大气压冷等离子体喷枪气体温度的比较研究

Comparative Study on the Gas Temperature of a Plasma Jet at Atmospheric Pressure

采用介质阻挡放电等离子体喷枪装置,在大气压下流动气体(氩气和痕量氮气)中产生了稳定的喷射等离子体。通过拍摄喷枪发光照片,研究了喷射等离子体长度随气体流量的变化关系。利用高分辨率光谱仪采集等离子体羽处的发射光谱,通过对发射光谱中N2+的第一负系(B2Σu+→X2Σg+,390～391.6nm)谱线拟合得到了射流等离子体的转动温度。利用该方法研究了不同电压下的气体温度,发现气体温度随着外加电压增加而增大。通过温度计直接测量气体温度随外加电压的变化关系,发现喷射等离子体的气体温度也是随外加电压增加而增大。对两种测量方法获得的气体温度存在的差别进行了解释。

A plasma jet of a dielectric barrier discharge in coaxial electrode was used to produce jet plasma in flowing work gas（argon mixed with trace nitrogen） at atmospheric pressure.The relation between the plasma length and the gas flow rate was obtained by taking the images of the jet plasma.A high-resolution optical spectrometer was used to collect the optical emission spectrum.The emission spectra of the first negative band of N＋2（B 2Σ＋u→X 2Σ＋g,390~391.6 nm） were used to estimate the rotational temperature of the plasma plume by fitting the experimental spectra to the simulated spectra.The gas temperature was investigated by this optical method and results show that the gas temperature increases with increasing the applied voltage.For comparison,a thermometer was used to measure the temperature of the gas emitted from the jet.The results also show that the gas temperature increases with increasing the applied voltage.The gas temperatures obtained by the two methods are consistent.The difference was analyzed.