本文对某燃煤电厂的两台锅炉除尘器前后的飞灰颗粒进行采样,研究了可吸入颗粒物(PM10)的排放浓度、质量粒径分布、排放特征、对静电除尘器的穿透率和锅炉运行负荷对其的影响。试验采用低压撞击器(LPI)按不同粒径大小从0.03-10μm共分为13级,分别采集燃烧后的可吸入颗粒物。研究表明,两台锅炉产生的PM10均呈双峰分布,其除尘器入口峰值分别在0.1μm和4.0μm左右,而出口峰值则为0.1μm和2.0μm;随着颗粒物粒径的减小,颗粒物对除尘器的穿透率是降低的,其中在0.2—0.6μm的穿透率达到一个峰值;相比除尘器入口,除尘器出口PMl和PM2.5的质量百分比都大大增加,这也是由于除尘器对飞灰中的大颗粒脱除效果更佳的原因造成的。随着锅炉运行负荷的降低,PM10占总灰颗粒的质量百分比含量下降。
Measurements of the characteristics of particulate matter (PM) were performed at the inlet and outlet of the electrostatic precipitators (ESP) in a full-scale pulverized coal power plant. The properties of PM included concentration, mass size distribution, emission characteristics, percent penetration of PM through ESP and effect of operational load of power plant were investigated. PM was collected with a 13 stages Low-Pressure-Impactor(LPI) having aerodynamic cut-off diameter ranging from 10.0 to 0.03 μm for a size-segregated collection. The experimental results indicate that, in all the cases the mass size distribution of PM10 had typical bimodal. In the inlet of ESP, the emitted PM has two peaks around 4.0 and 0.1 μm and in the outlet of ESP the emitted PM has two peaks around 2.0 and 0.1μm. Penetration as a function of particle diaamter had a clear peak in particle size range of 0.2-0.6 μm. Particles in the submicronmeter size range were much more difficult to collect with ESP than larger particles, hence in the outlet of ESP the mass fraction of PM1 and PM2.5 increase greatly. When operational load of power plant decrease, PM10 in mass percent of total ash particle reduce,