Application Of Vibration Signals In The Marine Equipment Inspection

The rapid development of modern transportation, especially ocean shipping makes ship even more important than before. It is necessary for marine surveyor to explore a new method for inspection. Against this background, this paper discusses the application of vibration signal in the inspection of marine equipment.The development and tendency of marine equipment inspection based on vibration signal processing and related technologies are summarized and analyzed in this paper. Vibration signals on marine oil separator were measured with modern advanced measuring technologies. Inspection and related monitoring of operation conditions of marine oil separator are carried out by means of different methods of technologies of vibration signal processing.Firstly, this paper analysis and studies the vibration measurement and signal processing technology. It describes the time-base analysis, wave form analysis, trace analysis and frequency spectrum analysis which are always used to evaluate the vibration signals measured on machines.Corresponding signal transformation ideas are also described, which can be conducted in amplitude domain, time domain and frequency domain according to different needs. In addition, the measured instrument and evaluation standard of vibration signal are introduced.Secondly, this paper discusses respectively the vibration principles of marine rotating machinery and reciprocating machines. On the basis of mechanical vibration, signal processing and fault diagnosis, the causes of vibration for marine equipment are described. It discusses the selection of measuring points and measuring conditions.vibration variables sensors and measuring systems for the inspection of marine equipment.Finally, Analysis and experiments were carried out for the investigation of the vibration characteristics of marine oil separator in this paper. The arrangement of the measuring points, measuring vibration variables , sampling frequency and vibration alarm threshold for each measuring point are determined. The data-base of vibration signal models in the normal and fault condition are established respectively by the signal processing methods as mentioned above. This standard provides a scientific base for inspection of marine oil separator. The inspection of marine oil separator based on vibration signal analysis was proved to be effective to promote working efficiency of marine oil separator, detect fault in time, and finally improve the shipping safety of vessels. All of the work above aims at providing some reference for inspection of ship equipment in the future.