산소 부화 조건의 메탄 무화염 연소에 관한 실험적 연구

Abstract

This study was conducted to analyze the characteristics of flameless combustion and emissions using the lab-scale flameless combustion system fueled with methane. Especially, experiments were performed under oxygen-enriched conditions to expand the applications of flameless combustion and NO<SUB>x</SUB> reduction. The combustor able to induce the internal flue gas recirculation was applied, while the preheating of fuel and oxidant was not considered. The fraction of oxygen in oxidant was varied from 24.4% to 26.3%. The heat input was fixed at 3 kW<SUB>th</SUB> in all cases. From the experimental results, there was three combustion modes as the conventional flame, transitional period and flameless combustion. In the transitional period, the ignition and extinction of flame occurred repeatedly. Also, the flue gas compositions and pressure of the combustor were unstable. In the flameless combustion, the hot-spot of the conventional flame disappeared and the temperature distribution of the combustor became uniform. Moreover, the thermal-NO<SUB>x</SUB> was reduced in the flameless combustion mode and the trade-off relationship between CO and NO<SUB>x</SUB> was improved.