Study On Characteristics Of Pollutant Emission Factors Of Passenger Cars In Northeast China

As the number of motor vehicles in Northeast China continues to increase,road traffic tends to deteriorate.In addition,the area is long in winter,the temperature is low,and the road is covered with snow and slippery,resulting in very unique vehicle emission characteristics.The emission factor is the main parameter describing the characteristics of vehicle emissions.The analysis of the relationship between emission factors and influencing factors is of great significance for optimizing vehicle emissions.Therefore,the study takes Changchun City,a typical city in the northeastern region,as an example,through the IVE model,the"calculation guide of air pollutant emission for road vehicles" and on-board measurements,obtaining the pollutant emission factors of passenger vehicles,establishing the mathematical relationships between emission factors and influencing factors,and then the system dynamics method is used to predict the pollutant emission factors of the national VI light gasoline vehicles on typical road,meanwhile thes study analyzes the characteristics of the start-up emissions At the same time,based on the measured data,the accuracy of the model and the guide emission factor is evaluated,the IVE model is revised,and the revised model is used to establish a reliable gasoline vehicle pollutant emission factor library in Changchun.Finally,the article analyzes the characteristics of emission factors of passenger cars in Changchun City,and proposes measures and recommendations to reduce the pollutant emission factors of passenger cars.The results show that emission standards,cumulative driving mileage and vehicle speed are important factors affecting the emission factors of passenger vehicles.With the increase of emission standards,the emission factors and emission reduction potential of motor vehicles are gradually reduced,and with the increase of accumulated mileage,the deteriorating speed of motor vehicles is gradually increasing.The emission factor of motor vehicles changes regularly with speed.Among them,the VOC emission factor decreases with the increase of speed,while other pollutants generally show a trend of increasing first and then decreasing with speed,which is related to factors such as emission standards and fuel types.Affected by the quality of vehicles converted from gasoline to gas,light CNG fuel vehicles did not have good emission reduction effects,and the CO,NOx,and VOC emission factors were 2.3,15.5,and 5.7 times that of National V gasoline vehicles,respectively.The starting emission contribution rate θ of passenger cars in Changchun City is large,and the emission contribution rate "θ" of up to 100 km at normal temperature is as high as 20%,which can be reduced effectively by increasing the initial temperature of the engine.The guide and IVE model have a certain degree of miscalculation of the pollutant emission factors of passenger cars in Changchun City,especially for CNG fuel vehicles,and the error is more than 10 times,which can be improved by correction.The vehicle emission factor has typical time and space characteristics,which shows a typical bimodal distribution during the day,that is,the traffic peak period is large in the morning and evening,and the other periods are smaller.In addition,pollutant emission factors show:the express road<main road<sub-main road and residential road.At the same time,due to the intersection of vehicles,the emission factors of road intersections,square loops and expressway entrances and exits are relatively large,about 15 times that of the middle section of the road.In summary,the study believes that in order to reduce the emission factors of passenger vehicles in Changchun City,we should further improve vehicle emission control technology;improve fuel quality,increase the promotion and popularization of clean energy;and strengthen the supervision of oil-to-gas vehicles.Try to use the original car to avoid the problem of pollutants increase caused by the mismatch between the air intake system and the engine of the modified car.At the same time,in order to improve the operating conditions of the motor vehicles in Changchun,the traffic organization structure should be optimized,and the rail transit should be further developed.It is necessary to solve the problem of traffic congestion in the main roads,expressway entrances and exits of the central business district;and at the same time,it is necessary to strengthen the inspection and maintenance system of vehicles and speed up the elimination of old vehicles.