A Study Of Steam Turbine Rotor Local Heating Straightening Process By ANSYS

Steam turbine rotor is a key component of the turbine,which plays the role as a converter to change the energy of steam into mechanical energy.Turbine rotor has a hurge mass,as well as a large radius of gyration.It keeps working at high speed in hightemperature and pressure conditions,bearing the synthesized influence of centrifuga l force and thermal stress.As a result,there are some turbine rotors come into the state of vibration and bending,leading to the breaking down of the turine.To sovle this problem,targeted,rightful and efficient straightening method must be taken to eliminate security threat and to reduce economic losses.This paper uses electromagnetism,thermodynamics,mechanics of materials to develop the local heating straghting technology for steam turbine rotor,basing on finite element method software ANSYS,through multi-physics coupling of electromagnet ic field,temperature field and stress field.At the same time,analyze the relations hip between the straightening process parameters and the consequents,including the temperature field,stress field and the result of straightening process,to draw and to verify the law.Local resistance heating straightening parameters were studied through analys is of the temperature field,stress field.The parameters include shape of the heating zone,coverage angle,axial coverage length,temperature,heating rate,holding time,cooling rate,etc.Size fators were also studied,such as the length,diameter,shaft section of the rotor and so on.Though these study,find the law and the reason of the distinctive of temperature field,stress field and the straightening rusult,providing basis for parameters selection.Local electromagnetic induction heating straightening parameters were studied as wel.The parameters include coil arrangement,distance between coil and the workpiece,current density and current frenquency.At last,local resistance heating straightening process experiment was carried.By finite element method,procedure and parameters of the experiment were designed and selected in advance,and the result of the experiment was predicted.The experime nt was carried according to the FEM analysis,confirming the law of the parameters,as well as the correctness of the study.