分离燃尽风反切角度对炉内空气动力场影响的试验研究

TEST STUDY ON INFLUENCE OF THE REVERSED TANGENTIAL ANGLE FOR SEPARATING OVER-FIRED AIR UPON THE AERODYNAMIC FIELD IN FURNACE

通过对采用LNCFS-Ⅲ燃烧系统的600MW机组锅炉进行冷态模化试验,得到分离燃尽风率在0.32时随反切角度变化分离燃尽风区平均相对切圆直径(Dxd)SOFA、炉膛出口残余旋转动量流率矩Jout、炉膛出口水平烟道作用速度偏差E及速度不均匀性系数M2的变化规律。分离燃尽风反切角度在0°～15°范围内变化时,炉内旋转气流方向仍能保持不变;随着反切角度的增大,Jout、(Dxd)SOFA、E及M2减小,在θ=15°时最小;分离燃尽风反切角度大于15°小于20°时,炉膛上部旋转气流的旋转方向出现不稳定现象;分离燃尽风反切角度等于或大于20°之后,炉膛上部旋转气流出现稳定的反方向旋转现象。

Through cold modelling test carried on boiler of a 600 MW unit adopting INCFS-Ⅲ combustion system,the vaiational regularity of the relative tangential circle diameter in the zone of separating over - fired air （SOFA）, （Dxd）SOFA , the flow rate moment o f residual rotational momentum at furnace outlet J the velocity deviation E, and the uneven coeffieienty of velocity M2 due to effect of horizontal flue duct at furnace outlet along with the variation of reversed tangential angle under condition of SOFA ratio is 0.32,has been obtained. When the reversed tangential angle is in a range of 0°-15°,the rotation direction of main gas flow keeps unchanged;Jout （Dxa）SOFA,E,and M2 decreases with increasing the revesed tangential angle,and being minimum at 0= 15°;under condition of the reversed angle is greater furnace than 15° but less than 20°,the rotation direction of rotational gas flow in upper space of the is unstable; after the reversed tangential angle is equal to or greater than 20°, the rotational gas flow in upper space of the furnace will be stable, but the rotation direction being reversed.