| At the same time as the rapid economic development,there are also phenomena that the concentration of particulate matter exceeds the standard in many cities in China.People's health is greatly threatened by fine particles,and it is imperative to control the pollution of fine dust.As the public's attention and participation for the treatment of air pollution is becoming stronger and stronger,national and local governments are increasingly strict on the formulation of environmental protection policies,and the crackdown on illegal activities has become increasingly stringent,the need for efficient dust collectors has become more and more urgent.The series of advantages of the electrostatic precipitator make it a major trend in the field of dust collectors.However,the drawbacks of conventional electrostatic precipitators for less efficient at removing ultra-fine particles also make the society pay more and more attention to the upgrading and reconstruction of electrostatic precipitators,so as to solve the problems of low ion concentration,low charge concentration,low probability of contamination,huge volume,excessive energy consumption and other issues.A new type plate of electrostatic precipitator is designed in this paper.The shape of the plate is V-shaped in top view,with arcs on both sides.The new structure makes the air flow direction and the plate form an angle,which can guide the flow direction of the air flow,reduce the operation resistance of the equipment.The velocity difference is formed between the high speed turbulence area in front of the plate and the low wind speed laminar flow area at the back of the plate,which is beneficial for the air flow to form double vortex on the back of the plate,prolonging the residence time of the fine dust particles,enhancing the probability of charge and collision of the dust particles,and increasing the collection efficiency of the ultra-fine dust.When the corona wire is set in the gap of the collecting dust plate facing the air flow,the kinetic energy of the charged particles is greatly increased,and the ion transport item is increased,thereby increasing the ion concentration and the driving velocity of the particles,thereby increasing the dust removal efficiency.In order to discuss the dust removal performance of this new type of electrostatic precipitator and optimize its design,this paper adopts Pro/E to build a 3D geometric model;ANSYS ICEM is used for parameter setting,meshing,etc.;ANSYS FLUENT numerical simulation software is used to simulate the pure gas phase and gas-solid two-phase coupling,the internal flow field characteristics and the movement law of dust particles are calculated and analyzed to obtain the structural parameters and applied voltages at the best performance.The electric field program is compiled and the electric field environment is load by UDF;combining with the simulation results,a set of laboratory-scale new type plate electrostatic precipitator device is designed to verify the dust removal efficiency experiment.The result is as follows:(1)The results of the simulated internal flow field of a pure gas-phase precipitator show that,when the row spacing L was 110 mm,the angle ? between the plates is 60°,when the average velocity v is 3.6m/ s,the internal flow field of the electrostatic precipitator is basically stable.The turbulence intensity and velocity near the discharge electrode are relatively high.And the turbulence intensity can reach a maximum of about 50%,and the minimum is about 9%;the velocity near the discharge electrode can be as high as 5 to 6m/ s,the plate back on the reference horizontal section of the precipitator has more double vortexes and better stability,its performance is best at this time.(2)The coupled simulation of gas-solid two-phase displays the trajectory of dust particles visually with DPM model,and the movement direction inside the electrostatic precipitator shows a clear vortex shape,which effectively prolonging the residence time of the particles,increasing the probability of coagulation and inertial separation of dust,thereby increasing the trapping efficiency of ultra-fine particles.When the applied voltage of the electric field is changed in the range of 0-23 kV,the dust removal efficiency obviously increases with the increase of the voltage,and the performance is best at 23 kV.(3)The dust removal efficiency verification experiment results are the same as the overall trend of the simulation results,and the degree of compliance is extremely high,and the specific values are slightly deviated.When the applied voltage of the electric field is 23 kV,the particle sizes of the dust particles are 0.1 ?m,0.5 ?m,1 ?m,2.5 ?m,5 ?m,10 ?m respectively,the dust particle collection efficiency is 81.3%,85.7%,92%,93.6%,95.4%,98.6%.From the point of ion concentration,it is verified that the new plate electrostatic precipitator is feasible by increasing the momentum of ions,reducing the ion recombination rate,and increasing the ion concentration to improve the dust removal efficiency.(4)The new type plate electrostatic precipitator can form good vortex airflow during operation.It can well adapt to high velocity operation,the inlet velocity is kept within a large range,and the dust removal efficiency is relatively stable.Compared with conventional electrostatic precipitators,it has a great advantage in dealing with the amount of flue gas.It can greatly reduce the device volume,while improving the efficiency and economic suitability.The pressure loss of the new type of plate electrostatic precipitator is very small;the pressure loss is only less than 20 Pa when the average velocity is 1.8 m/ s,is about 20% of the traditional electrostatic precipitator.With stable pressure and energy saving,it is more suitable for practical industrial production applications.In summary,the new type plate electrostatic precipitator can efficiently capture ultra-fine particles,and its small size and low energy consumption have high economic feasibility and technical advantages.It is a new type of electrostatic precipitator with market application prospects. |
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