Zhang Yin, Zhang Xiaoxing, Liu Chang, Li Yi, Cui Zhaolun, Fu Mingli
1 School of Electrical Engineering, Wuhan University, Wuhan, China.
2 Electric Power Research Institute, China Southern Power Grid, Guangzhou, China.
Appl Spectrosc. 2019 Aug;73(8):917-926. doi: 10.1177/0003702819833702. Epub 2019 Mar 8.
As an alternative to sulfur hexafluoride (SF) with great potential for application, heptafluoroisobutyronitrile-carbon dioxide (CFN-CO) gas mixture has been applied in various gas-insulated equipment. The insulation performance of the gas mixture is closely related to the mixing ratio. Therefore, accurate quantification of CFN in the CFN-CO gas mixture has very important engineering significance. At present, there are few reports on the rapid quantitative detection of the concentration of CFN in the gas mixture. In this paper, a rapid analytical method for CFN concentration based on ultraviolet (UV) absorption spectroscopy is constructed. The UV spectral characteristics of CFN molecules are calculated by density functional theory. The appropriate bands that can be detected are determined by analyzing the calculated results. A concentration detection system of CFN based on UV absorption spectroscopy is built. Through analysis of the calculated results and experimental results, a quantitative detection method of CFN in the CFN/CO gas mixture is determined. The method can achieve accurate detection of the concentration of the gas mixture in the conventional application range (including 4-10% CFN). The coefficient of the determination R of the concentration inversion curve reaches 0.999 and the inversion error ratio does not exceed 5%. The related research results provide an important reference for the engineering application of the gas mixture.
作为一种具有巨大应用潜力的六氟化硫（SF）替代品，七氟异丁腈 - 二氧化碳（CFN - CO）气体混合物已应用于各种气体绝缘设备中。该气体混合物的绝缘性能与混合比例密切相关。因此，准确量化CFN - CO气体混合物中的CFN具有非常重要的工程意义。目前，关于气体混合物中CFN浓度快速定量检测的报道较少。本文构建了一种基于紫外（UV）吸收光谱的CFN浓度快速分析方法。通过密度泛函理论计算CFN分子的紫外光谱特性。通过分析计算结果确定可检测的合适波段。建立了基于紫外吸收光谱的CFN浓度检测系统。通过对计算结果和实验结果的分析，确定了CFN/CO气体混合物中CFN的定量检测方法。该方法能够在常规应用范围内（包括4 - 10% CFN）实现对气体混合物浓度的准确检测。浓度反演曲线的决定系数R达到0.999，反演误差率不超过5%。相关研究结果为该气体混合物的工程应用提供了重要参考。
