不同负荷工况水轮发电机组轴系振动特性研究

Research on Vibration Characteristics of Shafting System of Hydroelectric Generating Set Under Different Load Conditions

建立水轮机组流道模型与轴系模型,采用流固耦合的方法,分析不同负荷稳态工况下水力因素诱发水轮机组轴系发生振动的动力学特性,并与电站的现场实测数据进行对比,验证该方法的可行性,进而研究典型稳态工况下的振动特性与内流特性的关联机理。结果表明,所得水导轴承处的振动特性与试验值基本吻合,振动变化与负荷变化趋势一致,因位置关系水导轴承与上导轴承的振动特性在幅值上存在一定差异,且在75%负荷工况运行时由于尾水管存在明显涡带机组水平振动幅值最大。研究结果可为水电站水轮机组在不同负荷下的稳定运行提供参考。

The flow channel model and the shafting model of the turbine unit were established, and the fluid-solid coupling method was used to analyze the dynamic characteristics of the shafting system vibration of turbine unit induced by hydraulic factors under the steady-state conditions with different loads. The measured data were compared to verify the feasibility of the method. And then the correlation mechanism between the vibration characteristics and the internal flow characteristics under typical steady-state conditions was studied. The results show that the vibration characteristics of the guide bearing obtained by this method are basically consistent with the experimental values, and the trend of vibration changes with the change of load is consistent. Due to the positional relationship, the vibration characteristics of the water guide bearing and the upper guide bearing have a certain amplitude difference. The horizontal vibration amplitude of the unit is the largest due to the obvious vortex belt in the draft tube when running at 75% load condition. The research results can provide a scientific reference for the stable operation of hydropower turbine units under different loads.