7th International Conference on Electric Power Equipment– Switching Technology (ICEPE 2024)

207 / 2024-04-17 16:41:29

Prediction of azeotrope system of insulating gas

azeotropic theory,group contribution,azeotry system,environmentally friendly SF6 alternative gas

Since sulfur hexafluoride (SF₆) has very excellent physical and chemical properties, insulation properties and arc quenching capability, it is widely used in the power industry, which greatly promotes the development of medium voltage (MV) and high voltage (HV) equipment. However, its use also results in serious environmental problems. Consequently, the search for an environmentally friendly SF₆ alternative gas has become a crucial task in the power industry. Researchers have carried out extensive and in-depth research in this field for a considerable period. Currently, the most prevalent SF₆ alternative gases are categorized into four main groups. While the new fluoride insulation performance is superior to that of SF₆, the liquefaction temperature is high, rendering it not meet the minimum operating temperatures in equipment. Typically, the boiling point of the mixture is reduced by the addition of a buffer gas, which, however, affects the insulation properties of the mixture. This paper introduces the azeotropic theory of the chemical industry into the electrical industry and presents a prediction model of vapor-liquid equilibrium data constructed by combining group contribution with the equation of state. This model enables the reduction of the boiling point without affecting the insulation properties of the mixture. The method can be used to screen a large number of gases in the azeotrope system, saving time and manpower. Furthermore, the method provides a theoretical foundation for the development of novel multicomponent insulating gases.