Dynamic Characteristics of SF_6-N_2-CO_2 Gas Mixtures in DC Discharge Process  

作　　者：ZHENG Dianchun WANG Jia CHEN Chuntian ZHAO Dawei ZHANG Chunxi YANG Jiaxiang 郑殿春;王佳;陈春天;赵大伟;张春喜;杨嘉祥(Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education,Harbin University of Science and Technology)

机构地区：[1]Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education,Harbin University of Science and Technology

出　　处：《Plasma Science and Technology》2014年第9期848-855,共8页等离子体科学和技术（英文版）

基　　金：supported by National Natural Science Foundation of China(No.51077032)

摘　　要：Dynamic characteristics of discharge particles are described within the framework of a two-dimensional photoionization-hydrodynamic numerical model for the discharge process of SF6-N2-CO2 gas mixtures at atmospheric pressure, under a uniform DC applied field. The finite difference flux corrected transport （FD-FCT） algorithm is used in the numerical implementation for improving the accuracy and efficiency. Then the tempo-spatial distributions of the gap space electric field and electron velocity are calculated from the microscopic mechanism, and the dynamic behaviors of charged particles are obtained in detail. Meanwhile, the tempo-spatial critical point of the avalanche-to-streamer in this model is discovered, and several microscopic parameters are also investigated. The results showed that the entire gap discharge process can be divided into two phases of avalanche and streamer according to Raether-Meek criterion; the electron density within the discharge channel is lower compared to that of positive and negative ions; space charge effect is a dominant factor for the distortion of spatial electric field, making the discharge channel expand toward both electrodes faster; photoionization provides seed electrons for a secondary electron avalanche, promoting the formation and development speed of the streamer.Dynamic characteristics of discharge particles are described within the framework of a two-dimensional photoionization-hydrodynamic numerical model for the discharge process of SF6-N2-CO2 gas mixtures at atmospheric pressure, under a uniform DC applied field. The finite difference flux corrected transport （FD-FCT） algorithm is used in the numerical implementation for improving the accuracy and efficiency. Then the tempo-spatial distributions of the gap space electric field and electron velocity are calculated from the microscopic mechanism, and the dynamic behaviors of charged particles are obtained in detail. Meanwhile, the tempo-spatial critical point of the avalanche-to-streamer in this model is discovered, and several microscopic parameters are also investigated. The results showed that the entire gap discharge process can be divided into two phases of avalanche and streamer according to Raether-Meek criterion; the electron density within the discharge channel is lower compared to that of positive and negative ions; space charge effect is a dominant factor for the distortion of spatial electric field, making the discharge channel expand toward both electrodes faster; photoionization provides seed electrons for a secondary electron avalanche, promoting the formation and development speed of the streamer.

关 键 词：hydrodynamic model PHOTOIONIZATION short gap streamer discharge ternarymixture 

分 类 号：O461[理学—电子物理学]