氧气含量对氦氧等离子体射流特性影响

Effect of Oxygen Content on Characteristics of Helium Oxygen Plasma Jet

大气低温等离子体射流具有成本小、温度低等特点,获得了广泛的工业应用。采用高压高频交流电源,通过PC控制系统调节氦气和氧气的比例,建立了等离子体射流试验系统。利用高速相机获得了放电图像,测量了射流发光长度和放电起始电压,系统分析了氧气含量对氦氧等离子体射流特性的影响。研究结果表明,氧气会抑制放电过程的发展,进而对等离子体射流的特性造成影响,使得等离子体射流的发光强度和长度大大降低;放电起始电压增大,放电频率增大,放电电流尖峰数值增大,而放电功率则没有太大变化;He和N的光谱强度随氧气含量增大而减小,O的光谱强度呈现先增大后减小的趋势。

With low cost and temperature,plasma jets,as a typical atmospheric pressure plasma,have found extensive industrial applications. In this paper,a series of experiments have been performed to investigate the influences of oxygen content on the characteristics of helium oxygen plasma jet. The plasma jet experimental system is built by using the alternating current power supply with high voltage and frequency and adjusting the ratios of helium and oxygen by PC control system. The discharging image,plasma jet length and inception voltage are then acquired by a high-speed imaging system. The experimental results indicate that the presence of oxygen can restrain the discharging,and then,it will affect the characteristics of plasma jet significantly. As a result,the luminance and length of plasma jet are remarkably reduced. Meanwhile,the inception voltage,the discharging frequency and the peak of current get increased. The power of the plasmas jet,however,has a minor variation only. Moreover,as the increase of oxygen content,the spectrum intensity of He and N declines,while the spectrum intensity of O increases firstly and then decreases.