The Effect of Soot nano-Particles Injection on Two-Phase Smoke Aerosol Formation in a Kerosene-Fired Burner

Abstract

Feeding a laboratory furnace with the gaseous kerosene, the resulting two-phase turbulent flame is simulated to study the effects of injecting soot nano-particles into the inflow air on the emissions of smoke aerosol, CO, and CO2 species pollutants, and the resulting radiation heat transfer. We use our past experiences in aerosol modeling of soot nano/micro particles in turbulent nonpremixed flames burning simple hydrocarbon fuels and extend them to study the effects of injecting gaseous kerosene on the aforementioned parameters. To model the evolutionary process of soot nanoparticle formation, i.e., the nucleation, coagulation, surface growth, and oxidation, we employ a two-equation soot model to solve the soot mass fraction and soot number density transport equations. Benefiting from a detailed chemical kinetic mechanism consisting of 121 species and 2613 elementary reactions, we construct the required flamelets library, i.e., the lookup table, and apply the flamelet combustion model to solve the transport equations for mixture fraction and its variance. We take into account the turbulence-chemistry interaction using the presumedshape probability density functions PDFs. To take into account the radiation heat transfer effects of the most important radiating species in the current modeling, we consider the optically-thin flame assumption. To evaluate the developed numerical method, we first examine a gaseous-kerosene/air turbulent nonpremixed flame. We compare the flame structure, i.e., the distributions of mixture fraction, temperature, and soot volume fraction, with those of the measured data. To investigate the effects of injecting soot nano-particles into the inlet air on the structure of flame and the resulting species, we need to implement suitable boundary conditions for the injected soot nano-particles. It is shown that the injection would enhance the radiation heat transfer inside the laboratory furnace and that it would increase the soot volume fraction and soot particles diameter in the exhaust gases. Our results also indicate that the soot nano-particles injection would decrease the inside temperature peak. They show that the injection has low influence on the CO and CO2 emissions. The present study can provide good primitive material for the researchers, who wish to enhance the radiation heat transfer in industry furnace applications.