甲烷/氨的添加对正十二烷对冲冷焰熄灭特性影响OA

The extinction limits of methane/n-dodecane mixture and ammonia/n-dodecane mixture flames were measured using a counterflow burner,and their chemical kinetics were analyzed.Based on the optimization and verification of previous mechanisms,a chemical reaction kinetics mechanism was established that can simultaneously predict the extinction limit of methane/n-dodecane and ammonia/n-dodecane mixtures,as well as the molar fraction of oxidation process substances.Through the extinction characteristics,it was found that with the addition of ammonia and methane,the extinction limits and flame temperature of n-dodecane for cool flames decrease.In addition,The concept of Density-Weighted Enthalpy and the extraction of cold flames radical index were used to quantify that the low-temperature inhibitory effect of ammonia is greater than that of methane.Chemical kinetic analysis shows that with the addition of methane or ammonia,the reaction n-C12H26+OH⇒H2O+C12H25 competes for OH.NH2 produced by ammonia is converted to NO through NH2+NO2⇔H2NO+NO,and NO is consumed through NO+C12H25O2⇔C12H25O+NO2,consuming C12H25O,thereby inhibiting the low-temperature reactivity of n-dodecane.