Thermomechanical analysis of the drum of a steam generator using the finite element method

Abstract

In electric power plants, the boiler drum has the function of generating steam for its later use in the turbines. Because of the steam inside the drum, this component is subjected to high temperatures and pressure during the startup of the boiler, causing temperature gradients through the wall of the drum generating thermal stresses coupled with the mechanical stresses induced by the steam pressure. The thermomechanical analysis of the drum presented here was carried out by means of the finite element method and using actual measurements of the starting-up process of a power plant boiler up to the drum temperature is stabilized. The simulation includes the temperature distribution through the wall of the drum and the effect of temperature gradients in the thick walls up to the temperature steady state is reached. In addition the drum stresses caused by the vapor pressure coupled with those generated by the temperature distribution in the wall of the drum were also analyzed. Finally, the simulation of the performance of the drum for a long period to evaluate deformations caused by creep is also presented, since the operation of the boiler has the conditions that can cause this phenomenon.