A numerical study of species and electric field distributions in pulsed DBD in oxygen for ozone generation

摘要

A numerical model including 29 reactions and 11 species is developed to investigate the spatial-temporal distributions of species and electric field in oxygen parallel-plate positive pulsed dielectric barrier discharge for ozone generation. Electron energy conservation equation is coupled to electron continuity equation, heavy species continuity equation and Poisson's equation. The spatial-temporal distributions of species and electric field are obtained at electron avalanche and during streamer propagation. The results show the dominant positive ion, negative ion and excited species are O-2(+), O-3(-) and O-2 ((1)Sigma(+)(g)), respectively. The average streamer propagation velocity is about 5.56 x 10(4) m/s. Overall electron density almost increases exponentially but with a violent oscillation in the vicinity of anode at electron avalanche. Electron density increases at first and then declines in the vicinity of anode and streamer channel during streamer propagation, and increases gradually in streamer head with the development of streamer, as well as reduces sharply to almost zero near cathode. Electron density almost remains constant in whole streamer channel at any one moment. Other species have a similar spatial-temporal distribution. (C) 2015 Elsevier Ltd. All rights reserved.