摘要
气体与气室内固体材料的相容性是设备安全运行的关键,现有的研究集中在主绝缘气体与固体的相互作用,而电热故障下分解产物也可能对固体材料性能产生影响.为此建立环保绝缘C4F7N主要分解产物(CO、CF4和C3F6)与金属材料(铜、铝)相互作用模型,基于第一性原理计算相互作用能、电荷转移、差分电荷密度等微观参数,从能量和电子结构层面探究分解产物与金属的相互作用机理,进而深入分析相容性.结果表明:CO、CF4、C3F6与Cu(1 1 1)的相互作用能分别为-0.552 eV、0.317 eV、0.132 eV,电荷转移量分别为0.231e、0.006e、0.156e,且成键效果均较差,为物理作用,进而表现出良好的相容性;CO以及CF4与Al(1 1 1)同样有着很好的相容性,而C3F6与Al(1 1 1)界面表现出很差的相容性.因此,从气体稳定性角度来讲,在填充C4F7N-CO2混合气体的绝缘设备气室内可使用铜作为导电材料,并避免C4F7N发生分解,从而更好地确保设备的安全运行.
Abstract
The compatibility between gases and solid materials within gas chambers is crucial for the safe operation of equipment.Existing research focuses on the interactions between the main insulating gases and solids,while the decomposition products under electrical and thermal faults may also affect the performance of solid materials.Therefore,an interaction model between the main decomposition products of the eco-friendly insulating gas C4F7N(CO,CF4,and C3F6)and metal materials(Cu,Al)was established for study.Based on the first principle,microscopic parameters such as interaction energy,charge transfer,and differential charge density were calculated,the interaction mechanisms between the decomposition products and metals were explored from the perspectives of energy and electronic structure,and their compatibility was analyzed in depth.The results show that the interaction energies between CO,CF4,C3F6,and Cu(1 1 1)are-0.552 eV,0.317 eV,and 0.132 eV,and charge transfer amounts between CO,CF4,C3F6,and Cu(1 1 1)are 0.231e,0.006e and 0.156e respectively.The bonding effects are all relatively weak,indicating physical interactions,which in turn demonstrate great compatibility.CO and CF4 also exhibit good compatibility with Al(1 1 1),while C3 F6 shows poor compatibility at the Al(1 1 1)interface.Therefore,from the perspective of gas stability,Cu can be used as a conductive material in the gas chamber of eco-friendly C4F7N-CO2 insulated equipment,while avoiding the decomposition of C4F7N,thereby ensuring better operational safety of the equipment.
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