高电压技术2017，Vol.43Issue(3)：765-771,7.DOI:10.13336/j.1003-6520.hve.20170303010
SF6/CF4混合气体的饱和蒸气压与绝缘特性计算
Calculation of Saturated Vapor Pressure and Insulation Characteristics on Mixtures of SF6 and CF4
摘要
Abstract
The relatively high liquefaction temperature of SF6 gas limits its use in cold areas,while adding some CF4 gas to SF6 gas is considered as an effective way to deal with the issue.We analyzed the saturated vapor pressure and insulation characteristics of SF6/CF4 mixture,and discussed the feasibility of applying SF6/CF4 mixture to substitute SF6 gas for cold areas.First,the Antoine constants of SF6 and CF4 gases were obtained by the global optimization method.Then the saturated vapor pressures of SF6/CF4 mixtures were determined by combining the Antoine equation and the basic law of vapor liquid equilibrium.Secondly,the critical electric field strengths of SF6/CF4 mixtures were calculated with Boltzmann analysis.Finally,the insulation properties and applications for cold areas of SF6/CF4 mixture were discussed by combining the saturated vapor pressure characteristic and critical electric field strength.The results show that the allowable gas pressure of SF6/CF4 mixture is remarkably higher than that of pure SF6 gas under a quite low temperature,and then the insulation strength of SF6/CF4 mixture can be superior to that of pure SF6 gas.At-40 ℃C,the saturated vapor pressures of 50％SF6/50％CF4 mixture and SF6 gas are about 0.64 MPa and 0.35 MPa,respectively,and the critical electric field strengths at corresponding pressures are about 43.5 kV/mm and 31.34 kV/mm.This means that the insulation strength of SF6/CF4 mixture at a mixed ratio of 50％/50％ reaches 1.4 times of SF6 gas,and the SF6/CF4 mixture under a proper mixed ratio and gas pressure can prevent the liquefaction of SF6 gas in cold areas.关键词
SF6/CF4/替代气体/饱和蒸气压/绝缘特性/Boltzmann方程Key words
SF6/CF4/substitution gases/saturated vapor pressure/insulation characteristic/Boltzmann equation引用本文复制引用
田雨,张晗,赵虎..SF6/CF4混合气体的饱和蒸气压与绝缘特性计算[J].高电压技术,2017,43(3):765-771,7.基金项目
国家高技术研究发展计划(863计划)(2012AA050209).Project supported by National High-tech Research and Development Program (863 Program)(2012AA050209). （863计划）
