300MW机组四角切圆锅炉SOFA反切消旋数值模拟

摘要

对某300 MW机组四角切圆煤粉锅炉进行了数值模拟,主要研究其分离式燃尽风(SOFA)水平反切角度对炉膛出口速度偏差和温度偏差的影响.通过分析SOFA不同反切角度工况下炉膛的流场和温度场的变化发现:SOFA反切与不反切工况下的主燃区流场相似,温度相差不大,说明SOFA反切对主燃区的燃烧影响很小;当SOFA反切角度为12°和18°时,水平烟道分别受逆时针和顺时针方向残余旋转的影响,炉膛出口处左右侧存在较大的速度和温度偏差,且温度偏差程度小于速度偏差;当SOFA反切角度为15°时,炉膛出口的速度温度场均匀.因此,最佳SOFA反切角度为15°.%Numerical simulations were performed for a 300 MW tangentially fired pulverized-coal boiler to investigate the influence of SOFA yaw angle on residual swirling of flue gas at the furnace outlet.The distributions of flue velocity and temperature under conditions with different SOFA yaw angles were analyzed,and the results show that,the temperature field and velocity field in the main combustion zone under condition with reversed SOFA are similar to that with unreversed SOFA,indicating the reverse-tangent at the SOFA has little effect on the main combustion zone.When the SOFA yaw angle is 12°and 18°,there are anticlockwise and clockwise residual swirling of flue gas in horizontal gas pass separately.Moreover,the bias of temperature is slight than that of the velocity.When the SOFA yaw angle is 15°,the distribution of velocity and temperature at the entrance of horizontal flue is more homogeneous.Therefore,the optimal SOFA yaw angle is 15°.