ABSTRACT
This study explored the typical features of flame from syngas/air premixed flame in a narrow gap disk burner based on diluted N2 and CO2. Four concentrations (i.e. 10%, 20%, 30%, and 40%) of CO2 and five concentrations (i.e. 10%, 20%, 30%, 40%, and 50%) of N2 were adopted in this study. The experiment was conducted in a narrow gap disk burner with a clearance of 2 mm. The results showed that the addition of N2 and CO2 significantly reduced the brightness of flame, the flame propagation velocity, and the pressure resulting from the explosion. When the CO2 concentration reached 40%, the maximum pressure was reduced to 60.78 kPa, which was 41.5% lower than that without diluent. When the N2 concentration was increased to 50%, the maximum pressure was reduced to 67.01 kPa, but at this point, the inhibition effect on the maximum pressure was not as good as 40% of CO2. Additionally, the dilution effect of CO2 was more obvious than of N2. An analysis on the dilution mechanism found that reduced moles of critical radicals H, O, and OH were an important reason for the inhibition effect. However, with the increase of N2 and CO2 concentrations, the unstable flame propagation behavior in a later stage was not inhibited, but enhanced. The unstable propagation behavior was related to the flow field disturbance caused by heat loss.
Acknowledgements
This paper is supported by the National Natural Science Foundation of China (No. 51774115); Henan Provincial Science and Technology Research Project (No. 222102320105).
Disclosure statement
No potential conflict of interest was reported by the authors.