The Emission Characteristics Study Of Typical Kind Of Vehicles Based On Vehicle-Mounted Test System(PEMS) In Wuhan

In recent years,frequent smogs and summer ozone pollution have attracted wide attention,which is closely related to exhuast emissions of motor vehicle.In this study,PEMS(Portable Emission Measurement System)equipment for vehicle-mounted motor vehicle emissions was used to investigate the gaseous pollutants of six typical kinds of vehicle in Wuhan.The emission characteristics of motor vehicle pollutants with different fuel types,different emission standards and different models were revealed from angel of operating conditions and output power by using two parameters:K value and VSP.At the same time,the emission factors in the process of PEMS test were used to evaluate the emission conditions of the testd vehicles,and were compared to the emission factos based on MOVES.The main conclusions are as follows:1.K value mainly distributed in-20m~2/s~3~20 m~2/s~3 and VSP mainly distributed in-20 kW/t~20 kW/t,and the frequency of the two corresponding intervals were both more than 98%.K value and VSP both presented a trend of small two heads and one big middle part,which meant the frequency of experimental data between 0m~2/s~3~1m~2/s~3(or 0kW/t~1 kW/t)was the largest,over 10%.The larger absolute value of the K value or VSP,the lower the frequency.What's more,it was found that VSP did not fit normal distribution by K-S(Kolmogorov-Smirnov)test.2.From the angle of the K Value,this study found that when K?0m~2/s~3,namely in the operation condition of acceleration or idle,there was higher emission rate.From the VSP perspective,the bigger the VSP was,the higher the emission rate was.When motor vehicle running in Wuhan urban road network,the larger acceleration will lead to the emergence of high VSP,which will result in an increase in pollutant emissions.Totally speaking,to control the high emission of motor vehicle,the frequency of driving behavior such as accelerating and idling should be reduced,and smooth driving should be kept as far as possible.3.Using“the technical compilation guidelines of road motor vehicle air pollutants emission inventory(trial implementation)”as the evaluation criterion,evaluated and found the emission of typical kind of vehicles in Wuhan exceeded the criterion.It was advised that the relevant departments should formulate stricter local emission standards,strengthen the supervision of in-use vehicle emissions and implement I/M Program(Inspection Maintenance Program).4.From meso scale,MOVES Model was adopted to simulate vehicle emission factors,and found that MOVES simulation value was lower than PEMS measured value on the whole.The difference between the emission factors based on PEMS and MOVES was relatively smaller for China?light-duty gasoline passenger car,and the ratio of the two was between 0.5~1.8.For other kind of tested vehicles,the difference were more obvious.Therefore,we should strengthen the localization research and revision of the model in the future to adapt to the actual situation of Wuhan.