화염 가시화를 통한 암모니아 혼소 비예혼합 스월 버너의 연료-공기 조성에 따른 연소 안정성 분석 = Investigation on Combustion Stability for Ammonia Co-Firing High-Swirl Combustor with Different Fuel-Air Composition by Flame Visualization

다국어 초록 (Multilingual Abstract)

This study experimentally investigates the flame stability and structure of a non-premixed high-swirl combustor fueled with NH -H 3 2 and NH3-CH4 mixtures. Power density ranged from 1.5 to 8 MW/m³, aligning with micro gas turbine scales, was investigated for the experiments. Lean blowout (LBO) limits, residence time, and momentum ratio were examined to assess stability characteristics.
Flame visualization using OH and NH chemiluminescence revealed that even under lean conditions 2 (φ = 0.37), flame was maintained near the nozzle due to strong recirculation, contrary to typical blowout trends. OH signals indicated compact and persistent reaction zones, while NH2 emissions highlighted rich-fuel regions. The results demonstrate that swirl-induced recirculation and hydrogen blending enhance flame stabilization under ultra-lean conditions, providing insights for future ammonia-based low-NOx combustion systems.