Abstract
Nowadays, researches have been concentrating on alternative fuels in the field of energy. Synthetic gas mixtures are gaining importance as one of these alternative fuels. By considering synthetic gas mixtures containing H2 and CO combustible gases, flame instabilities were investigated in case of burning of synthetic gas mixtures in different H2/CO (3, 1.5, 0.5) ratios with oxygen enrichment. Experiments were carried out under constant swirl number (1), constant equivalence ratio (0.7) and constant burning power (3 kW). Under normal conditions, the oxygen rate of 21% by volume in the air was increased to 23% and 25% by supplying oxygen from an additional tank. The results showed that the oxygen enrichment limit decreases as the hydrogen content in the fuel mixture increases. While the H2 / CO ratio was 0.5 and 1.5, the oxygen enrichment rate increased to 25%, but it could be increased up to 23% in the mixture with the H2 / CO ratio of 3. In addition, the flame stability was interpreted from the dynamic pressure fluctuations caused by external acoustic force at different frequencies by means of the speakers placed in the burner arms. Thus, it was determined that oxygen enrichment in mixtures with high hydrogen ratio triggers instabilities.

Keywords: Synthetic gas, Oxygen Enrichment, Acoustic Enforcement, Instabilities.