Experimental Study On The Actuation Characteristics Of Sliding Discharge Plasma And Formaldehyde Degradation

Formaldehyde(CH2O)is one of the common indoor air pollutants,which is recognized as a carcinogen by the World Health Organization.This article will address the issues of high power consumption and low degradation efficiency in the current plasma degradation of formaldehyde.The specific research work is as follows:(1)Independently developed a microsecond pulse plasma power supply.To meet the practical needs of high voltage and low current during plasma discharge,a semiconductor highvoltage switching circuit design scheme is determined;Simulate the dynamic circuit using Simulink simulation platform to obtain an ideal pulse waveform with a pulse width of 2 μs;Finally,a microsecond pulse plasma power supply was built and tested for performance.The results showed that it effectively outputs 0-20 kV adjustable high voltage,with a voltage pulse width of 1.5 μs,an output frequency of 0-10 kHz,and a duty cycle of 0.1-99%.The experimental test results were superior to software simulation.(2)Study on the actuation characteristics of sliding discharge plasma.Due to the low efficiency of formaldehyde degradation in dielectric barrier discharge(DBD),a sliding discharge(SD)plasma actuator is used in this paper and its characteristics are studied.Firstly,electrical characteristic experiments have shown that when microsecond pulses are used to excite sliding discharge,the actuation voltage is 12 kV and the instantaneous power is 14.16 kW,which can concentrate energy and release it in a shorter time to form a larger instantaneous power,rapidly accelerating particle motion in a short period of time;Secondly,the temperature characteristic experiment shows that the maximum surface temperature of the sliding discharge dielectric is 60.7℃,and the heat transfer area is covered with the distance between the two electrodes;Finally,the aerodynamic characteristics experiment found that compared to DBD,sliding discharge under microsecond pulse actuation can generate shock wave characteristics,with the wave speed is about 380 m/s,inducing the jet to flow in the opposite direction to DBD.(3)Experimental study on the degradation of formaldehyde by microsecond pulse sliding discharge plasma.The effects of actuation voltage and discharge structure on the degradation of formaldehyde were discussed,and experimental studies on the concentration of by-product ozone(O3)were also conducted.Experimental analysis shows that the higher the plasma actuation voltage,the greater the kinetic energy of free electrons.Firstly,the active particles generated by the discharge can be carried away from the wall surface and fully fused with formaldehyde gas;Secondly,the higher instantaneous power promotes the thermal motion of molecules,and the impact on the surface of the actuator increases the surface temperature of the dielectric,making gas molecules more prone to dissociation;Finally,under the same experimental conditions,the degradation rate of sliding discharge increased by 34.1%compared to DBD,and the byproduct ozone generation rate was almost the same(sliding discharge was 0.3 mg/m3·s-1 higher than DBD).