混流式水轮机转轮疲劳设计方法的研究

Study of the Fatigue Design Method for Francis Turbine Runner

本文系统而简要地介绍了混流式水轮机转轮疲劳设计方法的研究成果。通过大量的我国国情的完整数据统计分析与试验研究,得刭了疲劳设计所需要的载荷谱和材料性能等。通过深入系统的分析,提出了混流式转轮通用谱,建立了三频动应力迭加力学模型。在材料性能试验中,重点进行了频率影响与多频叠加影响的研究,取得了一系列影响系数。在此基础上,根据随机疲劳理论,推导出寿命估算方法和安全系数计算公式。根据所编制的设计规范和电子计算机通用程序,对三个电站转轮进行了试算,其结果与实际相符,从而为转轮设计由静强度分析转向动强度分析打下了基础。

This paper systematically introduces the fatigue design methods of Francis turbine runner. Based on a great deal of statistical analysis and experimental researches on the load spectra and material properties for fatigue design,a series of data which conform to China's practical condition have been obtained. Through further systematic analysis, the universal load spectra for Francis turbine were worked out,and the mechanics model for three frequency superposition was established. In testing material properties, the frequency and multi-frequency influences on material properties were studied and a series of infltential coeffcients were obtained. According to random fatigue theory, a method of life estimation and a formula of safety factor were recommended. For designer to be able to use this method simply, a design standard and an unified program for electronic computer has been compiled. The calculations for three runners at stations by this method have been done, showing conformation with the surveyed results in plant. Therefore, it may serve as a foundation to change the turbine runner design from statical strength analysis to dynamic strength analysis.