Isotope tracing experimental study on the effects of trace H₂O on the over-thermal decomposition of SF₆

Abstract

It has been recognized that the gas insulating medium SF6 decomposes when the partial over-thermal fault (POF) occurs inside the equipment. The insulation condition monitoring and fault diagnosis of the equipment can be carried out by utilizing the decomposition characteristics of SF6 under POF. Similar to the discharge decomposition of SF6, trace H2O is an important factor affecting the decomposition of SF6 under POF while its mechanism is not clear yet. In order to investigate the characteristics and micro mechanism of decomposition, the paper combines isotope tracer by adding H218O as a tracer into SF6 gas and carries out experiments. Detecting the concentration and isotope abundance of products by gas chromatography–mass spectrometry, the paper studied the influence of H2O on the production of decomposition products and the specific formation process of CO2, SO2F2, SOF2 and SO2 under the influence of H2O. The research further verified the assumption on formation process of CO2 and SO2 and also brought up with new theory on the formation of SO2F2 and SOF2 based on experimental results.

Review on decomposition characteristics of eco-friendly gas insulating medium for high voltage gas insulated equipment

“…In addition, in order to clarify the influence of O 2 or H 2 O on the discharge decomposition characteristics of the gas insulating medium, a non-radioactive isotope tracer method can be considered to reveal the method of decomposition and by-product generation by detecting the residual isotope content or isotope consumption after discharge and the isotope distribution in characteristic decomposition products [43].…”

First-Principle Insight into Ga-Doped MoS2 for Sensing SO2, SOF2 and SO2F2

“…[5]. On the one hand, some decomposition products are corrosive, which may cause certain damages to the equipment [6,7]. On the other hand, the stability and insulation of the decomposition gases are far inferior than that of SF 6 [8].…”

SF 6 decomposition and insulation condition monitoring of GIE: A review

“…With reference to the studies of Van Brunt and Zhao, Zeng et al used the isotope tracing method to study the decomposition of SF 6 under partial over‐thermal fault. The influence mechanism of H 2 O on the formation of main products was investigated [51]. They concluded that the generation of CO 2 is not sensitive to the content of H 2 O while SO 2 , SO 2 F 2 and SOF 4 are very sensitive to H 2 O content.…”