绝缘纸热裂解初期微观机理研究（英文）  

Microscopic Mechanism on the Incipient Pyrolysis of Insulation Paper

作　　者：王学磊 王硕 朱文兵 周加斌 许伟 

机构地区：[1]国网山东省电力公司电力科学研究院,山东济南250003

出　　处：《山东电力技术》2017年第6期8-16,共9页Shandong Electric Power

摘　　要：探究绝缘纸的微观热裂解机理,特别是初期裂解机理,对于深入认识变压器内部绝缘系统过热缺陷下的裂解过程以及绝缘裂化的早期评价与绝缘寿命评估具有潜在的指导价值。为此,采取实验与仿真相结合的手段,首先,对纤维素进行了350~900℃下的气相色谱/质谱联用实验,研究表明,阿洛糖是实验中生成量最高的产物,是绝缘裂化初期表征裂化程度最重要的产物。为了进一步厘清阿洛糖裂解生成机理以及后续裂解规律,对绝缘纸纤维素中的结构单元纤维二糖的裂解进行了高温反应分子动力学模拟。通过跟踪可视化的纤维素分解过程,观测不同时刻键的断裂和生成规律,发现阿洛糖生成由最易发生断裂的糖苷键C′4-O键断裂和1-吡喃环上C1-O5键两化学键断裂而来。裂解小分子产物作为新的微观特征量,可通过质谱仪测得并进行趋势分析,在变压器过热故障诊断中具有潜在应用价值。By investigating the microscopic pyrolysis mechanism of the insulation paper,especially on the incipient pyrolysis stage,it can reveal potential guiding values,such as further understanding on the pyrolysis process in internal insulation system of a transformer undergoing overheating defects and early evaluations of insulation deterioration and life expectancy.To this end,the way of experiment combined with simulation was adopted in this article.Firstly,the GC/MS experiment on cellulose under 350~900℃was conducted,and it is found that allose was the product of the highest ration and it is also the most important product for diagnosing the degree of deterioration on the incipient stage.For further clarification of the formation mechanism and the following rules of the pyrolysis of allose,the high temperature reactive molecular dynamics simulation for the pyrolysis of cellobiose which is the constitutional unit of the paper cellulose was investigated and discussed in this article.By tracking the visual decomposition process of the cellulose and observing the splitting and forming rules of the bonds at different time,it is found that allose was generated by the split of C′4-O glucosidic bond and C1-O5 bond at the 1-pyranoid ring.The small molecules generated during pyrolysis are measured by velocitron and can be used as micro-features in diagnosing thermal faults of the power transformers.

关 键 词：绝缘纸 初始裂解 反应分子动力学 微观机理 阿洛糖 

分 类 号：TM211[一般工业技术—材料科学与工程] TM853[电气工程—电工理论与新技术]