Reaction mechanism of transformer oil pyrolysis based on TG-DSC and molecular simulation

摘要

Thermal fault threatens the safe and stable operation of oil filled equipment. Based on TG-DSC and ReaxFF (reactive force field), in this paper, the reaction of molecular dynamics simulation method was used to establish the simulation model of mineral insulating oil molecules under different temperatures and to study dynamic pyrolysis process and produce regularity of gaseous molecules in transformer oil. First, thermal analysis technique TG-DSC is used to observe the quality and energy changes during the process of transformer oil decomposition. Then, by using reactive reaction force field, the three typical hydrocarbons in transformer oil-alkane, cycloalkane and aromatic is simulated in a liquid system and the microscopic decomposition mechanism of transformer oil is studied. Through the establishment of a liquid system consisting of three different kinds of hydrocarbons, and the minimization of energy balance system, the pyrolysis of them in NVT system is simulated under different temperatures. The initial decomposition temperatures of the three kinds of hydrocarbons is that alkane is lower than cycloalkane and aromatic is the highest. Then the relationship between temperature and the process of pyrolysis is concluded. This study reveals the pyrolysis dynamic mechanism of the transformer oil on the atomic level, corresponding to the real pyrolysis successfully.