Oxygen-enriched combustion is considered as a potential clean combustion and carbon capture technology because of its advantages in strengthening combustion and reducing pollutant emissions. Based on the finite rate chemical reaction model

the soot formation in propane co-flow diffusion flame under two oxygenenriched conditions was numerically studied by using GRI-Mech3.0 gas phase reaction mechanism combined with detailed thermodynamic and transport data

and the non-reactive substance FCO_2 was constructed. The influence of CO_2 chemical effect on propane flame soot formation was investigated. The results show that

with the increase of oxygen volume fraction

the flame temperature and soot volume fraction increases significantly

and the flame height decreases significantly

but compared with O_2/N_2 atmosphere

the flame temperature and soot volume fraction decreases significantly and the flame height increases dramatically in O_2/CO_2 atmosphere. In O_2/CO_2 atmosphere

the CO_2 thermal effect and chemical effect influences the flame morphology and reduces the mole fraction of key components such as H

OH and C_2H_2. The CO_2 affects soot mass nucleation rate and surface growth rate mainly by reducing H mole fraction but not by promoting soot oxidation process.