Coupled Thermal-Structural Analysis of a Turbine Rotor Using ANSYS for Finding Out Remnant Life

Abstract

An important characteristic of a steam power plant is its ability to maintain reliability and safety of the plant against frequent start-ups and load changes. Transient regimes arising during start-ups, shut-downs and load changes give rise to unsteady temperature distribution with time in steam turbine rotor, which results in non-uniform strain and stress distribution. The rapid increase of temperature and rotational speed during starts-ups, especially, makes conditions more severe and causes main components' damage and reduction of life span for steam turbine. Thus accurate knowledge of thermal and centrifugal stresses is required for the integrity and lifetime assessment for the turbine rotor. The remnant life assessment for steam turbine rotor was established by combining effects of thermal stresses due to temperature variation and stresses due to pressure load. This paper particularly focused on the time-dependent inelastic behavior of materials and cyclic loading under non-isothermal conditions. Remnant life assessment of steam turbine rotor can be obtained.