Abstract: The finite element software Abaqus is adopted to construct an axisymmetric finite element model of a high-pressure rotor of a 1000MW ultra-super critical steam turbine. The boundary conditions are determined based on the in-service steam temperature and pressure data from the power plant. After finite element calculation, the rotor mechanical behavior in the steady operation is analyzed, and the Lemaitre continuum damage model is further applied to study the creep-fatigue damage of the rotor. In addition, the calculating results without consideration of the steam temperature and pressure fluctuations are used for comparison. The results show that the fluctuations of the steam temperature and pressure exert a great influence on the thermo-mechanical behavior of the rotor; the temperature and stress of the rotor keep changing with the steam temperature and pressure; the creep-fatigue damage in the inlet area under the in-service conditions is more than double that under constant steam temperature and pressure conditions.

Key words: steam turbine, temperature, pressure, fluctuations, high-pressure rotor, creep-fatigue damage