单炉膛双切圆锅炉炉内空气动力场的数值模拟

采用计算流体力学软件PHOENICS,选择合理的数学模型,对某一台单炉膛双切圆锅炉炉内的空气动力场进行数值模拟研究,着重研究了下、中、上层燃烧器区域喷口截面上的速度矢量分布。计算结果表明:由于燃烧器布置在前后墙,使得燃烧器喷口连线成矩形,从而使得炉内气流流场均为椭圆形,且椭圆的长轴沿炉膛高度方向不断变化;在燃烧器区域的中下部,Y方向的气流旋转直径沿炉膛高度方向减小,两侧墙处的气流贴壁现象沿炉膛高度方向逐渐消失;但沿炉膛高度方向在燃烧器喷口截面前后墙处,均有气流刷壁现象存在,从而在热态运行时,在前后墙处易出现高温腐蚀和水冷壁结渣现象;炉内左右旋转气流的速度分布对称度较好。改变燃烧器投运方式,上部燃烧器区域的气相流速度分布规律有所不同,炉内热负荷分布情况也不同,相比较而言,原始投运方式较优。

Numerical Simulation of the Aerodynamic Field in A Dual Circle Tangential Firing Single Chamber Boiler

The Computational Fluid Dynamics(CFD)code PHOENICS and reasonable mathematical model were employed to evaluate the aerodynamic field in a dual circle tangentia l firing single chamber boiler,The analysis of velocity distribution on cross s ections of the deck,middle and upper combustion field was carried out.The resu lts showed that,the arrangement of burners on the front and back walls led to o val rotation flow pattern,the long axis of which directed diversely along with t he height of furnace.And in the nether and middle part of the combustion zone,t he size of rotation f low circle diameter of Y axes was decreasing with t he increasing height,which led to disappearance of the f low impingement on the side water-cooled walls.But the f low impingement on the front a nd back water-cooled walls was existing along all the whole height of the furnac e,so the high temperature corrosion and slagging at such zone were inevitable du ring the practical run.And the rotation f low in the furnace was well bil aterally symmetric.The velocity distribution on cross sections of the upper comb ustion field changed with the changing of the option style of burners.The origin al option style of burners gained an advantage over the other one.