Study On Hydraulic Transient Of Pressure Water Diversion System Of Hydropower Station

Pressure water diversion system is an essential component of hydropower station. Transient computing and analyzing of hydropower station is an important content in engineering design and operating maintenance of diversion type hydropower station, which is the most fundamental research on complex power generation system composed of head race system, hydraulic turbine generator units and electricity network, and also relates to optimum design of diversion power generation system, and to safe and stable operation and quality of electric supply of hydropower station. Based on a practical engineering project, this study thoroughly research some important problems involved in long distance diversion power generation system by using computing and numerical method.The dissertation consists of the following contents:(1) The author establishes an analysis mathematical model of hydraulic transient of pressure water diversion system of diversion type hydropower station, and manifold boundary conditions are reasonably treated, including water inlet boundary, bifurcate pipe boundary, impedance surge chamber boundary and water turbine boundary and so on. Especially in the water turbine boundary, the effects of changing rotation speed of water turbine set on hydraulic turbine discharge are fully considered, which meets the characters of mixed flow turbine even better and ensures the correctness of computing results.(2) The paper carried out combination calculation on two kinds unsteady flow problems of pressure water diversion of hydropower station (i.e. pressure fluctuation of water hammer and mass fluctuation of surge chamber), which changed many analytical error caused by considered these two phenomena separately, and such result meets the inherent rule of pressure water diversion system transient of hydropower station much more than before.(3) Based on optimal calculation, the author has acquired the closing procedure and time arrangement of hydraulic turbine propeller that meets requirement of relating technical codes.(4) Trough the calculation on mass fluctuation of surge chamber, the author optimizes the section size of surge chamber and the reasonable cross section area of impedance hole, and reasonable area scope of impedance section of surge chamber have been acquired creatively.