Design and Optimization Of A Skirt Of Hydrocarbon Columns Through Thermo-Structural Analysis

Abstract

This dissertation work describes approach for the design and optimization of a skirt of hydrocarbon column through thermo-structural (coupled-field) analysis. The main objective of this project is to optimize the existing design by redesigning the skirt of column through thermo-structural analysis. This report describes the considerations employed in the finite element analysis of a support skirt of hydrocarbon column. The support skirt is capable of sustaining the deadweight load in addition to resisting the effects of thermal displacement, wind loadings, overturning moments from external piping loads on the attached hydrocarbon column. The effects of multiple scenarios for the displacement boundary conditions are examined. A discussion of the two-part analysis is included and details the interaction between the heat transfer analysis and the subsequent structural analysis. The heat transfer finite element analysis is utilized to determine the temperatures throughout the bottom of the vessel shell and head, as well as the integrally attached support skirt. During analysis, prime importance is given to the axial thermal gradient present in the skirt from the base plate to slightly beyond the Skirt-to-shell junction. While the geometry of the subject vessel and skirt is best described as axisymmetric, the imposed loadings are a mixture of axisymmetric and nonaxisymmetric. This combination lends itself to the judicious selection and utilization of the harmonic finite element and properly chosen fourier series representation of the applied loads. Modeling and designing of column is done through pvelite software. Sequential method is used for thermo structural analysis. Design and Structural analysis of Base-Block assembly is also carried out for the given operating conditions.