中热值合成气微混组合火焰燃烧特性实验及数值研究

Micro-mixing combustion technology is an advanced lean-premixed combustion method with low pollutant emission characteristics. The combustion characteristics of a novel micro-mixing combustion burner fueled by syngas were investigated under different operation conditions. Numerical simulations were conducted using CFD software to investigate the combustion characteristics of the combined micro-mixing flames under varying equivalence ratios （0.388~0.518） and inlet air velocities （36.18~108.56 m/s）. The flow field and temperature distribution were analyzed in relation to changes in the equivalence ratio and inlet air velocity. Additionally， the trends of the characteristic variations obtained from the numerical simulations were verified against experimental data， and the emission characteristics of pollutants were analysed. The results show that as the equivalence ratio increases， the core reaction high-temperature zone area （T>1 700 K） keeps getting larger in the combustion chamber， but the area of the overall high-temperature zone （T>1 420 K） is almost unchanged， while the NO emission at the outlet increases significantly. With the increase of inlet air velocity， the low velocity zone between the nozzle tubes changes to a recirculation zone， and the axial length of the recirculation zone is constantly lengthened， the area of the core reaction high-temperature zone is decreasing， but the area of the overall high-temperature zone is increasing， and the high temperature zone of the flame is being “elongated” with the increase of the inlet air velocity， consequently the NO emission prominently reduces.