火电厂锅炉再热器联络管裂纹分析及处理

某火电厂亚临界锅炉墙式再热器蒸汽出口至屏式再热器联络管母管及排空气管接管座产生裂纹发生渗漏。通过对墙式再热器出口管道排空气管接管座裂纹特征、结构型式、管道现场布置情况、运行环境等方面进行综合分析,认为排空气管道安装布置不合理,无保温措施,导致冷凝水倒流,形成热疲劳裂纹并逐步延伸扩展。确认产生裂纹的原因后,优化管道安装布置、对接管座结构型式做出改进并对产生裂纹的管道进行了更换,改进后锅炉运行约1.8× 10⁴ h后复检无缺陷。

Analysis and Treatment of Boiler Reheater Connecting Pipe Crack in Thermal Power Plan

Cracks and leakage occurred in the connecting pipe header and vent pipe socket between wall reheater steam outlet and platen reheater in a thermal power plant.Based on the comprehensive analysis of crack characteristics,structure type,field layout and operation environment of the exhaust pipe of wall type reheater outlet pipe,it is considered that the installation layout of exhaust pipe is unreasonable and there is no thermal insulation measures,resulting in condensate backflow,forming thermal fatigue cracks and gradually extending and expanding.After confirming the causes of the cracks,the installation and layout of the pipes were optimized,the structure of the butt joint socket was improved,and the cracked pipes were replaced.After the improvement,the boiler operated for about 18000 h and there was no defect in the reinspection.