混流式水轮机进水管蝶阀活门裂纹分析

摘要

In order to explore the causes of the butterfly valve rib plate cracking of a turbine at a hydropower station, we calculated and anlayzed the strength and the vibration properties of the butterfly valve using the finite element software ANSYS. The strength analysis results show that the stress level of a 40-mm rib plate is very low. Obviously, high stress is not the reason for rib plate cracking. The results of modeling analysis show that the Karman vortices occurred at a 40-mm rib plate and a 90-mm cover plate. Referring to the results of FEM analysis, we conducted a site test for the butterfly valve at the hydropower station. The experimental results agreed with the calculated results. Hence, the cracks in the butterfly valve were caused by the Karman vortices.%为探讨某电站水轮机进水管蝶阀活门筋板开裂的原因，利用ANSYS有限元软件，分别对蝶阀活门的强度及振动特性进行计算和分析。强度分析结果显示40 mm筋板位置的应力水平很低，筋板的开裂并非是应力过高造成的；蝶阀活门、筋板及盖板的模态分析表明，蝶阀活门的40 mm筋板及90 mm盖板出现了卡门涡。结合有限元分析结果，对电站蝶阀活门进行现场结构模态测试，测试结果与计算结果吻合。分析结果表明，该电站蝶阀活门出现的裂纹是由卡门涡引起的。