燃煤机组经过超低排放改造后,除尘器对粉尘的脱除效率大大提升。然而,除尘器对PM2.5等细颗粒的捕获能力有限,导致许多细颗粒通过烟囱排入大气,降低了周边空气质量。基于化学团聚技术,在国内某600MW燃煤电站开展细颗粒物排放控制示范试验研究,旨在通过系统的采样测试探究化学团聚技术对PM2.5排放的控制效果。基于固定污染源采样标准(ISO23210-2009)开展现场采样测试。对化学团聚技术投运前后细颗粒物排放质量浓度进行检测,依托样品表征方法对颗粒样品进行测试分析,综合评价化学团聚技术对燃煤细颗粒排放的控制作用。结果表明:团聚吸附剂喷射后,静电除尘器(electrostaticprecipitator,ESP)入口粉尘的平均粒径由57.3μm增大至69.6μm,平均粒径增大21.5%;团聚后,ESP入口PM1,PM2.5,PM10质量浓度分别由124.2mg/m3,359.5mg/m3,947.7mg/m3减小至85.6mg/m3,240.6mg/m3,492.0mg/m3,团聚效率分别为31.1%,33.1%,48.1%。飞灰粒径筛分结果表明:团聚后,粒径在38μm以下的飞灰质量分数由32.7%减小至9.2%,而粒径在38μm~75μm范围内的飞灰质量分数由29.7%增大至62.8%;最终,在团聚吸附剂作用下,湿法烟气脱硫(wetfluegasdesulfurization,WFGD)出口总粉尘质量浓度由1.32mg/m3降低至1.09mg/m3。综上,化学团聚技术对燃煤电站细颗粒物团聚效果显著,PM2.5脱除效率显著提升。

The dust removal efficiency of dust collectors has greatly improved after the ultra-low emission transformation of coal-fired units. However, these collectors has limited abili- ty to capture fine particles such as PM , leading to the discharge of substantial quantities of fine particles into the atmosphere through chimneys and thereby reducing the surrounding air quality. Based on chemical agglomeration technology, a demonstration experiment research on fine partic- ulate matter emission control was conducted in a MW coal-fired power plant in China. The aim is to assess the effect of chemical agglomeration technology on PM emission control through systematic sampling testing. On-site sampling tests were conducted based on the fixed pollution source sampling standard (ISO 23210-2009). By detecting the emission mass concen- tration of fine particles before and after the operation of chemical agglomeration technology, and analyzing the particle samples based on sample characterization methods, the control effect of this technology on coal-fired fine particle emissions was comprehensively evaluated. The study shows that the average particle size of ESP (electrostatic precipitator) inlet dust increases from 57.3 μm to 69.6 μm, with an increase of 21.5% in average particle size; after agglomeration, the mass concentrations of PM , PM , and PM at the ESP inlet decreases from 124.2 mg/m , 359.5 mg/m , 947.7 mg/m to 85.6 mg/m , 240.6 mg/m , and 492.0 mg/m , respectively, with an agglomeration efficiency of 31.1%, 33.1%, and 48.1%. The screening results of fly ash particle size show that the mass fraction of fly ash with particle size smaller than μm after agglomera- tion decreases from 32.7% to 9.2%, while the mass fraction of fly ash within the range of μm μm increases from 29.7% to 62.8%. Finally, the total dust mass concentration at the WFGD (wet flue gas desulfurization) outlet decreases from 1.32 mg/m to 1.09 mg/m under the influence of the agglomeration agent. In conclusion, chemical agglomeration technology has a significant effect in enhancing the agglomeration of fine particles in coal-fired power plants and a marked improvement in PM removal efficiency.