羧基碳纳米管吸附SF_6放电分解组分的仿真计算

DFT Calculations on the Adsorption of Components of SF_6 Decomposed Under Partial Discharge Onto Carboxyl Carbon Nanotubes

通过SF6分解气体组分及组分含量检测,可以判断气体绝缘电器组合(gas insulated switchgear,GIS)内局部放电(partial discharge,PD)类型及发展程度,对GIS的故障诊断具有重要意义。提出利用羧基修饰碳纳米管(SWNT-COOH)提高碳管的灵敏度和选择性来检测GIS中的SF6分解组分。根据第一性原理,采用Materials Studio分子动力学仿真软件对羧基修饰的单壁碳纳米管吸附SF64种主要分解组分SO2、SO2F2、SOF2和CF4进行了详细的理论计算,分析吸附过程中吸附能、电荷转移量、作用距离、前线轨道和电子态密度的变化情况,结果显示SWNT-COOH对于4种气体检测的选择灵敏度为SO2>SOF2>SO2F2>CF4,可以利用羧基修饰碳纳米管制备气体传感器检测SF6局部放电分解组分。

The detection of partial discharge （PD） and analysis of SF6 gas components in gas insulated switchgear （GIS） is significant for diagnosing the operating state assessment of power equipment. The sensitivity and selectivity of the single-wall carbon nanotubes modified by carboxyl （SWNT-COOH） were expected to improve in detecting SF6 gas components. According to the first principle, the molecular dynamics simulation software of materials studio was adopted to theoretically calculate the process of that SWNT-COOH adsorbed the main components SO2, SO2F2, SOF2 and CF4 of SF6 decomposed under PD. We conclude that the detection sensitivity of SWNT-COOH for the four kinds of gas is SO2〉 SOFE〉SOzF2〉CF4, after analysis of the changes of the adsorption energy, transfer-charge, interaction distant, frontier Orbital of gas molecules and the electronic density, SWNT-COOH can be used to prepare the gas sensors to detect SF6 partial discharge decomposition components.