Fatigue Life Evaluation for Turbine Rotor Using Green's Function

Abstract

Turbine rotors of fossil power plant are operated under the severe stresses resulted from high temperature and high pressure during start up. While steam temperatures through components abruptly change from low temperature and high temperature, thermal stresses reach the design limit at the same time and reduce the remaining life of rotor. The purpose of this paper is to carry out fatigue analyses reflecting the results of the thermal stress simulation during start up and shutdown. The simple and quick simulation during turbine start up is developed with Green's Function. And temperature and stress transfer Green's functions applied to critical locations of rotor. Green's function is the thermal stress by the unit change of steam temperature. This method is useful of the thermal stress simulation at the start up. Therefore, it is anticipated that the proposed scheme adopting Green's function and operating histories can be utilized for remaining life time evaluation of turbine rotors.