某电厂50MW机组通流供热改造叶片失效分析

Analysis of Blade Ineffective in 50 MW Unit Flow Passage Heat Supply Reconstruction

以某电厂5号、6号凝汽50 MW机组通流部分改造为供热机组为例,主要论述了改造后投运在短期内发生3次叶片、叶轮断裂事故,经对断口宏观、微观以及机组改型前后运行实际状况、动叶结构及强度计算等分析,发现15级、16级叶片、叶轮在运行承受的动应力很大,且此区段的汽流扰动力极大,论证得出造成事故的主要原因是供热改造后15级、16级动强度不足所致。

Taking No. 5 and No. 6 50 MW condensed steam as an example, three times breakages of the blade and bladed disc after the reconstruction of No. 5 and No. 6 unit flow passage changed to heat supply unit in 2000 and 2002 are discussed. According to the analysis of the fracture and practical operation situation before and after the reconstruction, the rotor blade structure and intensity calculation, the dynamic stress of 15 and 16 level blade and bladed disc need to be burdened is large, and its gas flow disturbing stress is huge, which can be concluded that the main cause of the accident is the shortage of 15 and 16 level dynamic stress after the heat supply reconstruction.