湿法脱硫系统PM2.5排放特性分析

为系统分析湿法脱硫系统出口PM_2.5的排放特性，基于26台湿法脱硫系统出口颗粒物和PM_2.5的排放情况的现场测试，研究入口颗粒物浓度、烟气流速、液气比、pH值以及雾滴浓度对PM_2.5排放特性的影响。烟气经过湿法脱硫系统处理后，出口PM_2.5占颗粒物的比重随着烟气中颗粒物浓度的降低而显著增大，PM_2.5排放系数随着吸收塔烟气流速、液气比、pH值或雾滴浓度的增大而增大，PM_2.5排放系数的增大速率大于烟气流速、液气比和pH值的增大速率，与雾滴浓度的增大速率基本一致。因此雾滴浓度对PM_2.5排放系数具有直接影响，湿法脱硫系统中控制雾滴浓度是降低出口PM_2.5排放的关键。

Analysis on PM2.5 Emission Characteristics of Wet Desulfurization System

In order to systematically analyze the emission characteristics of PM_2.5 at the outlet of wet desulfurization system(WFGD), based on the on-site test of the particulate matter(PM) and PM_2.5 at the exit of WFGD in 26 ultra-low emission units, the effects of inlet PM concentration, flue gas flow rate, liquid gas ratio, pH value and droplet concentration on the PM_2.5 emission at the outlet of WFGD are investigated. The measurement results indicate that the proportion of PM_2.5 to PM surges with the decrease of mass concentration for PM. PM_2.5 emission coefficient increases with the increase of flue gas flow rate, liquid gas ratio, pH value or droplet concentration for absorption tower. The increase rate of PM_2.5 emission coefficient is higher than the increase rate of flue gas flow rate, liquid gas ratio and pH value, but it is basically consistent with the increase rate of droplet concentration. Which shows that droplet concentration has a direct impact on PM_2.5 emission coefficient, ant the key to reduce PM_2.5 emission factor is to control droplet concentration in WFGD.