Thermal Stress Forecast Analysis And Study Of Ultra-Supercritical Steam Turbine Rotor

Turbine rotor is one of important turbine components and high pressure rotor is more important in particular. When turbine is being started, stopped or on load, the metal temperature of cylinder casing and rotor become unsteady and the result is that a larger temperature gradient will be generated because of changing parameters of surface steam. The key to restrict starting/stopped rate is the thermal stress of turbine rotor, as well as to safe running. One of hot topics in power system field is enhancing abilities to safe and economical running. In order to achieve the goals, it is necessary that thermal stress is to be analyzed and calculated so as to realizing optimality of turbine starting and stop. This thesis study the analysis and control of the distribution of temperature and thermal stress in deeply on 1000MW ultra-supercritical steam turbine startup.Firstly this thesis establishes a two-dimensional symmetrical geometrical model and boundary condition of high pressure turbine rotor with COMSOL Multiphysics, analyzes the model in simulation and compares the data with the measured ones in power plants. The results show that it is probable to underestimate actual thermal stress of high pressure rotor with volume average temperature algorithm (thermal stress calculation algorithm) which is used commonly in turbine control.The model can be expressed as parametric one,as to be connected to Matlab conviently ,which can design high pressure rotor structure and aspects optimal,as well as startup/stop strategies.Then this thesis establishes a Matlab/Simulink simulation model used for calculating volume average temperature of high pressure rotor in real time, based on comprehensive comparison to the existing data which is from real time computing algorithm of high pressure rotor volume average temperature. A series of emulational calculation on high pressure rotor volume average temperature has been completed, which is sampled at cold starting, hot starting and on load respectively. Comparing with the field measured data, the calculation results are as good as the field ones.Lastly this thesis analyzes Siemens thermal stress control strategies in deep, based on detailed description of thermal stress real time online monitor of Siemens turbine. It is advantaged to develop thermal stress strategies and turbine life management system which have independent intellectual property rights.