Research On The Breakdown Characteristics Of The Two-Phase Mixture Of Gas And Micron Water Droplets

In recent years, discharge applied in many fields (impulsive discharge for water treatment, plasma for doctor treatment. e.g),it is better foreground in environmental treatments. And the conditions of discharge become complex, it is almost discharges in two-phase mixtures or more. The most studies are based on the pure air, water and solid or boundary surfaces, there are so few studies of two-phase mixtures. We often used the theories of gas discharge or water discharge solved problems of mixtures.Based on the primary processes of gas discharge, this paper analyzes several main influencing factors for the inception and development of discharge in two-phase mixture of gas and water droplets, and then a preliminary DC/Pulse discharge mechanism is presented. There are two actions of water in the process of discharge. On the one hand, the deformation of local electric fields induced by water droplets (including droplets in the air and layer on the electrodes surface). On the other hand, water droplets absorb the particles produced in discharge (including electrons and photons). These important factors induce the differences of discharge between air and air-water.A mirage-model is presented for calculate the deformation of local electric field in the paper. The results indicated that the average electric field intensity fall down, and with the dielectric constant of water increases, the electric field intensity fall down more. This result anastomose phenomena of experiments.The experiment investigated breakdown characteristics of the two-phase mixture of gas and liquid in a sphere-sphere DC gap. The results shows the breakdown voltage increases 1%~20%. And the bigger the mist flux is the higher the breakdown voltage is; the bigger the dielectric constant is the higher the breakdown voltage is. In uniform filed, breakdown voltage changed more, but less change in non-uniform field.The paper also studied breakdown characteristics of the air-water in a sphere-sphere impulse gap, and founded that breakdown voltage increases 5%~100%. And the bigger the mist flux is the higher the breakdown voltage is; the bigger the dielectric constant is the higher the breakdown voltage is. In uniform filed, breakdown voltage changed more, but less change in non-uniform field.