| With the development of China's urbanization process,the construction of urban rail transit had also been greatly developed.By the end of 2017,thirty eight cities had opened subway in china.Compared with other transportation,the subway is more convenient,quick and comfortable.However,because of the closed structure of subway and the poor ventilation,the air quality in the station of subway is poor.Therefore,many experts and scholars from home and abroad have investigated the distribution rules of particle concentration in subway station.But,due to the limitations of testing conditions,testing sites and other factors,there are still many shortcomings and problems in the current research.Based on the previous research,the subway system is divided into three systems studying the distribution law of particle concentration in in this paper,which are closed system?full height safety door?,screen door system and overhead system.The test period is mainly in the winter heating season:August 2016,December 2016-January 2017,and March 2017.The test time is daily off-peak period:13:00-15:00,peak period:17:00-19:00.The testing sites include outdoor,platform,hall,carriage,tunnel and part of work area.At first,the particle concentration of the different subway system is compared.in this paper.Secondly,the distribution law of the particle concentration is studied,especially for platform screen door system.Then,the factors that affect the PM2.5 concentration of the shielding door system are quantitatively analyzed by the SPSS22.0.Finally,the theoretical deduction is carried out to get the prediction fitting formula of the ARIMA.Based on the above analysis,the main conclusions obtained in this paper are as follows.?1?Through the comparison between the systems,we can found that the pollution of particle matter in the platform is greatly affected by the piston wind.The particle concentration of the whole high safety door system is much higher than that of platform screen door system.What's more,the percentage of PM2.5 accounts for PM10 is different in different environmental control systems,of which the all high safety door system>ground overhead>shielding door>half height safety door system.Finally,after the train enters,when the air quality is good,the increase rate of the particle concentration of the whole high safety door system>platform screen door system>the overhead elevated system.When the?2?outdoor air quality is seriously polluted,the opposite trend is found.?3?According to the study of PM2.5 distribution law of the platform screen door system,it is found that,in general,when the outdoor air quality is excellent,the particle matter concentration of platform>carriage>hall.Besides,for the platform and the hall of screen door system,the concentration of particle in different positions is also different.For the platform,the concentration of the particles near the staircase on both sides of the platform is greater than the position of the middle of the platform.For the station hall,the concentration of the two sides of the staircase is less than that in the middle position.?4?Firstly,the influence factors of the particle concentration have been found that the temperature and humidity have no effect on the concentration of the platform PM2.5.Secondly,the train frequency will affect the concentration of the platform PM2.5.Thirdly,the passenger flow has no significant influence on the concentration of the platform particles.At last,when the outdoor air quality is superior,the concentration of particles will increase with the increase of the operation length of the subway station.?5?The correlation analysis shows that there is a significant correlation between platform PM2.5 and PM10.The regression equation between particle concentration of the outdoor and the platform of different environment system is analyzed.The results show that the ground elevated platform>high safety door platform>screen door platform. |
PDF Full Text Request