Numerical Study On Strengthening The Removal Of Fine Particles In Wire-plate Electrostatic Precipitators

In recent years,China’s economy grows rapidly and stably,energy consumption continues to increase,which caused environmental damage.The government paid more and more attention to the fine particulate pollution problems produced by fossil energy.For this reason,professionals in industry and science put forward a variety of methods and devices to reduce the fine particulate pollution.Electrostatic precipitator is a dust removal equipment widely used in thermal power generation.With the use of electrostatic precipitators,the collection efficiency of fly ash particles in flue gas of thermal power plant can reach more than 99%,but the collection efficiency of submicron particles whose diameter less than 1μm can only reach 70%~80%.The present article take this as the background,based on the Fluent software,the numerical simulation of the fine particle charging,transport and collection process in the wire-plate electrostatic precipitator has been carried out in order to obtain the idea of strengthening fine particles collection.Firstly,numerical study on the charging and transport behaviors of fine particles has been carried out,based on wire-plate electrostatic precipitators with 3 wire electrodes.The effect of voltage on wires,inlet height and wire distance to particle charging and transport behaviors,and the influence of the wires’ arrangement structure in electrostatic precipitators on the particle collection effect,are analyzed in detail.Results indicate that,in case of the same amount of voltage increase,the voltage increase in the high voltage range is better for improving the particle capture effect in precipitators.The particles injected from the center of the precipitator are influenced most intensely,the particles injected at about 5mm from the center of the precipitator are worst in particle capture effect.The larger the particle size,the greater the distance the particles move towards the collecting plate,and the larger the particles are more sensitive to the different inlet locations.Increasing the wire distance is better to enhance the particle capture effect,within a certain range,and the larger particle size causes the more obvious enhancement.After changing the wires’ arrangement structure of the electrostatic precipitators the particle collection effect improvement is obvious.Finally,the influence of different wires arrangement structures on the particle collection efficiency was studied by numerical simulation.The results show,that the change of the wires arrangement structures(M1,M2)will cause the two adjacent wires in the center of the precipitator to produce a region with low electric field intensity.The generation of this region has a weakening effect on the collection of small size particles.Compared with the wires horizontal arranged electrostatic precipitator(M0),the M2 electrostatic precipitator has a good collection effect on particles with diameter of 0.6μm,0.8μm and 1.0μm,while the particle collection efficiency of M1 electrostatic precipitator is better in full particle size range.The higher the flue gas velocity,the lower the collection efficiency of the particles,and the lower efficiency of the M1 and M2 electrostatic precipitators at the larger flue gas velocity.As the voltage increases,the particle collection efficiency increases,and the M1 and M2 electrostatic precipitators are more efficient at larger voltages.