旋转滑动弧等离子体固氮的物理特性

Characteristics of rotating gliding arc on nitrogen fixation

采用旋转滑动弧等离子体(RGA)进行固氮实验研究.为了考察在N_(2)/O_(2)气氛下放电的物理特性,利用光谱仪、高速摄影仪、示波器等进行研究,考察放电参数、气体体积流量对于氮气的振动温度、氮气的转动温度和电弧特性的影响,以及以上因素对于RGA固氮效果的综合影响.实验结果表明,放电过程可以生产大量NO_(x)气体,通过光谱检测可以清晰观测到NO的γ带系、氮气第二正带系和氮气离子第一负带系.增加放电的氧气体积分数,氮气的振动温度将升高,并伴随着固氮产出的提高;在一定范围内(10%~40%),氧气体积分数提升在提升固氮效果的同时,对放电稳定性有不利影响.综合分析表明,接近空气的放电气氛(氧气体积分数为20%)或直接采用空气放电,能够实现旋转滑动弧等离子体放电固氮的最佳效果.

Rotating gliding arc(RGA)was applied to nitrogen fixation.Optical diagnosis,high speed photography and oscilloscope were used to investigate the physical characteristics of the N_(2)/O_(2) discharge.The effects of discharge parameters and volume flow rates on vibrational temperature,rotational temperature and arc characteristics were analyzed,which influenced the nitrogen fixation performance of RGA.Results show that NOx of high concentration was produced in the discharge process,and typical NO-γ,N_(2)(C-B)and N_(2)^(+)(B-X)bands were detected by optical diagnosis.The increase of oxygen volume fraction would raise the vibrational temperature of nitrogen,accompanied by the rise of NO_(x) concentration.Higher oxygen volume fraction(10%~40%)reached better output while led to instability of discharge.The mixture of 20%oxygen volume fraction or the air could be the most optimum gas supply to reach better nitrogen fixation performance.