Influence of critical parameters on combustion and emission characteristics of methanol/diesel dual fuel compression combustion engine

Replacing fossil fuels with clean fuels as power sources is an effective method to reduce greenhouse gas and pollutant emissions, and methanol is a potential solution due to its excellent physical and chemical properties. The study comprehensively investigated the influences of the methanol substitution ratio (Rm), three initial cylinder parameters, and three diesel injection parameters on the combustion and emission characteristics of a methanol/diesel dual fuel compression combustion engine. A CFD model coupling with the reaction mechanism for a dual-fuel engine was established and fully verified. The results indicate that methanol substitution for diesel benefits emissions reduction at low load and improves fuel economy at high load. Delaying the diesel injection time and increasing the diesel injection duration time deteriorate fuel economy but reduce NOx emissions. Soot and NOx emissions exhibit a sudden change at a diesel injection angle of 70 degrees. Increasing the initial temperature of the combustion chamber promotes combustion while increasing the initial pressure improves fuel economy. The effect of the initial swirl ratio is mainly observed at low load, where an increase in the initial swirl ratio improves fuel economy, reduces ringing intensity (RI), and lowers soot emissions. The conclusion of this article will guide the development of clean power sources.