轴封槽简化对汽轮机转子热应力计算结果的影响

利用ANSYS有限元分析软件对135 MW机组汽轮机有无中心孔的转子进行冷态起动条件下热结构耦合计算,得出在相同边界条件和初始条件下存在轴封槽及其简化为光轴时的应力和应变。选取调节级和中压第1级的相应特征点,对轴封槽简化前后计算结果进行对比分析,表明轴封槽模型适合于精确计算,而简化为光轴模型的计算结果偏于安全。结果为确定汽轮机转子危险截面的计算提供了参考。

INFLUENCE OF SIMPLIFYING SHAFT-SEAL GROOVES UPON THERMAL STRESS CALCULATION RESULT OF STEAM TURBINE'S ROTOR

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.