Research on Insulation and Application Characteristics of CF3I Gas Mixtures Based on Boltzmann Theory

Trifluoroiodomethane (CF3I), as a potential sulfur hexafluoride (SF6) alternative gas, has attracted much attention owing to the low global warming potential (GWP). However, the high liquefaction temperature limits the application scenarios of CF3I insulating gases. In this study, we discussed the insulation and application characteristics of CF3I binary and ternary gas mixtures based on Boltzmann theory. Electron energy distribution functions (EEDF), critical electric field stresses (E/N)cr, GWP, synergy coefficient ( \(\xi \) ), and liquefaction temperatures of CF3I gas mixture were calculated and analyzed. The results show that the (E/N)cr of 30%CF3I/70%N2 mixture is comparable to that of pure SF6 (355 Td), and the two gases show a positive synergistic effect ( \(\xi \) = 0.02). The 30%CF3I/70%N2 gas mixture has a GWP of 2.8, about 1/8000 that of pure SF6; saturated vapor pressure of 0.157 MPa at − 20 ℃; and a liquefaction temperature of − 31 ℃ at 0.1 MPa. The addition of CO2 to the CF3I/N2 reduces the dielectric strength of the gas mixture.