弯管和文丘里管组合结构燃烧器内气固两相流动的数值分析

通过数值计算方法研究了弯管和文丘里管组合结构燃烧器的浓淡分离特性，分析了煤粉颗粒直径和煤粉密度变化对燃烧器出口浓淡分离特性的影响．结果表明：弯管和文丘里管组合结构的燃烧器既可以实现浓淡分离，又可以达到煤粉浓侧气流不贴壁和中间给粉的效果；当煤粉颗粒直径为10μm时，浓淡分离效果不明显；当颗粒直径为50μm时，分离效果较好，并且浓度核心的最大煤粉浓度随着St的增大而增大；当颗粒直径为100μm时，随着St的增大，出现了多个浓度核心．

Numerical Analysis of Gas-Solid Two-phase Flow in a Composite Burner Made up of Elbow and Venturi Tube

The characteristics of rich-lean separation in a composite burner made up of elbow and Venturi tube has been numerically simulated, so as to analyze how the particle size and concentration of pulverized coal influence the rich-lean separation behavior at the burner outlet. Results show that the composite burn- er may not only help to realize rich-lean separation of coal, but also make the coal powder of high concen tration flowing away from the wall surface, i.e. realizing coal delivery in the centrally fuel-rich mode. For coal particles of size 10 μm, the effect of rich-lean separation is not obvious; for coal particles of size 50 μm, better rich lean separation effect can be achieved, in which case the maximum concentration increases with rising St number; for coal particles of size 100 μm, more cores of concentration will occur with the rise of St number.