变压器油纸绝缘的硫腐蚀微观机制与防护技术研究
发布时间：2019-04-03 11:06
【摘要】：近十几年来,国内外报道了数百起因变压器绝缘油中含有腐蚀性硫而引发的设备绝缘事故,已受到电力部门和研究学者的广泛关注。目前研究学者对硫腐蚀的腐蚀劣化机理和其对绝缘性能影响规律等方面已经展开了诸多试验研究。同时提出了向变压器油中添加钝化剂延缓铜绕组的腐蚀的方法,并已得到工程应用。但受到实验研究手段的限制,腐蚀性硫对于油纸绝缘材料破坏机理仍不清晰,对于防止硫腐蚀的钝化剂的有效添加浓度尤其在运行油和新油中防护效果的差异与受到影响因素的关系仍有待探究。因此,研究腐蚀性硫对油纸绝缘材料劣化作用微观机理及深入探索针对硫腐蚀的防护规律有重要的学术及工程应用价值。应用分子动力学的仿真技术,建立了基于纤维分子力学、均方位移、分子总能量计算的硫化物-纤维素模型,研究了不同硫化物在不同浓度下对绝缘纸纤维素材料的微观影响机制,通过计算纤维素分子力学参数,发现其机械刚性与韧性因H2S、十六硫醇的作用而削弱,且硫化物浓度愈高下降越明显。同时这两种硫化物的存在使纤维素玻璃化温度显著降低,而纤维素均方位移的计算显示分子链运动更剧烈,稳定度变差。反观二苄基二硫醚(DBDS)对纤维素材料抗拉伸强度的减弱作用不强,反而使其延展性和韧性随DBDS的含量变大而增强。纤维素分子的总势能和非键能部分计算显示,加入硫化物后总势能和静电能增加不明显,但H2S和十六硫醇造成氢键和范德华作用的减弱,即从能量角度给出材料机械性能下降的原因解释。同时设计并开展了添加腐蚀性硫化物的油纸老化试验,通过测量绝缘纸聚合度与抗张力,得出了与仿真较为吻合的规律。为获得钝化剂在运行油和新油中最佳添加浓度,设计并开展了不同钝化剂浓度的对比老化试验。通过测试变压器油介质损耗因素、工频击穿电压、水分、糠醛等特征参量,综合评判钝化剂在最佳添加浓度下,对油品和绝缘纸性能的影响处在标准范围以内。同时,两种钝化剂在温度达到130℃后无论在运行油还是新油中防护效果下降明显,且其作用效果受水分和氧气影响显著。
[Abstract]:In the past ten years, hundreds of equipment insulation accidents caused by corrosive sulfur in transformer insulating oil have been reported at home and abroad, which have been paid more and more attention by electric power departments and researchers. At present, many experiments have been carried out on the corrosion degradation mechanism of sulfur corrosion and its influence on insulation properties. At the same time, the method of adding passivator to transformer oil to delay the corrosion of copper windings is put forward, and it has been applied in engineering. However, the damage mechanism of corrosive sulfur to oil-paper insulation materials is still unclear due to the limitation of experimental research methods. The relationship between the effective addition concentration of passivator to prevent sulfur corrosion, especially in running oil and fresh oil, and the affected factors remains to be explored. Therefore, it has important academic and engineering application value to study the micro-mechanism of corrosive sulfur on the deterioration of oil-paper insulation materials and to explore the protective law of sulfur corrosion deeply. A sulphide-cellulose model based on fiber molecular mechanics, average azimuth shift and molecular total energy calculation was established by using molecular dynamics simulation technique. The mechanism of the microcosmic effect of different sulfides on insulating paper cellulose was studied. By calculating the molecular mechanical parameters of cellulose, it was found that the mechanical rigidity and toughness of cellulose were weakened by the action of H 2S and hexadecyl mercaptan. The higher the sulfide concentration was, the more obvious the decrease was. At the same time, the existence of these two sulfides significantly reduced the glass transition temperature of cellulose, while the calculation of average orientation shift of cellulose showed that the molecular chain movement was more intense and the stability became worse. On the contrary, dibenzyl disulfide (DBDS) has little effect on the tensile strength of cellulose materials. On the contrary, the ductility and toughness of the cellulose materials increase with the increase of DBDS content. The partial calculation of total potential energy and non-bond energy of cellulose molecule shows that the total potential energy and electrostatic energy increase little after adding sulfides, but H _ 2S and hexadecosulfide weaken the hydrogen bond and van der Waals interaction. That is, from the energy point of view, the reasons for the decline of mechanical properties of materials are explained. At the same time, the aging test of oil paper with corrosive sulfides was designed and carried out. By measuring the degree of polymerization and tensile resistance of insulating paper, a more consistent law with simulation was obtained. In order to obtain the best adding concentration of passivator in running oil and fresh oil, the contrast aging test of different passivator concentration was designed and carried out. The influence of passivator on the performance of oil and insulating paper under the optimum concentration of passivator is evaluated by testing the characteristic parameters of transformer oil dielectric loss, power frequency breakdown voltage, water, furfural, etc. The effect of passivator on the performance of oil and insulating paper is within the standard range. At the same time, when the temperature reaches 130 鈩，
本文编号：2453160
[Abstract]:In the past ten years, hundreds of equipment insulation accidents caused by corrosive sulfur in transformer insulating oil have been reported at home and abroad, which have been paid more and more attention by electric power departments and researchers. At present, many experiments have been carried out on the corrosion degradation mechanism of sulfur corrosion and its influence on insulation properties. At the same time, the method of adding passivator to transformer oil to delay the corrosion of copper windings is put forward, and it has been applied in engineering. However, the damage mechanism of corrosive sulfur to oil-paper insulation materials is still unclear due to the limitation of experimental research methods. The relationship between the effective addition concentration of passivator to prevent sulfur corrosion, especially in running oil and fresh oil, and the affected factors remains to be explored. Therefore, it has important academic and engineering application value to study the micro-mechanism of corrosive sulfur on the deterioration of oil-paper insulation materials and to explore the protective law of sulfur corrosion deeply. A sulphide-cellulose model based on fiber molecular mechanics, average azimuth shift and molecular total energy calculation was established by using molecular dynamics simulation technique. The mechanism of the microcosmic effect of different sulfides on insulating paper cellulose was studied. By calculating the molecular mechanical parameters of cellulose, it was found that the mechanical rigidity and toughness of cellulose were weakened by the action of H 2S and hexadecyl mercaptan. The higher the sulfide concentration was, the more obvious the decrease was. At the same time, the existence of these two sulfides significantly reduced the glass transition temperature of cellulose, while the calculation of average orientation shift of cellulose showed that the molecular chain movement was more intense and the stability became worse. On the contrary, dibenzyl disulfide (DBDS) has little effect on the tensile strength of cellulose materials. On the contrary, the ductility and toughness of the cellulose materials increase with the increase of DBDS content. The partial calculation of total potential energy and non-bond energy of cellulose molecule shows that the total potential energy and electrostatic energy increase little after adding sulfides, but H _ 2S and hexadecosulfide weaken the hydrogen bond and van der Waals interaction. That is, from the energy point of view, the reasons for the decline of mechanical properties of materials are explained. At the same time, the aging test of oil paper with corrosive sulfides was designed and carried out. By measuring the degree of polymerization and tensile resistance of insulating paper, a more consistent law with simulation was obtained. In order to obtain the best adding concentration of passivator in running oil and fresh oil, the contrast aging test of different passivator concentration was designed and carried out. The influence of passivator on the performance of oil and insulating paper under the optimum concentration of passivator is evaluated by testing the characteristic parameters of transformer oil dielectric loss, power frequency breakdown voltage, water, furfural, etc. The effect of passivator on the performance of oil and insulating paper is within the standard range. At the same time, when the temperature reaches 130 鈩，
本文编号：2453160
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