Combustion and emission characteristics of diesel with different distillation ranges on the China-VI diesel engine

Abstract

In this study, hydrocarbon compositions of two types of diesel with different distillation range indexes T90 and T95 were analyzed by gas chromatography-mass spectrometry combined with gas chromatography-field ionization-time of flight mass spectrometry (GC-FI TOF MS), to evaluate the effect on the combustion characteristics and exhaust emissions of three diesel engines. The diesel featured by lower T90 and T95 can improve diesel volatilization performance, shorten the ignition delay time and increase the engine combustion efficiency. The BSFC can be reduced by 0.7%, and the CO2 emission can be reduced by 0.69% (WHTC), and 0.94% (WHSC), respectively, as the increasing low carbon numbers of alkane (C8-C20), monocyclic cycloalkane (C7-C16), bicyclic cycloalkane (C9-C15) and tricyclic cycloalkane (C10-C19) and the decreasing of heavy components such as indane, indene, naphthalene, biphenyl, phenanthrene, etc. The diesel with lower T90 and T95 can reduce the original NOx emissions and the exhaust temperature after the vortex, then decrease the combustion temperature in the cylinder. Finally, tailpipe outlet NOx emissions of the China-VI diesel engine decreased by 7.64% (WHTC) and 12.93% (WHSC), respectively. Besides, the diesel with lower T90 and T95 can reduce the content of PAHs with π bonds, and generate a more uniform fuel–air mixture in the cylinder, thus achieving emission reduction of PM by 14.58% (WHTC) and 37.31% (WHSC), and PN reduction by 25.74% (WHTC) and 14.09% (WHSC), respectively.