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

Abstract

<p>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.</p>

Transport and radiation properties of C4F7N-CO2 gas mixtures with added oxygen

“…According to the IEC 62271-200 standard, the maximum allowable absolute pressure within an MV-GIS is 4 bars. We have presented a few preliminary results for C 4 F 7 N-CO 2 mixtures at 1 bar in our earlier work [18,19]. These properties are necessary for performing thermal plasma modeling of SF 6 alternative gas mixtures in both simple academic geometries and complicated GIS switchgear.…”

Radiative Properties and Numerical Modeling of C4F7N-CO2-O2 Thermal Plasma

“…Besides radiative properties, transport, and thermodynamic properties are needed as well to setup a complete model. The calculation approach and results are introduced in a companion paper of this conference [1]. Results of the radiation properties calculation and the CFD model for C 4 F 7 N − CO 2 will be compared with those of air and SF 6 .…”