【作者】 刘涛；

【导师】 张连水；

【作者基本信息】 河北大学 ， 光学， 2006， 硕士

【摘要】 本论文利用针—板电极负脉冲电晕放电实验系统,采用色散荧光发射光谱及时间分辨光谱方法,对电晕放电等离子体特性及大气压NO脱除反应动力学过程进行了实验研究,得到了有意义的研究结果。在对负脉冲电晕放电等离子体特性的研究中,根据跃迁谱线荧光强度正比于激发态粒子数的原理,通过测量不同激发态能级到同一低态能级跃迁谱线的相对荧光强度,就会得到等离子体电子温度和分子激发振动温度的有关信息。研究结果表明,当其它实验条件一定时,电晕放电等离子体的平均电子温度Te随着脉冲峰值电压或样品气压的改变而呈现出近线性的变化趋势。等离子体的分子激发振动温度Tv随着脉冲峰值电压的升高或样品气压的降低先升高至一极大值,而后随峰值电压的继续升高或样品气压的降低而下降。并且,在负电晕放电同一放电脉冲中,有效电子温度Te和分子激发振动温度Tv都随放电时间呈现先升高后下降的趋势,且两者在时间轴上都提前于放电电流的变化,原因就是放电区电场变化优先于电流变化。在上述研究的基础上,对大气压纯NO负脉冲电晕放电的荧光发射谱进行了实验测量,通过对其进行归属,确定了纯NO负脉冲电晕放电过程中产生的活性粒子的指纹特征跃迁谱线,进而对这些活性粒子的指纹特征跃迁荧光谱线进行了时间分辨测量,从而得到了它们在放电过程中的时间行为特性,以此分析了NO电晕放电脱除反应动力学过程。研究结果表明:由于NO特殊的电子壳层排布,在脉冲电晕放电过程中,NO分子首先与高能电子发生非弹性电离碰撞,变成NO+离子,随后NO+解离成N+和O;N+离子在向阴极运动过程中再与电子结合成激发态N原子,继而和其它的N原子结合成为激发态N2;而O原子则与其它O原子结合成为O2。这是最理想的NO脱除反应路径。此结果与人们对多组分气体中NO的电晕放电脱除过程的推断有很大不同,有待于对多组分气体中NO的脱除反应动力学过程进行深入的实验研究。本文所得结果对多组分气体脉冲电晕放电脱除NO的反应动力学研究及脱除效率的进一步提高具有重要的参考价值。更多还原

【Abstract】 Plasma’s characteristics and chemical reaction kinetics of NO in pulse corona discharge with needle-plane electrode were studied by means of optical emission spectroscopy and time-resolved spectrum. The electron temperature and vibrational temperature are obtained by using the intensity ratio of two spectrum lines. The results show that, the electron temperature and the vibrational temperature in pulse corona discharge have different changing tendency. The former increases when increasing discharge voltage or decreasing sample pressure, yet the later goes up to a maximum and then fall with the increase of discharge voltage or decrease of sample pressure. The electron temperature and vibrational temperature both go up primely and then come down with the discharge time, and both of them change ahead of the change of discharge current, for which the reasonable explanation is that the change of electric field are ahead of the change of discharge current. Based on these results, the dactylogram spectrum of free radicals and gases, which are produced in the process of discharge are confirmed by analyzing the fluorescence spectrum of pure NO in negative pulse corona discharge at atmospheric pressure, and then time behaviors of these particles are studied by analyzing these dactylogram spectrum. The results show that, NO molecule turns to NO+ ion after colliding with a high-energy electron, and then the NO+ ion breakdown to N+ and O. Subsequently, the N+ ion turns to N atom after absorbing an electron and then combines with another N atom, the O atom turns to O2 molecule when combining with another O. This is an ideal way to removal NO. The chemical reaction kinetics of pure NO in pulse corona discharge is different to that of the system which has other components except NO, so it is expected to be investigated further. The results are believed to be of great importance for the study on the chemical reaction kinetics of several components system and the increasing of NO removal rate.更多还原