Particle size distributions and OC, EC emissions from a diesel engine with the application of in-cylinder emission control strategies

• Increasing FIP and advancing SOI can improve combustion.
• Soot and AM emissions decrease with increasing FIP and advancing SOI.
• The application of EGR increases soot and AM emissions.
• Soot-EC emission increases with the application of EGR at high load.

In the present study, the effects of fuel injection pressure (FIP), the start of injection (SOI) and the application of exhaust gas recirculation (EGR) on particle number size distributions (PNDs) and organic carbon (OC), element carbon (EC) emissions from a common rail diesel engine were examined. The results showed that increasing FIP and advancing SOI promoted the quality of fuel mixing and atomization and made advance of combustion phase, which suppressed formation and emission of soot and accumulation mode particle (AM) during combustion. However, the application of EGR led to the low air–fuel ratio and in-cylinder temperature and resulted in the increase of soot and AM emissions along with a rise in the peak diameter of the size distribution. The experiment on the PM carbonaceous compositions indicated that the application of EGR significantly increased EC emission, especially increased soot-EC emission at high load. Therefore, a higher regenerating temperature of diesel particle filter (DPF) equipped in the diesel engine with the application of EGR will be required in order to promote oxidation of soot-EC.