烟气成分对湿式电除尘器电晕放电特性的影响

建立单通道线板式湿式电除尘器机理实验台,考察烟气中主要成分(O₂、H₂O和粉尘)对湿式静电除尘器放电特性的影响。随着烟气成分(O₂、H₂O和粉尘)浓度的增加,空间静电场中负电荷密度增加,电场分布均匀性提高,抑制电晕放电,电晕电流降低;随着电压升高,烟气成分对电晕放电的抑制作用减弱。其中,烟气中O₂的体积分数增加引起电晕电流下降的速率不为常数,O₂体积分数小于6%时,下降速率明显减小。烟气中液相水滴附着在电晕线表面引起表面电场畸化,起晕电压降低,击穿电压提高,湿式静电除尘器的工作电压窗口增大。电晕电流与烟气中粉尘浓度呈线性相关关系,粉尘粒径越小对电晕放电的抑制作用越明显。

Effect of gas components on the discharge characteristics of the wet electrostatic precipitator

To study the effects of gas components on the corona discharge characteristics of the wet electrostatic precipitator, a test bench was built. The effect of O₂, H₂O, and dust concentration on the discharge current were discussed in detail, results show than the O₂, H₂O and, dust in the flue gas had an inhibitory effect on the corona discharge and the negative ion concentration and electrostatic-field uniform were greatly improved with the increase of the O₂, H₂O, and dust concentration in the flue gas. The inhibitory effect of these components on the discharge current became weaker on a higher applied voltage. The descending rate of the discharge current was not a constant with the increase of O₂ concentration in the flue gas when the O₂ concentration was higher than 6%, the discharge current descended rapidly. The distribution of the electricfieldon the surface of the discharge electrode was twisted because of the aggregation of the liquid droplets. Wet electrostatic precipitator had a wide range of operating voltages and the onset voltage was lower and the breakdown voltage was higher under high water content in the flue gas. Dust concentration showed a linear correlation of the discharge current and the inhibitory effect increased when the dimensions of dust were smaller.