变压器油中酸与抗氧化剂协同作用对油硫腐蚀的影响

为了研究变压器油中酸与抗氧化剂2,6-di-tert-butyl-p-cresol(DBPC)协同作用下对油硫腐蚀的影响,在含有腐蚀性硫化物DBDS的变压器油中加入抗氧化剂DBPC与两种不同类型的酸,并在氮气环境下对油纸绝缘进行加速热老化。老化后对铜绕组进行展开并观察铜条与绝缘纸表面的腐蚀沉积;采用气质联动仪(GC-MS)对油中剩余DBDS含量进行测量;利用Arrhenius方程计算酸作用下的腐蚀性硫化物腐蚀铜绕组的活化能。结果表明:酸能加剧铜表面的油硫腐蚀程度;抗氧化剂DBPC在一定程度上能减缓铜表面的腐蚀,氮气环境下绝缘纸表面几乎不存在沉积物。采用Arrhenius方程计算得到油硫腐蚀铜绕组所需的活化能为88.37 k J/mol,酸作用下油硫腐蚀铜绕组所需的活化能相比下降了30.64%。酸的存在使得腐蚀性硫化物腐蚀铜的化学反应更易进行。

The Effect of Acid and DBPC on the Sulfur Corrosion Mechanism in Power Transformer

In order to investigate the effect of acid and antioxidant 2,6-di-tert-butyl-p-cresol( DBPC)on the sulfur corrosion in oil,antioxidant DBPC and two kinds of acid were added into transformer oil which contains corrosive sulfur DBDS. Then the oil-paper insulation was experienced accelerated thermal aging under N 2 environment. After the aging experiment,the copper winding was unfolded and the corrosion depositions on the copper and paper surface were observed. The GC-MS was used to measure the residual DBDS concentration in the oil. The activation energy of the corrosion reaction between DBDS and copper winding under the effect of acid was calculated using the Arrhenius equation. The results show that the corrosion degree of the copper conductor surface will be accelerated by acid;DBPC can mitigate the corrosion on copper surface to a certain extent;and Cu 2 S deposition can be hardly formed on the paper surface under N2 condition. In addition,the activation energy of the reaction between DBDS and copper winding is about 88. 37 kJ/mol using the Arrhenius equation,whereas with the effect of the acid the activation energy decreased by almost 30. 64%. The corrosion reaction between DBDS and copper winding will be easier to conduct under the effect of acid.