Reactive molecular dynamics simulation of transformer oil pyrolysis

Transformer oil pyrolysis is one of the main forms of degradation when internal insulation defects happen in transformers. In this paper, for revealing the microscopic reaction dynamic mechanism in the atomic level, hydrocarbon molecules with the same C atoms number 16 are taken as transformer oil examples, and ReaxFF (reactive force field) is introduced to carry out reactive molecular dynamics simulation for transformer oil pyrolysis at high temperature. By recording the distribution of reactants and products in the whole process of pyrolysis, the initial pyrolysis mechanism of transformer oil molecules was comprehensively described. According to the statistics of the cracking positions, the locations where C-C bond fracture occurs in C
16
H
34
, C
16
H
30
and C
16
H
18
are increasingly concentrated. The calculation of chemical bond dissociation energy (change of reaction enthalpy) in the process of pyrolysis shows that the initial position and frequency of pyrolysis are closely related to the chemical bond dissociation energy. The lower of the dissociation energy, the higher frequency of bond broken.