Design And Research Of A Vertical-axis Ocean Current Energy Power Generation Device

With the reduction of non-renewable energy worldwide,countries have increased their use of clean and renewable energy.There are many kinds of abundant energy in the ocean,among which the ocean current energy theory has a large reserves.At present,there are various forms of ocean current energy utilization devices in operation at home and abroad.Among them,the vertical-axis turbines have been vigorously developed with simple structure and high reliability.However,the energy utilization efficiency of vertical-axis turbines is currently low,and there is much room for improvement.In this paper,with the main goal of improving the energy utilization of the vertical axis turbine,a vertical axis ocean current energy power generation device is proposed.Firstly,a brief introduction and summary of the research methods of the hydrodynamic performance of the turbine,and then the force analysis of the blade,the force of the blade is decomposed on the impeller,the motion analysis of the impeller is completed,and the calculation formula of the energy utilization rate of the turbine is obtained.The output utilization rate is related to many factors,and the law of blade angle is one of the important factors.Based on the existing domestic and foreign power generation devices and the target sea area,a 10 kW vertical axis sea current energy power generation device is proposed,and the basic design parameters of the prototype are determined.The impeller is composed of three straight blades installed with double supports in the middle.The carrier is in the form of a seat bottom.At the same time,the material selection,corrosion protection and generator selection are completed.On the basis of the variable declination control method of the wind turbine,the key design of the variable declination mechanism of the turbine is carried out,and the prototype is modeled and assembled in Solidworks.Based on the single-disk multi-flow management theory,the utilization rate of the turbine is taken as the objective function,the blade declination is the optimization variable,and the sequence quadratic programming algorithm combined with the genetic algorithm is used to optimize the function.With the help of Matlab software,the results are obtained at different speed ratios.In order to facilitate the mechanism control,the cftool tool is used to perform a polynomial fitting on the declination law,and finally a continuous set of declination functions is obtained.Based on the declination law after fitting,the energy utilization rate is calculated,and The energy utilization ratio of the cycloidal declination law is compared,and the results show that the energy utilization rate of the impeller under the declination law is improved after optimization at each speed ratio.Using the CFD method in ANSYS software to simulate and analyze the turbine under the above-mentioned declination,first simplify the turbine model,and then use the ICEM software for pre-processing;use OC-type grid around the blade and grid around the blade Strengthen,which can improve the quality of the mesh and improve the authenticity of the simulation;import UDF custom functions to complete the implementation of the declination law;under a different tip speed ratio,with a fixed declination law,cycloidal declination law,optimization The three types of back declination laws are compared.The results show that the optimized declination laws can improve the utilization rate of the turbine,and the optimal tip speed ratio positions for different declination laws are different.