Numerical simulation of temperature effect on particles behavior via electrostatic precipitators

• Electro-hydrodynamics in wire-plate electrostatic precipitator is modeled with CFD method.
• High temperature weakens the particle charging.
• Increasing temperature will decrease the Coulomb, Saffman lift and Brownian forces and increase the drag force.
• High temperature enhances the interaction between particles and fluid.
• It becomes more difficult to collect particles when temperature increases.

A comprehensive numerical model is developed and applied to study the effect of temperature on the behavior of charged particles in a wire-plate electrostatic precipitator (ESP). In this model, the complex interactions in different temperature conditions between the electric field, fluid dynamics and the particulate flow are taken into account. The finite volume method is used to solve the electric field and Euler-Lagrange model is used to describe particle-laden flows. From the present simulation, the effect of temperature on electro-hydrodynamics (EHD) characteristics and particle charging and tracing are investigated. The numerical results show that high temperature thickens the boundary layer along the plate and strengthens turbulence. The corona onset electric field intensity and mean field intensity both decrease as temperature increases. Considering space charging and diffusion charging, high temperature weakens the particle charging. With the increase of temperature, the Coulomb, Saffman lift and Brownian forces go down while the drag force goes up. The Coulomb force and the drag force are the key forces acting on particles in the ESP for 10 μm particle. The variation of the two forces along with particles trajectories indicates that high temperature enhances the interaction between particles and fluid. Finally, it becomes more difficult to collect particles when temperature increases.