Transport Properties of Thermal Plasma Containing Fluoro-Nitrile (C₄F₇N)-Based Gas Mixtures

Gas mixtures containing fluoro-nitriles C<sub>4</sub>F<sub>7</sub>N or fluoro-ketones C<sub>5</sub>F<sub>10</sub>O as minority components (<20%) have been identified as promising alternatives to SF<sub>6</sub> in medium voltage gas-insulated switchgear (GIS) applications, because of their low Global Warming Potential together with their dielectric strength values being comparable to SF<sub>6</sub>. The buffer gases in such fluoro-nitrile or fluoro-ketone based gas mixtures are usually N<sub>2</sub>, O<sub>2</sub>, CO<sub>2</sub>, or air. In this contribution, we provide calculation results of transport properties, assuming local thermodynamic equilibrium (LTE), of thermal plasma containing following gas mixtures: C<sub>4</sub>F<sub>7</sub>N-CO<sub>2</sub> and C<sub>4</sub>F<sub>7</sub>N-CO<sub>2</sub>-O<sub>2</sub>. The modifications in the thermodynamic and transport properties upon the addition of oxygen to the C<sub>4</sub>F<sub>7</sub>N-CO<sub>2</sub> mixtures in the temperature range 300 K-30 kK at 1 bar are provided and discussed. These properties have been utilized to calculate the plasma temperature profile for a free-burning arc in a companion paper.