双锥燃烧室冷态流场的实验研究

根据五孔球形探针的测试原理,对应用于高效煤粉工业锅炉的双锥燃烧室内部冷态流场进行了测量,得出燃烧室内部流场是顺时针旋转并呈对称分布,前锥的流场分布分为3层,即边缘区、夹层区和中央区,存在回流;后锥流场随着出口锥形半径的逐渐缩小,总速度不断增大,不存在回流。同时也分析了流场分布对燃烧室燃烧性能的影响,前锥流场的布局有利于实现煤粉的着火,后锥流场影响煤粉和空气的混合流在炉膛的分布,使其既能保持足够的射程,又能防止气流冲刷壁面,避免结焦。

Experimental study on cold-condition flow field in double cones fine coal combustion chamber

Based on the testing principle of five-hole spherical probe,measure the cold-condition flow field in double cones fine coal combustion chamber.The results show that flow field in combustion chamber rotates clockwise and distributes symmetrically.The flow field of front cone involves three regions,marginal zone,central zone and zone between the two,and there is recirculation zone in front cone.The total velocity increases gradually with the narrowing of the outlet cone radius.The effect of the flow field distribution on combustion chamber performance of the combustor was also analyzed.The flow field of front cone is conducive to fireing fine coal,and that of behind cone controls the distribution of mixed flow in the furnace,which not only guarantee the effective range,also prevent the flow impinging combustion chamber wall.All those help to prevent fine coal coking.