Research Of Absorbing Wind Energy Efficiently Of H-type Vertical Axis Wind Turbine

Energy is the power of the development of human society.With the rapid development of global economy,a large amount of fossil fossil energy such as coal,oil,natural gas was consumed,making the human facing with unprecedented energy crisis and environmental threats.Energy and environmental protection has become a major problem to be solved at present.Wind power technique,as a renewable energy power generation,which is the most mature in technology,most development condition and development prospects in addition to the nuclear power,and it is also attracted by more and more governments.Vertical axis wind turbines have gradually been widely concerned by people in the field of small wind turbines because of its simple structure,and without considering the wind direction.However,the wind energy utilization rate of the existing H-type vertical axis wind turbine is low,about 30%-35%.According to the latest dual actuator disk theory,the wind energy utilization rate of vertical axis wind turbine is up to 64%,which has great development space for vertical axis wind turbine.In order to improve the energy absorption performance of H-type vertical axis wind turbine,firstly,the basic theory of wind turbine and related concepts are described in this paper.According to the parameters that affect the aerodynamic performance of the vertical axis wind turbine,some important aspects which mainly refer to the change of blade airfoil,the device design of blade automatic variable angle of attack based on wind energy,and the optimization of supporting bar structure.In addition,the improvement measures for improving the utilization rate of wind energy are put forward.For H-type vertical axis wind turbine,a new blade airfoil is obtained by using the positive problem design method.The aerodynamic parameters of the new airfoil and old airfoil are compared with the Profili software,and it is pointed out that the lift-to-drag ratio of the new airfoil is 1~2 times higher than that of the original airfoil.The velocity distribution and pressure distribution around the two kinds of airfoil were compared and analyzed by using the fluent fluid simulation software,the advantages of the new airfoil are verified,and the outflow fields of the wind wheel in the same position and the different blade installation angle were also simulated.The relative relationship between the angle of attack and the angle of installation is established.It is concluded that the optimum angle of attack is 7 degrees and 0 degrees,respectively,in the range of 0 ~180 degrees and 180 ~360 degrees.Based on it,a device of changing angle of attack device automatically based on wind energy is designed,and the device is mainly composed of a crank slider mechanism,a groove cam mechanism and a bearing,which can make the angle of attack in the most reasonable state.The flow field around the wind turbine before and after changing angle of attack is simulated respectively by using embedded EMRF model and it is proved that the driving force of the wind wheel is obviously increased after changing angle of attack.Considering the self-starting characteristics of wind turbine and the stability during operation,a resistance-type support bar is designed based on the structure and centrifugal effect of wind cup type resistance difference wind turbine.The wind turbine with resistance type support bar is tested many times in wind tunnel.The experimental results show that the self starting ability of the wind wheel with the resistance-type support bar is obviously improved.More important,the wind wheel can still maintain a relatively stable speed when the wind speed changes in a short time.