산화제 제어 화염의 구조 및 NO 생성 특성

초록

Numerical study with detailed chemistry has been conducted to investigate the flame structure and NOx formation characteristics in oxygen-enhanced-EGR(CH4/O2-CO2) counter diffusion flame with various strain rates. A small amount of N2 is inclouded in oxigen-enhanced-EGR combustion, in order to consider the inevitable N2 contamination by O2 production process or air infiltration. The results are as follows: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 differnt from that of air and oxygen-enhanced-EGR combustion in that thermal mechanism plays a role of destruction as well as production. In case CH4/O2-CO2 flame contains more than 40% 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. EINO decreases with increasing strain rate, and those effects are agumented in CH4/O2 flame. Complementary study is needed with extending the range of strain rate variation.