Study On Design Method For Outdoor Thermal Environment Based On Lumped Parameter Method

Improving the thermal environment of residential areas, not only can effectively mitigatethe urban heat island effect and improve the urban climate, but also can effectively reduce theenergy consumption of the entire city and the use of natural resources for human. At present,although the study on outdoor thermal environment of residential area has been graduallycarried out in our country, but the research is lack of comprehensive and quantitative analysis.While abroad, it’s usually to validate the model or conduct the numerical calculation beforethe planning of urban and residential area, but it’s also lack of simple design tools.Based on the outdoor thermal environment analysis tool of DUTE (Design UrbanThermal Environment) which is based on the lumped parameter method, firstly, the DUTEsoftware is validated in this thesis. Through the comparisons between measured results ofoutdoor thermal environment, simulated results of FLUENT and results of DUTE, we canfind that the calculation method of DUTE is scientific and reasonable, its prediction accuracycan meet the needs of the project.Thus it can lay the foundation for accurate prediction andquantitative evaluation the outdoor thermal environment, make the simulation guidance andoptimization design to improve the outdoor thermal environment become feasible.Secondly, simulation and analysis on the65residential districts’ site plan in Guangzhoucity are conducted to get the major factors influencing the outdoor thermal environmentdesign by using the DUTE software. Meanwhile, comprehensively and systematicallyanalyzing the relationship between influence factors and heat island intensity are carried out.Summary the index range of the main influence factors for the heat island intensity ofGuangzhou City residential area is less than1.5℃, can be used as an important reference forresidential planning and design.Then, the typical and actual residential areas of the Guangzhou city is used as theprototype to quantitatively analyze the effect of the index of different landscape design factorson the all day hourly heat island intensity of residential area and the contribution ratio onlowering the average by using the DUTE software. The ideal building clusters’ model isestablished, and the typical meteorological data of Guangzhou city is used to analyze the rulesof influences of building layout, building density, building floor area ratio on outdoor thermalenvironment. The results show that with the increase in the area, the hourly heat islandintensity distribution is different for the underlying surface of different materials, the treeshading is the most obvious in several ways to improve the thermal environment effects,followed by water, green and permeable brick ground. Building layout, building density and floor area ratio have a greater impact on the outdoor thermal environment, while buildingoverhead and building form is less.Finally, optimizing design the poor thermal environment of residential areas inGuangzhou to obtain the contribution ratio of different design methods on lowering the heatisland intensity. From the simulation conclusions in Guangzhou, we can sum up the heatisland mitigation measures in the detailed planning of residential areas and the optimal designmethods. In the case of building construction program is difficult to adjust or not changes, it’spriority to planting trees and offering structure shading for outdoor venues, and then should befollowed to improve the area of green and water to ensure a good outdoor thermalenvironment quality.