Reseasch On Safe And Stable Opevation Of Small And Medium-siyed Firancis Turbine

The design of mixed-flow-type turbine for overload moderate head hydropower station must meet the requirements of high power performance, anti-wear feature and good stability. The application scope of this type of turbine is very wide because all hydropower generation equipments in northwest area face the same problem, that is, quick wear by silt. So research in depth is very practical. Although researchers in this sector have done lots of work in studying it, the opinions still vary, and different people have different views. Systemic documents from both home and abroad on deep analysis of turbine power, reason for unstability of turbine, calculation method for unstable force, relatively reasonable and fixed anti-wear structure, and manufacturing technology are very rare. Taking the turbine of one medium power station as an example, this document discussed the above issues one by one.The second chapter mainly covers the turbine power. Started from type selection for design, the chapter mainly addresses the hydraulic design, which is to meet above requirements. Laying emphasis on hydraulic design of the runner, the difference between traditional and currently advanced runner hydraulic design, deficiency of traditional runner design, and how to improve the design with current method are analyzed.The third chapter mainly discusses wear resistance of hydraulic turbine, which is increasingly a severe problem affecting the generating set, especially the combination effect of cavitation and silt-wear is focused frequently by the personnel who engaged in hydroelectric industry. The author expounded the question in aspects of design selection, typical structure, technological process and material selection etc, and put them into the practice in expectation to reduce that destroy.The stability of the generating set is a main point discussed in this fourth chapter. By demonstrating the structure that is capable of reducing axial force of hydraulic turbine, and analyzing more than ten mixed-flow-type runners, the author summarized the formulas for calculations of the axial force of hydraulic turbine. To make efforts in this field is aimed at quantifying the unstable force, which can make the designer pre-estimate the force to hydraulic turbine, so as to take the relevant measures to ensure a stable running of generating set.