2nd China International Youth Conference on Electrical Engineering (CIYCEE 2021)

300 / 2021-11-09 16:06:37

Theoretical Study on the Decomposition Mechanism of Environment-Friendly Insulating Gas HFO-1234ze(E) in the Presence of Trace Water

alternative gas for SF6; density functional theory; decomposition mechanism; HFO-1234ze(E); trace water

High voltage and insulation technology > Other topics in high voltage and insulation technology

HFO-1234ze(E) has excellent insulating and environmental properties, but its decomposition mechanism in the presence of trace water is still unclear. Based on the density functional theory (DFT), the decomposition characteristics of HFO-1234ze(E) in the presence of trace water were analyzed at the B3LYP/6-311+G(d,p) level. The results show that in the presence of trace water, HFO-1234ze(E) will decompose and generate H₂, HF, CFH(OH)CH₂CF₃, CH≡CF, CH≡CH, CF₃OH, CF₃H, CF₄, C₂F₆, CF₂O, CH₂=CHF and CHF₂CH₃. By analyzing the ionization parameters of the main decomposition products, it can be found that the dielectric strengths of most of the products were lower than that of HFO-1234ze(E). Among the products, CF₃H, CF₄ and C₂F₆ are hazardous to the environment, while CH₂=CHF, CHF₂CH₃ and CF₂O are flammable or toxic, which may endanger the safety of staff. Therefore, water should be avoided when HFO-1234ze(E) is used as the insulating medium.