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Abstract Electrostatic precipitators (ESPs) are considered as cost-effective technology for separating the charged particle from flue gas. In this paper, a modified ESP model was developed to investigate the effects of charged particle on the electric field, ion density, particle charging and migration regarding various particle concentrations. Coupled processes of corona discharge, flow field, particle charging and transport were considered. Results showed that the particle space charge presented trajectory-dependent effects on the distributions of electric field and ion density in the gas flow direction. With the particle concentration increasing from 0 to 200 mg/m3, the electric field strength on the electrode surface was inhibited from 1.32 × 106 to 1.24 × 106 V/m, while the electric field strength on the plate surface was raised from 7.1 × 105 to 8.3 × 105 V/m. By contrast, the ion density within the whole domain decreased when particle space charge considered, and it decreased by more than 40% when the particle concentration was 50 mg/m3. The particle charging rate decreased due to particle space charge effects and consequently the overall particle charge decreased by 45.7% as particle concentration increased to 200 mg/m3. The correlation between collection efficiency and corona current was discussed, and it showed that the two didn't vary synchronously with the increasing concentration. A criterion for efficiency deterioration, under corona suppression conditions, was first proposed for instructing ESP design and operation. Graphical abstracts Unlabelled Image Highlights • A modified ESP model was established to study the particle space charge effects. • Corona discharge, flow field, particle charging and transport were coupled. • Correlation between corona current and collection efficiency was analyzed. • A criterion for ESP performance deterioration was first proposed. [ABSTRACT FROM AUTHOR]

The severe current reduction and a significant drop in collection efficiency appear when containing ultrafine particles. In this study, a comprehensive model was developed to investigate the role of optimizing the corona wire arrangement in the electrostatic precipitator (ESP) performance enhancement. The total current increased initially and then decreased with the increase in wire-wire distance (without PM 0.1). The decrease in the wire-plate distance could enhance the corona discharge. The collection efficiencies for 1, 2.5, and 5 μm enhanced by 58.1%, 45.2%, and 37.4% when the wire-plate distance decreased from 300 mm to 100 mm (without PM 0.1), respectively. Compared with the wire-wire distance optimization, the ESP performance enhancement was more obvious for wire-plate distance optimization when containing ultrafine particles. The collection efficiency of 5 μm particles could increase by 323.2% when the PM 0.1 concentration reached 50 mg/m3. Meanwhile, some potential methods were proposed to improve ESP performance in treating ultrafine particles. [Display omitted] • A comprehensive model considered particle space-charge was developed. • The role of corona wire arrangement in corona discharge and particle motion was quantified. • Variation of ESP performance when containing ultrafine particles was analyzed. • Some potential methods were proposed to relieve corona suppression. [ABSTRACT FROM AUTHOR]

The electrostatic precipitator is widely used in many industries, such as power plants, waste incineration and glass production. The optimization of electrode and collecting plate is important for higher efficiency in electrostatic precipitator. In this work, the simulation results of electrical characteristics, particle charge, migration velocity and collection efficiency in four electrode configurations and two shaped collecting plates are presented. The results show that the distributions of the electric field and current density are different in each electrode and plate configuration. Sharpness of the discharge needle wire (NW) can simply lead to the high peak value of the electric field strength near the electrode wire surface. The concave-convex structure of the collecting plate can easily generate high current density near a corner of the BE collecting plate. The particle migration velocity and relative collection efficiency are calculated within eight different electrode-plate combinations. The BE collecting plate and needle wire electrode (BENW) configuration has the highest collection efficiency. The implication of the results in practice is discussed on this basis. Unlabelled Image • The effects of electrode wires and plates on ESP performance were studied numerically. • The electrical characteristics and particle transports were examined under different configurations. • The optimum electrode-plate configuration was identified under certain conditions for practice. [ABSTRACT FROM AUTHOR]