CFD simulation of high-temperature effect on EHD characteristics in a wire-plate electrostatic precipitator☆

摘要

A computational fluid dynamics (CFD) model is carried out to describe the wire-plate electrostatic precipitator (ESP) in high temperature conditions, alming to study the effects of high temperature on the electro-hydrodynamic (EHD) characteristics. In the model, the complex interactions at high temperatures between the electric field, fluid dynamics and the particulate flow are taken into account. We apply different numerical methods for different fields, including an electric field model, Euler–Lagrange particle-laden flows model, and particle charging model. The effects of high temperature on ionic wind, EHD characteristics and collection effi-ciency are investigated. The numerical results show high temperature causes more significant effects of the ionic wind on the gas secondary flow. High viscosity of gas at high temperature makes particles follow the gas flow pattern more closely. High temperature reduces the surface electric strength, so that the mean electric strength weakens the space charging. On the contrary, there is an increase in the diffusion charging at high tem-perature compared with at low temperature. High temperature increases the ratio of mean drag force over mean electrostatic force acting on the particles which may contribute to a decline of collection efficiency.