锅炉燃烧器高宽比对燃烧影响的数值模拟

以蒸发量为670t/h的四角切圆布置煤粉锅炉为研究对象,在不同燃烧器高宽比下,模拟了燃烧器平面温度场、射流中心两侧静压差。燃烧器高宽比大于9时,炉内气流切圆直径达到最大,高温区域均到达壁面附近,易引起结渣或高温腐蚀等;在4～9时,气流切圆大小适中,燃烧组织合理;小于4时,炉内气流充满程度相对较差,炉膛中部火焰过于集中,不能发挥切圆燃烧组织的优势。燃烧器出口射流两侧静压差随着燃烧器高宽比的增大呈非线性增大。

Numerical Simulation of Influence of Depth-width Ratio for Boiler Burner on Combustion

Taking four corner tangentially fired pulverized coal boiler with evaporation capacity of 670 t/h as research object, the plane temperature field of burner and the static pressure difference on both sides of jet flow center are simulated at different depth-width ratios of burner. When the depth-width ratio of burner is more than 9, the diameter of airflow tangential circle is maximum, and the high temperature area is close to the wall, which easily leads to slagging and high temperature corrosion. When the depth-width ratios of burner is in the range of 4 to 9, the size of airflow tangential circle is moderate, and the combustion organization is reasonable. When the depth-width ratios of burner is less than 4, the full- ness of air in the boiler is relatively bad, and the flame in the center of combustion chamber is too concentrated, which can not exert the advantages of tangential combustion organization. The static pressure difference on both sides of jet flow outlet of burner is non-linearly increased with increase in depth-width ratio of burner.