Dynamic and Static Flame Behavior of Premixed H2/CO/CNG/CO2-Air Mixtures under Externally Modified Acoustic Conditions
Omer Cam Harun Yilmaz Ilker Yilmaz
AbstractIn this study, static and dynamic flame behavior of premixed H2/CO/CNG/CO2 blending synthetic gas flames were analyzed. Acoustic field in the combustor was altered via side mounted loudspeakers to trigger thermo-acoustic instabilities. Photodiodes and pressure sensors were used to detect static (blowout and flashback) instabilities, dynamic flame behavior and to evaluate the degree of coupling between heat release and pressure oscillations. Moreover, flame response (change in the flame shape, length, anchoring position etc.) to thermoacoustic instabilities was assessed through instantaneous flame images. H2/CO ratios was kept constant, when all experiments were conducted at different swirl numbers, equivalence ratios and varying amount of CO2 diluted conditions. Results of this study revealed significant impact of gas composition, turbulent intensity and inert dilution on dynamic and static behavior of studied flames. When increase in swirl number did not improve flame resistance against acoustic forcing, CO2 dilution improved stability. Also, it protects combustion chamber and burner from overheating (structural damage)