基于高压电晕除湿的烟气消白技术参数优化设计研究

Study on Optimization Design of Smoke Whitening Technical Parameters based on High Voltage Corona Dehumidification

为了探究离子风除湿机理,获得影响除湿效率的关键参数,基于ANSYS CFX均质成核理论建立了除湿过程的三维空间多场耦合多相流数值模型,分析了集电极筒结构、流动、物性等参数变化对除湿效果的影响。基于可视化后处理软件,分析了电/流场耦合作用下流场速度、液滴的分布规律,并进一步阐明离子风除湿机理和除湿过程。结果表明:渐扩形集电极筒效果最佳但难以并联组合;随着进口流速的增加除湿效果迅速减弱;温差的增大显著提高了饱和蒸汽凝结的效率;相比于入口饱和蒸汽,气液两相入口明显改善了圆柱形集电极筒内的整体凝结程度,且核心凝结区域不仅限于出口处的U形区域;而电压的增强可以促进气相凝结,但是电压超过38 kV之后,液相平均质量分数变化幅度很小;增加电极长度可以提高除湿效果,但当电极长度达到0.37 m时,继续增加电极长度液相平均质量分数没有显著变化。

In order to explore the dehumidification mechanism of ion wind and obtain the key parameters affecting the dehumidification efficiency,a three-dimensional spatial multi field coupled multiphase flow numerical model of dehumidification process was established based on ANSYS CFX homogeneous nucleation theory,and the influences of the changes of parameters such as collector cylinder structure,flow and physical properties on the dehumidification effect were analyzed.Based on the visual post-processing software,the velocity of flow field and the distribution law of droplets under the coupling action of electric and flow fields were analyzed,and the dehumidification mechanism and process of ion wind were further clarified.The results show that the effect of gradually expanding collector cylinder is the best,but it is difficult to combine in parallel;with the increase of inlet flow rate,the dehumidification effect decreases rapidly;the increase of temperature difference significantly improves the condensation efficiency of saturated steam;compared with the inlet saturated steam,the gas-liquid two-phase inlet significantly improves the overall condensation degree in the cylindrical collector cylinder,and the core condensation area is not limited to the U-shaped area at outlet;the enhancement of electric field intensity can promote gas phase condensation,but the change amplitude of liquid phase average mass fraction is very small after the voltage exceeds 38 kV;increasing the electrode length can improve the dehumidification effect,but when the electrode length reaches about 0.37 m,the average mass fraction of liquid phase does not change significantly with the continuous increase of electrode length.