某220kV变电所构架水泥杆钢圈焊接接头-本科论文.docVIP

变电所构架水泥杆钢圈对接焊缝 无损检测及应力分析 晏嘉陵1，陈安生1，陈庆涛2，田宇2 1.安徽省电力科学研究院，安徽 合肥 230601；2.安徽省电力公司，安徽 合肥 230022 摘要：通过对某220kV变电所构架水泥杆钢圈对接焊缝进行了X射线检测以及结构应力分析，随机抽检焊缝均不合格，存在严重的未焊透、未溶合等焊接缺陷；有限元结果显示在外部载荷以及焊接残余应力的综合影响下对接焊缝承受较大应力，随着钢圈厚度减小，等效应力越大。若焊缝存在未融合或未焊透等缺陷易形成裂纹源，在综合应力的作用下裂纹扩展而造成设备失效，将严重影响电网安全运行。并对GB 50233-2005《110～500kV架空送电线路施工及验收规范》中对焊接接头质量要求进行讨论。最后对相关的设计、施工、监理等各环节给出建议。 关键词：变电构架；水泥杆；对接焊缝；X射线检测；有限元分析 NDT and stress analysis on the butt welds of cement-poles of framework in a substation Yan Jia-ling1,Chen An-sheng1,Chen Qing-tao2,Tian Yu2 1. Anhui Electric Power Research Institute, Anhui Hefei 230601.2.Anhui Electric Power Corporation,Anhui,Hefei,230022. Abstract: Butt welds of steel ring at the cement-poles of framework are inspected by x-ray and its structural stress is analyzed in a 220kV substation. Both of them inspected at random were defective, which welddefects such as lack of fusion or incomplete penetration. Butt welds are suffered from stresses under external load and residual stresses. The thickness of steel ring is smaller, the equivalent stress is larger. If there are the welddefects such as lack of fusion, incomplete penetration in the welds ,the cracks are easy to form under all the stresses, which will have effects on safe running of power grid.And discuss on requirements of weldings in the GB 50233-2005. Reasonable Suggestion on designation, construction and supervision department is given finally. Keywords: substation framework;cement-pole;butt weld;X-ray inspection;FEM 1前言 某220kV变电所是该地区220kV网架的重要一环，70年代建成投运，担负着向该市区供电的任务。为保证该地区电网安全运行，对该变电所220kV配电装置区所有母线和构架，线路、主变、分段间隔和旁路母线间隔的跨线进行改造和更换。变电构架用于悬挂导体、支撑导体或开关设备及其他电气设备的刚性构架组合。数字式X射线实时成像技术技术是利用胶片，通过显影、定影等暗室处理后进行检测和评估的技术。DR数字实时成像系统包括 X 射线源、成像板系统、信号放大和数据采集处理单元、计算机图像处理存储传输系统、图像显示系统等。 图3门型构架示意图 图4 A型构架示意图 3.1有限元模型 为方便考察对接焊缝受力情况，只取整个立柱的上部分（具体如图3、图4所示，因A型构架最上方焊缝处采用槽钢加固不予以考虑），模型尺寸依据设计图纸，模型只考虑立柱，横梁以及拉线。假设母材和焊缝中均不存在任何缺陷，以最不利载荷情况下，按照简支梁端部受载，确定底部环焊缝应力情况。将实际导线张力、风载荷、振动载荷以及其他静载荷等载荷条件简化换算为集中载荷施加在立柱顶部。材料为Q235B(屈服强度