The Thermal Stress Analysis Of Reactionary Steam Turbine Rotor And Design Of Life Management Software

With the rapid economic development of China, the production and consumption of electricity is becoming more and more important in the national economy. The difference between the peak and valley of power grid is increasingly prominent. The original large and medium units with a rated load capacity will participate peak shaving instead of run at full capacity. And the shutdown, startup and load change of the units will become more and more frequency, leading to the turbine rotor have a greater temperature gradient inside and will have a great thermal deformation and thermal stress. The large alternating stress of rotor will appear, and in the high temperature conditions will cause plastic deformation of the material. In the surface of the rotor cracks will appear. Then the life loss of the units will greatly increase compared with the condition of running with base load. The steam turbine is playing an important role in the power production, so the length life of turbine directly affects the operation status of the entire production chain. And with more and more high-capacity and high-parameter units are putted into operation, the proportion of reactionary steam turbine is becoming bigger and bigger. So the in-depth study of the reactionary steam turbine rotor’s life loss has a very important practical significance.This paper takes a steam turbine manufacturers150MW reactionary steam turbine as a search project. Using ANSYS finite element analysis software to calculate and analyze the temperature field and stress field in the startup process. This paper establish a two-dimensional finite model of the rotor, and set the thermal properties of material and unit properties. At first, loaded the heat transfer coefficient and initial conditions, calculate the temperature field of the rotor. Then change the unit properties, loaded the structural properties of material and the result of temperature field to calculate the stress field.The blade uses orthogonal material instead of isotropic material to eliminate the counteract effect that the centrifugal force to the thermal stress in this paper. Compared with the result which chooses isotropic material, the stress is20MPa bigger in the left and right corner of the adjustable level. The surface stress is changing according to magnitude of the centrifugal stress at other place. In the first stage of high pressure cylinder and intermediate pressure cylinder, the difference is about40-50MPa. The starting time is300min, the maximum stress values are displayed in the beginning of the rotor start, the value is about160MPa, is much lower than the material yield strength.Based on the original life loss detection software, this paper designs a PI interface, changing process of the original calculation software. And eliminate the safety hazards of PI Database, then complete the real-time monitoring of a Power Plant steam turbine’s online operation.