静叶可调轴流式引风机叶片断裂原因分析及对策  

Cause analysis and countermeasures for blade fracture of static blade adjustable axial flow induced draft fan

作　　者：李永乐 骆贵兵[2] 杨辉[2] LI Yongle;LUO Guibing;YANG Hui(Baotou Third Thermal Power Plant,North United Power Co.,Ltd.,Baotou 014060,China;Xi’an Thermal Power Research Institute Co.,Ltd.,Xi’an 710054,China)

机构地区：[1]北方联合电力有限责任公司包头第三热电厂,内蒙古包头014060 [2]西安热工研究院有限公司,陕西西安710054

出　　处：《热力发电》2021年第4期114-119,共6页Thermal Power Generation

摘　　要：某600 MW机组静叶可调轴流式引风机采用小汽轮机驱动,运行中发生叶片断裂问题,断裂面启裂位置为叶轮与调频环焊接位置。通过分析风机运行参数及断裂叶片理化检测结果发现,风机叶轮与调频环焊缝处存在疲劳导致叶片断裂。为解决叶轮与调频环处焊缝开裂问题,对叶轮进气侧调频环位置及结构进行优化改进,新调频环焊接在叶片根部,并更改为口圈结构;为避开新调频环位置改变后叶片的固有频率,通过叶片测频工作测试引风机叶片在设计转速范围内叶片通过频率发生共振的转速约为752、1098 r/min,引风机实际运行转速应与共振转速保持一定的避开率。The static blade adjustable axial flow induced draft fan of a 600 MW unit is driven by a low-power steam turbine.One of its blades fractured during the operation.The cracking source was the weld between the impeller and the frequency-modulation hoop.The operating parameters and physicochemical analysis indicated that the blade fracture was caused by fatigue.To solve the above problem,the intake-side frequency-modulation hoop was designed to ring of port,and the frequency-modulation hoop was welded at the roots of blades.Moreover,the measured value showed that blade resonance occurred during normal operation when the rotate speed of was about 752 r/min and 1098 r/min.So the speed of the induced draft fan during operation should avoid the resonance speed.

关 键 词：静叶可调 汽动引风机 调频环 疲劳裂纹 叶片通过频率 共振 

分 类 号：TK227.1[动力工程及工程热物理—动力机械及工程]