Study on the Influence of Subway Entrance Space Layout on Indoor Air Quality

Urban subways are always located in busy areas and closed structures, with more pollution sources in the surrounding environment and easy indoor accumulation of pollutants. The study focuses on the influence of the spatial layout of subway entrances on the entry of outdoor particulate matter, and three morphological indicators of subway station entrance direction, roof morphology and entrance height/width ratio are selected as the influencing factors in the study. After the feasibility of CFD model was verified by real measurement, the RNG k-ε model was selected to simulate the indoor pollution of each subway entrance morphology under different wind speeds. The research shows that (1) the lateral direction is twice as high as the forward entrance particle interception rate, (2) the larger the entrance width when the entrance height-width ratio is less than 1∶1, the better the overall air quality of the subway station, (3) the arrangement of the roof morphology on indoor particle abatement is: sloping roof＞flat roof＞no roof, and (4) the spatial morphology of the subway entrance has different effects on particle interception of different diameters. The results show that the morphology design can improve the entry of particulate matter in the station and reduce the direct infusion of outdoor pollutants through air convection and return flow.