeration cycle which can be implemented using the present infrastructure at Cryo-Technology Division, Bhabha Atomic Research Centre (BARC). In this endeavour, a cryogenic cycle analysis tool is developed and is validated against the process data available for 2K cryogenic plant at LHC. Three cold compressor based modifications are proposed to the presently installed modified Claude cycle based helium liquefier. These three cases are analysed and compared.