Decomposition Characteristics of C4 F7 N/CO2 Gas Mixture at Different Gas Pressure

In recent years, C4 F7 N gas has been considered as one of the most promising alternative gases for SF6 due to its excellent insulation and environmental performance. At present, there are still many imperfections in the research of C4 F7 N decomposition characteristics, which make it difficult to be widely used in power equipment. In this paper, the kinetic model of C4 F7 N decomposition with different pressure is established on the Reaxff molecular dynamics method. It is found that the decomposition rate of C4 F7 N and CO2 increases with the increase of air pressure, and the C3 NF4 and C4 NF6 generated by the decomposition will undergo secondary decomposition at high temperature, while the decomposition rate of C4 F7 N to produce CF3 and F will increase with the increase of air pressure. The production rate of free radicals such as CF2, CN, CF, CNF and CF4 increases with the increase of air pressure, while the formation of C3 F8 is inhibited under high pressure. The results of this paper can provide some theoretical reference for C4 F7 N on application in electrical equipment.