Diesel fuel property and characteristics of particulate matter emission

摘要

The relation between diesel fuel property andcharacteristics of particulate matter (PM) emission was explainedbased on results acquired in our laboratory.The effects of cetane number on PM emission were noticed, but afixed relation between the parameters was not found. Concerningdistillation property of fuels, such effects on PM emission werenot found for the single-cylinder engine test under a stationaryoperating condition, but it was found that the increase of heavyfractions in the fuels increased PM emission for a diesel passengercar tested under a transient operating condition such as a 10 modetest procedure. It was to be noted that this tendency was higher forthe car conforming to the latest emission standard.The aromatic carbon atom content (Ca) in the fuels, comprisingaromatic samples separated from fractions distilled in every 40begC range, was correlated with PM emission. By using purehydrocarbon mixed fuels for investigating a relation betweenchemical structure of the fuels and PM emission, quaternary atomcontent (C-aro) in aromatic rings and carbon/hydrogen atomicratio (C/H) showed the highest correlation with PM emission, butother parameters such as Ca, tertiary carbon atom content inaromatic rings and I.S. index showed also high correlation coefficients.Concerning the test fuel with all the gas oil fractions, it wasconfirmed that the fuel's aromatic parameters strongly affect PMemission for both the single-cylinder engine tested under stationaryoperating and the diesel passenger car tested under transientoperating condition. Four parameters such as Ca, C-aro, C/H andI.S. index showed high correlation coefficients with PM emissionwhich was higher than a fuel factor representing aromatic contentsas volume percentages which had been extensively used.