SF6混合气体的液化特性研究

The study on liquefaction characteristics of SF6 mixed gas

SF6/N2、SF6/CO2和SF6/CF4三种混合气体,作为潜在的SF6替代气体,其液化温度是人们衡量替代可行性的重要依据,也是工程实践中必须考虑的参数。尤其是在较严寒的地区,SF6绝缘设备常常面临着因气体液化而丧失原有绝缘特性的问题。研究发现,通过掺入难液化的气体成分,可以提高混合气体液化温度的临界值,本文通过计算目标混合气体的Antoine蒸汽压方程,并结合汽液平衡的基本定律,计算得出三种目标混合气体在不同的混合比例系数k下,混合气体的饱和蒸汽压值和混合气体的液化温度的变化关系;并计算分析了当混合气体的饱和蒸汽压值分别为0.3MPa、0.5MPa和0.7MPa三种定值状态下,混合气体的液化温度和混合比例系数k的变化关系。对比三种目标混合气体的液化温度数据,得出三种目标混合气体在解决液化温度问题上的优势排序。

The liquefaction temperature of SF6/N2,SF6/CO2 and SF6/CF4 mixed gases,as potential substitute gases for SF6,is an important basis for people to evaluate the feasibility of substitution and a parameter that must be considered in engineering practice.Especially in the cold region,SF6 insulation equipment often faces the problem of loss of original insulation characteristics due to gas liquefaction.Studies have found that by incorporating difficult liquefied gas composition,can improve the critical value of mixed gas liquefaction temperature,based on the calculation target of mixed gas Antoine vapor pressure equation,and combining the fundamental laws of vapor liquid equilibrium,calculated three goals mixed gas under the conditions of different mix proportion coefficient k,saturated vapor pressure value of the mixed gas and the mixed gas liquefaction temperature changes in the relationship;The relationship between the liquefaction temperature of the mixed gas and the mixing ratio coefficient k was calculated and analyzed when the saturated vapor pressure of the mixed gas was 0.3MPa,0.5MPa and 0.7MPa respectively.By comparing the liquefaction temperature data of the three target mixed gases,the superiority order of the three target mixed gases in solving the liquefaction temperature problem is obtained.