Study On The Dynamic Behaviors Of Rotor-seal System

Most rotors of rotating machinery (such as turbine machinery, submersible motors,pumps and compressors) are usually equipped with mechanical seal system.To meetthe higher requirement of large-power, high-speed, high-efficiency and low energy, it isnecessary to research on various factors influence on vibration characteristics of rotorsystem. With the development of research on the system, now people find it can’t meetreal production that research focuses on vibration characteristics of rotor system inlinear range or considering single factor.Many academics have gradually understoodthat nonlinear sliding bearing oil film force and mechanical seal force for vibrationcharacteristics of rotor system influence are significant.This paper takes the proposed rotor systems as object. The typical rotor–sealsystem has be refined. On this basis, the related study is as follow.①rotor-seal systemmodel is established. The paper tries to study systematically the impact of operatingparameters and seal parameters on vibration characteristics of rotor system andbifurcation and chaos behavior from changes in operating parameters and sealparameters with Runge-kutta. The results show that period vibration, double periodvibration, and quasi-period vibration or chaotic motion of the rotor system withmechanical seal can occur with the speed of increase under certain condition. Researchalso suggests that the motion path of the rotor system with mechanical seal is doubleperiod vibration-quasi-period vibration-chaotic motion-period vibration.②The lawsof influences of eccentricity, sealing pressure differential and seal clearance on vibrationcharacters of the rotor with mechanical seal system are also deduced. Base on thenumerical simulation analysis, the dynamic stability of the rotor system including theeffects of mechanical seal is analyzed. Simulation results show that the rotor systemkeeps stable period vibration in low speed and the system keeps quasi-period vibrationeven more complex motions due to instability after instability speed. It also finds thatdifferent parameters have different affection of the stability of the system. Research alsosuggests that the different seal parameters embodied various effects on the stability ofthe system.The speed of losing stability of the system reduces when the seal gapincreases. But the speed of losing stability of the system rises when seal pressure differential increases under the same conditions.The paper finally proves the above theoretical analysis through experiment. Basedon theoretical analysis and related experimental research, the vibration characteristics ofthe shaft system and stability of the system and so on are studied in this paper. Theabove results provide the theory basis for vibration reduction and control, Stabilityanalysis of the rotor system, fault diagnosis, controlled operation and optimizationdesign.