Isotope tracing experimental study on the effects of trace H <sub>2</sub> O on the over-thermal decomposition of SF <sub>6</sub>
Fuping Zeng, Haotian Li, Mingxuan Zhang, Zhicheng Lei, Chen Li, Ju Tang
Abstract
Abstract It has been recognized that the gas insulating medium SF 6 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 SF 6 under POF. Similar to the discharge decomposition of SF 6 , trace H 2 O is an important factor affecting the decomposition of SF 6 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 H 2 18 O as a tracer into SF 6 gas and carries out experiments. Detecting the concentration and isotope abundance of products by gas chromatography–mass spectrometry, the paper studied the influence of H 2 O on the production of decomposition products and the specific formation process of CO 2 , SO 2 F 2 , SOF 2 and SO 2 under the influence of H 2 O. The research further verified the assumption on formation process of CO 2 and SO 2 and also brought up with new theory on the formation of SO 2 F 2 and SOF 2 based on experimental results.