Gas Production Mechanisms of Camellia Oil-paper Insulation under Thermal Stress Based on Molecular Dynamics Simulation

Abstract

As a new environmentally friendly liquid dielectric material, vegetable insulating oil has good fire-retardant and insulation properties, and it has been used in oil-immersed transformers more and more widely. Thermal ageing and thermal faults are usually occurred in transformers. During these processes the insulating oil and insulating paper will decompose, and gases will be generated and dissolve in the oil, then the dissolved gases formed. In this paper, the microcosmic molecular simulation of thermal decomposition of camellia insulating oil and insulating paper were studied. The molecular model system of camellia oil and insulation paper were established, the molecular dynamics (MD) simulation based on ReaxFF (Reactive Force-Field) was adopted to analyze the pyrolysis process of molecules in insulating oil and paper from 1400 K to 2200 K, and main gas products were obtained. Results showed that the increase of temperature and heating duration promoted the decomposition of the oil, and contents of characteristic gases were positively related to the temperature and the heating duration. C 2 H 6 was the main hydrocarbon gas of camellia insulating oil under thermal decomposition, in addition during the decomposition process there are lots of CO 2 and H 2 generated. H 2 O s the main product and CO 2 as well as CO are main gas products of insulating paper under thermal decomposition process. Finally gas production path and mechanism of camellia oil and insulating paper are obtained through atom tracking method.