Investigating the Impact of Storage Conditions on the Aging of Alkylbenzene Insulating Oils

This study aims to investigate the impact of three environmental factors, namely different metal materials, oxygen concentration, and temperature, on the degradation process of alkylbenzene insulating oil. Thermal aging experiments were conducted at 120 ℃ with different contact materials (Q235 carbon structural steel, 304 stainless steel, and copper) under various atmospheres. Additionally, thermal aging experiments were carried out at 135 ℃, and the changes of water content, acidity, dielectric dissipation factor, breakdown voltage, and Fourier Transform Infrared Spectroscopy (FTIR) in the oil samples were tracked. Among these three environmental factors, temperature is the primary factor affecting oil degradation. When the temperature increases by 15 ℃ the aging rate of alkylbenzene insulating oil will undergo a twofold increase. The results indicated that copper exhibited the most significant impact on the degradation process of alkylbenzene insulating oil, leading to a substantial amount of sludge. The catalytic effect of iron is relatively weak, thus Q235 was suitable for alkylbenzene insulating oil storing. In a sealed environment with low oxygen concentration, the degradation rate of the oil sample significantly decreased, while the corrosion rate of metals increased due to the acidity of oil. Therefore, the optimal storage conditions for alkylbenzene insulating oil should be involve maintaining a low temperature environment, and using sealed Q235 storage tanks. Additionally, regularly inspections should be conducted to assess both internal conditions and physicochemical indicators of the oil sample.