Turbine Rotor Thermal Stress And Fatigue Monitoring System Development

Turbine rotor working in harsh environments, during the startup,shutdown process, the rotor will produce greater thermal stress, causinglow cycle fatigue damage. This paper carried out the thermal stress andlife monitoring issues of the turbine rotor research, developedcorresponding online monitoring system to meet the needs of the safeoperation of the generator set.Deriving turbine rotor temperature field and thermal stress fieldin a one-dimensional analytical recursive method, one-dimensional finitedifference method and two-dimensional finite difference algorithm.Calculated the rotor shaft section and compared with finite elementsimulation results, analyzed the results of the calculation error of eachalgorithm.For calculating thermal stress problems in the two-dimensionalfinite difference method algorithm, using the average temperature of the turbine rotor node to calculate body average temperature. And thetwo-dimensional differential equation algorithm is modified to improvethe calculation accuracy. For the thermal stress concentration factorformula in the vane root, the formula is corrected by fitting based on thefinite element simulation results.Using the improved two-dimensional finite differencealgorithms and the improved stress concentration factor, introducing thecontinuum damage mechanics model to calculate the rotor damage andlife analysis, using object-oriented visual programming languageVB.NET, rotor thermal Stress and fatigue life online monitoring system isdeveloped based on the Visual Studio2005’s platform.