Analysis of Thermal Decomposition Characteristics of C5F10O/CO2 Mixed Insulation Medium

摘要

In recent years, C5F10O has attracted wide attention as a potential alternative gas of SF6, and its decomposition characteristics have become a research hotspot. To this end, this article analyzes the thermal decomposition characteristics of C5F10O/CO2 mixed insulating medium. Firstly, the saturated vapor pressure characteristics of the mixed insulating medium are obtained by using the Riedel vapor pressure equation and the basic law of vapor-liquid equilibrium, and the application schemes of the mixed insulating medium under different temperature limits are discussed. Secondly, the possible decomposition reaction of C5F10O was analyzed. The reaction energy of each reaction was calculated by using density functional theory, and the thermal decomposition path of C5F10O was determined. Finally, the Dalton law of partial pressure, the law of mass action, the quasi-neutral conditions of charge, and the stoichiometric equilibrium conditions are used to establish a mathematical model, and the particle number density of C5F10O/CO2 high-temperature plasma at pressure of 0.1mpa and temperature of 300 ∼ 30000K was obtained, and its electronegativity was discussed. The results show that: at 0.1MPa and 248K, the mixed insulating medium with C5F10O mole fraction below 9% can keep the gas phase. The lowest path of energy required for decomposition of C5F10O is C5F10O → CF3COCFCF3 → CF3CFCO → CF3CF → CF3. The decomposition products have strong electronegativity. The research results can lay a theoretical foundation for arc simulation of C5F10O/CO2 mixed insulation medium, insulation characteristics and other problems, and provide reference for the research of CnF2nO type alternative medium.