A Novel Damage Identification Method for Flue Gas Turbine Blades based on Tip Timing
A Novel Damage Identification Method for Flue Gas Turbine Blades based on Tip Timing
复制标题
基于叶尖正时的烟机叶片损伤识别新方法
DOI：
10.1016/j.isatra.2022.10.009
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发表时间：
2022
期刊：
影响因子：
7.3
通讯作者：
Wang Jinjiang
中科院分区：
文献类型：
--
作者：
Zhang Fengli;Yu Haotian;Wang Jinjiang
将叶尖定时信号分析应用于高速叶片在线状态监测。然而，传统的叶尖定时分析方法不适用于低速烟气轮机。因此，本文在研究低速叶片动态响应特性的基础上，提出了一种新的叶尖定时信号分析方法。首先，介绍了有限元模态理论，分析了叶片损伤的特点。其次，建立了烟气涡轮机叶片在复杂环境和工况下的等效悬臂梁分析模型。为了监测局部刚度的变化，提出了一种基于等效悬臂梁自由端挠度变化的损伤识别方法。最后，建立了旋转叶片叶尖定时监测试验台，验证了该方法的可行性。结果表明，裂纹起源于叶片高度的80%左右，对叶片刚度的影响最大，其次是叶片根部。计算得到的叶片损伤参数分别为4.8464 mm和3.7588 mm，裂纹影响因子分别为4.7476和3.6822，表明其变化趋势与叶片损伤规律一致。
Tip timing signal analysis has been applied to the online condition monitoring of high-speed blades. However, traditional tip timing analysis methods are not suitable for low-speed flue gas turbines. Therefore, this paper proposes a novel blade tip timing signal analysis method based on an investigation of the dynamic response characteristics of low-speed blades. First, the finite element modal theory is introduced to analyze the characteristics of blade damage. Second, an equivalent cantilever beam analysis model of flue gas turbine blades is established under complex environment and working conditions. In order to monitor the variation of local stiffness, a damage identification method based on the variation of the free end deflection of the equivalent cantilever beam is proposed. Finally, a rotating blade tip timing monitoring testing rig is established to verify the feasibility of the proposed method. The results show that the cracks originating at about 80% of the blade height have the greatest influence on blade stiffness, followed by blade root. The calculated blade damage parameters are 4.8464 mm and 3.7588 mm, and the crack influencing factors are 4.7476 and 3.6822, respectively, indicating that the change trend is consistent with the blade damage rules.