城市住区室外通风与空气负离子浓度评测研究

选取合肥市东南区域典型居住区为研究对象,运用CFD数值模拟和室外实地观测相结合的研究方法,量化模拟了夏冬两季住区室外环境的风速图,并分析了其模拟通风状况;在此基础上得到了住区内不同环境的通风特征,包括建筑布局、空间形态、建筑密度、交通路网、植物绿化等对通风的影响;再根据模拟参数,在住区内选取样点实地观测了不同环境特征下的住区夏冬两季的空气负离子和风速、温度、相对湿度以及空气正离子等数据,探索了住区室外环境中空气负离子浓度与风速、温度、湿度和空气正离子之间的相关关系。同时进一步整理了近4万个有效数据应用于空气负离子和风速的时空分布研究,推导出夏季风速与空气负离子的线性回归方程,并运用偏相关分析,得出城市住区环境中空气负离子与风速呈极显著负相关,给出了线性回归方程Y=-0.001X-0.003。最后结合建筑布局的组合、开敞空间的设计和线性道路的组织等分析了空气负离子和风速的分布规律,用以说明评价住区室外环境通风状况的可行性,为今后城乡规划和建筑设计提供科学依据和设计思路。

RESEARCH ON THE EVALUATION ON OUTDOOR VENTILATION AND NEGATIVE AIR ION CONCENTRATION IN URBAN RESIDENTIAL AREAS

In this study,a typical residential area in the southeast of Hefei is chosen as a modeling object.By use of CFD numerical simulation combining with outdoor field observations,ventilation map of the outdoor environment in this residential area in the summer and winter is simulated,and then the simulated results are analyzed.Based on the simulated results,the effects of different environment characteristics such as building layout,spatial form,building density,road network,greening plants,and other aspects on ventilation conditions in this residential area are obtained.Field observations on the negative air ion concentration,wind speed,temperature,relative humidity,and positive air ion concentration are conducted based on the simulated parameters,and then the correlations between negative air ion concentration and wind speed,temperature,relative humidity,and positive air ions in this residential area are explored.Meanwhile,nearly 40,000 pieces of valid data are used to study the temporal and spatial distribution of negative air ions and wind speed,and then the linear regression equation of wind speed with negative air ion concentration in summer is deduced,which is Y=-0.001X-0.003,indicating that there is obvious negative correlation between negative air ions and wind speed in the urban residential area.At last,with the combination of architectural layout,design of open space,and organization of linear roads,the distribution law of negative air ions and wind speed is analyzed,so as to illustrate the feasibility of the evaluation on ventilation conditions in outdoor environment in residential areas.This study hopes to provide theoretical foundation and design thoughts for the future urban and rural planning and architectural design.