摘要
对平圩发电有限公司2台引进型600MW汽轮机“474”叶片、叶根、轮缘事故原因作了分析,认为叶片断裂的原因主要由于单节线扭振共振,加之某些缺陷引起的应力集中所致;叶根、轮缘裂纹的原因,主要由于该级叶根设计单薄、强度裕量小等诸多因素造成叶根齿受力状况的变化,使叶根齿局部应力过大、二阶频率下降落入共振的边缘,加之应力集中、过渡区腐蚀环境的影响等,使叶根安全裕度下降、累积疲劳所致。
The causes for“474”blades,blade roots and diskrim failures of two imported type 600 MW steam turbines in Pingwei Power Generation Corp.were analyzed.It was held that,the blades cracked mainly owing to single node line torsional vibrationresonance,togetherwiththestressconcentrationduetosomedefects;whilethebladerootsanddiskrimcrackedmainlyowingtothethinandweakdesignofbladerootsandsmallstrengthmarginofthisstageetc.factors.Thesefactorsledto:variationsintheforcesonserratedbladeroots,excessivestressinpartofserratedbladeroots,fallingofthesecondorderfrequencyintothevergeofresonance,togetherwithstressconcentration,corrosionenvironmentinfluenceattransitionareaetc.,withtheresultthat,thesafetymarginofbladerootswasdecreasedandfatigueaccumulated.
出处
《中国电力》
CSCD
北大核心
2001年第10期7-11,共5页
Electric Power
