临街建筑采风口位置及气流组织形式的研究

Study on Location of Air Intakes and Air Flow Modes of Street Frontage Buildings

本文采用基于RNGk-ε湍流模型的CFD方法,模拟了典型街道峡谷环境中临街建筑周边机动车所排放污染物的分布情况。与风洞实验结果对比表明,数值模拟方法可以较好地预测街道峡谷内机动车尾气分布情况。其次,以建筑周边污染物浓度分布为基础,分析了机械通风采风口位置及自然通风气流组织形式对室内空气品质的影响。对于机械通风建筑,将采风口设于建筑顶部可在任何风向条件下减小机动车尾气对室内环境的影响;对于自然通风建筑,利用位于建筑临街侧上部的开口与背街侧开口进行穿越式自然通风,可在保证室内通风量的同时,减少机动车尾气向室内的传播。

In this paper, the spatial distribution of traffic-related pollutants around buildings located in a typical street canyon was firstly simulated using CFD method with RNG k-ε turbulence model. Comparing with the results of wind tunnel experiments, a general agreement between the numerical and experimental results was obtained. Secondly, based on the distribution of pollutant concentration around buildings, the influences of location of air intakes used in mechanical ventilation systems and the air flow modes of natural ventilation systems on indoor air quality were analyzed. For the building with mechanical ventilation systems, locating air intakes on buildings＇ roof could effectively reduce the adverse effect of outdoor pollutants in any wind conditions. While for the building with natural ventilation system, using the upper opening on the frontage and opening on back facade of the building could guarantee the ventilation rate and simultaneously control the diffusion of traffic pollutants from outdoor to indoor.