O_(2)对三元混合气体C_(4)F_(7)N/CO_(2)/O_(2)中界面闪络及固体析出特性的影响研究

Study on Influence of O_(2)on Interface Flashover and Solid Precipitation Characteristics in Ternary Gas Mixture C_(4)F_(7)N/CO_(2)/O_(2)

在环保气体C_(4)F_(7)N/CO_(2)中加入一定量O_(2)组成三元混合气体后,可以限制C_(4)F_(7)N深度分解形成固体产物,因此在部分环保替代方案中得到应用;然而,O_(2)的引入对气固界面放电特性以及固体产物形成特性的影响尚未得到深入研究,当前多数三元混合气体方案中O_(2)含量缺乏依据。为探究合适的O_(2)混合比例,研究C_(4)F_(7)N/CO_(2)/O_(2)三元混合气体下的气固界面闪络特性,获得O_(2)含量、C_(4)F_(7)N含量等对闪络电压的影响;分析三元混合气体下气固界面闪络放电电流以及放电后的界面宏观、微观图像。结果表明:O_(2)含量对闪络放电电压、放电电流幅值总体影响不大,制订混合方案时可主要考虑其对分解特性的影响;O_(2)含量过高时会促进气体电极绝缘材料三结合点附近区域的烧蚀现象,增强放电通道中的气体热解过程,从而形成烧蚀坑或黑色固体产物堆积,影响系统的绝缘水平;实际应用中O_(2)含量不宜超过6%。

By adding a certain amount of O_(2)to the eco-friendly gas mixture C_(4)F_(7)N/CO_(2)to form a ternary gas mixture,the deep decomposition of C_(4)F_(7)N and the formation of solid by-products can be restricted.This approach has thus found application in some eco-friendly substitution solutions.However,the specific effects of O_(2)introduction on gas-solid interface discharge characteristics and solid by-product formation have not been thoroughly investigated.Currently,the O_(2)content in most ternary gas mixture schemes lacks a solid basis.To explore the appropriate oxygen mixing ratio,this paper investigates the gas-solid interface flashover characteristics of the C_(4)F_(7)N/CO_(2)/O_(2)ternary gas mixture.The study examines the effects of O_(2)content and C_(4)F_(7)N content on flashover voltage.Additionally,it analyzes the flashover discharge current at the gas-solid interface and the macroscopic/microscopic images of the interface after discharge under the ternary gas mixture.The results indicate that the O_(2)content has minimal overall impact on flashover discharge voltage and discharge current amplitude.Therefore,when formulating the mixture scheme,the primary consideration should be its effect on decomposition characteristics.However,a high O_(2)content can exacerbate erosion near the triple junction of gas,electrode,and insulation material,enhancing the gas pyrolysis process within the discharge channel,leading to the formation of erosion pits or accumulation of black solid by-products,which negatively impact the system s insulation level.In practical applications,the O_(2)content should not exceed 6%.