对2家燃煤电厂湿法烟气脱硫(wet flue gas desulfurization,WFGD)系统前后细颗粒及SO_3酸雾进行了测试分析,对比分析了单塔、双塔脱硫工艺、燃煤组分等与细颗粒物和SO_3酸雾脱除作用的关系。结果表明,双塔WFGD系统对细颗粒物和SO_3酸雾的脱除效率明显高于单塔系统。WFGD系统入口细颗粒物粒径分布相似,脱硫后细颗粒物粒径分布向小粒径方向迁移,同时PM_(2.5)相对比例有所增加,双塔脱硫系统更为明显。WFGD系统在脱除燃煤烟气中颗粒物的同时,本身也会形成新的细颗粒物,其主要成分为硫酸钙,呈板状及棱柱状。单塔、双塔WFGD系统对燃煤烟气中SO_3酸雾的脱除效率范围分别介于30%~40%、50%~65%,随着塔入口烟气中SO_3及颗粒物浓度的增加,其脱除效率有所提高;燃用高硫煤时,会出现蓝烟现象。
Fine particles and SO_3 acid mist from the inlet and the outlet of the wet flue gas desulfurization(WFGD) systems in two coal-fired power plants were measured and the effects of different technologies and coal qualities on the removal of fine particles and SO_3 acid mist were investigated. The results show that the removal efficiencies of fine particles and SO_3 acid mist in the double-tower system are obviously higher than those in the single-tower system. The size distributions of fine particles at the inlet of WFGD systems are similar. They shift to the smaller end after desulfurization with higher proportion of PM_(2.5), which is more obvious in the double-tower system. Particles in the flue gas are removed by the WFGD system, while new fine particles are formed during desulfurization, which are mainly calcium sulfate with clintheriform and prismatic shape. The removal efficiencies of the double-tower system and the single-tower system on SO_3 acid mist are 30%~40% and 50%~65%, respectively. With the increase of the inlet concentrations of SO_3 and particles, the removal efficiencies increase and the blue plume occurs with the high-sulfur coal.