Diesel Engines Vibration Analysis Monitoring

Diesel engines are complex mechanical systems; using condition-based maintenance (CBM) for these machines requires observation, measurement and control of many parameters. The engine should be observed as a whole, but the individual components state can determine the cause of an observed or incipient anomaly. Monitoring pressure and temperature of fluids provides important data, whose statistical analysis is highly meaningful and can work as indicators of the machine's true state and alert to the existence of incipient failures. Vibration measurement has proved to be, by its own or combined with other monitoring techniques, an able and safe means of prognostic and diagnostic of machine availability. In this article, the main causes of diesel engine vibrations are not only because of the fast-changing pressures and temperatures associated to the thermodynamic cycle inside cylinders but also the large and fast-changing mechanical forces associated to the accelerations that take place in the moving parts and other specific structures of those machines. In this paper, analysis of diesel engine vibration is done, considering ship propulsion plants, and a pre-specified set of measurement or observation points (OPs) will be assumed. Real vibration data from six diesel propulsion engines corresponding to one observation time-one observation-will be analyzed and studied. The vibration signal will be statistically studied using biplots to relate in a single plot several pieces of equipment, observation points (Ops), and observation conditions (Cs).