Design and Analysis of Shop-Built Spherical LNG Pressure Vessel Using Autodesk Fusion 360

Pressure vessels are containers specifically designed to hold fluid at high pressure. In this case, the design analysis is concerned with the containment of Liquefied Natural Gas. Due to the sudden rise in demand for liquefied natural gas around the world, there has been an equivalent rise in demand to improve storage of this gas. As a result, Engineers and Scientist design high pressure vessel containers that will hold LNG at high pressure without failure.Shop-built spherical pressure vessels are designed for uniformity in inner shell thickness, unlike the field-fabricated ones. Field fabricated spherical pressure vessels have gained lots of attention by engineers with regard to its design and analysis, but there is a dearth of material on the subject of shop-built LNG spherical pressure vessel design and analysis. This study expands upon the earlier work that employed the FORTRAN-solved numerical analysis-finite element approach. Models of pressure vessels made of A516 Grade 65 steel of inner shell radius of 1m, subjected to different internal pressure were simulated using a finite element software-Autodesk Fusion 360. The shell thicknesses were calculated using a predetermined safety factor, and Autodesk Fusion 360 was utilized to examine the stress distribution in the spherical pressure vessel. Membrane stresses were developed which was viewed in color codes using Von-mises yield stress criteria. The Von-mises stress distribution was compared to the yield strength of the material and the result showed safe value of stress developed. Thus the pressure vessel is adequately able to withstand the specified internal pressures assumed in each case.Analytical methods from the literature were used to validate the results, and no discernible differences were found. This proved that Autodesk Fusion is a good software tool for finite element analysis application.

Keywords: Shop-built, Pressure Vessel, Membrane stress.