Based On The Finite Element Of The Turbine Rotor Low Cycle Fatigue Life Prediction And Reliability Of The Online System Research

Based on the structure of certain unit of Banshan Electric Power Cooperation Limited company, the transient temperature and thermal stress fields of rotor under typical cold start was calculated by building the finite element model of the high and low pressure turbine rotor with ansys. On account of the exist of flute and other special transition structure, Transient Characteristies of Thermal Stress Concentration Coefficient on the front root of control strage impeller and root of first compressor stage impeller was studied. Then a nonlinear Continuum Damage Mechanics model(CDM) was proposed to assess the low cycle fatigue life of 135MW steam turbine rotor, in which the effects of mean stress were taken into account and the damage is accumulated nonlinearly.For the lack of theory of the rotor stress monitor and life management system without center bore, stress theory formula validated by the finite element was deduced. On the basis of theory, Stress security ruler different from certain direction synthesis stress ruler was proposed) filling in the gaps of rotor without center bore on-line theory in china.Reliability about on-line system was analyzed from its getting parameters, theory adopted and model selection of low cycle fatigue life. Firstly, difference in temperature between rotor surface and measure part in cylinder was calculated by the finite element model. Then the stress result calculated by the finite element methods and the finite difference methods on-line system were analyzed. Finially, better assessing methods was proposed by studying the deficiency about certain direction thermal stress ruler online system.