燃烧器内部气体流动特性的计算及对燃烧器性能的影响

该文运用数学方法计算分析了二次配风燃烧器主要的结构特征尺寸(包括火盆、火道直径、风门面积以及喷嘴扩散角等)对其内部气体流动特性的影响。计算结果显示1)一次风率随火盆直径增大而单调增加，但受火道直径的影响非常小；2)二次风率随火盆直径的变化呈单峰曲线关系，且随火道直径直大而增加；3)风门的调节方式对燃烧器的运行性能有很大影响，采用分调形式更有利。风门面积与火盆、火道进风口面积有一定的匹配关系，目前燃烧器设计原则中风门面积取进风口面积1.2～1.5倍的关系是合理的；4)喷嘴的引射作用对一次风较强，致使一、二次风量的比例远大于其进口面积比。具体表现为火盆越小，引射作用越强；燃气压力越高，引射作用越强；喷嘴扩散角越小，引射作用越强；5)喷嘴的引射作用不仅极大地改变了一、二次风的比例关系，而且因此改变了燃烧器的总供风量——总供风量与二次风量有完全一致的变化关系，表明了火道对燃烧器供风的重要性等等。

THE CALCULATION OF INTERNAL GAS FLOW CHARACTERISTIC OF BURNER AND ITS INFLUENCE ON BURNER PROPERTY

In this article by means of mathematics method,the constructioncharacteristic size of secondary air distribution burner is analized and calculated(including fire pot,fire path diamenter,air gate area,and burner diffusion angle etc).The calculating results denote that:1)The primary air rate is directly increasing with the increasing of fire pot diameter,but the influence of fire path diameter on it is very small;2)The relationship between secondary air rate and the variance of fire pot diameter is single peak curve,and secondary air rate is increase with the increase of fire pot diameter;3)The influence of air gate adjusting method on the operating property of burner is very large,and it is more advantageous by the use of separated adjusting method.There are a certain matching relationship between air gate area and the areas of fire pot,fire path air inlet.It is reasonable to make air gate area equal to 1.2～1.5 times of air inlet area;4)The burner injecting action on primary air is relatively strong,so the ratio between the quantilies of primary air and secondary air is greatly larger than the ratio between the area of its inlets.It shows that:the smaller fire pot,the stronger injecting action;the higher fuel gas pressure,the stronger injecting action;the smaller burner diffusion angle,the stronger injection action;5)The injecting action of burner not only changes greatly the ratio between primary air and secondary air,but also changes consequently the total air supply volume of burner,the total air supply volume and secondary air volume have the absolutely identical change relationship.It shows the importance of fire path to the burner air supply and so on．