Diagnosing of ship propulsion elements by vibration measurement

In the present time the technical progress, make us use more and more complicated machines in our everyday life. The application of turbine engines as the main propulsion engines of a vessel impels, according to requirements, operation procedures. It alters considerably the usage of gas turbine engines in the navy from the ones in aviation. The relatively low load is characteristic to the operation of the marine engine. In the case of the technology used at sea, the necessity of highly specialized service is especially evident. In the paper, we present the diagnostic systems elaborated to support the exploitation of the vessel power plant with gas turbines. Application of computer simulation for diagnosing a technical state of gas turbines rotor sets should be applied during calculation and project process. During engine assembly, the rotating components are mounted with great care with the main objective of minimizing shaft unbalance. However, even with the best of care, such factors as machining imperfection, differential thermal expansion etc cause a small residual unbalance of gas turbine rotor. The dynamic problems of Marine Gas Turbine Engines are connected with such basic elements: rotors, bearings, struts of bearings, engine body and type of substructure. The proposed diagnostics method makes it possible to determine the limiting value of vibration symptoms .