【作者】 张帝；

【导师】 原永涛；

【作者基本信息】 华北电力大学 ， 环境工程， 2015， 硕士

【摘要】 2011年以来,我国很多大中城市持续发生了雾霾天气,由我国气候中心的监测数据可知,很多城市的污染物排放水平已达到临界值,雾霾天数高达全年的30%以上,其根本原因在于大气中所存在的微细颗粒物。微细颗粒物的排放主要来源于电厂,而现有电除尘器在清除微细颗粒物方面,难以达到相应的排放标准,且传统的电除尘器所要求的烟气气流速度较低,因此设备占地面积大、投资费用高。因此,如何能在高速烟气流下收集细微粉尘颗粒将成为一个日渐重要的课题。本文针对电厂微细颗粒物的特点,提出了在烟道高速气流下以撞击粘附方式捕集微细颗粒物的概念。目前,撞击粘附的相关研究主要集中在级联式撞击采样器上,很少作为一种除尘设备来进行研究。本文通过对颗粒物在静态下的粘附机理进行研究,在撞击粘附理论的基础上,首先对颗粒物的撞击进行受力分析,得出影响颗粒物粘附的影响因素,然后利用Comsol软件,建立了半管式和平板式撞击粘附装置的二维气固两相流的流场模型,并对模拟结果进行了分析比较,并利用上述模型对半管式和平板式撞击粘附装置进行结构优化设计,从而探究撞击粘附技术对微细粉尘颗粒的脱除效果。结果显示,半管式撞击粘附装置在清除电厂微细颗粒物上具有更高效率的可行性方案。更多还原

【Abstract】 Since 2011,many of big and medium-sized cities have constantly emerged haze weather. The monitoring datas from National Climate Center, the pollutant emission has approached critical value, and the haze days account for 30% or above all the whole year. The fundamental cause is due to the fine particles in the atmosphere, which mainly come from power plants. The current electrostatic precipitator is inefficient for removing fine particles; and the allowing flue gas flow velocity is rather low for traditional electrostatic precipitator, leading to the large floor area and high investment. Thus, how to capture dust particles in high gas flow rate becomes a more and more important subject.Aiming at the fine particles of power plant, this article puts forward the concept of capturing fine particles in high speed airflow by an impactive and adhesive force. Currently, the related research on impact and adhesion primarily concentrates on the cascade impactor, researchers rarely study it as the dust removal equipment. Based on the impactive and adhesive theory of particles, this article firstly studies the adhesive mechanism of particles in the static state, conducting force analysis for particles’ impaction and deducing the influence factors for adhesion; then build the two-dimensional gas-solid flow fields for semi-tubular and tabulate devices, and analyzes the simulated results s; finally optimized the structure design of the two devices by the simulation and explore the removal effect of fine particles by the impactive and adhesive technology. It’s discovered that the semi-tubular devices is more efficient in removing fine particle.更多还原