汽轮机功率控制模式切换引发轴系振动异常的机理分析及实验研究

Mechanism Analysis and Experimental Research on the Abnormal Turbine Shaft Vibration Caused by Power Control Mode Switching

汽轮机高压调节阀在进行功率控制模式(单阀-顺序阀状态之间)切换时,可能引起高压转子-轴承系统振动异常增大的问题,且较为普遍。通过对实际机组异常过程的相关数据进行分析,发现高压调节阀门切换时阀位晃动与振动异常存在相关性,进而通过机理分析和数值模拟,判断异常原因在于阀位晃动引起径向汽流力突变冲击。在实际机组上开展验证实验,通过优化阀门流量特性减小调节过程阀位晃动,消除了这一异常问题。

Abnormal vibration may be induced at steam turbine HP rotor-bearing system when power control mode switches between throttle control and nozzle control. The data of a power plant unit is analyzed and the correlation between the abnormal vibration and the oscillation of governing valve position is found. By mechanism analysis and numerical simulation,the cause is inferred to be steam forces which change suddenly to impact the rotor. The inference is demonstrated by a verification test on the unit, where the abnormal problem is eliminated by optimizing valve flow characteristic to reduce the valve oscillation.