Research On Performance Optimization Of Vertical Axis Tidal Current Turbine Blade And Deflector

Tidal energy is a kind of inexhaustible and renewable resource.The research and development of-power generation technology and equipment has important strategic significance and significant social and economic benefits.Impeller is the core part of tidal current energy generation device.Meanwhile,setting up deflector outside the impeller to increase the flow velocity is an effective way to improve the efficiency of impeller energy recovery.In this paper,the method of simulation is mainly adopted,theoretical analysis and model test is used as a supplementary method.Taking Savonius turbine as research object,its optimization and performance are studied.The main research contents and results are as follows:(1)The 2D simulation model was established by FLUENT which used for the simulation analysis of a vertical axis water turbine(VAWT).The applicability of the simulation model was verified by the combination of related research and model test.The performance curves of S impeller under different working conditions were obtained.It is found that the optimal ratio of tip speed to speed is 1 and the maximum power factor is 25.49%.(2)The quadratic Bezier function was used to optimize the basic S impeller.Introduced the camber of X and Y,designed different types impeller,and simulated under various conditions.The results show that under the same X camber,the impeller has better working performance when Y camber is 5/6;The optimal leaf type is X and Y camber both were 5/6,the optimal tip speed ratio coefficient is 1.4,the maximum power coefficient is 0.3291,29.09%higher than the basic S type impeller.(3)The one-way deflector was designed which had simple structure.The parameters were optimized under the condition of the ratio of tip speed ratio of 0.4.The optimal parameter combination is angle a is 50°,angle β is 40°,and distance L is 5/6R.The maximum power factor of the optimized impeller is 0.3902,which is 18.57%higher than that of the optimized impeller,and 53.05%higher than that of the basic impeller.However,it is not suitable for the impeller when the tip speed ratio is higher than 1.2.(4)The tidal energy power generation test-bed device for VAWT was setting up.The device mainly includes:the power flow simulation part,the impeller motion part,the data collection part,and the related test table and accessories.The model test shows that the performance of the optimized impeller is better than that of the basic S impeller,and it is verified with the simulation results.