Transport properties of CF3I thermal plasmas mixed with CO2, air or N2 as an alternative to SF6 plasmas in high-voltage circuit breakers

Abstract This paper is devoted to the calculation of equilibrium compositions, thermodynamic properties (mass density, enthalpy and specific heat at constant pressure) and transport coefficients (viscosity, electrical conductivity and thermal conductivity) of air/CO 2 /N 2 –CF 3 I mixtures. These data are computed in the temperature range 300 K–50 kK and pressure between 1 and 32 bar. Results obtained for pure gases (CF 3 I, CO 2 , air and N 2 ) are systematically compared with SF 6 . Transport coefficients for N 2 , CO 2 , CF 3 I and mixtures of CO 2 , N 2 or air with CF 3 I are also confronted with previous published values. Particular attention is paid to the collision integral database by the use of the most accurate and recent cross-sections or interaction potentials available in the literature.