静电除尘高压电源的优化控制系统

针对静电除尘器的粉尘排放浓度和电能消耗等问题,以及最佳工作电压会随着工况的变化而变化,进而提出了一种提高和改善电除尘器性能的整体优化控制方法。用全监督RBF神经网络建立电除尘器出口浓度-供电电压模型,最小二乘法辨识电功率模型,采用遗传算法GA寻找最佳工作2次电压的设定值。结果证明,该优化控制方法,在保证除尘效率的同时又兼顾了节能问题。     

新型复合静电除尘器脱硝性能研究

NO是燃烧产生的重要气体污染物之一。脉冲放电与直流放电相结合的新型除尘方式在有效提高对粒径小于 2.5 mm的颗粒物(PM2.5)脱除效率的同时,还具有氧化NO的能力。高压脉冲放电产生的高能电子可以产生强氧化性的自由基,对NO进行氧化,同时还可以直接打断N-O键,游离态的N原子大部分生成了N2分子。线筒式放电结构氧化NO的能力明显优于线板式放电,与除尘能力具有一致性。氧化效率随着电压的升高而升高,由于一定电压下对NO的处理量趋于定值,氧化效率与NO的初始浓度具有重要的关系,同时也受NO2浓度的影响。在该文讨论的反应器中,当脉冲峰值电压达到50kV,NO初始体积分数低于10-4时,NO的氧化率可以达到90%以上。氧化产物NO2可以在湿法脱硫设备中脱除。     

电除尘改造对厂用电的综合影响分析

对比2台机组大修前后引风机、电除尘器用电单耗变化情况,对电除尘控制系统改造的节能效果进行了综合分析,得出电除尘改造后虽然对引风机单耗有一定的负面影响,但电除尘器本身节电效果显著,除尘效果有了明显改善,从机组整体来看,所起的节能降耗作用也是很可观的。     

Combined use of an electrostatic precipitator and a high‐efficiency particulate air filter in building ventilation systems: Effects on cardiorespiratory health indicators in healthy adults

High‐efficiency particulate air (HEPA) filtration in combination with an electrostatic precipitator (ESP) can be a cost‐effective approach to reducing indoor particulate exposure, but ESPs produce ozone. The health effect of combined ESP‐HEPA filtration has not been examined. We conducted an intervention study in 89 volunteers. At baseline, the air‐handling units of offices and residences for all subjects were comprised of coarse, ESP, and HEPA filtration. During the 5‐week long intervention, the subjects were split into 2 groups, 1 with just the ESP removed and the other with both the ESP and HEPA removed. Each subject was measured for cardiopulmonary risk indicators once at baseline, twice during the intervention, and once 2 weeks after baseline conditions were restored. Measured indoor and outdoor PM_2.5 and ozone concentrations, coupled with time‐activity data, were used to calculate exposures. Removal of HEPA filters increased 24‐hour mean PM_2.5 exposure by 38 (95% CI: 31, 45) μg/m³. Removal of ESPs decreased 24‐hour mean ozone exposure by 2.2 (2.0, 2.5) ppb. No biomarkers were significantly associated with HEPA filter removal. In contrast, ESP removal was associated with a ?16.1% (?21.5%, ?10.4%) change in plasma‐soluble P‐selectin and a ?3.0% (?5.1%, ?0.8%) change in systolic blood pressure, suggesting reduced cardiovascular risks.     

Numerical modeling on simultaneous removal of mercury and particulate matter within an electrostatic precipitator

A computational fluid dynamics (CFD) model coupled with gas-particle mass transfer, electrohydrodynamic (EHD) effect, electric field, particle motion and particle charging is established to advance the understanding of combined particulate matter precipitation and mercury capture within industrial electrostatic precipitators (ESPs). The comparisons between experimental data and numerical results demonstrate that this model can reasonably predict the mercury removal efficiency by powdered sorbent injection (PSI). The mechanism of simultaneous removal of mercury and particulate matter is then discussed in detail by considering the complex interactions among multi-physics. The influences of particle size, mercury concentration, particle injection rate and the EHD effect are investigated. The simulation results indicate that the mercury removal process is primarily controlled by the sorbent particle residence time, surface area and mass transfer rate. Accordingly, reducing the size of sorbent particles (activated carbon) can promote mercury removal efficiency while decreasing the particle collection efficiency. Increasing the initial mercury concentration and adsorbent mass loading also benefit mercury adsorption by influencing the mass transfer rate and the surface area. The EHD effect plays important roles in mercury removal and particle collection by means of altering the flow patterns and particle migration. The two mechanisms of in-flight and wall-bounded mercury adsorption affected by ionic wind are also evaluated and some interesting phenomena are observed.     

一种新型直接耦合式静电除尘脉冲电源

研制了一种新型静电除尘脉冲电源。该电源采用脉冲电容器通过开关直接对静电除尘器放电产生脉冲的工作方式,以封闭式循环旋转吹气型场畸变火花间隙为开关元件,以单相Ｔ形Ｌ—Ｃ变换器为恒流充电回路,具有充电速度快、效率高、充分利用充电设备容量、脉冲幅值和重复率易调节、工作稳定、重复率高、寿命长、工作电压高、通流能力强、噪音小等优点。模拟试验中,以接地的１２０ｋΩ水阻为负载,当脉冲回路的放电电容为０．０７７μＦ,开关工作电压为５８．７ｋＶ时,脉冲电源可稳定地工作在４０Ｈｚ。     

高烟气流速下湿式静电除尘器脱除细颗粒物的研究

湿式静电除尘器对PM_(2.5)等细颗粒物有着显著的脱除效果。通过改进其结构,并结合实验,探索了一种可以处理大烟气量的湿式静电除尘器。实验证明,新型湿式静电除尘器9 m长的除尘筒在60 k V电压和4m/s的风速下对PM2. 5的脱除效率可达85%。     

Mercury emissions from coal combustion: modeling and comparison of Hg capture in a fabric filter versus an electrostatic precipitator

Mercury emissions from coal combustion must be reduced, in response to new air quality regulations in the U.S. Although the most mature control technology is adsorption across a dust cake of powdered sorbent in a fabric filter (FF), most particulate control in the U.S. associated with coal combustion takes the form of electrostatic precipitation (ESP). Using recently developed models of mercury adsorption within an ESP and within a growing sorbent bed in a FF, parallel analyses of elemental mercury (Hg(0)) uptake have been conducted. The results show little difference between an ESP and a FF in absolute mercury removal for a low-capacity sorbent, with a high-capacity sorbent achieving better performance in the FF. Comparisons of fractional mercury uptake per-unit-pressure-drop provide a means for incorporating and comparing the impact of the much greater pressure drop of a FF as compared to an ESP. On a per-unit-pressure-drop basis, mercury uptake within an ESP exhibited better performance, particularly for the low-capacity sorbent and high mass loadings of both sorbents.     

HL型恒流源在电收尘器和电除雾器中的应用

通过GGAJ型和HL型两种控电柜在锌冶炼烟气电收尘器和电除雾器扩产改造中的应用效果对比,提出电收尘器和电除雾器应优先选用HL型恒流源控电柜。