Using ANSYSinfinite element analysis software

the thermal structural coupled calculation for rotor

with or without a central bore

of a 135 MW steam turbine unit under coldstate startingup condition has been carried out

the stress and strain in case of existed shaftseal grooves as well as in case of simplifying them into smooth shaft under same boundary condition and initial condition having obtained respectively.Selecting corresponding characteristic points of the governing stage and the first stage of medium pressure

the calculation results before and after simplifying the shaftseal grooves have been compared and analysed.It shows that the model of shaftseal grooves to be suitable for accurate calculation

while the calculated result of simplified smooth shaft model to be somewhat safer.These results provide reference for calculating the risky section of rotor for steam turbines.