Research And Application Of Real-World Vehicle Emission Characteristic

More and more people have concern about vehicle emissions. The traditional laboratory vehicle emission evaluation method is unable to reflect the real-world emission perfectly, for the reason of its drive cycle can not reflect actual driving behavior and so on. In order to understand real-world vehicles emission thoroughly, and provide the scientific data for our country to establish policy on emission control, this study uses on-board emission test method to research real-world vehicle emissions.Through the research of Portable Emission Measurement Systems (PEMS) and on-road vehicles emission characteristic, with the EPACFR1065 regulations foundation, we proposed suitable on-road vehicles emission test method for our country. And basis on the different emission pollutants between the light-duty vehicles and heavy-duty vehicles, we has designed the different test plan separately. The light- duty vehicles mainly uses OBS-2200 to measure CO, THC, NOx emissions, and heavy-duty vehicles uses OBS+ELPI to measure CO, THC, NOx, PM emissions.The emissions test of 70 light-duty gasoline car indicated that real-world vehicles emission factors is higher than the laboratory test results.The vehicle emission durability deteriorate coefficient CO is 6.2, NOx is 5.4, THC is 7.1, much higer than the regulation recommendatory value 1.2, and we proposed the emission control policy base on the emission factor, the standard of which vehicle can be drive continue, or should be maintenance, or should be wash out.The light-duty diesel vehicle emissions test indicated that CO emission value conforms to regulations requirement, but NOx which is the important emission pollutant in diesel had achieve 6.34g/km, greatly surpassed regulations limiting value(HC+NOx is the 2.38g/km). This research also studied the diesel vehicle NO and NO2 emission rule for the first time. NO mass emission rate growth sharply when vehicles drive on freeway, but the NO2 mass emission rate is not change too much when drive different roads.The heavy-duty vehicle emission test indicates that the design of on-road heavy-duty vehicle emission test system is works well. The heavy-duty bus...