Comparison of discharge mechanism of negative corona between hyperboloid and hemispherical electrodes

Electrostatic precipitators based on corona discharge are a research hotspot in recent years. It is of great significance to investigate the characteristics of corona discharge under different system parameters for improving the dust removal efficiency. In this manuscript, the continuity equations coupled with Poisson’s equation are solved by the finite element method (FEM) to explore the different mechanisms of the generation of Trichel pulses when hyperboloid and hemispherical electrodes are used in negative corona discharges for a needle-plate configuration under atmospheric pressure. The fitting curve of the Trichel pulse frequency versus systematic macro parameters, including the applied voltage, the needle tip radius and the needle-plate distance, are given and their mechanisms are analyzed. Subsequently, the features of the Trichel pulses of the hyperboloid electrode and the hemispherical electrode at similar power are compared. From precipitation point of view, the hemispherical electrode is obviously better than hyperboloid electrode.