Conceptualization and preliminary studies on the development of a 2K refrigeration system at BARC

Conceptualization and preliminary studies on the development of a 2K helium refrigeration system at BARC are reported in this article. Two different refrigeration schemes are considered and studied. In Scheme A, a separate cold box with 2 heat exchangers, a liquid helium bath and a sub atmospheric heat exchanger is considered and 2K refrigeration capacities for different liquid helium flow rates corresponding to LHP 50 and LHP 100 (BARC helium liquefiers), are computed and reported. In Scheme B, the 2K refrigeration system is considered to work in tandem with a back-up 4.5K helium liquefier (LHP 50/LHP100), receiving a stream of cold supercritical helium from the liquefier. Different cases, with and without liquid nitrogen precooling options of the 4.5K liquefier, are considered. After preliminary studies, Scheme B is preferred over Scheme A and the process inputs for the sub atmospheric pressure heat exchanger are also arrived at and presented.