A method for quantitative diagnosis and monitoring of rotor misalignment faults in turbine machinery
MA Bo1, YANG Ling1, SHEN Wei2
1. Diagnosis and Self-Recovery Engineering Research Center, College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029; 2. Nuclear and Radiation Safety Center, MEP, Beijing 100082, China
Abstract：It is difficult to diagnose quantitatively the degree of misalignment in a turbine rotor system. A quantitative method for diagnosis of parallel misalignment based on monitoring data, utilizing the relationship between the misalignment of the rotor and the vibration amplitude of the node, is proposed in this work. The steps involved in the method are as follows. The rotor misalignment force is obtained by analyzing the state of the parallel misalignment rotor. A rotor model is then established to analyze the variation of rotor node vibration for different misalignments based on dynamics theory. The relationship between the vibration amplitude of the node with the misalignment is then analyzed, and modified according to the data obtained with the normal operation of the rotor. By monitoring the vibration amplitude of the node, the parallel misalignment of the rotor can be derived, and the aim of diagnosing the faults in the parallel misalignment is thus achieved. Using a test rig, the vibration of the rotor with different misalignments was analyzed by experiment. The experimental results show that the proposed method of monitoring and assessment is valid.
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2017, Vol. 44 
