Theoretical Analysis And Numerical Calculation Of Steam Flow Excitation Force Of Steam Turbine

With the development of modern society, the demand of growth in electricity demand become fast, development of turbine generator set in the direction of high parameter and large capacity. With the capacity and steam parameters of steam turbine improve, the problem of safety operation of the steam turbine unit is exposed, the problem of steam flow excited vibration of steam turbine is becoming more and more serious. Therefore, it is very important for the study of the steam flow excited vibration.In this paper, the mechanism of steam flow induced vibration of steam turbine is studied and the numerical simulation is carried out. Firstly, analyze the failure mechanism of steam flow excited vibration theoretically, summarize the cause of the vibration fault of the steam flow and the location of the fault, then research on the steam flow excitation force theoretically, master the mechanism of steam flow excited vibration basically, lay a theoretical foundation for the follow-up study. And for the main reason for the occurrence of steam flow excited vibration, use computational fluid dynamics to simulate flow filed of tip clearance and diaphragm gland numerically. Use the high pressure cylinder rotor of 300MW turbine in a steam turbine factory as an example, establish a physical model of the gap of the top of the leaf and the sealing of the separator, use FLUENT to Simulate actual operating conditions. For the tip of the moving blade, analyze and simulate the flow field both eccentric and no eccentric, and compare the calculation results of the flow field characteristics, discovery that the flow is complex in the flow field. With the increase of the tip clearance, steam force of steam to rotor increase, turbulent kinetic energy of fluid in the flow field increase, the flow becomes unstable. Numerical simulation of the flow field of the separator shows, the pressure of the separator reduces along with the inlet to the outlet gradually. In export of the steam seal, the pressure decreased significantly. Through the numerical simulation of tip clearance and diaphragm seal, the influence factors of steam flow excited vibration are understood in practical sense. Combined with theoretical research, do the research on the vibration fault of steam flow.