REMAINING LIFE ASSESSMENT OF DRUM IN THERMAL POWER PLANT

Abstract

This paper presents the estimation of the remaining life time of the thermal power plant drum. Remaining life time assessment was done using finite element method as well as standards. The analysis was performed using thermo-elastic-plastic material model while creep deformation were neglected. The method of the stress determining in accordance with the standards do not take into account many possible conditions that can occur during plant operation. This applies particularly to the sudden temperature changes that occur in conditions of cold start, turns and correction of operation parameters of the drum. During drum operation, it is necessary to locally introduce a cooling medium in the form of water mist for rapid local cooling due to evaporation of water. This is characteristic of the elements that are close to temperature controller, such as preheating chamber. The frequency change of thermal loads and temperature changes size in such cases several hundred times greater than the frequency of start-up and shutdown unit.