Experimental Study On Effect Of Gasoline Quality On Vehicle Emission And OBD System

With the continuous tightening vehicle emission standards and the application of advanced emission control technologies, the effect of the fuel quality on vehicle emission is increasingly important. Therefore, in the USA, Japan, Europe and other countries and regions, the automotive and petrochemical industries have cooperated to initiate the"Vehicle-Engine-Oil"program. Through their research results, they have established the key index limits of the fuel quality which meet the gradual tightening vehicle emission regulations. With publication of the National Stage III, IV emission standard, the relevant fuel quality index should be established. Since 2004, CATARC has undertaken the"Research on the relation between the fuel quality and vehicle emission"- program II. 2005,CATARC cooperated with Beijing EPA to undertake the"Research in the fuel quality to meet the standard of StageIV". The main task of the thesis is experimental study on the effect of the gasoline quality on vehicle emission and OBD system.Through scientific experiment designing(include durability test and OBD demo), the effect of the gasoline sulfur, olefin on the initial emission of LEV and effect of gasoline quality on vehicle durability emission and OBD system has been studied in this thesis. Main works in this thesis include:(1) Analyzing the result of"Vehicle-Engine-Oil"of other countries to learn their experience.(2) Analyzing and summarizing the development history of fuel in Europe, and analyzing the current institution of our country.(3) Through scientific experiment design, studying the effect of the quality of gasoline on the initial emission of LEV. The sulfur and olefin content had been especially studied.(4) Through scientific experiment design, studying the effect of gasoline quality on vehicle durability emission and OBD system. Discussing the effect of fuel of our country on emission of LEV.(5) Combining with the relevant test and research results, giving the revised proposal of the un-lead gasoline. Through comparing the effect of different fuel quality on same type of vehicle in initial emission and durability emission, the results show that:(1) Reducing the olefin content(and increasing equivalent aromatic content at the same time)and sulfur content can reduce the THC, CO, NOx emission of the Euro III vehicles, and the effect of the sulfur on emission is generally linear.(2) Also through scientific designed fleet road test and OBD certification test, the effect of the different grade gasoline on the vehicle emission durability and OBD system has been studied and analyzed. The fleet road test indicates that on condition of the Euro 3 test oil, most of the sample vehicles can meet the Euro III emission durability requirement, but the emission aging is significant, the DF is obviously over the recommended 1.2.(3) During the emission durability contrast test, the emission of vehicle which uses high quality gasoline is significant low. The vapor pressure will influence the emission of THC.(4) The OBD certification test indicate that the effect on the OBD system is gradual, and using some low quality gasoline occasionally for LEV may not result permanent emission problems; On condition of the Beijing Euro III standard gasoline, the vehicle emission control system and OBD system can work normally.(5) At last, combining with the relevant test and research results, the revised proposal of the un-lead gasoline which meet the national stage IV emission standard was given in this thesis. That is to reduce the olefin content and sulfur content, to raise the vapor pressure of gasoline, to add cleanser of gasoline.