Rotor Vibration Analysis For High Pressure Hot Water Pump Used In Waste Liquid Incinerator

By taking the rotor vibration performance of the high pressure hot water pump used in a waste liquid Incinerator in Jihua Group as the research object, the axial force, dynamic reaction force and radial force of the rotor system are calculated based on the analysis of impeller structure and mechanical analysis. The life of the bearings supporting the high pressure pump is predicted. The results show that the bearings are reliable. The differential equation describing the lateral bending vibration of bearing-rotor system is derived. The basic theory of transfer matrix is introduced. The vibration model of rotor in the high pressure pump is established by discretizing the rotor system with transfer matrix. The numerical calculating procedure of the rotor vibration analysis is also proposed. A set of formulas for calculating stiffness coefficient and damping coefficient of the bearing are developed on the basis of bearing mechanical analysis and EHD film mechanical analysis. The bearing-rotor system is discretized. Some vibration parameters of the high pressure pump, including natural frequency, critical speed, vibration response, vibration mode, are calculated through Matlab coding. The results show that the pump working speed is between the second order speed and the third order speed. The actual speed of the pump is very close to the third critical speed, which is the main cause of the long-term strong vibration of the high pressure pump rotor system. Some curves are plotted for three cases:the left impeller being eccentric while the right impeller being not eccentric, the left impeller being not eccentric while the right impeller being eccentric, the left and right impellers being eccentric simultaneously.The results obtained in this research will provide some theoretical reference for improving the vibration performance of high pressure pump used in waste liquid Incinerator in Jihua Group Coporation of CNPC.