No abstract

This paper presents the planning of an experiment aimed at determining the scope of scientific research. It has been demonstrated in the conducted reliability investigations that main and auxiliary combustion engines, chosen as the objects of marine vessels, are the most unreliable components of injection apparatus as a weak link of a fuel feed functional system. The author seeks to use the minimum number of diagnostic parameters to obtain the maximum amount of information about the state of the test object. Reliability indexes, theoretical research and preliminary diagnostic tests were used to select the diagnostic signal reception points. In the initial determination of the measured quantities, the following methods were used: decomposition of the combustion engine on a functional systems, significant assemblies and elements, analysis of working and residual processes. Preliminary tests of the injection subsystem were carried out outside the internal combustion engine, as well as tests on real objects in laboratory conditions and in the conditions of marine vessels. To obtain a lot of information about the research object, a lot of diagnostic parameters were used at the beginning. On this basis, the preliminary selection of signals and diagnostic parameters related to the technical state was carried out, conducting the analysis in the various domains. Methodical and experimental diagnostic models were elaborated.

The article presents the stages of fuel injection modeling of the four-stroke marine diesel engines as a set of functional blocks the of the fuel waves flow. The elaborated model includes the values of changing pressures in the combustion chamber and the course of changes of the pressure in spaces of the injection pump, injection pipe and the injector. Linear and local losses, as well as the conditions for the functioning were taken into account in stages of the fuel flow. The influence of different values of the engine load on the pressure course of the in individual spaces of injection apparatus and in the engine cylinder during the working cycle depending on the crank angle of rotation of the crankshaft have been simulated. The mathematical relationships were selected and the structural and experimental data are used, allowing the calculation of the parameters of interest for the simulated process.

No abstract

The operation of injection apparatus in self-ignition engines results from the design, manufacturing technology and wear and tear during operation. The technical state of the injector apparatus significantly affects the engine performance, fuel consumption, toxicity and smoke opacity of outlet gases. The most unreliable element of the injection apparatus is the injector nozzle, the quality of which depends on the quality of construction and production, operating conditions and the of the fuels used, etc. One of the design parameters of the injector nozzles, determining the technical state is the geometry of the nozzle holes. An attempt was made to optimize the selection of the dimensions and surface condition of the spray holes to significantly affect the flow properties of the injector nozzles and, consequently, to decide on the size and form of fuel dosed streams to individual cylinders of a self-ignition engine and the quality of fuel atomization. In work, a simulation model was developed, and the pressure losses and the mass fluid of the injected fuel were minimized for selected significant geometric features, taking into account the influence of operating conditions. With the use of Mathematica software, simulation optimization methods and methods based on evolutionary algorithms were elaborated.

No abstract

To choose the receive locations of diagnostic signals, reliability and preliminary investigations were applied. The functional systems and the most unreliable subassemblies were determined. The studies were conducted for the auxiliary marine engines with the same rated speed and fueled with same distillation and residual fuels. In the article a choice of the ship's object, which has a significant impact on reliability, operating costs and the functions performed, is presented. Reliability, economic and risk of exploitation investigations were carried out, which allowed selecting the facility with the highest failure, costs of adverse events and threat to the natural environment. The research covered the objects of a ship owner operating mainly bulk cargo vessels for mass transport and their essential assemblies - combustion engines.In order to obtain a reasonable amount of information on the state of the examined combustion engine, the following experimental planning methods were used: experiment type, essential elements, location of measurement sensors, measured quantities, test conditions, measurement frequencies, measurement data analysis and inference methods, etc.The reliability indicators and preliminary diagnostic tests were used to select the diagnostic signal reception points. Functional systems and the most unreliable subassemblies were defined in this way. The tests were carried out for auxiliary marine engines with the same rotational speed and fueled by distillation and residual fuels. The tests were conducted for several types of combustion engines.

During scientificstudies on reciprocating self-ignition marine engines, varying data are often needed. Such data are often in various collections and obtaining some of these is very difficult. Therefore, as it was elaborated in the electronic database about the important marine reciprocating combustion engine producers for the needs of operating scientific investigations aiming at gathering the essential information and technical data in one set. This article also presents a reference to existing databases. Important and globally known companies, as well as their constant and variable data, were described. These data were obtained from various printed and virtual sources of information. These data were selected and compiled in the environment of the Microsoft Access computer program. The collected information was divided between main propulsion and auxiliary engines, containing data about manufacturers, types, and technical parameters of slow, medium, or high-speed combustion engines. This database is constantly updated and rebuilt according to the constructions and changes on the engine production market as the result of economic and ecological functions. It is a relative type database, which contains information about technical data of combustion engines. Marine combustion engines are usually operated for dozens of years after they have been produced, whereas producers merge, change their names, or stop existing. Therefore, a digital-knowledge-management platform was developed in the virtual space in which information on scientific and technical resources was integrated of competing manufacturers with the option of introducing updates.