Thermal Decomposition Process of C₄F₇N/CO₂ Mixture with a Chemical Kinetic Model

This paper establishes a chemical kinetic model to analyze the composition of decomposition products of C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf>F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</inf>N/CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> mixture in the temperature range of 300-3500K with C4F7N content to be 5%, 8%, and 11%. The model involves 237 chemical reactions, and 65 species, containing neutral species, electrons, positive and negative ions. For C4F7N, due to its lower content and more complex reaction pathway, only the decomposition and recombination reactions of neutral species are considered, while for CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, the decomposition pathway is more mature. In addition to reactions between neutral species, electron impact reactions and ion related reactions are also considered. This article establishes a two-temperature chemical kinetic model,in which the electron temperature and heavy species temperature are not equal. The electron temperature is defined as a function of the electron number density to make the model more accurate. Assuming that all reactions are reversible, for reactions without a reverse reaction rate constant, it can be calculated by the ratio of the forward reaction rate constant to the equilibrium constant. The decomposition components of C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf>F<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</inf>N/CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> under three different proportions are analyzed. In addition,the main formation pathways of each component are analyzed.