基于烟道喷射蒸发的脱硫废水处理数值模拟研究

Numerical simulation study on spray evaporation of desulfurization wastewater in flue duct

针对脱硫废水在烟道内的喷射过程,通过计算流体动力学(CFD)进行数值模拟,研究了烟气性质与操作参数对废水蒸发过程的影响.结果表明:随着烟气温度的升高,液滴蒸发时间逐渐降低,完全蒸干距离缩短;当烟气流速增加,蒸发时间逐渐减小,但完全蒸干距离先减少后增加,流速为5m/s时,废水液滴的完全蒸干距离最近;随着液滴粒径的增加,液滴的完全蒸发时间明显变长,流场内相对低温区域范围扩大;当喷射速度由20m/s升高至60m/s过程中蒸发时间由约0.21s下降至0.16s,但随烟气流速增加,其减少蒸发时间的作用减弱.该模拟结果可以为废水烟道喷射技术的相关工程应用提供优化设计方案和运行指导.

In this paper,the effect of flue gas properties and operating parameters on the evaporation process of wastewater was studied by using Computational Fluid Dynamics(CFD).The results showed that with the increase of the temperature of the flue gas,the evaporation time of the droplets gradually decreased,and the complete evaporation distance decreased.When the flow rate of flue gas increased,the evaporation time gradually decreased,but the total evaporation distance decreased first and then increased.At the flow rate of5m/s,wastewater droplets got to the shortest evaporation distance.With the increase of the droplet size,the complete evaporation time of the droplet became significantly longer,and the range of the relatively low temperature region within the flow field was enlarged;When the evaporation time increased from about0.21s to0.16s when the injection speed increased from20m/s to60m/s,but with the increase of flow rate,the effect of reducing evaporation time was weakened;.The simulation results can provide optimized design solutions and operational guidance for the related engineering applications of spray evaporation of desulfurization wastewater in flue duct.