高压电力变压器用NBR密封圈极端低温老化研究  

Study on Ageing of NBR Sealing Ring for High Voltage Power Transformer in Extremely Low Temperature

作　　者：刘文凤[1] 郑雪梅[1] 张子琦[1] 安义岩 迟晓红 LIU Wenfeng;ZHENG Xuemei;ZHANG Ziqi;AN Yiyan;CHI Xiaohong(State Key Laboratory of Electrical Insulation and Power Equipment,Xi'an Jiaotong University,Xi'an 071000,China;State Grid East Inner Mongolia Electric Power Research Institute,Hohhot 010090,China)

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,陕西西安071000 [2]国网内蒙古东部电力有限公司电力科学研究院,内蒙古呼和浩特010010

出　　处：《绝缘材料》2022年第8期72-75,共4页Insulating Materials

基　　金：陕西省重点研发计划项目(2020ZDLGY09-10)。

摘　　要：为了研究在极端低温和油介质共同作用下丁腈橡胶(NBR)密封件的可靠性,对极寒地区服役高压变压器中的密封圈进行力学性能和微观结构的研究。通过拉伸实验、微米压痕、扫描电镜(SEM)、红外光谱(FTIR)、差示扫描热量分析(DSC),测试极寒环境中服役1年后密封圈的力学性能、形貌变化、化学结构特性及热响应特性。结果表明:在极寒环境中服役的NBR密封圈的弹性模量和硬度均发生下降,进而导致密封作用丧失。这是由于在低温和油介质共同作用下,密封圈表面发生了溶胀,出现了微裂纹。油介质浸入NBR使其分子链间距增大,NBR分子主链柔顺性提高,同时NBR中的氰基发生水解反应,分子结构发生变化。In order to study the reliability of nitrile butadiene rubber(NBR) sealing element under the action of extremely low temperature and oil medium, the mechanical properties and microstructure of sealing rings in highvoltage transformers in extremely cold regions were studied. The mechanical characteristics, morphology change,chemical structure characteristics, and thermal response characteristics of the sealing ring after serviced for one year in extremely cold environment were obtained by tensile test, micron indentation test, scanning electron microscope(SEM), infrared spectrum(FTIR), and differential scanning thermal analysis(DSC). The results show that the elastic modulus and hardness of NBR sealing ring decrease in extremely cold environment, which leads to the loss of sealing effect. This is because the surface of sealing ring swell under the joint action of low temperature and oil medium, and micro-cracks appear. Oil immersion in NBR makes the molecular chain spacing increase, and the compliance of main chain of NBR is improved, meanwhile, the molecular structure of NBR changes due to the hydrolysis reaction of cyanide group.

关 键 词：丁腈橡胶 极端低温 老化 油介质 密封圈 

分 类 号：TM215[一般工业技术—材料科学与工程] TM403.3[电气工程—电工理论与新技术]