摘要
水分在油纸绝缘中的分布及扩散一直为大家所关注,但受取样及测量等技术手段的限制,水分在油纸界面位置的迁移和聚集行为缺乏深入的研究。为此从分子层面对升温过程中水分子在矿物油与纤维素界面的迁移和聚集行为进行了研究。建立了105原子量级的矿物油与纤维素复合介质模型,对其从20℃快速升温到80℃的过程进行了模拟,分析了水分子的聚集程度、运动轨迹、扩散系数以及水分子间氢键的数量。研究结果表明,升温过程中,纤维素中的水分子会向矿物油中迁移。当纤维素中水分质量分数>5%时,快速升温会导致水分子在油纸界面通过分子间氢键作用聚集成水分子簇,形成局部液态水;当水分质量分数>7%时,则会形成较大的液态水分区,严重危害变压器安全。
The distribution and diffusion of moisture in oil-paper insulation have stimulated enormous research interest;whereas,due to the limitations of sampling and measurement techniques,there is a lack of in-depth research on the migration and aggregation of moisture at the oil-paper interface.Therefore,we studied the migration and aggregation of water molecules at the interface between mineral oil and cellulose in the process of temperature increase at the molecular level.A model of a 105 atomic-scale mineral oil and cellulose composite medium was established.The process of rapid temperature increase from 20℃to 80℃was simulated.The degree of aggregation,trajectory,diffusion coefficient,and number of hydrogen bonds were analyzed.The results show that water molecules in cellulose migrate to mineral oil during the heating process.When the moisture in cellulose exceeds 5%,a rapid temperature rise will cause water molecules to accumulate into clusters through intermolecular hydrogen bonding at the oil-paper interface to form local liquid water.When the moisture content exceeds 7%,a large liquid water region will form,which seriously jeopardizes the safety of the transformer.
作者
王伟
董文妍
李芳义
蒋达
宁中正
WANG Wei;DONG Wenyan;LI Fangyi;JIANG Da;NING Zhongzheng(Beijing Key Laboratory of High Voltage&Electromagnetic Compatibility,North China Electric Power University,Beijing 102206,China;Qingdao Power Supply Company,State Grid Shandong Electric Power Company,Qingdao 266002,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2019年第11期3539-3546,共8页
High Voltage Engineering
基金
国家自然科学基金(51307053)
中央高校基本科研业务费专项资金(2018MS009)~~
关键词
油纸绝缘
水分
温度
分子模拟
氢键
oil-paper insulation
moisture
temperature
molecular simulation
hydrogen bonds
