Influence of fuel injection pressure and injection timing on nanoparticle emission in light-duty gasoline/diesel RCCI engine

This work investigates the influence of fuel injection events on the nanoparticle emission characteristics of light-duty gasoline-diesel RCCI engine. The formation of nanoparticle emissions strongly depends on fuel injection events. The present study experimentally investigates the influence of diesel injection pressure, injection timing, and port-injected gasoline mass on the nanoparticles emitted from the gasoline-diesel RCCI engine. For this purpose, the engine is tested at different engine speeds and a fixed load of 1.5 bar BMEP without exhaust gas recirculation. The particle-size and number distribution (PSD) and total particle number (total PN) concentration are measured using a differential mobility spectrometer. The results depict that at higher diesel injection pressure (IP) operation, the peak of the NMP increases while the AMP peak decreases for neat diesel operation as well as RCCI engine. Nucleation, as well as accumulation mode particles, increases with advanced diesel injection timing in RCCI combustion. An increase in port fuel injected mass also leads to an increase in the total particle concentration and total unburned hydrocarbon (THC) emissions.

Automated summary

This study investigates the influence of diesel injection pressure, injection timing, and port-injected gasoline mass on nanoparticle emissions from a light-duty gasoline-diesel RCCI engine. The results show that changes in diesel injection pressure and timing have a significant impact on nanoparticle emissions, while increasing port fuel injected mass leads to higher particle concentration and unburned hydrocarbon emissions.