The article presents the acoustic method of marine low-speed engine turbocharger parameter estimation under operating conditions when a prompt assessment of instantaneous turbocharger speed and rotor vibration level is required. The method lies in the analysis of the acoustic signal that is generated by the compressor of the turbocharger with the diesel engine running under load. The spectral analysis reveals that the compressor blades generate acoustic oscillations that are always present in the overall acoustic spectrum of the turbocharger regardless of its technical condition. The harmonic components corresponding to the blades can be detected in the spectrum using the limit method. The calculated instantaneous turbocharger speed makes it possible to analyze the main harmonic amplitude in the spectrum. The method presented in this paper helps eliminate discrete Fourier transform (DFT) spectral leakage so that the amplitude of the main harmonic can be estimated. Further analysis of the amplitude of the main harmonic allows for efficient estimation of the turbocharger rotor vibration level when in operation. The method can be practically applied by means of a smartphone or a computer that has the dedicated software installed. The proposed method lays the foundations for a permanent monitoring system of turbocharger speed and vibration in industrial and marine diesel engines.

The article discusses methods for determining top dead center, based on the analysis of pressure diagrams of a marine engine. The advantages and disadvantages of different methods are shown. Diagnostics of marine engines during operation and the selection of optimal operating conditions is based on the analysis of gas pressure diagrams, as well as fuel supply and gas distribution diagrams. As a result of the analysis of the pressure diagrams, the indicator engine power is calculated, which is further used in the management of engine operation modes, in the calculation of specific indicators, as well as in the calculation of energy efficiency coefficients of marine vessels according to International Maritime Organization recommendations. The influence of the accuracy of determining the position of the top dead center on the calculation of the mean indicated pressure and indicator power is shown. The authors considered a method for determining top dead center, based on the solution of the equation P'= 0, which provides the required accuracy in calculating the mean indicated pressure and indicator power of the engine during operation. It is shown that the method can be applicable in marine engine working process monitoring systems as an alternative to hardware methods for determining the top dead center.

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Although direct measurements of the fuel injection pressure and the travel of the injector needle in conjunction with measurements of the valve train mechanism timing can provide complete diagnostic information about the technical conditions of the fuel injection and valve train systems, this requires the installation of sensors and other equipment directly into the systems, which is possible within research laboratories but is generally forbidden during operation of the ship. Malfunctions in the fuel injection and valve train systems can also be identified from the indicator diagrams of an engine operating cycle, expressed as P(V) and P(deg) diagrams. The basic parameters of the engine operating cycle, such as the maximum combustion pressure Pmax, compression pressure Pcompr, and indicated mean effective pressure IMEP, can also be used to indicate deviations from proper engine operation. Using a combination of a vibration sensor with an in-cylinder gas pressure sensor widens the capabilities of diagnostics for marine diesel engines under operational conditions. A vibration sensor with a magnetic base can help in determining the timings of the lifting and landing of the injector needle, fuel delivery by the fuel injection pump, opening and closing of the circulation of heated heavy fuel oil, and opening and closing of the gas distribution valves. This also offers a promising solution for diagnostics of the cylinder lubrication oil injectors. The proposed approach allows valuable information to be received during engine operation in accordance with the principle of non-destructive control, and can help in early detection of possible engine malfunctions.

Present state of the Danube shipping is differed by insufficient provision of navigation conditions, age composition of the fleet, as well as the fleet specifics – its ability to work throughout the Danube (over 2000 km) when loaded with heavy caravans from non-self-propelled vessels. This specificity significantly differentiates the Danube navigation from navigation on other inland waterways in Europe, which provided year-round through depths, range of transitions to ten times less, and the work carried out for the most part self-propelled dry cargo and tanker vessels. The study deals with the build a common model for managing energy efficiency and environmental performance of a self-propelled river towing and traction fleet. The differences in transportation technologies in international maritime, European inland and Danube shipping are shown. The issues of rationing of harmful emissions into the atmosphere in shipping on European inland waterways are considered. The analysis of energy efficiency indicators established in international maritime shipping, as well as the peculiarities of their use in inland navigation, was carried out. The principles of the application of energy efficiency indicators to the assessment of environmental indicators of ships in inland navigation have been determined, taking into account the specifics of navigation conditions and other factors determining the operating modes of the ship propulsion complex. Innovative approach in the study lies in the fact that in the known studies carried out earlier, were considered the Danube fleet operating on the upper sections of the Danube. According to this, the practical solution to the problem of determining the potential to reduce harmful emissions for the existing fleet as well as the formation of the concept of energy efficiency management in the shipping industry is unresolved. Consequently, the ways of achieving energy efficiency while reducing the amount of harmful emissions into the atmosphere were identified. A possibility of controlling characteristics of energy efficiency of existing Danube traction and self-propelled fleet without significant modernization and upgrades is presented.