Analysis of transient thermal cycling for life assessment of steam turbine rotors

Abstract

Transient temperatures and stresses in the rotor during start-up and shut down cycles were evaluated using finite element analysis. Thermal gradients developed during thermal transients are the key source of stress generation in the rotor. Stress-strain response during thermal transients revealed non-proportional loading at the rotor surface and proportional loading in the rotor. Life assessment methodology of turbine rotors subjected to thermal power plant operating conditions is presented. Predictions from linear damage summation are compared with the results of nondestructive study of an actual steam turbine rotor.