Design And Simulation Of Small Hydropower For Water Flow Energy

As one of new energy technologies, marine current turbine is not only at the stage of theoretical and experimental research, but also have achieved both economic and environmental benefits considerably by the application of some products using this technology. While China's Yangtze River upstream tributaries is rich in hydropower resources, similar technology can be used in the river-Hydropower for water flow energy which can work properly in the water with low speed.This paper studies the Hydropower system.The system is a complex nonlinear, multivariable and strong interference system. The random variation of flow velocity, flow impeller with nonlinear coupling and generator nonlinear factors has been fully considered in the model analysis. In order to forecast and prevent the impeller cavitation.,this article utilizes the CFD technology on the impeller for the numerical simulation. At the same time,the simulation can be used as a reference in the structure design of generator device, so as to capture the energy as much as possible.Preliminary design of the power plant's model structure and its'size has been made according to the hydrological data of Yangtze River. Verify the feasibility of the design respectively from power,impeller rotational speed and torque of main shaft by analogy with wind turbine's calculation or design method. Then selected a suitable DC generator and speed increasing device. Subsequently compared the vertical axis and the horizontal axis devices and designed the vertical model by AutoCAD and Pro/E.Then analyzed the uses of Fluent in this project based on the fluid mechanics theory.The emphasis is placed on the software of turbulence models,as well as the analysis of the fluid machinery by using MRF model. Initial comparison of different airfoil's dynamic performance index has been made by studying the lift coefficient, drag coefficient and lift-drag ratio.Finally, MRF model has been selected to carry out the simulation of flow field in the Hydropower for water flow energy. Combined with the simulation results and the vertical axis of the impeller tip speed ratio theory, that is required to improve the transmission speed increasing ratio, in order to meet the project of Hydropower for water flow energy with low water speed. In the point of energy capture efficiency, preliminary design has been carried on for the drainage device. The simulation results showed that with ideal conditions, nozzle contraction ratio increased, so as the flow velocity. But in considering the foil's rotates on the flow field, simulation results of the flow field showed that the flow drainage device decentralized part of the flow kinetic energy. And vortex separation emerged at tail of the device, thus reduced hydrodynamic performance of Hydropower for water flow energy.