Investigations On The Effect Of Helix Angle On The Transient Chill Down Of Helically Coiled Liquid Nitrogen Transfer Lines
Chill down in helical transfer lines were investigated using validated computational fluid dynamics code. Mass
of fluid required and the time taken to completely chill down 4 helical transfer lines with different helix angles, at constant
heat flux, were compared in this study. Important flow parameters for multiphase system such as volume fraction, liquid
velocity, and temperature distribution were plotted and displayed. The measurement of two phase flow parameters like
volume fraction of the fluid has given more insight into the much complicated chill down process. It was found that
centrifugal forces due to shape of helical transfer lines play an important role in the phase, and temperature distribution in
helical pipes. It was also observed that the mass of fluid used and time taken for complete chill down of helical transfer lines
were much smaller as opposed to a straight transfer line. Among the various helix angled helical transfer lines, it was
observed that as helix angle increases chill down time decreases.
Keywords- Chill down, Liquid Nitrogen, CFD analysis, Cryogenics, Helical Transfer lines, Two Phase flow.