산화제 제어 확산화염의 NOx 생성특성

초록

Numerical Study with detailed chemistry has been conducted to investigate the flame structure and NOx formation characteristics in oxygen-enhanced(CH4/O2-N2) and oxygen-enhanced-EGR(CH4/O2-CO2) counter diffusion flame. A small amount of N2 is included in oxygen-enhanced-EGR combustion, in order to consider the inevitable N2 contamination by O2 production process or air infiltration. The results are as follws : In CH4/O2-CO2 flame it is very important to adopt a radiation effect precisely because the effect of radiation changes flame structure significantly. In CH4/O2-N2 flame special strategy to minimize NO emission is needed because it is very sensitive to a small amount of N2. Special attention is needed on CO emission by flame quenching, because of increased CO concentration. Spatial NO production rate of oxygen-enhanced combustion is different from that of air combustion in that thermal mechanism plays a role of destruction as well as production. In case CH4/O2-CO2 flame contains more than 35% CO2 it is possible to maintain the same EINO as that of CH4/Air flame with accomplishing higher temperature than that of CH4/Air flame. Complementary study is needed about radiation effect, flame structure, NO formation characteristics with strain rate in oxidizer-controlled flame.