CF3I混合气体比例及放电参数分析

CF_3I气体是一种极具潜力的SF_6替代气体。为研究CF_3I混合气体的最佳比例及电气特性,首先根据CF_3I气体饱和蒸气压方程计算其液化条件,采用两项近似的Boltzmann方程求解三种CF_3I混合气体在不同混合比下的电子能量分布及电离和吸附系数,并计算混合气体的折合有效击穿场强及协同效应指数。结果表明:三种混合气体的绝缘强度都随CF_3I气体比例增加而增加,但混合气体的适用范围会随CF_3I比例增加而减小;在相同混合比例时,CF_3I-CF_4及CF_3I-N_2混合气体的绝缘能力较强,CF_3I-CO_2的协同系数更高,电场均匀度对CF_3I-N_2及CF_3I-CO_2的绝缘能力的影响相对较小。综合考虑,N_2更适合作为CF_3I的缓冲气体,15%～30%CF_3I比例的混合气体有较高的实际应用价值。

Analysis of CF3I Mixed Gas Proportion and Discharge Parameters

CF3I gas is a promising alternative to SF6. In order to study the optimum ratio and electrical characteristics of CF3I mixed gas, the liquefaction conditions were calculated according to the CF3I gas saturated vapor pressure equation. Then the two approximate Boltzmann equations were used to solve the electron energy distribution, ionization and attachment coefficients of the three CF3I mixtures at different mixing ratios, and the equivalent effective breakdown field strength and synergy index of the mixed gas were calculated. The results show that the insulation strength of the three mixed gases is increased with the increase of the CF3I gas ratio, but the applicable range of the mixed gas is decreased with the increase of the CF3I ratio. At the same mixing ratio, the CF3I-CF4 and CF3I-N2 mixed gases have stronger insulation capacity, the synergistic coefficient of CF3I-CO2 is higher, electric field uniformity has little effect on the insulation ability of CF3I-N2 and CF3I-CO2. Considering that N2 is more suitable as buffer gas for CF3I, the mixed gas of 15~30% CF3I ratio has higher practical application value.