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Electrode configuration is a key parameter that affect the operation of ESPs. In this study, through a wire-plate ESP at wide temperatures, the dynamic and ultimate removal characteristics of coal-fired power plant and coal pyrolysis furnace fly ash (ash A and B) with different resistivity under four electrode configurations were investigated. For ash A, the sawtooth electrode DE3 exhibited the largest current density under identical applied voltage. Each discharge electrode configuration had its efficient operating temperature. DE3 had the best removal performance when the temperature was 363 K and DE1 performed excellently at 500 K. For ash B, the removal efficiency with rod electrode DE4 was only 91.2% at 700 K in the simulated inert atmosphere. Through the optimization of electrode configuration with DE1, particles were effectively removed with collection efficiency exceeding 95%, and the particle removal efficiency of each diameter distribution was remarkably higher than that of DE4. Unlabelled Image • Four different electrode configurations were conducted to enhance the performance of ESP at high temperature. • The dynamic and ultimate removal characteristics were investigated. • The barbed electrode performed relatively best to remove particles at high temperatures. • A discharge electrode optimization with temperature regulation method was proposed. [ABSTRACT FROM AUTHOR]

Abstract A hybrid modeling scheme for electrostatic precipitators (ESPs) integrating particulate matter (PM) removal mechanism and the data-driven compensation method is presented in this article. The structure of the training and coupling method for the mechanism model, which considers electrodynamics, including corona discharging, particle charging, and removal, and the data-driven method that was trained based on operation data to compensate for the distortion and flaw of the mechanism model was constructed. Design parameters and operation data of an ESP in a coal-fired power plant were collected for model training, and prediction performances were compared. Different combinations of correction factors, including exponential, proportional, and bias, were studied. The form with the highest prediction R2 of 0.889 on the training set and 0.867 on the validation set was chosen as the mechanism part of the model. Deep neural networks with the highest R2 of 0.885 on the training set and 0.857 on the validation set were also trained as a comparison group. The performance of the hybrid model achieved a R2 of 0.933 on the training set and 0.887 on the validation set and outperformed the mechanism and data-driven models, thereby indicating that the hybrid modeling method could enhance prediction performance while maintaining the generalization capability of the PM removal mechanism in ESP. Graphical abstract Unlabelled Image Highlights • Hybrid modeling scheme for electrostatic precipitators is proposed. • PM removal mechanism model with best combined of correction factors is derived. • Performance of deep neural networks is compared with mechanism models. • Data-driven model is coupled with mechanism model to enhance performance. • Hybrid model has better prediction performance compared with other models. [ABSTRACT FROM AUTHOR]

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]

Ionic wind propulsion plays a vital role in charged particle transport during flue gas purification, which is closely related to high-efficiency particulate removal. Here, we establish a comprehensive model to investigate the effect of ionic wind on the transport and deposition of charged particles. The high-speed ionic wind disturbs the space flow field in a meaningful way, which also causes the formation of 'U'-shaped high-speed zones within the near-plate region. After the dusty flue gas enters the electrostatic field, due to the disturbance of high-speed ionic wind, apart from the electric force, particle transportation is acted by ionic wind propulsion. Charged particles can be significantly accelerated with ionic wind propulsion, while it also introduces an uneven distribution of deposited particles. Based on these findings, a novel electrostatic precipitator is proposed to optimize the space flow field, and the collection efficiency and dust layer shape are both significantly improved. [Display omitted] • A comprehensive particle removal model considered ionic wind is developed. • The flow field is visualized through different presentations to indicate ionic wind performance. • The roles of ionic wind in particle transport and deposition are quantified. • A novel electrostatic precipitator is proposed to improve removal performance. [ABSTRACT FROM AUTHOR]