多喷嘴对置式气化炉内颗粒挥发分火焰可视化研究

Visualization study on particle volatile flame opposed multi-burner impinging entrained-flow gasifier

基于实验室规模多喷嘴对置式水煤浆气化炉及其可视化装置,研究了气化炉喷嘴平面非射流区颗粒挥发分燃烧过程。结合图像处理技术,在气化条件下对粒径小于300μm颗粒挥发分火焰尾迹形态及变化过程进行分析。研究结果表明,颗粒挥发分火焰非典型包络型火焰,而是形成挥发分火焰尾迹。颗粒挥发分尾迹形态受颗粒脱挥发分所处阶段和颗粒相对于气流的运动状态的影响,随时间不断变化。颗粒挥发分最大火焰尺寸随颗粒粒径增加而增加。气流床气化还原性气氛条件下颗粒挥发分燃烧时间较颗粒在富氧气氛中燃烧时间显著增加。

Based on the bench-scale opposed multi-burner(OMB) coal-water slurry entrained-flow gasifier and its visualization device, the combustion process of particle volatiles in the plane non-jet zone of the gasifier nozzle is studied. Image processing technology was applied to analyze the change of particles’ volatile flame trail shape under the gasification condition with the particles smaller than 300 μm. The results show that the particle volatile flames are not typical envelope flames, but a volatile flame trail is formed. The trail shape of particle volatile matter is affected by the phase of the particle devolatilization and the movement condition of the particle relative to the air flow, which changes continuously with time. The maximum flame size of particle volatiles increases as the particle size increases. The combustion time of the volatile matter of the particles under the condition of reducing atmosphere of entrained-flow gasification is significantly longer than that of the particles in the oxygen-rich atmosphere.