Transient Thermal Stress and Temperature Change Rate Analysis of Fixed Tubesheet

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.