Chemical effect of CO2 on the laminar flame speeds of oxy-methane mixtures in the condition of various equivalence ratios and oxygen concentrations

The Effects of CO2 Additional on Flame Characteristics in the CH4/N2/O2 Counterflow Diffusion Flame

“…Therefore, dilution combustion has drawn unprecedented attention in recent years since it can be easily and economically implemented. As the main product of hydrocarbon fuel, CO 2 is usually selected as the diluent for diluted combustion [ 1 , 4 , 5 , 6 , 7 ].…”

“…They categorized the effects of diluents into a dilution effect, thermal diffusion effect, and chemical effect, concluding that, for CO 2 dilution, the dilution effect had a dominant effect on the laminar burning velocity. The chemical effect of CO 2 on the laminar flame speeds of O 2 /CH 4 mixtures was numerically studied in a range of oxygen concentrations and equivalence ratios by Hu et al [ 4 ], with the results showing that the chemical effect on the laminar flame speeds was smaller than the thermal effect, but much bigger than the radiative effect in the calculation domain. They also identified the important reactions involving the third-body efficiency of CO 2 .…”

“…Knowledge of the effects of CO 2 dilution on the flame can be categorized into four aspects, chemical effect, thermal effect, transport effect, and radiative effect, due to the special properties of CO 2 . However, few studies [ 4 , 14 ] placed emphasis on a comparison of these four effects of CO 2 , especially with respect to the diffusion flame. In this regard, CO 2 can not only dilute the oxidizer side [ 9 ] but also the fuel side [ 8 ].…”

Laminar flame characteristics of natural gas and dissociated methanol mixtures diluted by nitrogen

“…However, in-cylinder temperature also increases when adding dissociated methanol into natural gas [10], which will increase the emission of NOx. Adding diluent gases, which can function as exhaust gas recirculation (EGR), is a feasible way to solve this problem since combustion temperature can be decreased by increasing the specific heat capacity of the mixtures and hindering the chemical reaction [11]. Nitrogen (N 2 ), an important component of EGR gas, is of great research value and has been investigated in many studies [5, 12 and 13].…”

The Effect of Initial Conditions on the Laminar Burning Characteristics of Natural Gas Diluted by CO2

“…However the burning velocity was not taken into account. Xu [14] investigated the chemical effect of CO 2 on laminar flame speed of CH 4 . The conclusion that the chemical effect was stronger than radiative effect but weaker than thermal effect was confirmed, but the flame instability was not investigated.…”