Spectral Diagnostics Of Plasma Produced By Pulsed Arc Discharge In INO Producer

Since 2003, our team has made many researches, the former work is mostly focus on discharge conditions, but the study on the discharge plasma parameters is less.As a part of the task, the purpose of this paper is to measure the optical emission spectroscopy of pulsed arc discharge in air. And calculate the plasma temperature of different discharge conditions by using Boltzmann equation. Then analyze the influence of the gas flow rate, the distance between electrodes, the material of electrodes on the plasma temperature. and as a base for searching the optimize discharge conditions of controlling NO₂ and other deleterious gas, acquire the significative conclusions. The main conclusions are as follows:(1)The phenomena of spectrum intension is depressed gradually along with the increase of gas flow rate was be found through investigating the optical emission spectroscopy of different gas flow rate. When the flow rate increased from 1l/min to 4l/min, the spectrum intension decreased rapidly; decreased slowly when the flow rate increased from 4l/min to 7l/min.The plasma temperature of pulsed arc discharge increased at beginning and then decreased with the increase of gas flow rate, when the gas flow rate is 3l/min, the plasma temperature has a max.(2)The spectrum intension and the plasma temperature on the conditions of different gap distance also be analyzed and calculated. It can be seen that the emission spectrum intension and the temperature of pulsed arc plasma with gap distance is not a linear relationship, when the gap distance is 3.5mm, the spectrum intension of N4+ has a high value. The temperature has a maximum at about the 3.5mm distance between electrodes.(3)It was found that the spectrum intension and the plasma temperature were higher than others when Al as the needle electrode,and that of Cu was the lowest,based on the study of effects of material of electrodes on the spectrum intension and the plasma temperature. The number of excitated particles is different when the material of electrodes are different,which must affect the concentration of NO,NO₂ and the ratio of NO/NO₂.(4) The component in NO produced by pulsed arc discharge was investigated,it's found that the mixed gas contains most of NO,part of NO₂ and a small quantity of H2O,O3,CO,CO2 and CH4,without N2O.(5) After studying the effects of plasma temperature on the concentration of NO, NO₂ and the ratio of NO₂/NO, the follow results were found: when the electrodes distance and the material of electrodes were constant, the concentration of NO, NO₂ and the ratio of NO₂/NO has no relation with the plasma arc temperature; when the flow rate and the material of electrodes were constant, the concentration of NO and the plasma arc temperature increased non-linearly with increasing the distance between electrodes;and the temperature of different material has evident effect on the concentration of NO, NO₂.