1025t/h锅炉后屏再热器泄漏原因分析及防范措施

Analysis on the leakage of the rear platen reheater of the 1025 t/h boiler and preventive measures

通过宏观特征分析、管样化学成分分析、机械性能检测、金相组织分析等多种检测分析手段,对某电厂1025 t/h锅炉后屏再热器泄漏原因进行分析。结果表明,原始漏点为后屏再热器夹管变径台阶处裂纹,该部件结构设计不合理,导致变径台阶截面产生应力集中,在内应力和残余应力等综合应力的长期作用下开裂泄漏。结合现场实际对该结构进行优化,直接采购壁厚7 mm规格的夹管,在现场使用坡口机加工过渡坡口,消除夹管截面突变引起的应力集中,实施效果良好。

The reasons for the leakage of the rear platen reheater of a 1025 t/h boiler in a power plant are analyzed,using various detection and analysis methods,such as macroscopic characteristics,chemical composition of tube samples,mechanical properties,metallographic structure.The results show that the original leakage point is the crack at the chaning diameter step of the pinch pipe of the rear platen reheater.Components with unreasonable structural design lead to stress concentration in the chaning diameter stepped section,which causes cracking and leakage under the long-term action of comprehensive stresses such as internal stress and residual stress.Based on the actual situation,the structure has been optimized.The pinch pipe with a wall thickness of 7 mm is processed with a beveling machine to process the transition groove to eliminate the stress concentration caused by the sudden change of the pinch pipe section.The results show that this method is effective.