中文摘要：

混流式水轮机在运行过程中产生大量裂纹，严重危及水电站的安全运行。介绍了水轮机组检修现状，结合混流式水轮机转轮提出了3种转轮安全评估方法并进行了可行性分析。利用声发射技术，可在线监测水轮机转轮叶片裂纹的产生和扩展过程，结合振动技术对水轮机进行安全评估，实现了对水轮机的转轮叶片在线状态监测和故障诊断。

英文摘要：

A considerable number of cracks are often engendered in the mixed flow turbine runnel＇ during operation. These cracks are harmful seriously to the safety operation of the hydroelectric power station. The current status of the mixed flow turbine overhaul was introduced in this paper. Three methods of the runner safety assessment and their feasibility analysis were proposed in connection with mixed flow turbine runner, The engendering and extending process of fatigue cracks on the mixed flow turbine runner blade can be monitored by using Acoustic Emission （ AE ） on - line technique, and safety assessment of mixed flow turbine can be executed by combining with vibration technique. Thus the on - line monitoring and fault diagnosis of mixed flow turbine runner blade can be realized.