Microscopic Mechanism Effect of Oxygen and Moisture on Pyrolysis of Transformer Insulating Paper

Abstract

Cellulose paper constitutes a crucial element of oil-paper insulation, crucially influencing the lifespan of transformers. Throughout its aging process, the cellulose paper generates moisture, while the insulating oil contains varying levels of oxygen. Understanding the aging mechanism of cellulose paper necessitates an exploration of the synergistic interplay between moisture and oxygen. This article establishes models incorporating varying moisture, oxygen, and cellobiose concentrations. Molecular dynamics simulations employing the reactive force field (ReaxFF) are employed to investigate the effects of moisture and oxygen addition on the decomposition of cellobiose. The mechanisms underlying the effects of moisture and oxygen on cellobiose decomposition are examined. The changes in the content of the major end products, including H2O, CO2, CO, HCHO, and HCOOH, are also analyzed. It is found that oxygen promotes the formation of C = O bonds and the production of free H from cellobiose. Moisture provides free H and promotes further reactions. The synergistic effect of moisture and oxygen accelerates the aging process of cellulose paper. This investigation provides theoretical support for further research into the aging mechanism of cellulose paper.