变压器矿物油中糠醛的稳定性研究

Stability of Furfural Dissolved in Transformer Mineral Oil

为了掌握糠醛在变压器运行环境下的化学稳定特性,提高利用糠醛判断油浸式变压器绝缘老化程度的可靠性,充分参考变压器实际运行环境,设计了矿物油中存在金属铜和硅钢片的情况下,3个不同初始质量浓度的糠醛分别在80°C和130°C下的稳定性实验。通过定期取样测量表明,在2个实验温度下,油中糠醛质量浓度均随时间呈线性关系下降。相同糠醛初始质量浓度下,温度越高,糠醛消耗速度越快。相同温度下,油中糠醛的初始质量浓度越高,其消耗速度越快。可见,矿物油中糠醛的消耗速度与变压器运行温度和油中糠醛初始质量浓度有关,实际工程中利用糠醛来判断变压器纸绝缘老化程度时,应参考变压器的运行温度及油中糠醛的历史记录情况。

In order to investigate the chemical stability characteristic of furfural under the transformer operating conditions and to improve reliability of aging conditions for transformer insulation paper estimated with furfural indicator, according to the filed operating conditions of transformer, the furfural stability experiment in laboratory conditions similar to practical conditions of field transformer is designed. Three different initial concentrations of furfural, dissolved in transformer mineral oil with the copper and silicon steel, at 80℃ and 130℃are used. By the periodic sampling and measuring, the results indicate that with effect of temperature and metal, the mass of furfural in oil decreases and the good linear relationship between concentration of furfural and time is found at the two tempera- tures. Under the same initial concentration of furfural, the higher the temperature is, the faster the loss rate of furrural becomes. In addition, it is also found that the higher the initial concentration of furfural at the same temperature is, the faster the lost rate of furfural becomes. Therefore, the lost rate of furfural is related to the operating temperature of transformer and the initial concentrations of furfural. Then, when furfural is used to estimate transformer insulation conditions in practice, both the operating temperature and the historical concentrations of furfural should be considered at the same time.