高温空气无油点火技术对贫油的我国来说是一种较好的弥补,而我国火力发电又以劣质煤为主,导致高温空气点火时会使煤粉着火不稳定。如果采用高温富氧点火会很好的弥补这一缺点。本文采用Fluent对富氧直接点火燃烧器内部的多种运行工况进行数值计算,对空气气氛及富氧气氛时的温度场、不同的一次风量、热风流量、热风温度等参数对煤粉着火过程的影响进行了分析。结果表明,其它边界条件相同情况下富氧气氛的温度场比空气气氛高出许多;富氧气氛下的燃烧器出口区域的一氧化碳含量比空气气氛下低,煤粉能在富氧气氛下更充分燃烧;煤粉的着火距离随着热风流量的增加先缩短后延长;初始热风温度对燃烧温度场的影响是随着热风温度的增加,着火距离缩短、燃烧温度提高;一次风温度的提高有效缩短着火距离。研究结果对煤粉富氧无油直接点火的优化运行提供了参考。

Simulate the ignition process of oil-free pulverized-coal in high-temperature oxygen-enriched by using Fluent software.Compare the oxygen-enriched condition with air condition in the difference flow rate of high-temperature air,as well as in different flow rate of primary air, and in different temperature of high-temperature air when igniting the pulverized coal.The results show that the temperature of oxy-enriched condition is higher than in the condition of air.Carbon monoxide content from burner exit is higher in air condition than in oxygen-enriched condition,and it could be seen that pulverized coal could completely burned in the oxygenenriched condition.Ignition distance of pulverized coal increase after decrease as the rate of high-temperature is increasing.High temperature of primary air could decrease the ignition distance of pulverized coal.