Investigation on the combustion performance enhancement of the premixed methane/air in a two-step micro combustor

After a two-step global reaction mechanism is used to compute the chemical reactions of the reacting flows, a premixed methane/air combustion model of a two-step micro combustor is established based on some effect factors such as step angle, wall materials and inlet velocity. Moreover, the three or four kinds of the micro two-step combustors are used to investigate the effect of flame shape in the micro-channel, temperature characteristic, velocity field on the premixed methane combustion and field synergetic degree of the premixed methane/air combustion. It's shown that a suitable step angle and inlet velocity are very useful for enhancing the stability of methane premixed combustion of the two-step micro combustor, and the methane premixed combustion of the two-step micro combustor is also influenced by the wall matericals. Average temperatures of the outlet and combustion efficiencies of the two-step micro combustor at different inlet velocities are verified by the measurement results. It's shown that there are good comprehensive performance and higher synergy degree of the two-step micro combustor at the inlet velocities of 2 m/s and 4 m/s, and there are more and more obvious differences between combustion efficiency after field synergy and original combustion efficiency when the inlet velocities are increased.