Transient Thermal Stress and Temperature Change Rate Analysis of Fixed Tubesheet

Abstract

Some fixed tubesheet heat exchangers suffer amount of system startup and shutdown causing large thermal stress for tubesheets. It will make an impact on the fatigue damage of the equipment. Transient thermal and stress analysis were carried out in many papers, but the geometry models were simplified, the non-expanded part of the tube and tubesheet were not modeled in detail at the end of tube. In fact, there is a tiny gap enclosed by tube, tubesheet and weld. So in this paper, a simplified model and an accurate model are established, the transient thermal and stress analysis were performed in ANSYS Workbench. The difference between two models was compared and the influence of temperature change rate on thermal stress was discussed.

Evaluation methodologies of damage related issues for heat exchangers in the thermal storage energy system

“…The chemical composition of the weld joints was discovered to be different from what was needed. To avoid such failure, timely examination of the heat exchanger base and weld materials for longterm creep exposure is required [23][24][25].…”

“…The purpose of this appendix is to describe the technique for obtaining the fatigue damage constitutive equations from the elasto-viscoplastic laws and evolution laws. A very simple problem is studied in order to better understand the properties of the model and the role of the thermomechanical couplings [24].…”