煤粉高温富氧无油点火的优化设计研究

设计了一种煤粉高温富氧无油点火装置,利用高温氧气与高浓度煤粉气流的混合直接点燃煤粉,进而取代油枪,实现煤粉的无油点火。通过冷态流场测定实验对点火装置进行了结构优化,并以此为基础,对煤粉高温富氧无油点火进行了数值模拟。结果表明:煤粉高温富氧无油点火装置采用三角形导流锥,中心管喷口扩口半角取15°,高温氧气通道喷口扩口半角取25°时组织的流场状况较好;点火装置形成的富氧燃烧高温火炬温度最高可在3 000 K上,烟气平均温度可在2 000 K以上,能有效保证主燃烧器的顺利点火。

Study of the Optimized Design of High Temperature Oxygen-enriched Oil-free Ignition of Pulverized Coal

Designed was a pulverized coal high temperature oxygen-enrichend oil-free ignition device.It utilizes the mixture of high temperature oxygen and high concentration pulverized coal to directly ignite the pulverized coal and to replace the oil gun,thus realizing an oil-free ignition of pulverized coal.Through a cold-state flow field measurement test,the device under discussion was structurally optimized.On this basis,a numerical simulation of the high temperature oxygen-enriched oil-free iginition of pulverized coal was performed.The research results show that when the device adopts a triangular flow guiding cone,the semi-angle of the spout flaring of the central tube is set at 15 degrees and that of the spout flaring of the high temperature oxygen passage is set at 25 degrees,the conditions in the flow field thus organized is relatively good.The temperature of the high temperature torch of the oxygen-enriched combustion formed by the device can be as high as 3000 K and above,and the average temperature of the flue fas can reach over 2000 K,thus effectively guaranteeing a successful ignition of the main burner.