Research on the corrosive effect of inactive sulfur on oil-paper insulation
Research on the corrosive effect of inactive sulfur on oil-paper insulation
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DOI：
10.1109/ichve49031.2020.9280058
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发表时间：
2020-09
期刊：
影响因子：
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通讯作者：
Sihang Gao;Jiajun Li;T. Ke;Yang Liu;D. Ding
中科院分区：
文献类型：
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作者：
Sihang Gao;Jiajun Li;T. Ke;Yang Liu;D. Ding
活性硫磺引起的硫磺腐蚀已被证明会显著降低油浸式设备的绝缘性能。为了保护油纸绝缘不受硫腐蚀，在原油精制过程中要清除活性硫。矿物油中还残留了一些含有高效抗氧化剂的非活性硫磺，以改善油品的氧化安定性，如含硫化合物。然而，非活性硫磺对油纸绝缘的腐蚀作用尚不清楚。为此，选择绝缘油中硫化物含量最大的噻吩类化合物为研究对象，进行了不同温度下油纸在不同温度下的加速热老化实验，并用配有能谱仪的扫描电子显微镜(SEM/EDX)和电感耦合等离子体原子发射光谱(ICPAES)对油纸绝缘的腐蚀程度进行了表征。结果表明，即使在很高的温度下，不含噻吩组的油纸绝缘表面也没有观察到腐蚀层，而含500 mg/kg噻吩组的油纸绝缘层表面有少量的腐蚀层。随着温度的升高(130°C~180°C)，噻吩型油纸绝缘的腐蚀程度呈上升趋势，初步表明在油浸式变压器过热故障的作用下，油纸系统中的噻吩型化合物可能被激活，对油纸绝缘构成腐蚀威胁。
Sulfur corrosion induced by active sulfur has been proved to significantly decrease the insulation performance of oil-immersed equipment. In order to protect the oil-paper insulation from sulfur corrosion, active sulfur is cleared in the refining process of crude oil. Some inactive sulfur with high-efficiency antioxidant is still retained in the mineral oil to improve the oxidation stability of oil, such as thiophenic compounds. However, the corrosive effect of inactive sulfur on the oil-paper insulation has not yet clear. Therefore, thiophene that is the largest content of sulfide in the insulating oil was selected as the research object, a series of accelerated thermal ageing experiments of oil-paper without and with thiophene under the different high temperature were conducted, scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (SEM/EDX) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were used to characterize the corrosion degree of oil-paper insulation. The results show that no corrosive deposit was observed on the surface of oilpaper insulation without thiophene even at very high temperature, while a few corrosive deposit was accumulated on the surface of oil-paper insulation with 500 mg/kg thiophene. The corrosion degree of oil-paper insulation with thiophene had an uptrend as the increase of temperature (130°C-180°C), preliminarily indicating that thiophene may be activated in the oil-paper system under the action of overheating fault of oil-immersed transformer and posed a corrosion threat to oil-paper insulation.