生物质气与煤混燃锅炉分离式燃尽风反切消旋数值模拟  

Numerical simulation of reverse-tangent and swirling-elimination for SOFA of boiler co-firing biomass gas with coal

作　　者：张小桃 黄勇 赵伟 李柯颖 段佛元 

机构地区：[1]华北水利水电大学电力学院,河南郑州450011

出　　处：《热力发电》2019年第2期23-30,共8页Thermal Power Generation

基　　金：河南省教育厅自然科学研究计划项目(2011A140014);河南省科技发展计划项目(112102210281)~~

摘　　要：为了研究分离式燃尽风(SOFA)水平摆动形成反切角度对生物质气与煤粉混燃切圆锅炉出口速度偏差和温度偏差的影响,基于Fluent模拟软件搭建了纯煤掺烧松木气模型,对某电厂330MW机组掺烧10%松木气的燃煤锅炉SOFA不反切、反切10°、反切15°、反切20°等4种工况的燃烧过程进行数值模拟,分析不同工况下主燃烧区、折焰角、炉膛出口的速度场、温度场的分布特征。结果表明:在主燃烧区,SOFA反切对其流场影响较小;当SOFA开始反切时,折焰角残余切圆消失,流场趋于均匀,有效削弱了烟道的残余旋转,出口烟气速度偏差和温度偏差明显降低;当SOFA反切角度达到15°,出口左右侧速度偏差比和温度偏差比达到最低,其中心温度集中在其中心区域,速度场和烟气温度场的均匀性最好;当SOFA反切角度增大到20°时,出口烟速偏差比和烟气温度偏差比有所增大,其中心温度开始向其右侧偏移,速度分布和温度分布的均匀性下降。因此,最佳的SOFA水平摆动形成的反切角度为15°。In order to study the effect of reverse tangent angle formed by horizontal swing of separated over fire air(SOFA) on velocity deviation and temperature deviation at outlet of tangential boiler co-firing pulverized coal with biomass gas, a model of pure coal blending with pine wood gas was built up using the Fluent software. By taking a boiler co-firing coal with 10% biomass gas as the object, the combustion process under different conditions(with the SOFA reverse angle of 0°, 10°, 15°, 20°) was simulated, and the velocity and temperature fields in the main combustion zone, arch nose zone and furnace outlet zone were analyzed. The results show that,the SOFA reverse tangent has a little effect on velocity and temperature fields in the main combustion zone. When the SOFA begins to reverse, the residual tangential circle of the arch nose disappears, the flow field tends to be uniform and the residual swirling of the flue gas is obviously weakened, and the velocity deviation and temperature deviation of the outlet flue gas dramatically reduces. When the SOFA reverse angle is 15°, the velocity and temperature deviation ratios at the left and right sides of the furnace outlet reach the lowest, the center temperature is concentrated in the central region, and the uniformity of velocity field and temperature field reaches the best. When the SOFA reverse angle rises to 20°, the velocity and temperature deviation ratios at the outlet increases, the center temperature begins to shift to the right side, and the uniformity of velocity field and temperature field decreases. Therefore, 15° is the optimum SOFA reverse angle.

关 键 词：燃煤锅炉 生物质气 混合燃烧 速度场 温度场 SOFA 反切角度 数值模拟 

分 类 号：TK16[动力工程及工程热物理—热能工程]