Comparison of two FEA models for calculating stresses in shell-and-tube heat exchanger

摘要

Two finite element analysis models of tubesheet of shell-and-tube heat exchangers are highlighted. Traditional theory of elastic foundation model is used for tube to tubesheet interaction in model I. Pipe elements are used to represent actual interaction between tube and tubesheet in model II. By the comparison of model I and model II results, it is confirmed that the distributions of the deformations and stress intensities for both models have very little differences under complicated mechanical and thermal loads. Model I is suitable for FEA of shell-and-tube heat exchangers, because model I is enough accurate and model II is more complicated and it takes more time and memory spaces of computer. The axial forces at tube-to-tubesheet for two models are nearly the same and the axial forces generated by bending moments are very small. The elastic foundation theory of the standards of design is suitable.