基于超低排放典型工艺的钢铁烧结模拟烟气冷凝特性研究  

Research on Gas Condensation Characteristics of Sintering Simulation Based on Ultra-Low Emission Typical Process

作　　者：陶泓帆 黄妍 李思密 肖岭 张俊丰 赵令葵 TAO Hongfan;HUANG Yan;LI Simi;XIAO Ling;ZHANG Junfeng;ZHAO Lingkui(College of Environment and Resources,Xiangtan University,Xiangtan 411105,China)

机构地区：[1]湘潭大学环境与资源学院,湖南湘潭411105

出　　处：《环境科学研究》2023年第7期1297-1305,共9页Research of Environmental Sciences

基　　金：湖南省科技厅资助科研项目(No.2019SK2071)。

摘　　要：在钢铁烧结烟气超低排放背景下,为有效控制可凝结颗粒物(CPM)的产生以及有色烟羽问题,本文针对钢铁烧结烟气的“半干法(干法)脱硫+中低温SCR脱硝”超低排放典型工艺,参考稀释间接法原理设计模拟冷凝试验装置,结合大气气溶胶相关热力学及动力学模拟计算结果,考察探究了烧结烟气中各组分(NH_(3)、HCl、SO_(3)、H_(2)O)冷凝的相互影响及机制.结果表明:①逃逸NH_(3)的存在将显著提升SO_(3)成核速率,形成潮解点较低、易团聚的硫酸盐气溶胶,使得SO_(3)平均冷凝比提升至84%.②HCl则主要以离子态形式存在于硫酸盐气溶胶中,平均冷凝可达80%.③HCl和SO_(3)均可促进NH3的冷凝,对NH3冷凝的促进效果依次为HCl<SO_(3)<HCl+SO_(3),改变烟气组成可使NH3的平均冷凝比从27%升至78%.研究显示,改变初始NH3浓度对CPM冷凝总量的影响最大.Under the background of ultra-low emissions of steel sintering flue gas,condensable particulate matter(CPM)rapidly condenses into the ambient air and produce a large number of ignored secondary pollutants.As a gaseous substance in the flue,CPM is condensed into liquid or solid particulate matter in a short time after condensed and diluted by ambient air after discharging from the flue.In order to effectively control the color plume caused by excessive discharge of CPM,this work aimed at the ultra-low emission typical process of‘semi-dry method(dry method)desulfurization+medium-low temperature SCR denitrification’of sintering flue gas,and designed the simulation condensation experiment device based on the principle of dilution indirect method.The interaction and mechanism of condensation of each component(NH3,HCl,SO3,H2O)in sintering flue gas were investigated based on the thermodynamic and kinetic simulation results of atmospheric aerosol.The experimental results showed that:(1)The existence of escaping NH3 will cause the nucleation rate of SO3 to increase significantly.The formed sulfate aerosols with low deliquation point and easy agglomeration increasingly lead the average condensation ratio of SO_(3) to 84%.(2)HCl mainly exists in sulfate aerosols,so the average condensation can reach 80%.While in NH_(3)-HCl-H_(2)O system,the condensation ratio will decrease to 38%.(3)Both HCl and SO_(3) can promote the condensation of NH3.The promotion effect of NH3 condensation is ranked as HCl<SO_(3)<HCl+SO_(3),and the average condensation ratio of NH3 can be increased from 27% to 78% by changing the composition of flue gas.Moreover,by comparing the total amount of condensable particles,initial NH_(3) concentration was found to be the main factor affecting the total CPM condensation.This work shows that the change of initial NH3 concentration has the greatest impact on the total condensation of CPM,which can provide basic data for the contribution of sintering flue gas to soluble ions in the atmosphere and give the con

关 键 词：烧结 无机组分 可凝结颗粒物 热力学平衡 治理对策 

分 类 号：X51[环境科学与工程—环境工程]