Study On The Degradation Of PM2.5 By Surface Dielectric Barrier Discharge Of Double Helical Electrodes

With the economic development and rapid urbanization,urban air pollution has become the focus of common concern in China.In recent years,many cities have severe haze weather for many times,and the detection index of PM2.5 is the peak,which has a huge impact on daily work and life,and all kinds of new practical technology arises for the environmental pollution.The surface dielectric barrier discharge(SDBD)could generate plasma with the property of large area and uniformity on the dielectric.It has some advantages such as controlled easily,low power consumption,high power density and generating a variety of active particles,which make it have a promising application prospect at the field of environmental protection,airflow control andbiomedical.We design the surface dielectric barrier discharge(SDBD)of double helical electrodes and build the photoelectric detection platform.The discharge voltage,current and other optical parameters of the new DBD in the process of discharge are studied,and the cyclic degradation of PM2.5 at a certain concentration are also studied,the main work is as follows:1?This paper reviews the research status of environmental technology at home and abroad,states the conventional degradation method of PM2.5,introduces the application of plasma technology in the field of environmental and the work principle,characteristics and advantages of PM2.5 degradation using SDBD.2?A SDBD of double helical electrodes is designed,and the relationship between the applied voltage amplitude and discharge current,discharge power,dielectric capacitor C,gap capacitor C is discussed.The results show that with the increase of applied voltage amplitude,the greater the discharge current,the greater the discharge power.When the voltage frequency is 7.5kHz,the voltage increases from 6kV to 7.5kV,the current growth rate is 80%,the discharge power growth rate is up to 43%.The dielectric capacitor C has a little change,but the gap capacitor C is nonlinear due to the ionization level of the air.The three dimensional electric field distribution is obtained by simulation,and the plasma thickness is estimated to be 1.5mm.3?The experiment on the degradation of PM2.5 by SDBD of double helical electrodes is done.The vibration temperature of plasma is calculated using emission spectrum.We explores the effect of voltage amplitude and frequency on vibration temperature.The effect of some factors,such as the initial concentration of smoke,voltage amplitude,frequency and fan speed,on PM2.5 degradation rate is studied.At the same time the effect of fan speed and voltage amplitude on ozone concentration is also explored.The results show that we do experiment on the smoke of 200?g/m for 24 min with the condition U=7kV?v=0.5m/s and f=9kHz,the PM2.5 degradation rate is 80%,the largest concentration of ozone controlled is 66 ppm.In this paper,the SDBD of double helical electrodes,developed for PM2.5 degradation,can provide a new technical means for local air purification.