Load Modeling And Power Supply Design Of Coaxial Cylindrical DBD For NO Conversion

Dielectric Barrier Discharge?DBD?can easily generate low-temperature plasma at atmospheric pressure,produce strong chemically active particles such as radicals,gas atoms,excited atoms,and ions,and cause chemical reactions that are difficult to perform under normal conditions.One of the major air pollutants,Nitric oxide?NO?,is chemically inert and difficult to remove by conventional chemical means.It can be converted to NO₂,which is chemically active,and can be removed much more easily,by oxidation reaction caused by DBD.The DBD technology has received extensive attention for its high NO conversion rate,low equipment cost,and simple maintenance.The voltage source resonant converter is a DBD driving power supply widely used in industry,and its performance greatly affects the effect of NO removal.Compared with the structure of medium on both side,the coaxial cylindrical reactor having medium on only one side has a simpler structure and better heat dissipation,and the electrode material can participate in the physicochemical reaction and improve the DBD treatment effect.It is often used for gas treatment and ozone generation.However,when this kind of load is discharged,the forward and reverse half-cycle discharge characteristics are different,and its load equivalent model is also half-cycle asymmetric.For this traditional model is no longer applicable,it is necessary to propose a new equivalent model to guide the design of DBD power supply.Therefore,in this paper,a half-cycle asymmetric equivalent load model is established for this kind of load,and the state analysis of the voltage source resonant converter with half-cycle asymmetric load,the optimized design of the DBD power supply,the construction of the gas treatment experimental platform,and the NO removal experiment is carried out.First of all,the forward and reverse half-period electrical characteristics of the traditional nonlinear clamping model are completely symmetrical,which is not true on a coaxial cylindrical reactor with a medium on only one side.To this end,this paper studies and discusses the asymmetric discharge phenomenon of the load at different frequencies and different powers,explains the mechanism,and proposes a half-cycle asymmetric segmented load model,which can accurately represent such loads.Then,based on the half-cycle asymmetric segmented load model,this paper continues to present the operating state of the voltage source resonant converter driving the load,and points out the conditions under which the voltage source resonant converter remains operating in discontinuous current mode.Based on the above analysis,a voltage source resonant converter,a tunable inductor,and a high-frequency step-up transformer are designed and built.The experiment proves that the power supply can work in the expected state,which verifies the theoretical analysis and power supply design theory of this article.A MODBUS remote communication and control system is added for the DBD power supply.Finally,a gas treatment experimental platform using this voltage source resonant converter and the coaxial cylindrical reactor is set up to carry out NO conversion experiments.The influence of electrode materials on the NO conversion rate is studied in this paper.It is shown that the bare electrode materials of the coaxial cylindrical reactor have a great influence on the NO conversion effect.The research on the NO conversion effect under the condition of high gas flow rate and flow rate is carried out.At the high flow rate of 2000L/h,the same NO removal effect as that under the low flow rate environment is still obtained.Under the experimental conditions of this article,the NO conversion rate can reach 97%.The NO conversion rate reached 97%under the experimental conditions in this paper.The effect of power frequency on NO conversion effect under high flow rate and flow conditions is explored.It is found that 20-22 kHz is the most suitable power frequency in the experimental environment of this paper.This part of the study reveals the application value of the coaxial cylindrical reactor DBD under high gas flow rate and flow speed,which has reference and guiding significance for industrial applications.