Application On Fault Diagnosis For Certain Centrifugal Compressor Units Used In Petrochemical Industry

The paper based on a project from some petrochemical enterprise. The investigated subjects are a set of cyclic hydrogen compressor, a set of cracking gas compressor and two sets of propylene refrigeration compressor. The aim of this paper is application on condition monitoring and fault diagnosis of those centrifugal compressors units after a period of research and most of attention is put on the vibration condition of compressors' axes.The accident problem of centrifugal compressor units and the importance of its in national economy both are seriously surveyed. At the same time the development level of online monitoring system for mechanical equipment are deeply investigated home and abroad. So it's significant to do as much as possible work on condition monitoring and fault diagnosis for centrifugal compressor and development of online monitoring system for mechanical equipment.The structure character and operating principle of centrifugal compressor are introduced, which show that the rotor of compressor is trend to be damageable comparing to other components. So it needs to pay more attention on it. It discusses the character of rotor vibration, from which the conception of positive and negative eddy. Beside, the fault mechanics and methods to fault identification of rotor system are also studied. The common fault diagnosis methods to rotor are generalized, which include three aspects: amplitude domain, time domain, frequency domain analysis. Full spectrum analysis is emphasized in frequency domain analysis. After introducing VI and advantages of LabVIEW on programming in general, a module for fault diagnosis of rotor based on LabVIEW is discussed. It is a valuable part of the online monitoring system. The module is comprised of axis orbit and full spectrum and in the axis obit module three choices are available: original axis obit, average axis obit and certain frequency multiplication axis obit. Those two modules are practical in the fault diagnosis for rotary after putting them in use of the typical fault signal from rotor experimental bench. So these could be applied to the fault diagnosis of centrifugal compressor.Methods to rotor of centrifugal compressor's condition monitoring and fault diagnosis are summed up. Peak-to-peak value is an essential reference value of centrifugal compressor's condition monitoring, which is easy to implementation in practice. On the other hand, according to fault diagnosis, power spectrum and axis obit also works. The direction of eddyis gained from full spectrum, which is vital in fault diagnosis. In a word, to make sure make an exact conclusion, different method should be put in used.