Unstable combustion behavior of syngas/air mixture with different components in a narrow gap disk reactor.

In this paper, the combustion behavior of the syngas/air mixture in a narrow gap disk reactor were explored. Besides, the influence of the hydrogen volume fraction and the mixture equivalence ratio in syngas on the property of propagating flames were investigated in the narrow gap disk reactor under the gap thicknesses of 8 mm, 6 mm, 4 mm, 3 mm, and 2 mm, respectively. The focus was placed on the behavior of the flame propagation under the gap thickness of 2 mm. The research results demonstrated that the increase of the hydrogen volume fraction from 5 % to 30 % exerted a significant impact on the flame propagation velocity (FPV) and the pressure in the tube. Moreover, the equivalence ratio of this mixture could markedly affect both the propagation characteristics and morphology of flames. Strong flame instabilities accompanied by pressure oscillations were observed in the reactor at a 2 mm gap thickness during the later stages of flame propagation. Notably, there were significant differences in unstable combustion behavior between different syngas components. Moreover, the combined action of heat losses and compression waves leads to significant flame instability. The insights gained from this study have practical implications in various production applications. For example, optimizing hydrogen volume fraction and mixture equivalence ratios can enhance combustion efficiency and reduce pressure fluctuations in industrial reactors, leading to improved energy utilization and reduced environmental emissions. • The combustion characteristics of syngas in a narrow gap disk reactor were studied. • Hydrogen content affects flame propagation but has little effect on cell structures. • The syngas/air mixture equivalence ratio affects the flame cell structure. • Strong instability manifests when the flame propagates within a 2 mm gap thickness. [ABSTRACT FROM AUTHOR]