Design And Research Of The Adjustable Guide Vanes System For Radial Hydraulic Turbines

It is of great significance to recover energy in industrial processes for development of energy-conservation technology.Hydraulic turbine,as one of the main energy-recovery equipment,has been widely used for pressure energy recovery in the processes and has been well developed.At present,a radial hydraulic turbine has attracted attention due to its small size and high energy conversion rate.However,the efficiency of the hydraulic turbine will decrease and consume energy under the condition of low flow rate.The research shows that adding adjustable guide vanes at the inlet of hydraulic turbine can effectively broaden its performance curve and improve its working efficiency.In this paper,the theoretical calculation method of adding guide vanes between turbine volute and impeller to improve the performance of radial hydraulic turbine is studied.Firstly,some main hydraulic components,such as guide vane,volute and so on,are designed based on the hydraulic calculation design theory,and the 3D model is built;Secondly,the radial hydraulic turbine impeller model is created by ANSYS-BladeGen,and is meshed by TurboGrid;Then,the method of theoretical calculation and numerical simulation was applied to analyze two cases of hydraulic turbines,with guide vanes and without guide vanes,and the performance curve is obtained.The pressure contours,velocity contours and law of hydraulic loss distribution are analyzed and the results prove that the adjustable guide vanes have the function of widening the optimum range of efficiency of hydraulic turbines.The airfoil,number and opening of NACA guide vanes are studied to summarize their effect on hydraulic turbine performance.Finally,a scotch york type guide vane adjustment mechanism is designed and installed in the hydraulic turbocharger to adjust the opening of the adjustable guide vanes.In this paper,the method of theoretical calculations and numerical simulations are applied to study the influence of airfoil,number and opening of adjustable guide vanes which are added at the inlet of the radial hydraulic turbines on the performance of hydraulic turbines.The theoretical calculation and design method for guide vanes of energy recovery hydraulic turbines are obtained,which provides the basis and reference for the future research.