Study On The Particle Removal Characteristics In A Novel Wire-plate Electrostatic Precipitator

As an important dust removal equipment,electrostatic precipitator(ESP)is widely used in the purification of coal flue gas.However,with the increasingly strict limits of new emission standards,the performance of electrostatic precipitator needs to be continuously improved.Electrostatic field,flow field,particle charge and trajectory are the important factors that affect and characterize the performance of particle removal.At present,many researches focus on the structure improvement of the discharge and collecting electrodes of ESP.But there are few studies on the matching performance of the two electrodes.In this paper,the particle removal characteristics were studied under different matching modes of the discharge and collecting electrodes.The influence rules were investigated among the electrostatic field,flow field,particle trajectory and dust removal rate.A good matching mode was obtained to improve the performance of ESP.The main research contents and conclusions are as follows:1.In this paper,a kind of ESP with expansion-shrink plates is designed.The effects of three types of expansion-shrink plates(M1,M2 and M3)on the electrostatic field,flow field,particle trajectory and dust removal rate in ESP were analyzed by numerical simulation.And the ESPs with expansion-shrink plates were compared with the conventional ESP with parallel plates.It is found that M3-ESP has good dust collection performance.The addition of expansionshrink plate is beneficial to strengthen the electric field near the collecting electrode,effectively enhance the charge capacity of particles,and improve the dust collection rate.This advantage is especially prominent at high voltages and low flow rate.At the same time,the expansion-shrink plate increases the surface area of the collecting electrode,which is helpful for particle collection.In addition,the arrangement of the expansion-shrink plates is closely related to the dust collection rate,and the arrangement of periodic high and low with uniformly spacing is more helpful to improve the particle removal effect.The height of the expansion-shrink plate should be set reasonably to avoid the narrowing of the main airflow channel caused by the high height and to inhibit the phenomenon of particle removal.2.In this paper,a star type discharge electrode was presented.The effects of three discharge electrode configurations(E0-ESP,E1-ESP and E2-ESP)on electrostatic field,flow field,particle trajectory and dust collection rate were investigated in ESP with expansion-shrink plates by numerical simulation.It is found that compared with the cylindrical discharge electrode,the star discharge electrode promotes the corona discharge and strengthens the electric field,and the region with high electric field intensity near the discharge electrode expands.The arrangement of the discharge electrode also has an important effect on the particle removal performance.E2-ESP effectively enhances the electric field in the inlet region.Particles have a strong charge capacity in the front section of the channel and far away from the discharge electrode area in E2-ESP.And it increases the charge of fine particles and makes up for the weak charge capacity of fine particles caused by small surface area.Without occupying the channel space in the Y direction,the main stream acceleration caused by the channel narrowing is alleviated duo to addition of expansion-shrink plates.These are helpful to improve the efficiency of particle dust collection and have good comprehensive performance.3.In this paper,an ESP dust collection rate experimental system was designed and established.Through experiments,the accuracy of the numerical simulation method was verified.It is concluded that the ESP combined with the M3-ESP collecting electrode and the E2-ESP discharge electrode has better comprehensive performance.