Research On Emission Limits For Exhaust Pollutants From In-Use Light Duty Vehicle With Acceleration Simulation Mode Test Procedures

Since 2000,the amount of private cars in China has increased by a large scale.The automobile has brought convenience to the people,while the exhaust emissions from automobiles have become an important source of air pollution.In 2017,the China's New Car Emission Standards have already begun to implement the Fifth National Standards,but the standards for Acceleration Simulation Mode Test Procedure in many backwards,this situation is not conducive to the control of In-Use vehicle emission pollutants.Analysising the implementation of the Acceleration Simulation Mode Test Procedure Standards,and researching the Emission Limits for Exhaust Pollutants from In-Use vehicle under Acceleration Simulation Mode Test Procedure,are very important to prevent and control InUse vehicle emission pollution.Based on the principles of HJ/T240 – 2005 and 6 vehicle environmental testing agency's test deta in 2016,this paper determined the Emission Limits for Exhaust Pollutants under Acceleration Simulation Mode Test Procedures,and researched on vehicle emissions of different mileage.The main research results are as follows:1.In the promotion of the implementation of I/M system,the Acceleration Simulation Mode Test Procedures is more practical than other Test Procedure.At present,15 provinces choose the Acceleration Simulation Mode Test Procedures to test In-Use vehicle emission performance in China.Most of them are useing the minimum emission limits set in HJ/T240 – 2005.2.Using the data normalization method to draw the relative concentration and cumulative frequency chart,analysising vehicle's CO,HC and NO tested data,finding that the influence of NO emission limits on the overall pass rate is higher than that of CO and HC.3.Fitting the curve of relative concentration and cumulative frequency,combining the analysis of the passing rate and the overall qualified rate,the paper determineed the recommended ASM5025' emission limits for CO and HC,and a series of ASM5025' emission limits for NO from low to high.4.Analysising the correlation between ASM5025 testing and ASM2540 testing,the results shows that the correlation coefficient of the two testings is above 0.8.A linear regression model was established for the two testings,and the significance of the regression model was tested.Using the recommended ASM5025' emission limits and the linear regression model,the paper determineed the recommended ASM2540' emission limits for CO and HC,and a series of ASM2540' emission limits for NO from low to high.5.According to emission limits for CO and HC and a series of ASM5025' emission limits for NO from low to high,the paper determined the most stringent and loose recommended emission limits forms.Combined with the actual situation in Jilin Province,the local recommended emission limits in Jilin province were determined,when the overall qualified rate was 83.58%.6.The paper analysised the data structure of vehicle mileage.The first stage of the national standard before,the national standard ? / II stages,the national standard III stage and the national standard IV stage,the vehicles were concentrated respectively in the range of less than 300 thousand Km,260 thousand Km,150 thousand Km and 120 thousand Km,occupied respectively for 92.36%,94.18%,93.12% and 95.25%.7.Analysising the average emission concentration of exhaust pollutants in different national standards,the results shows that the average emission concentration decreased significantly with the increase of the national standard.The mileage in the range of 110 thousand Km as a reference point,vehicle's CO,HC and NO average emission concentrations of the national standard ? / II stages are 1.6 times,1.3 times and 1.8 times of the national standard III stage,and 2.2 times,2.3 times and 2.6 times of the national standard IV stage.8.Using the regression model and the GM(1,1),the paper predicted respectively the vehicle emissions exceeding standard mileage of the national standard ? / II stage,the national standard III stage and the national standard IV stage.It is show that the vehicle's NO average emission concentrations will exceed respectively the emissions standard at a place of 187 thousand Km,190 thousand Km and 180 thousand Km of three national standard stages.