Research On Optimal Layout Of Decentralized Wind Farm Considering Flow Around Buildings

With the continuous expansion of my country’s economic volume,the demand for energy has also continued to rise.The storage of traditional fossil energy continues to decrease,the consumption of fossil energy causes environmental pollution,and the country promotes the optimization of energy structure and vigorously develops green and clean energy.Under the background,vigorously developing new energy represented by wind power has become an effective way to solve energy problems.Distributed wind power generation is another important form of wind power generation that is different from centralized wind power generation.It has the characteristics of being close to the load center,local consumption,and improving the reliability of the power grid.However,because the installation location of the wind turbines in the decentralized wind farm is close to the load center,there will inevitably be buildings in the decentralized wind farm.When the natural wind passes through the building,the wind speed,direction and turbulence intensity are unavoidable changes will occur,so local high wind speed areas and low wind speed areas will be generated around the building,which will have an important impact on the power generation of wind turbines in distributed wind farms.In response to the above-mentioned problems,based on CFD theory and building flow theory,this thesis uses numerical simulation to analyze the influence mechanism and factors of building flow on the wind field around the building,focusing on the two sides of flat-roofed buildings and above the leeward side of the building,the two local high wind speed areas caused by the building’s circumfluence change with the height,length and width of the building.Finally,combined with the local high wind speed area around the building obtained by the numerical simulation,the layout of the wind turbines in the local high wind speed area of the decentralized wind farm is optimized based on the niche genetic algorithm.First of all,this thesis establishes the mathematical model of the wind turbine,based on Solid Works to carry on the three-dimensional modeling of the wind turbine;Analyzes the principle of the flow around the building,elaborates the characteristics of the flow field around the building;Establishes the wind acceleration factor to related parameters to measure the characteristics of the flow field around the building.Secondly,this thesis studies the circumfluence of two types of buildings(flat-roofed buildings and double-inclined roof buildings)that are common in distributed wind farms.The study found that due to the effect of circumfluence,the surroundings of the two types of buildings there are two local high wind speed areas: both sides of the building,above the roof of the building,and above the leeward surface of the building extending from the roof of the building to the rear of the building;Considering that flat-topped buildings are more common in actual projects,this thesis conducts further analysis of the wind field around flat-roofed buildings.The study found that the range of high wind speed areas on both sides of flat-roofed buildings tends to shrink with the increase in height.In the direction of the ground,the wind speed has experienced a process from small to large and then to small,and tends to the flow of wind speed.In addition,through numerical simulation of wind fields around flat-roof buildings of different lengths and widths,it is found that as the length of the building increases,the area of the two local high wind speed areas around the building also increases accordingly.With the increase in width,the area of the local high wind speed area above the roof of the building and the leeward surface of the building extending from the roof of the building to the rear of the building does not change much.However,due to the increase in the width of the building,the area of the leeward surface of the building is empty.The area of local high wind speed areas is reduced,which reduces the area available for installation of wind turbines in this area.On the other hand,when the width of the building increases,the area of the high wind speed area on both sides of the building does not change much,and it has little impact on the installation of wind turbines in this area.Finally,this thesis combines the range of the local high wind speed area obtained by the numerical simulation,and considers the influence of the wind turbine wake on the wind turbine layout.Based on the niche genetic algorithm,the layout of the wind turbines in the local high wind speed area of the decentralized wind farm is optimized.