Evaluation method for factors affecting marine diesel engine vibration caused by cylinder-piston group operation

Abstract

The efficiency of the use of the marine fleet is associated with a reduction in the cost of transportation, the need for which is steadily increasing. A significant share of the total transportation costs is occupied by the costs associated with the operation of ships, therefore, reducing these costs is a reserve for reducing the cost of maritime transportation. The problem of increasing the efficiency of the operation of marine vessels is closely related not only to reducing the cost of it, but also to reducing the time for maintenance and repair of ships. The existing system of scheduled preventive maintenance and repair provides for the maintenance and restoration of the normal technical condition of the vessel and its elements with a pre-planned frequency. The transfer of ships to work with extended repair periods is possible only when solving a whole range of engineering and technical measures and scientific research aimed at improving the quality of repairs, the level of technical operation, improving logistics, etc. An essential role in this is played by the use of modern methods and means to determine the technical condition of shipboard devices and mechanisms, primarily engines of shipboard power plants (SEUs), without disassembling them. High vibration loads of SEU parts lead to fatigue stresses, accelerate wear of the contacting surfaces, reducing the reliability and service life of marine diesel engines, therefore monitoring of their vibration activity is important, especially during operation. The safe operation of ships of the transport fleet largely depends on the reliability of marine diesel engines. Technical means of monitoring their operability in the process of work are currently insufficiently effective and need to be improved. It is relevant not only to develop new, more advanced and mobile hardware and software, but also to search for new scientific and methodological approaches to using the information contained in the spectrum of vibration parameters. Marine diesel internal combustion engines are complex systems that involve many variable parameters. The study of such engines requires the use of methods that can be used to systematically investigate the influence of various factors on their operation, in particular, random experimental schemes are used, since they provide systematic control over variable parameters and maximize the accuracy of estimates. The results of the application of the method of ranking the factors influencing the vibration of a marine diesel engine are presented in order to establish the most significant of them. A mathematical model is presented that allows calculating current values and predicting changes in the most significant indicators, among which the most important is the size of the gap between the piston and the cylinder sleeve.