Study on the influence mechanism of trace H2O on SF6 thermal decomposition characteristic components

Concepts

EngineeringMaterials EngineeringMaterials ScienceHeat TransferThermal AnalysisThermodynamicsDecomposition AnalysisHeat ConductionHeat Transfer AnalysisHeat Transfer FundamentalsThermal History AnalysisThermal ManagementDecomposition MechanismsExperimental Thermal AnalysisTemperature DiagnosticsThermal DecompositionThermal Decomposition ReactionsThermal Degradation StudiesThermal Fault Detection

Abstract

To explore the influence mechanism of trace H 2 O on SF6 decomposition characteristics under partial thermal fault and establish the foundation of using SF6 thermal decomposition principle to diagnose the thermal fault of SF 6 electrical equipment, a series of artificial thermal fault decomposition experiments with different H 2 O concentrations were conducted on the designed SF6 thermal decomposition experimental system. A trace water injector was used to control the content of trace H2O accurately and gas chromatograph, chromatography-mass spectrometry as well as Fourier transform infrared spectroscopy were used to measure decomposed components. Finally, the thermal decomposition characteristic under 340 ° was achieved. The analysis results indicate no matter how much H 2 O content is, SF 6 can decomposes into many kinds of decomposition characteristics, such as CO 2 , SOF 2 , SO 2 , SOF 4 , SO 2 F 2 , H 2 S, HF. The concentrations of all these decomposition characteristics increase with the time extended, but change differently with the increase of H 2 O content, because H 2 O plays different role in the formation process of each decomposition characteristic components. The variation of H 2 O content not only affects the production of the decomposition characteristic components, but also makes SO 2 and HF gradually evolved into the main characteristic components of SF 6 thermal decomposition. In addition, the higher the H 2 O content is, the stronger the promoting effect on SO 2 and HF is.