烟气成分对静电除尘器放电特性的影响

为了研究烟气中O₂、H₂O、CO₂体积分数变化对负电晕放电特性的影响机理，采用实验和数值模拟方法分析静电除尘器在不同气体成分下的伏安特性，应用COMSOL软件建立模拟烟气的电晕放电模型. 研究结果表明：当CO₂体积分数增大，O₂体积分数降低时，起晕电压增大，电流在低电压时与CO₂体积分数负相关，在高电压时正相关；当相对湿度增大时，起晕电压降低，电流在低电压时与相对湿度正相关，在高电压时负相关；当CO₂体积分数增大，O₂体积分数降低时，电子数量增大；当相对湿度增大时，空间中的负离子团数量增大，离子迁移率降低. CO₂体积分数和相对湿度增大，空间电荷密度增大，有利于增大扩散荷电量，从而提高细微颗粒物的脱除效率.

Effect of gas composition on discharge characteristics of electrostatic precipitator

The volt ampere characteristics of electrostatic precipitator under different gas composition were studied by experiments and numerical simulation, and a corona discharge model of simulated flue gas was established by COMSOL software in order to analyze the influence mechanism of concentration changes of O₂, H₂O and CO₂ in flue gas on the negative corona discharge characteristics. Results show that when the CO₂ concentration increases and the O₂ concentration decreases, the corona onset voltage increases, the current is negatively correlated with the CO₂ concentration at low voltage, and positively at high voltage. When the relative humidity increases, the corona onset voltage decreases. The current is positively correlated with the relative humidity at low voltage and negatively at high voltage. With the increasing of CO₂ concentration and the decreasing of O₂ concentration, the number of electrons increases. When the relative humidity increases, the number of anion clusters increases and the mobility of ions decreases. The increasing of CO₂ concentration and relative humidity contributes to the increasing of space charge density, which is conducive to enhancing the diffusion charge and the removal of fine particles.