烟气增湿自冲刷柔性电极湿式电除尘器的试验研究

发布时间：2018-08-02 19:50

【摘要】：近年来PM2.5污染严重,大气雾霾现象频繁出现,燃煤锅炉产生的细颗粒物是造成其污染的主要原因之一。燃煤锅炉产生的烟气在经过脱硫装置之后,又会产生新的颗粒物,加上前端未脱除的超细颗粒物,实际的颗粒物排放可能超标或达不到超净排放要求。湿式电除尘器作为一个终端控制设备,能够有效地解决该问题。但目前广泛采用的湿式电除尘器,存在水量消耗大、废水处理困难、布水不均等问题。针对这些问题,本文采用烟气增湿自冲刷柔性电极湿式电除尘方式,对颗粒物的脱除过程进行了研究。本文设计并搭建了烟气增湿自冲刷柔性电极湿式电除尘器实验台,对实验台进行了系统的调试,并研究了除尘器集尘极材料及系统运行参数对PM10、PM2.5及总尘颗粒的脱除性能。在借鉴前人研究的基础上,所搭建实验台在湿式电除尘器入口烟道前增加一文丘里管段,并在其喉管部位使用双流体喷嘴雾化增湿,水雾在高速气流的作用下进一步雾化并均匀分散。在雾化液滴增速过程中,小液滴与气流中的粉尘颗粒发生碰撞而被捕获,在扩散管段以粉尘颗粒为凝结核的速度逐渐加快,最终形成直径较大的含尘液滴,有利于后续湿式电除尘器的捕集。二次电压、风速、给粉量、集尘极、喷雾量对总尘脱除效率都有一定的影响。其中,随着给粉量和入口风速的增加,除尘效率呈下降趋势;随二次电压的增加和喷雾量的增加,除尘效率呈上升趋势;集尘极840A(丙纶)的性能要略优于3927(涤纶);随后通过不同情况下除尘效率公式的分析,发现除尘效率都与多伊奇数有关。最后,本文对不同工况下PM10、PM2.5以及分级去除效率进行了测试。实验发现在0.2μm~0.5μm以及2μm处,除尘效率有极小值;风速的增加使PM10、PM2.5的粒数去除效率增加而使其质量去除效率下降;随给粉量的增加,PM10、PM2.5以及分级除尘效率都呈现先增加后减小的趋势;随喷雾量以及二次电压的增加,PM10、PM2.5以及分级除尘效率都呈现逐渐上升的趋势。
[Abstract]:In recent years, PM2.5 pollution is serious, atmospheric haze phenomenon occurs frequently, the fine particles produced by coal-fired boiler is one of the main causes of its pollution. After the flue gas produced by coal-fired boiler goes through the desulphurization device, it will produce new particulate matter, plus the superfine particle which is not removed from the front end, the actual particulate matter emission may exceed the standard or meet the requirement of super-net emission. As a terminal control device, wet electrostatic precipitator can solve this problem effectively. However, the wet electrostatic precipitator, which is widely used at present, has the problems of large water consumption, difficult wastewater treatment and uneven distribution of water. In order to solve these problems, the removal process of particulate matter was studied in this paper by means of wet electrodedusting method with self-scouring flexible electrode for flue gas humidification. In this paper, a wet electrostatic precipitator with self-scouring flexible electrode is designed and built. The system is debugged, and the removal performance of dust collector electrode material and system operating parameters on PM10 / PM2.5 and total dust particles is studied. On the basis of previous studies, a Venturi section was added in front of the inlet flue of wet electrostatic precipitator, and the atomization and humidification of two-fluid nozzle were used in the throat. The water mist is further atomized and evenly dispersed under the action of high velocity airflow. In the process of atomizing droplet growth, the small droplets collide with the dust particles in the airflow and are captured. The speed of using the dust particles as the condensation nucleus in the diffusion pipe section is gradually accelerated, and finally the dust-containing droplets with larger diameters are formed. It is propitious to catch the wet electrostatic precipitator. The secondary voltage, wind speed, powder feed, dust collector and spray amount have certain influence on the total dust removal efficiency. The dust removal efficiency decreases with the increase of powder feed and inlet wind speed, and increases with the increase of secondary voltage and spray quantity. The performance of the dust collector 840A (polypropylene fiber) is slightly better than that of 3927 (polyester), and through the analysis of the formula of dust removal efficiency under different conditions, it is found that the dust removal efficiency is all related to the Deutsch number. Finally, the removal efficiency of PM10 / PM2.5 and its classification were tested under different operating conditions. The experimental results show that the dust removal efficiency is minimal at 0.2 渭 m 0.5 渭 m and 2 渭 m, the particle number removal efficiency of PM10 / PM2.5 decreases with the increase of wind speed, and the dust removal efficiency increases first and then decreases with the increase of powder feed. With the increase of the spray amount and the secondary voltage, the PM10 / PM2.5 and the dust removal efficiency increased gradually.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X701.2

【引证文献】