温湿电场对PM2.5及SO3的脱除性能  

Removal performance of PM2.5 and SO3 by temperature and wet electric field

作　　者：黄怡民 HUANG Yimin(College of Environmental and Chemistry Engineering,Chongqing Three Gorges University,Chongqing 404000,China)

机构地区：[1]重庆三峡学院环境与化学工程学院,重庆404000

出　　处：《环境工程学报》2020年第4期1042-1051,共10页Chinese Journal of Environmental Engineering

基　　金：重庆市科委自然科学基金资助项目(cstc2018jcyjA1711)。

摘　　要：为深入研究温湿电场对PM2.5及SO3的脱除性能,采用实验室研究、工程调研或实测相结合的手段,系统分析了湿式电除尘器(WESP)对PM2.5及SO3的脱除规律,尤其是高SO3浓度对湿式电除尘器性能的影响及其应对措施。实验研究发现:电源电压分别为35、45、55 kV时,湿式电除尘器对总尘、PM2.5和SO3的脱除效率分别为60.8%、75.2%、82.4%,53.7%、67.1%、76.8%和43.4%、58.6%、72.7%;随着电压的增加,各粒径段颗粒的分级脱除效率均有明显提升,但0.1~1μm提升最为明显;鉴于烟尘的吸附及SO3的调质作用,烟尘和SO3两者有一定的相互促进脱除作用,但SO3浓度过高,容易在放电极线周围形成高密度的空间电荷,导致电晕电流降低,除尘效率下降;针对高浓度的SO3,采用降温方式,可有效提高湿电场的烟尘及SO3脱除性能。工程实测发现:单独使用湿式电除尘器或是与其他相关技术耦合应用,均对烟尘及SO3有较高的脱除效率;湿式电除尘器对烟尘及SO3脱除效率分别为63.5%~88.3%、65.1%~71.9%,与湿法脱硫耦合使用,效率分别达82.1%、86.1%,与相变凝聚器(PCA)耦合使用,效率分别达92.3%、90.1%。上述研究可为湿式电除尘器的宽范围、多场合应用提供参考。In order to study the performance of temperature and humidity electric field on PM2.5 and SO3 removal,the removal rules of PM2.5 and SO3 by wet electrostatic precipitator(WESP) were analyzed systematically by means of laboratory research,engineering investigation or field measurement,especially for the influence of high SO3 concentration on the performance of WESP and its countermeasures.The experimental results showed that at the power supply voltages of 35,45 and 55 kV,the removal efficiencies of total dust,PM2.5 and SO3 by WESP were 60.8%,75.2%,82.4%;53.7%,67.1%,76.8% and 43.4%,58.6%,72.7%,respectively.With the increase of voltage,the grade removal efficiencies for particles within each size interval also increased significantly,and the most remarkable increase occurred for particles with size of 0.1-1 μm.In view of the adsorption of soot and tempering effect of SO3,the removal performance of dust and SO3 can promote each other to some extent.However,at too high SO3 concentration,a high density space charge around the discharge electrode line was easy to form,which could lead to the reduction of corona current and dust removal efficiency.Aiming at high SO3 concentration,adopting cooling method could effectively improve the soot and SO3 removal performance of wet electric field.Engineering field measurements indicated that high removal efficiency of dust and SO3 for wet electrostatic precipitator happened no matter it was used alone or coupled with other related technologies.The dust and SO3 removal efficiencies of the wet electrostatic precipitator were 63.5%-88.3% and 65.1%-71.9%,respectively,and when it was coupled with the wet desulfurization,the efficiencies could reach 82.1% and 86.1%,respectively,and when it was coupled with the PCA,the efficiencies could reach 92.3% and 90.1%,respectively.The analysis shows that this study can provide reference for the wide range and multiple applications of wet electrostatic precipitator.

关 键 词：燃煤电厂 湿式电除尘器 PM2.5 SO3 

分 类 号：X505[环境科学与工程—环境工程]