Experimental study on the effects of High-Temperature Gas-Solid mixed fuel properties on jet flame behavior

• Effects of High-Temperature Gas-Solid Mixed Fuel Properties on Jet Flame Behavior were studied. • Increased fuel velocity broadens flame width and divergence angle, but the temperature decreased. • As the fuel temperature increases, the flame length slightly increases, while the high-temperature region decreases. The gasification-combustion technology offers a new pathway for the efficient, clean, and flexible utilization of coal. The gasification reaction of coal was carried out first, producing a gas–solid mixed fuel primarily consisting of high-temperature coal gas and highly reactive semi-coke (referred to as high-temperature gas–solid mixed fuel). The control of high temperature reaction process of high-temperature gas–solid mixed fuel is one of the keys to gasification-combustion technology. However, research on high-temperature gas–solid mixed fuel is currently limited. The paper focuses on the effects of high-temperature gas–solid mixed fuel properties on the characteristics of jet flames, using a self-designed and constructed high-temperature fuel test platform, along with image-processing-based visualization techniques. The fuel temperature and velocity interact with other parameters in the combustion process to affect the geometric shape, temperature distribution, and oscillation characteristics of jet flames. The results indicate that as the fuel velocity increases, maximum flame width and divergence angle of flame increases, but the temperature decreased while temperature fluctuations magnify. Increased fuel velocity not only broadens the frequency distribution of flame oscillation but also intensifies its amplitude . As the fuel temperature increases, the flame length slightly increases, while the area of the local high-temperature region decreases. Furthermore, the intensify oscillation amplitude without substantially altering the fundamental oscillation frequency.