Influence Of Main-post Injection Interval On The Regulated Exhaust Emissions From A Diesel Engine Fueled With Fischer-Tropsch And Biodiesel Fuels

The effects of main-post interval(MPI)on the pollutant emissions and the characteristics of soot were investigated using a direct-injection diesl engine equipped with a high-pressure,common-rail fuel injeciton system.Test fuels were F-T diesel and biodiesl.For different values of MPI,exhaust pollutants,including CO,THC,NOx and smoke,and surface functional groups(SFGs)and oxidation reactivity of soot were characterized in detail.Experimental results indicated that for both test fuels,increasing the MPI resulted in the increases in the CO and THC emissions and a decrease in NOx emissions.With an increase in MPI,the ratios of aliphatic C-H SFGs firstly decreased and then gradually increased,while the O/C ratio and the amount of hydroxyl and carbonyl SFGs showed marginal change after a decrease.At the same time,the oxidation reactivity of soot showed an increase after a decrease.For both fuels,the soot oxidation reactivity had a positive correlation with sp3/sp2 hybridization ratio.Under the applied operating conditions,the soot oxidation reactivity for biodiesel was higher than that for F-T diesel.The research work in this dissertation will benefit the wide acceptane of F-T diesel and biodiesl on diesel engines and the further reduction in the pollutant emissions from diesel engines.