Research On Glow Discharge Plasma Generation Technology For Marine High Temperature Tail Gas Treatment

With the rapid development of international maritime trade,ship exhaust emissions will have a continuous impact on the future air quality,climate and human health.In recent years,plasma technology is in the stage of rapid development,and the application of plasma technology to ship exhaust treatment has good prospects and advantages.However,the exhaust emissions from ships are of high temperature.Most of the current glow discharge studies are carried out at room temperature.Therefore,glow discharge under high temperature is of great value to the market application of glow discharge plasma.In this dissertation,a high temperature atmospheric pressure glow discharge plasma discharge electrode is designed,and the generation of glow discharge plasma in high temperature environment is discussed.The fluid simulation of the designed reactor was carried out.Finally,glow discharge plasma was generated in high temperature environment.The application of glow discharge plasma in high temperature environment was promoted.First,according to the typical dielectric barrier discharge model,the effects of the different material and gas gap distance and the thickness of the dielectric on the discharge characteristics are discussed.It is concluded that the larger the dielectric constant of the insulating material is,the greater the electric field intensity of the gas gap is;the wider the dielectric thickness is,the greater the electric field intensity of the gas gap is,while the distance between gas gaps is constant.The wider the dielectric thickness is,the smaller the field strength of the gas gap.A high temperature spiral contact electrode is designed,and its field strength distribution and discharge characteristics are analyzed.The results show that the "dielectric trap" of alumina ceramics with large dielectric constant and the material surface can store electrons and provide seed electrons for the discharge when the electric field is reversed.These characteristics are conducive to the development of discharge.Secondly,an improved double helix contact electrode structure is proposed.The formation of glow discharge plasma in high temperature environment is studied.The results show that the overall glow discharge area of the double helix contact electrode structure is larger than that of the single helix electrode,and the first wound carbon fiber electrode is completely covered by glow discharge.The discharge is uniform and stable.The interaction between the double helix electrodes increases the maximum electric field intensity,influences the electric field distribution and the power line trend,and ismore conducive to the formation of discharge.With the increase of temperature,the discharge of electrodes becomes more uniform and the electrical discharge is more full and the dark area gradually decreases.This is because the high temperature environment will increase the molecular and electronic kinetic energy.It is easier to collide and ionize,and the high temperature environment will make the spatial diffusion of electrons more intense,which is conducive to the realization of larger area glow discharge.Finally,a laboratory reactor platform is designed,and its design structure and electric field distribution simulation and reactor fluid simulation are analyzed.The conclusion is that the combination of multiple electrodes makes power lines complicated.The distribution of strong field intensity is more uniform.The main reflection area of reactor electrode and gas pollutants is the positive surface and two sides surface of the electrode.Funnel type reactor can slow down the inlet gas velocity,reduce wind speed or reduce the diameter of single electrode,which can reduce the amplitude and area of the velocity behind the electrode.In order to increase the reaction area of the plasma and the pollutant gas,the existence of external electrodes makes the flow of gas between the electrodes more disorder,and the air convolution is formed between the electrodes,thus increasing the chance of being processed.