脱硫吸收塔深度除尘气液固三相模拟研究

Numerical simulation of deep dedusting of three-phase flow in desulfurization absorption tower

脱硫吸收塔内部流场较为复杂,涉及到气液固三相介质流动。采用欧拉(Eluer)多相流模型和DPM(discrete phase model)模型,建立惯性撞击、拦截和热泳捕集作用机制的液滴捕集颗粒物模型;利用CFD数值模拟分析了液滴粒径等6种运行参数对脱硫吸收塔除尘效率的影响规律。结果表明:亚微米级颗粒物的除尘效率较低,全塔对其除尘效率只有10%左右,而微米级颗粒在全塔内的除尘效率在99.98%以上;通过减少液滴粒径,增加烟气流速,适当增加液气比,均能有效提升微米级颗粒的脱除效率,尤其是1.30~2.05μm之间的颗粒物;而通过调节喷淋参数,对颗粒物除尘效率的提升作用并不大。

Because of three-phase flow,the internal flow field of desulfurization absorption tower is complex.By adopting the multi-phase Euler model and discrete phase model(DPM),this paper establishes a model of droplet trapping particles based on the mechanism of inertial impact,interception and thermophoresis.Through numerical simulation using CFD,the influences of six operation parameters including droplet size on the dust removal efficiency of desulfurization absorption tower were analyzed.The results show that,the dedusting efficiency of submicron particles is low and the dedusting efficiency of the whole tower is only about 10%.However,the dedusting efficiency of micron particles in the whole tower is higher than 99.98%.The removal efficiency of micron particles,especially the particles with size of 1.30~2.05μm,can be effectively enhanced by reducing the droplet size,increasing the flue gas flow rate and properly increasing the liquid gas ratio.Adjusting the spray parameters has little improving effect on the dust removal efficiency of particulate matters.