基于氧同位素示踪技术的H_(2)O对SF_(6)电弧放电分解产物的影响研究

Study on the Effect of H_(2)O on SF_(6) Decomposition Products Under Arc Discharge Based on Isotope Tracer Technique

SF_(6)分解产物与SF_(6)开关设备故障放电类型和严重程度存在内在联系,可通过分解产物分析实现对开关设备的故障诊断。H_(2)O对SF_(6)电弧放电分解产物具有显著影响,但其影响规律及相关作用机制目前尚不清楚,严重制约了分解产物分析法的工程应用。为解决这一问题,文中搭建了SF_(6)开关设备电弧放电分解产物实验研究平台,利用H_(2)^(18)O作为示踪剂开展了电弧放电实验,利用气相色谱质谱联用仪分析了放电过程中和放电后含^(18)O同位素物质的变化规律,明确了电弧放电下SF_(6)分解产物的形成途径及H_(2)O对SF_(6)分解产物的影响,阐明了其深层化学反应机理。研究发现,H_(2)O会直接参与SOF_(2)、SO_(2)、SO_(2)F_(2)和CO_(2)的生成反应,化学反应机理的不同导致各物质的形成与演化规律具有显著差异。其中,SOF_(2)和SO_(2)F_(2)的生成主要由放电过程中发生的分解反应和复合反应主导,SO_(2)的生成主要由放电后发生的分子间反应主导,CO_(2)的生成则来自两者的共同作用。

The SF_(6)decomposition products are intrinsically related to the type and severity of fault discharge of SF_(6) switchgear,and the fault diagnosis can be realized through the analysis of SF_(6)decomposition products.H_(2)O has a significant effect on the SF_(6) decomposition products under arc discharge,but its influence law and related mechanism are still unclear,which seriously restricts the engineering application of SF_(6decomposition) product analysis method.In order to solve this problem,a research platform for SF_(6decomposition) products of switchgear under arc discharge was built.The arc discharge experiments were carried out by using H_(2)^(18)O as tracers.The change law of^(18)O isotopic substances was analyzed by gas chromatography-mass spectrometer.The formation pathway of SF_(6decomposition) products and the influence of H_(2)O on SF_(6) decomposition products were clarified,and the reaction mechanism was clarified.It has found that H_(2)O will participate in the formation reactions of SOF_(2),SO_(2),SO_(2)F_(2) and CO_(2).The different reaction mechanisms lead to significant differences in the formation and evolution laws of each substance.SOF_(2) and SO_(2)F_(2)are dominated by the decomposition reaction and composite reaction during the discharge.SO_(2)is dominated by the intermolecular reaction after discharge.CO_(2)comes from the combined action of the two.