脱硫废水旋转雾化蒸发塔的流场特性模拟研究

SIMULATION STUDY ON FLOW FIELD CHARACTERISTICS OF ROTARY ATOMIZATION EVAPORATION TOWER FOR DESULFURIZATION WASTEWATER

为分析脱硫废水旋转雾化蒸发塔内部的流场特性,基于CFD仿真软件建立了数值模型,并通过热态实验验证了数值模型的可靠性。在此基础上,以某600 MW燃煤机组旋转雾化蒸发塔为研究对象,模拟研究了塔径、塔高、导向锥等结构对塔内流场的影响。结果表明,随着轴向距离的增大,雾滴的蒸发速率会逐渐降低,径向上的分布范围会逐渐变广,最大粒径和中值粒径会逐步减小;塔体直筒中下部碰壁概率大于上部,且靠近灰斗的区域增幅明显,是相对易结垢区域;设计范围内,塔径和塔高对雾滴的蒸发过程影响较小,适当降低塔径和塔高可以降低产物碰壁概率;无导向锥时,导流装置易出现结垢,导向锥体的存在对烟气起到聚拢作用,但过高的导向锥会增加较大的阻力。

In order to analyze the flow field characteristics in the rotating atomizing evaporation tower for desulfurization wastewater,establishing the numerical model based on CFD software,and verifying its reliability by hot state experiments.On this basis,taking the rotating atomizing evaporation tower of a 600 MW coal-fired unit as the research object,and simulating studies the influence of structure such as tower diameter,tower height and guide cone on the flow field characteristics in the tower.The results show that as the axial distance increases,the evaporation rate of droplets gradually decreases,the radial distribution range gradually widens,and the maximum and median particle sizes gradually decrease.The probability of hitting the wall in the lower part of the tower is greater than that in the upper part,and the area near the ash hopper has a significant increase,making it a relatively easy area for scaling.Within the design scope,the diameter and height of the tower have a relatively small impact on the evaporation process of droplets,and appropriately reducing the diameter and height of the tower can reduce the probability of product wall collision.When there is no guide cone,the guide device is prone to scaling,and the presence of the guide cone plays a role in gathering flue gas,but excessively high guide cones will incur higher resistance.