Wang Run-Fang, Ma Da-Wei, Jiang Shao-Yi, Zhu Ren-Bin, He Jun, Zhang Ben-Yao
Anhui Province Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei 230026, China.
State Grid Anhui Electric Power Corporation Research Institute, Hefei 230601, China.
Huan Jing Ke Xue. 2020 Jan 8;41(1):98-105. doi: 10.13227/j.hjkx.201904162.
Since the introduction of ultra-low emissions, the characteristics of particulate matter (PM) emissions from coal-fired power plants have changed. We quantitatively evaluate the emission characteristics of each component in PM and the impact of purification equipment by analyzing three ultra-low emission units of coal-fired power plants (FP1, FP2, and FP3). A DGI was used to sample particles from the wet flue gas desulfurization (WFGD) unit and wet electrostatic precipitator (WESP) inlet and outlet, which were then analyzed by various methods. The results showed that the mass concentrations of PM, PM, and PM discharged from the outlets of the three units were 0.25-0.38, 0.31-0.42, and 0.42-0.57 mg·m, respectively, and that the mass concentration of PM discharged under the two kinds of units was equivalent. However, there were differences in the particle size distribution and composition of the particles. In comparison to the FP1 and FP2 units, the PM/PM ratio of the FP3 unit was the highest. A possible reason for this is that the unit was equipped with a WESP, which can better remove particle sizes of 2.5 μm or more. The total concentrations of water-soluble ions in PM discharged from the FP2 and FP3 units were 0.20 and 0.06 mg·m, respectively. The water-soluble ions emitted from the FP2 unit were mainly Ca and SO, whereas those mainly emitted from the FP3 unit were NH and SO. Analysis of the PM from the WFGD import and export of the FP2 unit showed that the WFGD process increased the water-soluble ion discharge by entraining the desulfurization slurry containing limestone and gypsum. Addition of a WESP after WFGD can effectively remove PM and PM particles and reduce the influence of water-soluble ions on the atmospheric environment.
自引入超低排放以来，燃煤电厂颗粒物（PM）排放特征发生了变化。通过分析三座燃煤电厂（FP1、FP2和FP3）的三个超低排放机组，我们定量评估了PM中各成分的排放特征以及净化设备的影响。使用稀释气体撞击器（DGI）对湿法烟气脱硫（WFGD）装置和湿式静电除尘器（WESP）进出口的颗粒进行采样，然后采用各种方法进行分析。结果表明，三个机组出口排放的PM、PM和PM的质量浓度分别为0.25 - 0.38、0.31 - 0.42和0.42 - 0.57 mg·m，两种装置下排放的PM质量浓度相当。然而，颗粒的粒径分布和组成存在差异。与FP1和FP2机组相比，FP3机组的PM/PM比值最高。一个可能的原因是该机组配备了WESP，它能更好地去除2.5μm及以上的粒径。FP2和FP3机组排放的PM中水溶性离子的总浓度分别为0.20和0.06 mg·m。FP2机组排放的水溶性离子主要是Ca和SO，而FP3机组主要排放的是NH和SO。对FP2机组WFGD进出口的PM分析表明，WFGD过程通过夹带含石灰石和石膏的脱硫浆液增加了水溶性离子排放。在WFGD后添加WESP可有效去除PM和PM颗粒，并减少水溶性离子对大气环境的影响。
