植物油中水分对糠醛扩散作用影响的分子动力学模拟

Molecular Dynamics Simulation on Effect of Water in Vegetable Oil on Furfural Diffusion

糠醛含量是反映电力变压器油纸绝缘老化程度的重要参数,水分则是影响糠醛分子在油纸绝缘系统中扩散行为的重要因素,然而糠醛分子在不同含水量的植物油变压器中的微观扩散机理规律尚未明确。本文利用分子动力学方法,分别构建糠醛在无水、1%、3%、5%水分含量下的植物油模型并进行动力学模拟,研究分析糠醛的动力学轨迹、与介质的相互作用能和自由体积等参数,并与矿物油系统进行对比。结果表明:糠醛分子的动力学轨迹随着水分含量的增加表现出明显的空间松散性。植物油模型中,水分优先与植物油产生氢键,而糠醛与植物油之间氢键的含量较少。随着水分含量的增加,油纸绝缘系统中糠醛的扩散行为逐渐加强。

Furfural content is an important parameter reflecting the ageing degree of oil-paper insulation in power transformers.Water content is an important factor affecting the diffusion behavior of furfural molecules in oil-paper insulation system.However,the micro-diffusion mechanism of furfural molecules in vegetable oil transformers with different water content is not clear.In this paper,the vegetable oil models of furfural with anhydrous,1%,3%,and 5%water content were constructed by molecular dynamics method,and the kinetic trajectory,interaction energy,and free volume of furfural were studied and compared with the mineral oil system.The results show that the kinetic trajectory of furfural molecules show obvious spatial looseness with the increase of water content.In vegetable oil model,water would produce hydrogen bonds with vegetable oil preferentially,while the hydrogen bonds content between furfural and vegetable oil is small.With the increase of water content,the diffusion behavior of furfural in oil-paper insulation system is enhanced gradually.