Effect of air distribution mode on jet flame and emission characteristics of high temperature gas-solid mixed fuel

The characteristics of the flame can not only intuitively reflect the flow, mixing and reaction processes of fuel and oxidant, but also provide detailed information on combustion efficiency and stability. The present study aims to delve into the jet flame characteristics and emission properties of high-temperature gas-solid mixed fuel. A comprehensive series of experiments were conducted on a custom-designed test platform. During the experiments, variations in both the position (h3 3 = 200, 600, 1000 mm) and velocity (v3 3 = 67, 138, 223 m/s) of the tertiary air were introduced. The study focused on analyzing the flame lift-off distance, the correlation coefficient of the flame root, the normalized root mean square temperature distribution within the flame body area, and the NOx x emission characteristics across various air distribution scenarios. The experimental findings reveal that alterations in the position of tertiary air exert a greater influence on the flame lift-off distance than variations in its velocity. Furthermore, temporal fluctuations in the correlation coefficient of the flame root and the normalized root mean square temperature distribution within the flame body region serve as effective indicators of flame stability. Notably, an increase in both the tertiary air position and velocity leads to a notable reduction in NOx x emissions. Additionally, through a quantitative analysis of flame stability, temperature distribution uniformity, and NOx x emission characteristics, this study establishes a correlation between flame characteristics and pollutant emission profiles. This correlation offers a more comprehensive understanding of the combustion process involved in high-temperature gas-solid mixed fuel.