A Molecular Dynamics Study of the Generation of Ethanol for Insulating Paper Pyrolysis

Abstract

Cellulosic insulation paper is usually used in oil-immersed transformer insulation systems. In this study, the molecular dynamics method based on reaction force field (ReaxFF) was used to simulate the pyrolysis process of a cellobiose molecular model. Through a series of ReaxFF- Molecular Dynamics (MD) simulations, the generation path of ethanol at the atomic level was studied. Because the molecular system has hydrogen bonding, force-bias Monte Carlo (fbMC) is mixed into ReaxFF to reduce the cost of calculation by reducing the sampled data. In order to ensure the reliability of the simulation, a model composed of 20 cellobioses and a model composed of 40 cellobioses were respectively established for repeated simulation in the range of 500–3000 K. The results show that insulating paper produced ethanol at extreme thermal fault, and the intermediate product of vinyl alcohol is the key to the aging process. It is also basically consistent with others’ previous experiment results. So it can provide an effective reference for the use of ethanol as an indicator to evaluate the aging condition of transformers.

A review on a novel method for aging evaluation of transformer insulating paper based on methanol

“…Molecular dynamics plays an irreplaceable role in discovering new phenomena and clarifying new mechanisms [62]. Zhang's research group [63] used the molecular dynamics method based on reaction force field (ReaxFF) modules of Amsterdam Modelling Suite (AMS) software to simulate the pyrolysis process of cellobiose. A model composed of 40 cellobiose is established, and the simulation temperature is 500 to 3000 K. In order to make ReaxFF closer to the actual situation and ensure reliability, the force‐biased Monte Carlo method is introduced into ReaxFF.…”

Investigation on Formation Mechanisms of Methanol During Cellulose Insulation Aging Based on Molecular Dynamics Simulation

“…It was found that cellulose chains with different DPv have the same molecular conformation and physical and chemical properties. Thus, the repeating unit of the cellulose chain (cellobiose molecule) was used as the simulation model with the consideration of computational power and efficiency [31], as shown in Fig. 1.…”

“…Based on the TAD theory, the temperature of 1600 K, 1800 K, and 2000 K was set to investigate the formation mechanisms. Besides, Zhang et al used the same assumptions and conditions for the cellulose model to study the reaction mechanism of methanol [38] and ethanol [31].…”

Transformer Oil Generation and Regeneration Techniques Based on Recent Developments (A Review)

“…By the way the efficiency of impurities removal obtained with a decline of 14% of polar substances and 32% of oxides in polymer organic membranes applications. The advantages of employing the ultrasonic separation technology refer to wide and continuous applications, high efficiency, low contact, and low pollution but it demands a microfluidic chip and acoustic radiation force (generator) [57][58][59][60][61][62][63][64].…”