Design and Optimization of Heat Exchanger with Liquid Helium Chamber for Cooling of Supercritical Helium

The Proposed indigenous helium plant will have mixed mode operation (simultaneous operation as liquefier and as refrigerator) provision having equivalent 2 KW refrigeration at 4.5 K at IPR. there will be a liquid helium chamber will contain a heat exchanger to cool the supercritical helium from about 6 K to 4.8 K. this project will involve the design and optimization of this LHE chamber and internal component of it.this vacuum chamber of cold box will be a horizontal cylinder with tentative diameter of 2.5 m and length 7 m. This vacuum chamber will contain many cold component to produce liquid helium. A part of the flow will be taken to the LHe chamber though J-T valve to produce liquid helium and cool the supercritical helium coming out of the cold circulator using heat exchanger. This cold circulator (CC) will circulate helium in closed loop within the cold box. This CC will provide 300 g/s supercritical helium flow at 4 bar pressure and 6 K temperature. The heat energy going to the supercritical helium due to pumping work and external heat load of the CC need to be removed by heat exchanger contained in liquid helium chamber. The vapour from the chamber will return to the low pressure cold return line passing though the heat exchanger of the main cycle of the helium plant. As this chamber will be within the vacuum vessel, its size has to be minimized considering the size of the heat requirement of operation of helium plant when external helium Dewar is not available, in which this internal LHe chamber will be used to produce liquid helium for performance test of helium plant. This project will involve design and analysis taking into account of manufacturing assembly and maintained aspect and different off-normal condition.