Development of a chemically non-equilibrium model on decaying SF6 arc plasmas

This paper describes the development of a chemically non-equilibrium model on an SF₆ arc plasma in decaying phase. The SF₆ arc plasma in decaying phase can be seen in a high voltage SF₆ gas circuit breaker during a large current interruption process. The developed mode here does not assumes chemical equilibrium in the arc plasma, although the conventional numerical model often assumes the quilibrium. This developed model accounts for 19 species including molecules, atoms, monatomic ions, polyatomic ions and the electron. It also takes into account totally 122 reactions including dissociation, ionization, and other chemical reaction in SF₆ plasmas. As a result, transient distribution of the temperature and chemical reaction fields were calculated for SF₆ arc plasma under a free recovery state for a fundamental study.