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在发展一个三维计算程序的基础上研究了二次风反切对大容量切向燃烧锅炉烟气偏差的影响。数值模型应用在一个不同二次风反切工况下的 6 0 0MW切向燃烧炉。模型采用空度方法以较好地模拟复杂的屏式过热器结构 ,采用修正的非均分QUICK格式以有效减小伪扩散的影响 ,采用标准k ε模型来处理湍流。计算结果与试验数据吻合较好。模拟结果表明 ,烟气偏差成因于炉膛出口的残余旋转 ;二次风反切在一定程度上能有效地削弱炉膛出口的残余旋转 ,从而降低水平烟道的烟温偏差 ;但是过量反切可能会破坏炉内流场 ,并可能加大烟温偏差。因此必须优化反切角度与反切动量流率。该文认为合理的反切方式应该是无量纲准则数XJ为 1左右时的配风工况。
Based on the development of a three-dimensional calculation program, the influence of secondary air back-cutting on flue gas deviation of high-capacity tangential fired boiler was studied. The numerical model is applied to a 600MW tangential fired furnace under different secondary air anti-cutting conditions. The model uses space method to simulate the structure of the complex screen superheater. The modified non-uniform QUICK scheme is adopted to effectively reduce the effect of pseudo-diffusion. The standard k ε model is used to deal with turbulence. The calculated results are in good agreement with the experimental data. The simulation results show that the flue gas deviation is caused by the residual rotation of the furnace outlet. The secondary air reverse cutting can effectively weaken the residual rotation of the furnace outlet to a certain extent, thus reducing the smoke temperature deviation of the horizontal flue. However, excessive back-cutting may destroy the furnace Internal flow field, and may increase smoke temperature deviation. Therefore, it is necessary to optimize the anti-cutting angle and anti-tangent momentum flow rate. This paper considers that a reasonable method of anti-cutting should be a dimensionless criterion XJ is about 1 with the wind conditions.