Practical Measure Research On The Spatial Distribution Of Fine Particulate Matter In Subway Stations

With the rapid development of city construction,the subway has become one of the main mode of transport for people to travel.Compared with the above ground traffic,the subway has the advantages of fast and no blockage.However,due to the semi closed structure of the subway station,its air quality should be noticed.In recent years,the pollution problem of the outdoor atmosphere has aroused the attention of the people,and the government departments have also intensified their efforts to deal with it.However,compared with the high openness of the concentration of fine particles in the outdoor air,the air quality and fine particle concentration in the domestic subway have not attracted the public's attention,and the related research is more rare.The main content of this paper is the measurement and analysis of the distribution of fine particles in different space in the subway station.The concentration of fine particles in each space in the subway station is obtained through the field test,then the measured data are arranged and analyzed,and the distribution of particles in each space in the subway station is summed up.By comparing the concentration of fine particles in the platform with adjustable screen doors in the all high safety door system mode and the screen door system mode,the influence of the environmental control system on the concentration of fine particles in the station is explained.According to the relevant specifications,field tests were carried out for the concentration levels and changes of fine particles in various space of different system forms of Beijing subway station under different outdoor conditions.The distribution rule of fine particles in each space of subway station was obtained,and the conclusion is as follows:(1)The concentration level and fluctuation range of each measuring point in the subway station hall are different,and the concentration field in the station hall varies greatly;The concentration level and fluctuation range at the two ends of the platform are both greater than the middle position;The spatial distribution of the concentration of fine particles in the carriage in the flat peak period of passenger flow is: head > tail > middle.At the peak period of the passenger flow,the concentration difference between the three positions is small,and the concentration field is more uniform.(2)Under two working conditions,the concentration levels of fine particles in different space of the two stations with different environmental control systems are: platform > station hall;the concentration level of fine particles in the station hall and platform is higher than that in the peak season of passenger flow.(3)When the outdoor environment quality is good,the platform with adjustable screen doors is transferred from the screen door system mode to the full height safety door system mode.After running for two hours,the concentration of fine particles in the platform dropped by 32%.In this paper,the distribution of fine particles in the space of the subway station is obtained through the analysis of the measurement and data processing,and the reasons for the formation of the spatial distribution are analyzed.In addition,the effect of the subway environment control system on the concentration of fine particles in the platform is compared and analyzed.This not only improves the domestic research on the air quality in the subway,but also provides a reference for the control of the air quality and the design of the subway structure in the future,and is of great significance for further research in the future.