Differences of SF6 Byproducts in Simulated Electric Equipment of Overheating Faults in Different Condition

摘要

The decomposition of sulfur hexafluoride (SF6) in overheated electric equipment at different temperature and humidity was simulated in the study. SF6 is significantly decomposed at 350°C. SF6 is more easily decomposed in high humidity than in low humidity. The concentrations of SF6 byproducts, such as sulfur dioxide (S02), sulfureted hydrogen (H2S) and hydrofluoric acid (HF), in high humidity are much higher than those in low humidity. Moisture in electric equipment accelerates the decomposition of SF6. In order to insure the safety operation of electric equipment, moisture in the equipment should be strictly controlled. SF6 will be decomposed to format HF. The concentration of HF will decrease when its concentration increases up to a certain concentration. It may be because that HF was strongly corrosive and its corrosion to inner equipment made the concentration of HF decreasing.