Life Assessment Of Steam Turbine Rotor Based On Finite Element Method

Steam power plant is a large scale equipment in equipment manufacturing industry; equipment failure would not only cause economic loss to the power plant, but also bring about casualties, so it is very significant to study the life of the equipment so as to ensure the steam power plant run safely and economically. Steam turbine rotor running under the high temperature is one of the most important components in steam power plant; its life may represent the entire life of the steam turbine basically. The life of domestic 50MW steam turbine rotor is taken as research object in this paper, the results have great significant for the power plant unit safety, the worker safety and the optimization of plant operation. The main contributions and works are as follows:(1) The life calculation methods of the low-cycle fatigue life loss, the high temperature creep life loss and the total life loss were studied in this paper based on the analysis of turbine rotor under high temperature and high pressure working conditions.(2) The cold-state startup with sliding of the steam turbine was studied; the startup program under this condition was made. A full-size finite element analysis model for turbine rotor was established and it was simplified by using the method of loading equivalent mass block. The steam temperature and heat transfer coefficient of the steam turbine rotor were calculated and then loaded to the finite element model of the turbine rotor as boundary conditions.(3) Both temperature and stress fields of steam turbine rotor under the cold-state startup with sliding were calculated using ANSYS. The temperature distribution, the moment and part of the maximum temperature difference, the stress distribution, the maximum value of equivalent stress and the moment and part of it were obtained and analyzed.(4) The fatigue life loss of the steam turbine rotor was estimated using Miller theory, the items and measures of the rotor life management were put forward on the basis of above results of calculation and analysis.The fatigue life loss of domestic 50MW unit under the cold-state startup with sliding was obtained in this paper; it has some instructional significance to calculate life loss under the other work conditions and life management.