Stress Analysis of Ellipsoidal Head With Heating Spiral

Abstract

The thermal load is one of important design condition that should be considered carefully in engineering practice. In most instances, the heat source is located inside the vessel, which causes a temperature gradient along the thickness, especially when the thickness is large. In this case, secondary stress should be considered and thermal ratcheting should be checked. In this paper, a thin-walled ellipsoidal head with heating spiral was studied. In this structure, temperature is uniformly distributed along the thickness but changes alternately between hot and cold along the meridional direction. This has a significant effect not only on the head itself but also on the nozzle. For the nozzle, its elastic support condition has been changed and then its stress distribution will also be changed. In this paper, several cases have been calculated and some laws are established. Finally, some useful conclusions and suggestions are proposed for engineering design.