Experimental investigation of laminar flame speeds of propane in $O_2/CO_2$ atmosphere and kinetic simulation
AbstractAbstract
In this paper, the laminar flame speeds of $C_3H_8$ in $O_2/CO_2$ atmosphere were investigated experimentally and numerically. The laminar flame speeds of C3H8/O2/CO2 were measured using a Bunsen flame under the condition of different equivalent ratios and $O_2$ concentrations at ordinary pressure and temperature. It was found that the laminar flame speed gradually increased with the increase of $O_2$ concentration. The equivalent ratio of the highest laminar flame speed is between 1.0 and 1.1 under each fixed oxygen concentration. The high concentration $CO_2$ reduces the laminar flame propagation velocity of $C_3H_8$, which is due to thermal, radiative and chemical properties of $CO_2$. The calculations were performed to investigate the effects of $CO_2$ on the laminar flame speed. Results show that the thermal effect of $CO_2$ is the determining factor, the chemical effect is the second factor and radiative effect is the last one. Reaction $H + O2 = O + OH$ is the most important chain reaction for the oxidation of C3H8. In addition to this, the third body effect in reaction $H + O2 + M = HO2 + M$ changed the laminar flame speed significantly in the condition of very low equivalent ratio and $O_2$ concentration.
