Graphite production in two‐temperature non‐LTE plasmas of C<sub>4</sub>F<sub>7</sub>N and C<sub>5</sub>F<sub>10</sub>O mixed with CO<sub>2</sub>, N<sub>2</sub>, and O<sub>2</sub> as eco‐friendly SF<sub>6</sub> replacements: A numerical study
Linlin Zhong, Qi Gu, Bing-Yu Wu
Abstract
Abstract Many recent works have shown that C 4 F 7 N and C 5 F 10 O have a great potential to replace SF 6 as a greenhouse gas. One of the biggest problems for their application is that condensed species (i.e., graphite) may be produced during gas discharges. However, all the previous works are performed under the assumption of local thermodynamic equilibrium (LTE). Therefore, this study investigates the departure of thermodynamic equilibrium and the corresponding effects on the graphite production in the plasmas of C 4 F 7 N, C 5 F 10 O, and their mixtures with CO 2 , N 2 , and O 2 , based on the two‐temperature (2T) non‐LTE plasma compositions calculated by the Gibbs free energy minimization. The results show that neglecting the nonequilibrium effect can lead to a very inaccurate description of graphite condensation in the above plasmas.