The Effection Of Outflow Of Kaplan Turbine Volute To Stability Of Turbine Group

Hydraulic turbine is the core equipment of the whole hydropower station.The merits of its performance has a great influence on entire unit equipment. There are many factors determining the turbine stability, including electrical, mechanical and hydraulic factors,and the main reason is hydraulic factor. Therefore, dynamic balance model of the turbine is a complex model. It is necessary to ignore some secondary causes if we want to establish an accurate and effective dynamic balance model in order to simplify model.The main function of turbine volute is letting water flow into runner evenly and axisymmetricly.In the actual power plant, however,the uniformity and symmetry of water are very difficult to be ensured when the water flow to runner through the guide vanes. Therefore it may lead to unbalanced radial force of the turbine which can cause vibration.In recent years, CFD numerical simulation technology develope rapidly.It has been widely used in the internal flow of fluid mechanical analysis and hydraulic design.CFD numerical simulation technique is intuitive and efficient.It can researches the fine institutions and distribution of the interal flow field of turbine,and reveals the main hydraulic factors which impact the turbine stability.Now, CFD numerical simulation technology has a very important significance on researching the stability of turbine.The three-dimensional flow field in two types volute of the turbine of a real power station was simulated by numerical simulation software CFX.Comparing the internal flowstate of two types volute of the turbine,quantifying the differences of outflow status of twotypes volute,we can find the effection of diversion components to stability of turbine group.