Effects of fuel preheat temperature on soot formation in methyl linolenate co-flow diffusion flames

Abstract

The objective of this study was to investigate the mechanism of soot formation in biodiesel by analyzing the combustion of individual components. The paper presents a numerical analysis of the effect of preheat temperatures on nucleation rates, coagulation rates, and soot volume fraction in methyl linolenate (MLe) co-flow flame. In this work, Moss-Brooke’s soot model and a reduced kinetic mechanism containing 177 chemical species and 2904 chemical reactions were used to simulate the pyrolysis and combustion of MLe. A laminar jet flame with inlet velocities of 0.4 m/s was studied. The preheat temperature of the fuel was varied between 300 and 450 K. The burner walls were stationary and no-slip conditions were applied. The pressure outlet had Neumann boundary conditions and the tangential velocity was set to zero at the wall. It was established that an increase in fuel preheat temperatures causes an increase in nucleation rates and the amount of soot due to accelerated fuel pyrolysis, improved diffusion, acceleration from buoyancy, and earlier formation of PAHs. It was discovered that increasing the fuel preheat temperature had a greater impact on soot formation along the centerline than on the wing.