The thermal stress analysis and structure optimum of neck tube with vertical cryogenic insulated cylinders based on ANSYS

As an important support structure between inner and outer vessel in cryogenic insulated cylinders, the root of neck tube becomes the weakest link because of opening in inner upper end for connecting. The main purpose of this paper is to present a study of thermal stress analysis and structure optimum of the neck tube support system of cryogenic cylinders subjected to internal pressure, self weight, lateral inertia load and temperature difference with the aid of ANSYS tools. The cryogenic cylinders with different height-diameter (H/D) ratios are studied in this study, as well as a wide range of geometries of neck tube. A parametric study of the effects of neck tube on the maximum stresses in the vessels under different loading conditions was performed by finite element analysis method. As that the stress concentration mainly occurs at the vicinity area of the opening of the inner upper heads, how reinforcement ring affects the stress distribution is also discussed. The study results will serve as the available data for structure design and optimization of cryogenic cylinders.