| At present,indoor air pollution is becoming more and more serious,and harmful gases affect people's health for a long time.With high-energy active groups and oxidized particles,plasma can not only effectively decompose major air pollutants such as formaldehyde and TVOC,but also kill bacteria and viruses.As a new method to remove air pollutants,plasma technology has a broad application prospects.In this paper,electric field simulation,fluid simulation and discharge experiment are combined to explore the conditions for forming stable glow discharge under atmospheric pressure,and glow discharge electrode,array discharge module,primary filter module,duct device,exhaust gas treatment layer and ac power supply are designed.A plasma indoor air purifier for formaldehyde treatment has been preliminarily developed,which is of great significance for promoting the application of plasma technology and the development of air purification.First of all,this study combines a single-sided dielectric barrier discharge and non-uniform electric field distribution mechanism,and designed two types of discharge electrodes:hollow barrel carbon fiber spiral and double-sided metal sheet,which provide equipment support for purifier to achieve stable atmospheric pressure glow discharge.Maxwell software is used to build the electrode model and simulate the spatial electric field and electric field line vector distribution;at the same voltage,the area radius of the gas breakdown field strength(E?3×10~6V/m)of the double-sided metal electrode is 35.5%larger than that of the carbon fiber spiral electrode,and the volume of the formed diffused plasma increased by about 1.83 times.In order to improve the efficiency of plasma removal of pollutants,a multi-row array discharge module based on two kinds of electrodes is designed,which has good glow discharge characteristics.Secondly,a folding primary filter module equipped with ISO Coarse 70%grade filter element was designed to effectively remove PM2.5 and larger solid particles;A plasma ac power supply with the highest output voltage of 6k V and the highest frequency of 20k Hz is designed after the deployment test with the discharge module.GAMBIT and FLUENT fluid software are used to analyze the influence of three array discharge module with single spiral,double-sided metal sheet and louver on the air flow in the straight-through air duct;the velocity vector distribution of the airflow in the two side inlet and flared air ducts is simulated,the results show that increasing the flow path of the airflow and cooperating with the staggered discharge module are beneficial to improving the pollutant removal efficiency.The ozone emission of a single spiral electrode under different voltages within 60 minutes is tested,and the results all met national safety standards;a exhaust gas treatment layer with Mn O2 as catalyst and activated carbon as carrier is designed to absorb and decompose ozone formed by glow discharge.Finally,two spiral electrode modules with 16 copper pillars and 14 nickel-plated copper wires are tested for discharge,both can form large-area glow discharge and generate plasma with good uniformity.The natural attenuation of formaldehyde gas under normal temperature and pressure is measured by 3m~3experimental purification cabin and HTV formaldehyde detector,the formaldehyde concentration decreased by about 1.85%within 50 minutes,and the slope of the attenuation curve is about 0.0007.Three electrical modules are assembled into a single purification layer,containing 21glow discharge electrodes,and the preliminary removal effect of formaldehyde was tested in the purification cabin;according to the data records of 15 times,the formaldehyde concentration decreased by 30.53%,about 16.5 times of the self-attenuation,while the theoretical formaldehyde removal rate of the purifier prototype equipped with 120 to 135 electrodes could reach more than 90%. |
PDF Full Text Request