Concentration Diffusion And Control Measures Of Automobile Exhaust Pollution In Underground Garage Of Large Complex

In recent years,with the increasing development of the economy,more and more complexes have sprung up in the center of the city.People's main places of life and entertainment are almost centered on the large complex,the large volume of passenger flow brings about the sudden increase of traffic flow around the mall,and the scale of the underground parking lot also continues to extend with the scale of the mall,and the use of its underground garage is accompanied by the increase of car ownership.With a sharp increase in the number of motor vehicles,automobile exhaust contains a large amount of CO,hydroxides,nitrogen oxides and solid dust particles,which can cause serious pollution to the atmosphere,once absorbed by the human body.will cause many diseases and threaten people's health.So for the people who work and live in the complex,the accumulation of pollutants in the underground garage gradually penetrates into the air,and its concentration of pollutants directly affects their lives.The effects of indoor pollutants fine particulate matter(PM_2.5),carbon dioxide?CO₂?,TVOC and formaldehyde are harmful to human health and indoor pollution.Therefore,this paper will explore three aspects of large complex underground garage vehicle exhaust pollutant concentration related changes diffusion and treatment measures.Firstly,the correlation changes of fine particulate matter(PM_2.5)concentration and carbon dioxide?CO₂?concentration in different locations in the underground garage of the complex were investigated.1)The trends of fine particulate matter(PM_2.5)and carbon dioxide?CO₂?concentration in different underground locations of the same underground garage were analyzed.2)The effects of different vehicle movement states?starting,idling,flameout?and different vehicle types?sedan,SUV,truck?on fine particulate matter(PM_2.5)and carbon dioxide?CO₂?were analyzed.3)Analysis of fine particulate matter(PM_2.5)in the limited time range from vehicle movement to termination influence of carbon oxide?CO₂?concentration.In the experiment,honeywell's generation of indoor air detectors were used to record changes in data when the environment changed in each test area of the underground garage.The experimental results show that the concentration of fine particulate matter(PM_2.5)in underground garage increases and decreases,and the horizontal expansion increases.the change of CO₂ concentration increases with the longitudinal increase,and the lateral expansion of the reservoir increases.From the datacomparison and analysis of the three types of vehicles and the three kinds of motion state cross,it is found that the vehicle idling speed The influence of truck on PM_2.5concentration is great under idle condition.from the limited time diffusion range of the vehicle,it was found that the concentration of contaminant PM_2.5 in the garage showed a rapid rise in the 30s-60 s after the end of the motion state,and the contaminant co2 in the garage showed a slow rise in the 5s-60 s after the end of the motion state.Secondly,it explores the correlation change of different pollutants TVOC and formaldehyde concentration in the underground garage of the complex:1)analyzing the change trend of TVOC and formaldehyde concentration in different underground locations of the same underground garage 2)analyzing the influence of different vehicle movement state?start-up,idle speed,flameout?and different vehicle types?sedan,SUV,truck?on TVOC and formaldehyde concentration.3)To analyze the effect of moving state on TVOC and formaldehyde concentration in limited time range.The experimental results show that the variation of TVOC concentration in underground garage can reach 2-5 times in different regions.and The formaldehyde concentration ranged from 5 to 15 times higher than that of the underground layer,which was beyond the normal acceptance range of human life.From the comparative analysis of the data of the three types of vehicles and the three kinds of motion state cross combination,it is found that the underground garage car of the complex has the greatest influence on the concentration of TVOC in the starting state,and the concentration of TVOC produced by the SUV in the flameout state is higher than the national standard,and the average value of TVOC concentration in the idle state of the truck is the largest,the change of concentration is stable and almost all does not conform to the national standard value 1.6 times.The change trend of the concentration of TVOC and formaldehyde in the underground garage of the complex in a limited time is as follows:L.The rising peak of TVOC concentration was 0.05 ppm,the rising range of termination value was 0.02 ppm,the rising peak of formaldehyde was 0.008 ppm,and the rising range of termination value was 0.002 ppm.Therefore,the concentration of TVOC and formaldehyde should not diffuse in a short time.Finally,based on the above two points,the building structure and ventilation form of the large complex are analyzed and summarized respectively,and the problems existing in the building structure of the complex are summarized,and themeasures to reduce the pollution can be put forward by improving its natural ventilation position and increasing the exit of underground parking lot.Then it probes into the advanced technology of underground garage treatment from the point of view of mechanical ventilation,and puts forward some suggestions for improving the measures of mechanical ventilation and underground garage in order to achieve the purpose of controlling and changing the concentration of pollutants in time.