低气压板-板与多针-板电极结构甲烷气体介质阻挡放电的对比

Comparison of DBD in Methane Between Parallel-plate and Multi-needles to Plate Electrode in Low Pressure

为深入理解低气压板–板与多针–板电极结构甲烷气体DBD放电特性的差异,主要设计并测量了两种电极结构的放电特性,研究了放电电气参量随气体压强变化规律,测量了两种电极结构的放电区发射光谱,诊断了两种电极结构CH双原子分子的转动温度,利用转动温度近似气体温度,得到了气体温度随气压变化的规律,并对所得到的结果进行了分析和讨论。结果表明:在等气隙条件下,两种电极结构随着气压的升高放电逐渐过渡到不稳定状态,放电半径逐渐缩小,有明显的同心圆形貌;多针-板阵列结构电极相对于板–板电极结构,在电压正半周期时放电电流较大,在电压负半周时放电电流十分微弱。当气压较高时多针–板阵列结构起始放电的极间电压较低;光谱计算表明在其他条件相同条件下,多针-板阵列结构的气体温度较低。

In order to deeply understand the differences of DBD characteristics of methane gas between plate-to-plate and multi-needles to plate electrode structures in low pressure, we mainly measured the discharge properties of the two kinds of electrode structures, and investigated the variation trend of discharge electric parameters as a function of different pressures. The emission spectrum of discharge was measured by iStar DH 334T, and the rotational temperature of CH molecule was diagnosed. The variation regularity of gas temperature can be obtained by the law that rotational temperature, which is similar to gas temperature. The results shows that when the air gap is constant, the two electrode structures gradually transit to unstable status with the increase of gas pressure. Discharge radius gradually decrease, and present an obvious appearance of concentric circles. Compared to plate-to-plate electrode structures, multi-needles to plate electrode array structures have a higher discharge current in the positive half cycle of voltage and a lower discharge current in the negative half cycle of voltage, respectively. When gas pressure is relatively high, the ignition voltage of multi-needles to plate electrode array structures is relatively low. The spectrum calculation results indicate that gas temperature of mul- ti-needles to plate electrode array structures is low.