Abstract The collection performance of wet electrostatic precipitators (ESPs) considerably deteriorates in the presence of ultrafine particles, which confer difficulties in realizing the ultra-low emission of particulate matter (PM). In this work, the use of a wet ESP combined with a perforated precharger was proposed to investigate its electrical and collection characteristics in flue gas containing ultrafine particles and compared these characteristics with those of the common wet ESP. Results indicated that the distributions of ion density and electric field were affected by ultrafine particle loadings. With increased PM0.1 concentration from 0 mg/m3 to 100 mg/m3, the average ion density of the common wet ESP decreased by more than two orders of magnitude. Meanwhile, the particle charging and transport performance deteriorated, even for large particles (10 μm), and migration velocity sharply decreased by more than 85 %. The corona electrostatic field was significantly improved by installing the precharger. The combined wet ESP can be operated well even under problematic conditions. Additional electrons were generated by the corona discharge of the precharger, which contributed to subsequent particle capture. When the applied voltage of the precharger exceeded 15 kV, the electrostatic precipitation of 1 μm particles only slightly weakened with increased PM0.1 concentration to 40 mg/m3, and the capture of >5 μm-diameter particles was nearly unaffected by ultrafine particles.

中文翻译：

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通过预充电增强含超细颗粒烟气中的颗粒沉淀

摘要 湿式静电除尘器（ESP）在超细颗粒物存在下的收集性能显着下降，这给实现颗粒物（PM）的超低排放带来了困难。在这项工作中，建议使用湿式 ESP 与多孔预充电器相结合来研究其在含有超细颗粒的烟气中的电气和收集特性，并将这些特性与普通湿式 ESP 的特性进行比较。结果表明，离子密度和电场分布受超细颗粒负载量的影响。随着 PM0.1 浓度从 0 mg/m3 增加到 100 mg/m3，普通湿式 ESP 的平均离子密度下降了两个数量级以上。同时，粒子的充电和传输性能恶化，即使对于大颗粒（10 μm），迁移速度也急剧下降了 85% 以上。通过安装预充电器，电晕静电场得到了显着改善。即使在有问题的条件下，组合式湿式 ESP 也能正常运行。预充电器的电晕放电产生了额外的电子，这有助于随后的粒子捕获。当预充电器施加的电压超过15 kV时，随着PM0.1浓度增加至40 mg/m3，1 μm颗粒的静电沉淀仅略微减弱，并且对>5 μm直径颗粒的捕获几乎不受超细颗粒的影响。即使在有问题的条件下，组合式湿式 ESP 也可以很好地运行。预充电器的电晕放电产生了额外的电子，这有助于随后的粒子捕获。当预充电器施加的电压超过15 kV时，随着PM0.1浓度增加至40 mg/m3，1 μm颗粒的静电沉淀仅略微减弱，并且对>5 μm直径颗粒的捕获几乎不受超细颗粒的影响。即使在有问题的条件下，组合式湿式 ESP 也可以很好地运行。预充电器的电晕放电产生了额外的电子，这有助于随后的粒子捕获。当预充电器施加的电压超过15 kV时，随着PM0.1浓度增加至40 mg/m3，1 μm颗粒的静电沉淀仅略微减弱，并且对>5 μm直径颗粒的捕获几乎不受超细颗粒的影响。