Mid-infrared photoacoustic spectrum analysis of SF6 gas-decomposition system

The article explores the application of mid-infrared photoacoustic spectroscopy for the detection of sulfur hexafluoride (SF6) gas decomposition products, which are critical for the safety and reliability of high-voltage electrical equipment. SF6 gas is widely used in electrical systems due to its insulating properties and safety advantages. However, in the event of an insulation fault, SF6 gas can decompose into toxic gases, posing significant risks. The article highlights the limitations of existing detection methods, such as gas chromatography and mass spectrometry, which require specialized laboratory conditions. To address these challenges, the authors introduce a system that combines a mid-infrared quantum cascade laser (MI-QCL) with an integrated photoacoustic cell. This system allows for the rapid and precise detection of SF6 decomposition products on-site, making it a promising solution for early fault warning and accurate assessment of potential dangers. The article delves into the design and experimental setup of the photoacoustic cell, including the calculation of sound pressure signals and the optimization of cell structure. The results demonstrate the system's ability to detect SO2, H2S, and CO gases with high accuracy and repeatability, even at low concentrations. The study concludes with the potential of this technology to significantly reduce the volume of detection systems, making it ideal for on-site rapid detection in photoacoustic spectroscopy.