Numerical evaluation of the interaction between corona discharge and particles/droplets

Abstract

Effects of density, relative permittivity, diameter and mass concentration of typical particle/droplet on the corona discharge process were numerically evaluated. Results demonstrate that the inhibition effect exerted by particles/droplets on the discharge current enhances with the decreasing density and the increasing relative permittivity of particles/droplets. Submicron sulfuric acid aerosol droplets with a concentration of several tens mg/m3 result in a current decrease of more than 20%. The injection of water droplets with a diameter of 5 µm and a mass concentration of 50 g/m3 leads to a reduction in the current by 10%− 100%. A smaller diameter and a higher mass concentration of water droplets result in a stronger inhibition effect on the discharge current. In an electrostatic precipitator containing several discharge electrodes, the inhibition effect leads to a difference in the discharge current at different discharge electrodes. Spraying water droplets near the collection electrode or from multiple surfaces results in a weaker influence on the corona discharge process than spraying from the inlet. The effect of the initial velocity of sprayed water droplets on the discharge current is negligible.