Experimental and kinetic modeling studies on oxidation of n-heptane under oxygen enrichment in a jet-stirred reactor

Oxygen-enriched combustion can improve thermal efficiency and reduce CO, unburned hydrocarbons soot emissions in internal engines. There are significant differences the process pollutant between oxygen-enriched air condition. In order to develop an improved understanding of effect oxygen concentration on n-heptane oxidation, jet-stirred reactor oxidation characteristics were experimentally tested at temperatures 450–950 K pressures 1.03 atm with residence time (?) 2 s, under condition mole fractions from 0.055 0.6. Meantime, simulations performed CHEMKIN. Results show that, firstly, increase concentration, NTC (Negative Temperature Coefficient) is weakened, mainly due strengthening low-temperature reaction path, which also reason for improvement ignition stability cold-start Secondly, activity system improves concentration. Within 500–750 K, it enhancement path. When temperature higher than 750 decomposition H2O2 addition H O2. Thirdly, both generation consumption CO strengthened, leads tip diesel spray flame changing area chemiluminescence.