基于改进颗粒凝结方程模拟生长管内微细颗粒凝并与脱除  

Simulation of Fine Particles Agglomeration and Removal in Growth Tube Based on the Improved Particle Agglomeration Equation

作　　者：王健[1] 潘伶[1] 王帅 张昊 WANG Jian;PAN Ling;WANG Shuai;ZHANG Hao(College of Mechanical Engineering and Automation,Fuzhou University,FuZhou 350108,China)

机构地区：[1]福州大学机械工程及自动化学院,福州350108

出　　处：《工程热物理学报》2021年第4期944-952,共9页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No:51875106);福建省自然科学基金面上项目(No.2016J01226);晋江市福大科教园区发展中心科研项目(No.2019-JJFDKY-54)。

摘　　要：微细颗粒严重危害人类健康与环境,针对湿法烟气脱硫系统后烟气中微细颗粒浓度不降反升,湿式相变凝并技术是脱除烟气中微细颗粒物的新技术。本文首先考虑颗粒性质的不同以及颗粒与载流气体的速度差造成颗粒凝结长大速率不同,改进了颗粒凝结长大解析式并建立了颗粒凝并长大数学模型;其次,在普通生长管中加装两层旋流装置,以增加颗粒的离心力与烟气湍流强度;最后,采用CFD方法对普通生长管与旋流生长管流场进行数值模拟。结果表明:采用改进后的颗粒凝并长大数学模型能更准确地模拟生长管内微细颗粒凝并长大特性,模拟结果为试验测量值的88.2%,比原数学模型模拟精度提高了11.3%;对比旋流生长管与普通生长管,烟气在旋流生长管内不仅停留时间长,而且可以获得较高且均匀的过饱和度,有效促进了微细颗粒凝并长大;旋流生长管对微细颗粒的数量浓度脱除效率高达65.8%。Fine particles endanger our health and the environment seriously.The concentration of fine particles in the flue gas after the wet flue gas desulfurization system increases instead of decreasing.Wet phase transition agglomeration technology is the newest way to remove the fine particles in the flue gas.Considering the velocity difference of particle agglomeration and growth triggered by the properties of various particles and the speed difference between particles and carrier gas,this paper improved the particle agglomeration equation and established mathematics model of particle agglomeration and growth.Thereafter,a two-layer cyclone device was installed in the normal growth tube to increase the centrifugal force of particles and the turbulence intensity of flue gas.Besides,simulation of flow fields of the normal growth tube and the improved one was implemented respectively through CFD method.It is indicated that the simulation of particle agglomeration and growth in the growth tube with the improved mathematical model has a higher accuracy.Actually,the simulation accuracy reaches 88.2%compared with the experimental result,which is enhanced by 11.3%based on the previous models.Flue gas in the growth tube with cyclone device not only stays for a longer time than that in a normal growth tube,but also gets higher and homogeneous degree of supersaturation which facilitates the agglomeration and growth of particles.Moreover,the removal efficiency of fine particles number concentration is up to 65.8%with the improved growth tube.

关 键 词：微细颗粒物 湿式相变 凝并长大 生长管 颗粒群平衡模型 

分 类 号：TB611[一般工业技术—制冷工程]