降低烟温偏差是塔式锅炉的特性之一，但实际运行过程中其烟温偏差仍存在，目前还缺乏其偏差形成机理的深入研究。以一台660 MW 四角切园燃烧的塔式锅炉为对象，研究了额定工况下的屏式受热面区域烟气流场偏斜与温度偏差特性；设计了3种不同的烟道结构和屏式受热面布置工况，研究其烟温偏差机理。结果表明：模拟值和烟温偏差特性与试验值和实际运行偏差特性一致。屏式受热面区域存在明显的烟气流动偏斜和温度偏差，左侧区域的速度和温度明显高于右侧区域；随着高度增加，左右两侧的流动和烟温偏差先增后减，在标高68 m的三级过热器入口附近烟温偏差达到最大值。引起烟气流动和烟温偏差的原因有两方面：一是在受热面管屏分割约束的作用下，旋转上升进入屏区的烟气垂直于管屏方向的速度分量被迫发生转向，导致靠近左侧区域烟气主要向前墙流动，而右侧区域烟气主要向后墙流动。二是由于炉膛顶部烟气出口不对称布置在后墙，在引风机的抽吸作用下，左侧区域的烟气流动先向前墙倾斜，而后转向后墙，在整个屏式受热面区域分布较居中；而右墙区域的烟气先向后墙倾斜，后沿后墙区域被抽走；左右两侧不同的烟气流动偏差导致温度偏差。

Reducing the flue gas temperature deviation is one of the characteristics of tower boiler，but the flue gas temperature deviation still exists in the actual operation，and there is still a lack of detailed research on its formation mechanism. In this paper，a 660 MW tangentially fired tower boiler was used to study the characteristics of flue gas flow field deflection and temperature deviation in the penal heating surface area under rated working conditions. Three cases with different flue structures and heating surface layout were designed and analyzed，and the smoke temperature deviation mechanism was deeply and carefully studied. The results show that the deviation characteristics of simulation are consistent with the experimental values and actual operation deviation characteristics，and there are obvious flow deflection and temperature deviation in the area of penal heating surface. The velocity and temperature in the left area were significantly higher than those in the right area. With the increase of height，the flue gas temperature deviation in the left and right region increases firstly and then decreases，and reaches the maximum near the entrance of the third-stage superheater. The mechanism of flow field deflection and gas temperature deviation is as follows:First，after the gas rotates and rises into the pipe penal，it is constrained by the pipe penal，and the velocity component perpendicular to the direction of the pipe penal turning around，causing gas near the left wall flowing to the forward wall，and gas near the right wall flowing to the back wall. Then，because the flue gas outlet at the top of the furnace is asymmetrically arranged on the rear wall，under the suction of the downstream induced draft fan，gas near the left wall first inclines to the forward wall，then turns to the back wall，and is more centered in the area of the penal heating surface. On the contrary，gas near the right wall is first inclined to the back wall，and then is drained away by the draft fan along the back wall，resulting in a serious deflection of the flow field and a large scale of reflux.

0 引言

1 模型概况

2 数值模拟及工况设置

   2.1 数学模型与网格划分

   2.2 数学模型工况

3 结果及讨论

   3.1 数值模拟可靠性验证

   3.2 基本工况流动及烟温偏差特性

   3.3 流场与温度场偏差形成机理

4 结论