Study On The Diffusion Characteristics Of Pollutants At Toll Stations And Air Quality Control In Toll Booths

With the constant construction and development of highway traffic,as well as the increasing number of motor vehicles,China’s highway traffic environmental problems deserve attention.There are a large number of toll stations.Due to the large traffic flow and the running state of vehicles in the tollbooth,the pollution of vehicle exhaust is serious.Under the manual charging mode,the air environment in toll booth in the heavily polluted area has long been polluted by automobile exhaust emissions,which seriously threatens the health of the toll booth workers and tends to lead to occupational diseases.In order to study the effect of automobile exhaust emission on the air environment of toll stations,a physical model of pollutant diffusion in toll station area was established,numerical calculation was made on the diffusion of pollutants in toll station area,and the diffusion characteristics of pollutants in toll stations were studied by monitoring the mass concentration of NO₂ in toll booths.In order to solve the problem of poor air quality and pollution in the toll booths of expressway,the method of personalized air supply is adopted to improve the air quality in the toll booth.Airpak software was used to simulate the air quality in the toll booth at different air supply speeds and positions.It is proposed to use the air curtain partition method to inhibit pollutants from entering the toll booth.The suppression effect of air curtain under different air supply velocity and air supply angle is simulated numerically.The results show that with the increase of height,the pollutant concentration of the toll station shows a decreasing trend,and the pollutant concentration is higher in the height of 0-3m.The external wind environment has a great impact on the diffusion of pollutants in toll stations.When the wind direction is parallel to the lane,the concentration of pollutants is the lowest,and when the wind direction is perpendicular to the lane,the pollution is the most serious.The increase of the outdoor wind speed is beneficial to reduce the pollution situation of the toll station.When personalized air supply is adopted,the air supply port is arranged directly to the human body.When the air supply speed is 1.8m/s,the air quality in the breathing area of the staff can be guaranteed to reach the stipulated standard.When the air supply speed is 2.0m/s,it can ensure that there is no negative pressure area in the booth window.The air quality improvement effect is better than 1.3m when the air inlet height is 1.5m,and the effect of the air outlet is arranged to the human body better than to the right side of the human body.Air curtain can effectively inhibit the intrusion of pollutants into the toll booth.When the air is supplied vertically downward,the inhibition effect increases as the air supply speed increases.When the air supply velocity reaches 2.0m/s,the inhibition effect is not obvious if the air supply velocity continues to increase.Changing the air supply Angle of the air curtain has a certain effect on the inhibition effect.When the air supply Angle is 0°,5°and 10°,the air curtain can play a better inhibition effect.