Numerical Simulation Study On Flow Condition Improvement Of Intake Of Dongping Hydropower Station

Intake of hydropower station is located at the head of the water diversion system and is an important part of the hydropower station.When hydropower station is running,it is necessary to ensure that the flow of intake is smooth,the inflow is uniform and the flow pattern is stable,so as to avoid the harmful suction vortex,and minimize the head loss to improve the efficiency of power generation.The head loss has a great influence on the design of the hydropower station,and the problem of the low head hydropower station is more prominent.Therefore,it has great significance to study hydraulic characteristics of intake of hydropower station,optimize size of the intake and ensure safe and efficient operation of the hydropower station.Dongping hydropower station is located in the middle and lower reaches of Zishui River,running nearly 9 years.In this paper,in order to solve the difficult flow patterns of the diversion channel of Dongping Hydropower Station,such as swirling flow,lateral flow and intense vortex,the boundary conditions such as the guide wall,the sand barrier and the side slope are changed by numerical analysis software.seeking remediation optimization program,through the multi-mode simulation,comparative analysis of the Intake flow pattern,head loss,velocity distribution and other hydraulic characteristics,proposed hydraulic structure remediation optimization plan.The main research contents are as follows:(1)According to the actual data,ANSYS ICEM CFD was used to establish the three-dimensional model of the related reservoir area of hydropower station,the whole area of the intake,the intake and the whole flow channel and the downstream local area;(2)The model is introduced into FLUENT for three-dimensional numerical simulation of various operating conditions,verify the similarity between simulated flow and prototype flow,analysis the reason of the difficult flow patterns of the diversion channel of Dongping Hydropower Station,such as the swirling flow,lateral flow and intense vortex;(3)In order to improve the difficult flow patterns of the diversion channel of Dongping Hydropower Station under the present situation,the boundary conditions such as the guide wall,the sand barrier and the side slope are changed,propose guide wall length program,guide wall height program,the side slope program,the sand barrier height program,guide wall and sand barrier height program,and so on.Through the simulation and comparison of multiple schemes,the lateral flow,oblique flow,the swirling flow,the vortex position,the vortex strength and the vortex area of the simulated flow are comprehensively compared,and the optimal layout of the hydraulic structures optimization program is put forward;(4)Under the optimal layout of hydraulic structures,the mathematical model was established to analyze the effect of changing the layout of hydraulic structures on flood.The initial flow rate of the intake of the model should be determined by using the real velocity of the different parts of the different sections of the elevation in the field as the initial condition,and further simulation study is carried out.Numerical simulations have made many simplifications to the complicated boundary conditions and river bed roughness.Access to engineering for the optimization of the program,need to further through the physical model test to verify each other.