Study On Fast Fatigue Damage Assessment Method For Rotor Torsional Vibration Of Large Turbo-generator

The rotor of the turbine generator unit is operated under the balance of the steam torque and the electromagnetic moment.The disturbance of the grid side and the adjustment of the working condition will take the rotor twist away from the equilibrium state.If the external disturbance torque frequency is similar with the natural frequency of the rotor,the shaft stress will be too large and it may lead to journal fracture,coupling failure and other serious consequences.At present,the torsional vibration on-line monitoring technology has been effective,can to a certain extent,effectively prevent the torsional vibration caused by significant losses,and the accompanying shaft fatigue assessment technology has also been widespread concern.Therefore,timely monitoring of torsional vibration,and can quickly and accurately make fatigue evaluation is the stage of steam turbine generating units an important guarantee for safe production.In this paper,a number of turbo-generator sets are used to study the torsional vibration characteristics,and the shaft model is established.The finite element analysis method is used to evaluate the existing rapid fatigue evaluation methods.In the case of applying the same electromagnetic moment,the stress response of the dangerous shaft section of each unit is checked,and the fatigue damage of the shaft section is evaluated on the basis of this.Finally,the results of each unit are compared.The results show that the rapid fatigue assessment method can evaluate the life loss of the shaft system accurately when the turbine shaft is obviously torsional vibration.In addition,with the turbine shaft power increases,the shaft size becomes longer,relatively thinner,torsional vibration damage will become more and more serious.Through the research of this subject,the operation and vibration of the turbine shaft system are deeply understood,and the shortcomings of the rapid fatigue assessment of the shafting system are pointed out.On the basis of this,the relevant suggestions are put forward for the later fatigue assessment The study provides a useful.