三氟甲基磺酰氟绝缘介质理化特性的分子动力学模拟

采用分子动力学模拟方法， 研究了新型绝缘介质三氟甲基磺酰氟(CF₃SO₂F)的理化特性, 为高压电气设备应用CF₃SO₂F替代SF₆气体提供了理论依据. 基于量子化学计算的分子结构、 内转动、 偶极矩和振动频率等优化设计了mPCFF力场模型, 计算了243~323 K温度范围内CF₃SO₂F的各种气-液相平衡性质(饱和蒸汽压、 密度、 热容、 蒸发焓和临界参数等)与关键输运特性(扩散系数、 介电常数、 黏度和热导率等)基础参数, 并考察了CF₃SO₂F与N₂或CO₂形成混合气体的理化特性. 通过对比SF₆以及C4/CO₂混合环保绝缘气体, 针对混合比、 液化温度、 扩散和热导等因素提出了CF₃SO₂F的电气设备应用建议.

Molecular Dynamics Simulation of the Physicochemical Properties of Trifluoromethanesulfonyl Fluoride Dielectrics

Physicochemical properties of trifluoromethanesulonyl fluoride（CF₃SO₂F） dielectric medium， which is a promising eco-friendly insulation gas to replace SF₆ for the high-voltage electric applications， were calculated using molecular dynamics simulations. An optimized mPCFF force field was proposed and validated on the basis of the theoretically predicted molecular structures， internal rotation， dipole moments， and vibrational frequencies， which were in good agreement with the experimental and quantum chemical data. The physical properties of CF₃SO₂F in the phase envelope including vapor pressures， densities， heat capacities， enthalpies of vaporization， critical properties， together with the key transportation parameters including self-diffuse coefficients， dielectric constants， shear viscosities， and thermal conductivities， were examined systematically for the first time in the temperature range 243—323 K. In addition， the gas mixtures of CF₃SO₂F with N₂ or CO₂ buffer gas were investigated to compare with the electrical performance of SF₆ and C4/CO₂. A few critical suggestions on the use of CF₃SO₂F were proposed in terms of mixing ratio， liquefaction temperature， self-diffuse， and thermal conductivity for the purpose of realistic electrical applications.