Research On Air Pollutant Concentration Distribution And Ventilation Mode In Xi'an Urban Highway Tunnel

Since twenty-first Century,with the development of the national economy,the national highway tunnel construction has entered a period of rapid development,in the past10 years,the average annual growth rate of highway tunnel is 24%,much higher than the growth rate of road and bridge,and the importance of highway tunnel is becoming increasingly prominent.with the rapid development of highway tunnel,more and more attention has been paid to the quality of air environment in highway tunnel,because in the tunnel,the main pollutant source is the exhaust gas emitted by the automobile,and with the rapid increase of car ownership,the number of vehicles in the highway tunnel is also increasing rapidly,the air tunnel caused a lot of pressure,and the tunnel is a relatively closed region,the vehicle exhaust emissions contain harmful ingredients of CO,NO,SO2,organic compounds,aldehydes,hydrocarbons and other easily gathered in the tunnel,with the air in the tunnel,pose a serious threat to the human body health.therefore,knowing the characteristics of the pollutant concentration distribution in the tunnel can effectively reduce the concentration of various pollutants in the tunnel and avoid the arrival of personnel in the tunnel.and it is of great significance to select the best ventilation mode,reduce operating costs,speed up the design speed and form a standardized design system.therefore,the main content of this subject is as follows:?1?The completion of the Xi'an Wen Changmen-He Pingmen tunnel,Jinhua tunnel,South Gate tunnel,Shang Xinlu tunnel four different ventilation tunnel in summer,autumn and winter three season,and the statistics of each side measuring tunnel gas concentration of sunny,cloudy or rain three kinds of weather conditions in the tunnel,the early peak peak afternoon and evening peak time period three CO,CO₂,NO₂,PM_2.5,formaldehyde,vehicle flow and vehicle.?2?complete the analysis of the measurement data shows that the distribution of the concentration of major pollutants in the tunnel in different seasons,different weather conditions,four different modes of ventilation of the tunnel,and analyzed the influence of meteorological factors on the distribution of pollutant concentration.?3?Based on the measured data of tunnel ventilation design for tunnel ventilation in different ways,respectively by means of theoretical calculation and numerical simulation,obtained after optimizing the distribution of pollutant concentration inside the tunnel,compared with the test data,get the best ventilation arrangement.