Oxidation stability is an important property of transformer oil.
In order to improve the oxidation stability of transformer oil and oil, oxidation inhibitors are usually added. However, the addition of oxidation inhibitors will also affect the voltage resistance and dielectric loss performance of transformer oil, so the amount of inhibitors is strictly limited.
Reducing the amount of inhibitor or no inhibitor is the development trend of transformer oil. Especially the UHV Transformer oil tends to contain no inhibitor. For type I and type II transformer oils, the base oils are required to have good oxidation stability. Only the naphthenic alkyl oils can be treated properly or the aromatics base oils can meet the requirements of oxidation stability. At the same time, it can also meet the requirements of gas evolution of ultra-high voltage transformer oils.
The use of naphthenic base oil to modulate transformer oil has the advantage of other types of base oils. Large transformer manufacturers at home and abroad specify transformer oils produced from naphthenic base oils.
The main function of transformer oil is insulation and cooling. Because of the low viscosity index of naphthenic alkyl oil, when the temperature of transformer rises, the viscosity decreases rapidly and the circulation speed is accelerated, thus improving the heat dissipation effect.
Transformer oil with naphthenic alkyl as raw material has low solidification point. The solidification point of the base oil prepared by the above process is usually below - 30 C. It can directly produce No. 25 transformer oil products. 45 transformer oil products can be produced with a little treatment. Other types of base oils require dewaxing and even deep dewaxing to meet the requirements.
It can be seen that naphthenic alkyl oil has certain advantages in producing low pour point transformer oil or other low pour point oils.