为探究国内某超低排放燃煤电厂中污染物控制装备（APCDs）对可凝结颗粒物（CPM）排放的影响规律，采用美国环保署推荐的EPA Method 202A方法对机组湿法脱硫系统（WFGD）前后和湿式电除尘器（WESP）后的烟气进行平行取样。通过样品分析得到了该燃煤电厂CPM在烟道不同位置处的质量浓度以及成分组成，通过进一步数据分析研究了CPM在APCDs中的迁移转变过程以及电厂现有APCDs对CPM的协同脱除效果。结果表明：ESP后的烟气中CPM含量已经占据主导地位，在WFGD入口、WFGD出口和WESP出口的质量浓度分别为24.07、12.71和7.72 mg/Nm³；在总颗粒物（TPM）中占比分别为61.83%、53.34%和76.06%。随着烟气流动，CPM中无机部分占比逐渐下降，从WFGD入口的69.38%下降至WESP出口的54.40%。CPM无机部分中主要以SO₂^-4、NO^-3、Cl-等酸根阴离子为主，SO₂^-4质量浓度占比始终最高。WFGD和WESP对CPM的脱除效率分别为47.20%和39.26%。WFGD+WESP对CPM的联合脱除效率为67.93%。研究结果可为燃煤电站CPM排放规律和控制方法提供数据支撑。

In order to study the influence of air pollution control devices(APCDs）on the condensable particulate matter(CPM）emission characteristics from an ultra-low emission coal-fired power plants in China,the EPA Method 202A recommended by the U.S. Environmental Protection Agency was used to simultaneously sample the flue gas before and after the wet flue gas desulphurization(WFGD）and after the wet electrostatic precipitator(WESP). Then the migration,transformation and emission characteristics of CPM in the flue gas were obtained based on sample analysis. Through further data analysis,the migration and transformation process of CPM in APCDs and the synergistic removal effect of existing APCDs on CPM in the power plant were studied. The results indicate that CPM dominates the particulate emission in the flue gas after ESP. The mass concentrations of CPM at the WFGD inlet,WFGD outlet and WESP outlet are 24.07,12.71 and 7.72 mg/Nm³ respectively,while the proportions in TPM are 61.83%,53.34% and 76.06% respectively. With the flue gas flow,the proportion of the inorganic composition of CPM gradually decreases,from 69.38% at the WFGD inlet to 54.40% at the WESP outlet. The inorganic part of CPM is mainly composed of acid radical anions such as SO₂^-4,NO^-3 and Cl^-,and the mass concentration of SO₂^-4 is the highest. The removal efficiency of CPM by WFGD and WESP is 47.20% and 39.26%,respectively. The combined removal efficiency of CPM by WFGD and WESP is 67.93%. The results can provide a good reference to the CPM emission and control from an ultra-low emission coal-fired power plant.

0 引言

1 材料与方法

   1.1 研究对象

   1.2 样品采集

   1.3 样品分析

   1.4 质量控制

2 结果与讨论

   2.1 CPM、FPM的质量浓度和化学组分

   2.2 CPM、FPM无机水溶性离子分布特性

   2.3 现有APCDs对CPM、FPM的脱除效率

3 结论