In order to understand the gas generation process of vegetable insulating oils and guide fault diagnosis of transformers

the macroscopic experiment and microcosmic molecule simulation of camellia oil thermal decomposition process were studied. Thermal decomposition experiments of camellia insulating oil from 363 K to 403 K during 5

10

15

and 20 days were conducted

and gas production characteristics and acid value change rules were obtained. Moreover

the molecular model system of camellia oil was established

the molecular dynamics simulation based on ReaxFF（Reactive Force-Field） was adopted to analyze the pyrolysis process of molecules in oil from 1 400 K to 2 200 K

and the product formation was obtained. In addition

gas production generation paths and mechanisms were obtained through tracking observation of molecules in the reaction system. The experiment and simulation results show that C2 H6 is the main hydrocarbon gas of camellia insulating oil under thermal decomposition. The more unconjugated double bonds the triglyceride have

the poorer the thermal stability will be

and the more easily a molecule will decompose. The increase of temperature and heating duration promotes the decomposition of oil

and contents of characteristic gases are positively related to the temperature and the heating duration. For gas production path and mechanism

it is found that the C—O bond which connects to the center carbon of triglyceride molecule is broken at the beginning of the reaction

then the CO2 and free radicals of hydrocarbons are generated through decarboxylation reactions

the free radicals of hydrocarbons continue to decompose and are combined with H·

then various characteristic gases generated by pyrolysis of vegetable oils are obtained.