超微细粉尘荷电凝并的关键技术研究

The ionic concentration (106~107/cm3) in the ESP applied electrical field and charged agglomeration rate of ultra-fine particles is relatively low. It results in the ultra-fine dust particles low drift velocity (3cm/s~20cm/s) and collection efficiency is always less than 90%. In order to escape the electric field constraint,double-vortex-type high efficiency plate ESP technology is applied to increase the charging particles momentum. Thereby increasing the rate of ion transport in ion concentration can be increased more than two orders of magnitude.Ion concentration can be increased from the current 106/cm3 ~ 107/cm3 to 108~109/cm3.Current particles drift velocity can be increased from 3cm/s~20cm/s to 20cm/s~200cm/s, average velocity of the flue gas in ESP is expected to 2~3m/s.It is seemed that double-vortex-type high efficiency plate ESP can increase the charged agglomeration to solve the present problems. A new type ESP is designed as the research object aimed at increasing the ultra-fine dust particles collection efficiency. To reveal the law of physic parameters (such as particles momentum etc.) effects on the ionic concentration, the physical transport mode of corona discharge is developed. For the charging and agglomeration mechanism of the vorticity, the relation between structural parameters of double-vortex-type collection plates and the vortex vorticity is studied to reveal the law of the electric collecting plate designing. At the same time, the mode of charging and agglomeration and particles transport equation is established to reveal the particles moving law in the ESP. Within the theoretical and experimental researches, the optimum design parameters are eventually obtained. In a word, this work presents an effective way to improve the ultra-fine particles collection efficiency.

现有电除尘器放电电场中产生离子浓度低(106~107/cm3),超微细烟尘颗粒荷电凝并几率低下。导致烟尘颗粒驱进速度低(3cm/s~20cm/s),造成超微细烟尘颗粒捕集效率低(一般<90%)的问题。采用双旋涡型收尘极板高效电除尘技术,利用提高带电粒子动量方法,可使离子有效摆脱电场束缚,采用双涡旋型收尘极板提高荷电凝并几率,有望解决电收尘器存在问题。课题拟以新型电除尘器为研究对象，以提高超微细烟尘颗粒捕集效率为目的。建立电晕放电离子输运物理模型,揭示带电粒子动量等物理参量对离子浓度影响规律;研究双旋涡型收尘极板结构参数等物理参量与旋涡涡量的关系,揭示适合电凝并的收尘极板设计规律,构建双涡旋型收尘极板形成旋涡荷电凝并机制;建立电除尘过程中的荷电凝并模型和粒子输运方程,揭示烟尘颗粒在除尘器内运动规律。通过理论和试验研究,确定新型电除尘器最佳设计参数。为提高超微细烟尘颗粒捕集效率提供有效方法。

现有电除尘器放电电场中产生离子浓度低(106~107/cm3),超微细烟尘颗粒荷电凝并几率低下。导致烟尘颗粒驱进速度低(3cm/s~20cm/s),造成超微细烟尘颗粒捕集效率低(一般<90%)的问题。采用双旋涡型收尘极板高效电除尘技术,利用提高带电粒子动量方法,可使离子有效摆脱电场束缚,采用双涡旋型收尘极板提高荷电凝并几率,有望解决电收尘器存在问题。课题拟以新型电除尘器为研究对象，以提高超微细烟尘颗粒捕集效率为目的。进行新型除尘器的理论和试验研究工作，并取得了以下研究成果：. （1）进行了电除尘器电晕放电离子输运特性研究，揭示了带电粒子动量等物理参量对离子浓度的影响规律。. （2）研究了双旋涡型收尘极板结构参数等物理参量与涡流强度的关系，利用PIV 技术来揭示截面旋涡结构演化规律，寻找适合除尘器电凝并的收尘极板设计规律，构建了双旋涡型收尘极板形成旋涡式粉尘荷电凝并的机制。. （3）研究了双旋涡型收尘极板结构形式下直流电场同极性粒子荷电凝并的变化规律，建立了区式双涡旋型极板ESP烟尘粒子荷电凝并的数值模型。. （4）通过对电除尘器内部尘粒荷电分布、电场分布、速度场分布、输运过程中所受外力的分析，建立了单区式双涡旋型极板电除尘器的荷电粒子输运方程；揭示带电粒子在除尘器内的运动规律。. （5）进行模拟烟气电除尘性能试验研究，探讨带电粒子动量（或烟气流速）、粉尘粒径、电场工作电压、双旋涡型收尘极板和放电极结构参数等物理参量对不同粒径分布的烟尘颗粒除尘效率影响规律，为单区式双旋涡型收尘极板电除尘器工业示范试验提供最佳设计参数。. （6）基于本基金项目的研究，在国内外核心期刊正式发表研究论文6篇，其中EI检索论文4篇，中文核心论文1篇；4篇研究论文录用待刊，其中SCI收录期刊论文1篇，EI收录期刊论文2篇，中文核心论文1篇。授权发明专利2项，申请发明专利1项。以本基金项目为依托，已培养博士研究生1人，硕士研究生10人（其中已毕业硕士生6人，均获得硕士学位）。