GIS壳体焊缝缺陷的安全评定方法  

Safety assessment method for weld defects of GIS shell

作　　者：王炯耿 唐夏焘 罗宏建 郑三龙[2] 陈冰冰[2] WANG Jionggeng;TANG Xiatao;LUO Hongjian;ZHENG Sanlong;CHEN Bingbing(State Grid Zhejiang Electric Power Research Institute;Engineering Research Center of Process Equipment and Remanufacturing Ministry of Education, Zhejiang University of Technology)

机构地区：[1]国网浙江省电力公司电力科学研究院 [2]浙江工业大学过程装备及其再制造教育部工程研究中心

出　　处：《油气储运》2019年第6期617-622,628,共7页Oil & Gas Storage and Transportation

摘　　要：针对某在役特高压电网GIS壳体焊缝发现的缺陷,引入缺陷断裂安全评定和疲劳评定方法。采用与原壳体相同的材料和焊接工艺制作的焊接试板,通过试验获得母材和焊缝试样的力学性能、疲劳裂纹扩展及断裂性能。采用GB/T 19624-2004《在用含缺陷压力容器安全评定》中的推荐方法,对壳体纵焊缝中两个最大缺陷进行断裂评定和疲劳评估。结果表明:该GIS壳体中的两个缺陷在当前工况下是安全的,按焊接试板测试的疲劳裂纹扩展速率估算,壳体左筒体缺陷的疲劳寿命循环次数为6 971次,壳体右筒体缺陷的疲劳寿命循环次数为37 915次,估算的疲劳寿命还有待于实践校验。建议在运行中特别关注缺陷疲劳扩展的状态监测,约5年后应进行无损检测,并与现缺陷对比,进行安全评定。评定结果与该设备投用以来的安全运行状态相符,说明,GB/T 19624-2004的评定方法可适用于高压电网GIS壳体的安全评定。In this paper, a method for fracture safety assessment and fatigue assessment was introduced to assess the defects discovered in the welds of GIS shell in one in-service ultra high voltage power system. The weld specimen was prepared from the same material by the same welding technology as the original shell. The properties of the base material and the weld specimen were experimentally measured, including mechanical property, fatigue crack propagation and fracture property. And fracture assessment and fatigue assessment were carried out on two biggest defects in the longitudinal welds of the shell by means of the assessment method stipulated in the Safety Assessment on In-Service Pressure Vessels with Defects(GB/T 19624-2004). It is shown that these two defects in the GIS shell are safe under the current working condition.Then, the fatigue life of the defect was calculated based on the fatigue crack propagation rate of the weld specimen. And the fatigue life of the defect in the left cylinder of the shell is 6 971 cycles, and that in the right cylinder is 37 915 cycles. The estimated fatigue life shall be validated in the future practice. It is recommended to pay much attention to monitoring the fatigue propagation state of defects in the process of operation. And in order to carry out safety assessment, nondestructive testing shall be performed and compared with current defects in the following 5 years. It is concluded that safe operation state of this GIS shell since its commissioning is accordant with the assessment result, so the GB/T 19624-2004 is applicable to the safety assessment of GIS shell in high voltage power system.

关 键 词：缺陷 GIS壳体:5083铝合金 安全评定 

分 类 号：TM595[电气工程—电器] TE88[石油与天然气工程—油气储运工程]