锅炉烟道脉冲喷吹清灰均匀性优化研究

Optimization study on the uniformity of pulse jet soot removal in boiler flues

锅炉系统中水平烟道积灰显著影响锅炉安全运行和集中供热稳定性,压缩空气脉冲喷吹可有效解决积灰问题,其中喷吹均匀性是清灰效果的关键指标。针对脉冲喷吹不利于实验研究的特点,采用CFD数值模拟对脉冲喷吹均匀性进行研究。首先,通过正交试验法建立了32种几何模型,研究喷吹管、喷孔、喷嘴的几何参数对于脉冲喷吹均匀性的影响。用方差分析找到了对喷吹均匀性有显著影响的几何参数,影响次序为Φ>N>D>P,用极差分析找出了喷吹均匀性最佳时对应的最优几何参数,最优几何参数为Φ=18 mm、N=10、D=110 mm、L=290 mm、d=50 mm、H=55 mm。然后,对最优几何参数对应的工况进行了具体分析,对显著影响均匀性的几何参数进行了单一变量分析,影响喷吹均匀性的决定性因素为喷孔处的静压。最后,通过修正各喷孔直径参数,找到了符合工程设计标准要求且喷吹均匀性更佳的喷孔直径参数,各喷孔直径参数为28 mm、24 mm、20 mm、18 mm、18 mm、16 mm、16 mm、16 mm、16 mm、16 mm。

Horizontal flue ash accumulation in the boiler system significantly affects the safe operation of the boiler and the stability of centralized heat supply,compressed air pulse blowing can effectively solve the problem of ash accumulation,in which the uniformity of blowing is a key indicator of the effectiveness of ash cleaning.Aiming at the characteristics of pulse blowing that are not favorable to experimental research,CFD numerical simulation is used to study the uniformity of pulse blowing.Firstly,32 geometrical models are established by orthogonal test method to study the influence of geometrical parameters of blowpipe,orifice and nozzle on the uniformity of pulse blowing.ANOVA iss used to find the geometrical parameters that have significant effect on the blowing uniformity,the order of influence isΦ>N>D>P,and polar analysis is used to find the optimal geometrical parameters corresponding to the best blowing uniformity,the optimal geometric parameters areΦ=18 mm,N=10,D=110 mm,L=290 mm,d=50 mm,H=55 mm.Secondly,the working conditions corresponding to the optimal geometric parameters are specifically analyzed,the decisive factor influencing blowing uniformity is the static pressure at the orifice.Finally,through the correction of each nozzle diameter parameter,the nozzle diameter parameter that meets the requirements of engineering design standards and has better blowing uniformity is found,parameters for each hole diameter are 28 mm,24 mm,20 mm,18 mm,18 mm,16 mm,16 mm,16 mm,16 mm,16 mm,16 mm.