Development Of Fault Diagnosis And Field Dynamic Balancing System For Rotating Machinery

Fault diagnosis and field dynamic balancing system for rotating machinery is commissioned by a company in Nantong, and is designed and developed by high-speed rotating machinery laboratory of Chemical Machinery Institute in Zhejiang University. The system is to monitor the state of medium-sized or large-sized fan during operation, and to predict and judge equipment fault to avoid serious harm when some faults occur, and to solve rotor unbalance fault and reduce mechanical vibration to make it run smoothly. The main research work in this paper is as follows:(1)The dissertation studies fault feature extraction and fault pattern recognition method. In view of the wavelet packet energy do not have characteristics of time and adaptability, the paper use wavelet packet energy moment as signal feature parameters, and put forward the relation of rotor speed and sampling frequency. It not only makes extraction of fault feature with time and frequency characteristics, but also makes the same fault under different speed with adaptability. What is more, use the simulation signal and unbalance fault data of different speed to verify this method. It simplifies the wavelet packet selection process and unifies the feature parameters of the same fault under different speed. Simulate sudden unbalance, unbalance, unparallel and rubbing fault state, analyze the data with time, frequency and wavelet packet, and extract the feature of energy moment to train and test the BP neural network. The result proves that the BP Neural network designed in this paper has high recognition.(2) The dissertation studies the field dynamic balance methods for rigid rotor, establishes the calculation model of the axis trajectory and the high vibration of unbalanced vibration, applies influenced coefficient method based on high vibration to flied dynamic balance. This method solves the problem of tradition dynamic balance that it must find the high vibration on the site. The vibration reduction rate of a dynamic balance is obvious and short the time of field dynamic balance greatly.(3) The dissertation designs and develops the fault diagnosis and field dynamic balance system of rotating machinery. Use industrial PC, PLC, sensors, acquisition card and instruments to set up a set of system hardware, and develop corresponding software of fault diagnosis and field dynamic balancing. It can implement the functions of condition monitoring, fault diagnosis and field dynamic balance of rotating machinery. The system carries on the test on a big fan. Seen from the test results, the system has high reliability, meets the design requirements, and efficiency of dynamic balance is as high as 90% above.