双馈式风力发电机组叶片变桨连接螺栓断裂故障分析及预防

Fault analysis and prevention of blade pitch connecting bolt fracture of doubly-fed WTGS

叶片变桨螺栓为风力发电机组主要连接部件,叶片高强度连接螺栓的材质标准和施工安装工艺对螺栓运行寿命长短至关重要。通过宏观分析、安装工艺分析、化学成分检验、机械拉伸试验分析等方法,对螺栓断裂原因分析验证。结果表明,从材质各元素及杂质含量导致螺栓质量不合格,装配螺栓预紧力精度不足、螺栓润滑不到位造成叶片连接螺栓预紧力不均匀,叶片自重、旋转离心拉力和风载荷等疲劳过载,都有可能造成螺栓断裂。研究结果可为风机叶片螺栓安装过程中,安装工艺不到位、材质不合格等问题,有效的预防螺栓频繁断裂提供更多的理论依据。

The blade pitch bolt is the main connecting component of the WTGS.The material standard and construction and installation process of high-strength connecting bolts for blades are crucial to the service life of bolts.Through macroscopic analysis,installation process analysis,chemical composition inspection,and mechanical tensile test analysis,the causes of bolt fracture are analyzed and verified.The results show that the bolt fracture may be caused by the unqualified bolt quality due to various elements and impurity contents of the material,insufficient pre-tightening force accuracy of assembly bolts,the uneven pre-tightening force of blade connecting bolts caused by poor lubrication of bolts,and fatigue overloads such as dead weight of blades,rotating centrifugal tension and wind load.The research results can provide more theoretical bases for effectively preventing the frequent fracture of bolts during bolt installation for wind turbine blades caused by improper installation processes,unqualified materials,etc.