老化对纤维素与矿物油间水分平衡影响的规律及机制

Cellulose and mineral oil are the main insulation material of power transformer, the increase of moisture will reduce their insulation strength. Moisture equilibrium curves are the basis of power transformer moisture detection, however, the service data and theory analysis both indicate the present curves are not fit for old transformer. The project will research the law and mechanism of the impact of aging on moisture equilibrium of cellulose and mineral oil. The moisture absorption mechanism and impact factors of cellulose and mineral oil will be theory analyzed, various aged cellulose and mineral oil samples will be prepared by thermal aging method, the specific surface area of the cellulose sample and the interfacial tension of the mineral oil sample will be measured, the moisture in cellulose and mineral oil will be measured at various temperature and humidity condition, the mathematical model of moisture equilibrium of cellulose and mineral will be presented and the moisture equilibrium curves will be corrected in aging condition. The proposed project will uncover the moisture equilibrium law and mechanism of cellulose and mineral oil, which have both theoretical significance and applicabel potentials.

纤维素与矿物油是油浸式变压器的主要绝缘材料，水分含量的增加会显著降低其绝缘强度。纤维素与矿物油间的水分平衡曲线是检测变压器水分含量的重要依据，运行数据及初步理论分析表明现有曲线在变压器老化条件下不再适用。本项目拟对老化对纤维素与矿物油间水分平衡的影响机制进行研究。理论分析纤维素与矿物油的吸湿机制及影响因素；利用加速热老化方法制备不同老化程度的纤维素与矿物油试样，测量纤维素试样的比表面积以及矿物油的界面张力等影响其吸湿机制的微观结构特征量；测量不同老化程度纤维素与矿物油组合试样在不同温度与湿度条件下水分平衡含量，建立纤维素与矿物油间水分平衡的数学模型，并对现行纤维素与矿物油间的水分平衡曲线进行老化条件下的修正。本项目的研究成果将揭示老化对纤维素与矿物油间水分平衡影响的规律及机制，具有重要的理论意义及工程实用价值。