Research On The Microsting Of Roof Mounted Wind Turbine On The Top Of High-rise Building

With the development of urbanization,the combination of small wind turbines and buildings has become one of the effective ways to alleviate the problem of power shortage in cities.However,the wind field at the top of buildings in urban environment is characterized by increased turbulence and decreased wind speed.The increase of turbulence will reduce the operation safety and service life of wind turbine,and the reduced wind speed will affect the output power of wind power generation system.Therefore,the study on microsite selection of wind turbines in urban environment is crucial for the implementation and use of wind turbines in urban building environment.In this paper,with an increasing number of typical monomer tall buildings in a city and a high building group as the research object,using CFD method,for all kinds of buildings or not high above the top of the building group of wind field characteristics are studied,preliminarily determines the different architectural appearance,single length-width ratio on top of the tall building,and different layout,lengthwidth ratio of high building group of the micro site selection of the wind turbine.Then through the field test measurement of the wind speed characteristics of the real wind field above the roof of a complex building,the wind speed characteristics of the real wind field above the roof of a building are further mastered,which lays a certain theoretical foundation and experimental support for the effective installation of the rooftop wind turbine in the urban environment.First,in order to determine the architectural appearance to the top of the building the micro site selection of the wind turbine,in this paper,the building shape of cuboid,cylinder,respectively cubes and ellipsoid of 4 kinds of monomers in high-rise buildings top surface wind field characteristic has carried on the contrast analysis,the results show that the has rounded the curve shape building than blunt edges and shape of buildings is more suitable for the installation of the wind turbine;For buildings with rounded curves,the installation height of wind turbine can be reduced appropriately.When wind turbine is installed on the top surface of a cylindrical building,the center and the edge of the leeward surface should be the first choice.The installation height should not be lower than 1.07 H.The top surface of the cube building at the edge of the windward surface and the corner is more conducive to the installation of the wind turbine.The installation height should not be lower than 1.16 H.On the top of the rectangular building,the wind turbine is most suitable to be installed at the edge of the windward surface and the corner of the windward surface,and the lowest installation height of the wind turbine should not be less than 1.18 H.When installing wind turbine on the roof of ellipsoid building,the top edge of the building should be preferred,and the installation height should not be lower than 1.15 H.Secondly,in this paper,the aspect ratio were 0.25,0.3,0.4,0.5,0.6,0.7,0.8,0.9,eight kinds of rectangle building roof surface wind field characteristics are simulated calculation,determine the length-width ratio on rectangle at the top of the building the micro site selection of the wind turbine,the results show that the aspect ratio,the greater the low wind speed,the greater the area of the end face and the wind speed with height growth is slow;At the same time,the turbulence intensity of its top surface is larger.The smaller the aspect ratio is,the lower the height suitable for wind turbine installation.For example,when the aspect ratio HAR=0.25,the minimum installation height is 1.118 H.When the aspect ratio HAR=0.9,the minimum installation height is 1.199 H.Then,the CFD method was used to study the micro-site selection of wind turbines in three non-uniform buildings with different layouts.18% of the area continues above the top of the highest building and is not suitable for wind turbines;The wind turbine should be installed on the front edge and the near front edge of the top face of the highest building in the non-vertical buildings.The installation height of the front corner point wind turbine is the lowest,which is higher than 1.13-1.24 H.When the installation height reaches 1.4H,the wind turbine can be installed in any position on the top of the highest building in the nonuniform buildings.The fourth,The micro-site selection of wind turbines in five buildings with height ratio of 0.3,0.45,0.6,0.75 and 0.9 were studied,the results show that the height of buildings than lambda,the greater the turbulence intensity is,the greater the tallest building in the same group buildings under the influence of low buildings.When the building height ratio ??0.6,the highest building in the building group can be considered as a single building;The smaller the buildings are than,the lower the height suitable for wind turbines.In addition,the top surface of the highest building in each length-width ratio group changes from the windward surface to the leeward surface,and the installation height of the wind turbine increases gradually.When the installation height reaches 1.281 H,the wind turbine can be installed in any position on the top of the highest building in 5 types of buildings.Finally,Zeph IR 300 Lidar Wind Measuring System was used to test and measure the characteristics of the wind field around a building in the energy base of Inner Mongolia university of technology for 15 months.Data are collected synchronously for multiple measurements.Then,relevant data were processed,including the variation of wind speed and direction with the height,so as to further master the wind speed characteristics of the real wind field on the top of the building,which provided a certain theoretical basis and experimental support for the effective installation of rooftop wind turbine in the urban environment.