Abstract Heptafluoroisobutyronitrile (C4F7N)-carbon dioxide (CO2) gas mixture has been gradually applied as an excellent environment-friendly insulating medium. The research on the decomposition characteristics of C4F7N-CO2 gas mixture not only helps to better understand its decomposition mechanism under insulation fault, but also provides effective basis for monitoring the insulation state of electrical equipment based on decomposition products analysis. Due to infrared spectroscopy has good potential for on-line monitoring of electrical equipment, this paper studies the feasibility of the decomposition products detection by infrared spectroscopy. The infrared spectrum of C4F7N and its decomposition products were obtained by theoretical calculation. The possibility of detection by infrared spectroscopy was theoretically analyzed. The experimental platform for overheating decomposition of C4F7N-CO2 gas mixture was built, and a long path gas cell with 4 m light path was developed for the detection of trace decomposition products. The results show that C3F6, COF2 and CO can be effectively detected by infrared spectroscopy with the long path gas cell. At last, the decomposition experiments under different temperature and pressure have been employed and the decomposition products growth trend has been analyzed. The study illustrates the detection feasibility of decomposition products of C4F7N-CO2 gas mixture by infrared spectroscopy, and lays a foundation for future on-line monitoring technology of electrical equipment with the gas mixture based on infrared spectroscopy.

中文翻译：

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基于红外光谱的C4F7N-CO2混合气体分解产物检测

摘要 七氟异丁腈（C4F7N）-二氧化碳（CO2）混合气体作为一种优良的环保绝缘介质已逐渐得到应用。研究C4F7N-CO2混合气体的分解特性，不仅有助于更好地了解其在绝缘故障下的分解机理，而且为基于分解产物分析监测电气设备绝缘状态提供有效依据。由于红外光谱在电气设备在线监测方面具有良好的潜力，本文研究了红外光谱检测分解产物的可行性。通过理论计算得到了C4F7N及其分解产物的红外光谱。理论上分析了红外光谱检测的可能性。搭建了C4F7N-CO2混合气体过热分解实验平台，研制了4m光程长程气室，用于痕量分解产物的检测。结果表明，C3F6、COF2 和 CO 可以通过红外光谱与长程气室进行有效检测。最后进行了不同温度和压力下的分解实验，分析了分解产物的增长趋势。该研究说明了红外光谱法检测C4F7N-CO2混合气体分解产物的可行性，为未来基于红外光谱的混合气体电气设备在线监测技术奠定了基础。并开发了具有 4 m 光程的长路径气室，用于检测痕量分解产物。结果表明，C3F6、COF2 和 CO 可以通过红外光谱与长程气室进行有效检测。最后进行了不同温度和压力下的分解实验，分析了分解产物的增长趋势。该研究说明了红外光谱法检测C4F7N-CO2混合气体分解产物的可行性，为未来基于红外光谱的混合气体电气设备在线监测技术奠定了基础。并开发了具有 4 m 光程的长路径气室，用于检测痕量分解产物。结果表明，C3F6、COF2 和 CO 可以通过红外光谱与长程气室进行有效检测。最后进行了不同温度和压力下的分解实验，分析了分解产物的增长趋势。该研究说明了红外光谱法检测C4F7N-CO2混合气体分解产物的可行性，为未来基于红外光谱的混合气体电气设备在线监测技术奠定了基础。最后进行了不同温度和压力下的分解实验，分析了分解产物的增长趋势。该研究说明了红外光谱法检测C4F7N-CO2混合气体分解产物的可行性，为未来基于红外光谱的混合气体电气设备在线监测技术奠定了基础。最后进行了不同温度和压力下的分解实验，分析了分解产物的增长趋势。该研究说明了红外光谱法检测C4F7N-CO2混合气体分解产物的可行性，为未来基于红外光谱的混合气体电气设备在线监测技术奠定了基础。