The Study Of Urban Residential Thermal Environment Multi-objective Optimization Design Base On Parametric Method

Urban outdoor thermal environment has been in a serious situation in China,especially in hot-humid area.Residential area is an important part of the city and also an area of the closest relations with people's life.China has issued several standards related to green residential area,so as to control and handle outdoor environmental problems from the design and planning stage.However,the existing evaluation system of green residential areas is more focusing on system evaluation rather than design.Moreover,imperfect performance optimizing plan and software tools of residual area plan cannot satisfy requirements of optimizing design of green residential areas.Therefore,focusing on optimizing the outdoor environment of residential areas,the paper has studied on optimizing design of residential areas based on parametric design and multiobjective optimization algorithm.First of all,the paper determined the early optimization in schematic stage and put forward corresponding optimizing design method of green residential areas upon study on the design process of residential areas and evaluation system of green residential areas.Optimizing targets oriented at a preliminary stage of the plan and its performance evaluation index have been selected.It studied generating rules and methods of residual areas plans as well as tested multiobjective optimization performance of SPEA2 and Octopus of HpyE on the basis of parametric software RH& GH.Next,starting from intensity calculation of the existing residential heat islands,definition of heat-island intensity of residential areas and relevance of heat-island intensity of different spaces have been determined through testing outdoor summer thermal environment of residential areas in hot-humid areas,so as to provide scientific basis for reasonably guiding calculation and design of heat-island intensity in residential areas.Calculation method of heatisland intensity in residential areas based on improving green CTTC model has been proposed and verified.Key parameters of improving green CTTC model have been obtained through actual measurements: tree shielding rate of solar radiation and convective heat transfer rate,which provide technical support for the quantitative calculation of average temperature and heat-island intensity in residential areas.Thirdly,typical numerical model of regularly aligned layout has been established on the basis of a statistical investigation of regularly aligned layout residential cases.Multiple linear regression method has been adopted to determine parametric experience calculating formula of building wind pressure difference in residential areas through calculating surface leeway of building windward and leeward surfaces with numerical simulation method.With the calculating formula,only inputting small parts of planning layout and design parameters can be quickly predicted pressure difference of each building in residential areas,which can be used in the pressure difference prediction of common determinants residential building in the southern area.Finally,targeted at the shortcomings of current optimization design tools,a urban sky obstruction simplified algorithm based on obstruction angle and inverse trigonometric has been put forward to compile and develop optimizing design platform for green residential areas in early planning stage according to survey on above optimizing design methods and plan performance calculation.The platform based on parametric design software RH & GH,adopts Python scripting language and visual programming technology to compile and develop with combinations of SPEA2 and HpyE evolutionary algorithms.The platform can not only conduct quantitative calculation,evaluation and optimization on technical and economic indicators as well as environmental performance indicators,but also obtain the optimal solution set of overall layout satisfying multi-objective optimization,providing reasonable and scientific solution support for early plan planning and design of residential areas.Calculation accuracy and reliability of the software platform can meet the needs of engineering design upon validation.