The analyses of working process unstable in combustion chamber of ship internal-combustion engine

The article considers examples of unstable combustion processes in individual cylinders of marine diesel installations. It is shown that the instability of thermal engineering processes is determined by the grade of fuel, fuel preparation, wear of the cylinder-piston group and fuel equipment. The necessity of continuous monitoring of the technical condition of the power plant during operation is shown.

Research and development of commercially viable lubricants to intensify working life of marine diesel engines and cylinder piston group in internal combustion engines

The paper presents the results of studying the influence of variable characteristics of lubricating oils for marine diesel engines (concentration of layered friction modifier in lubricating oil, viscosity of lubricating oil, contact pressure in the friction zone) on the tribological parameters of parts of the cylinder-piston group of marine diesel engines. There are considered the aspects of increasing the reliability and wear resistance of the cylinder-piston group of marine diesel engines when a layered friction modifier is added to the base lubricating oil in a concentration of 1.5 vol.%. There have been carried out the comparative tribological studies of M-16G2CS lubricating oil including an additive based on molybdenum diselenide. Dependences of the wear of parts of the cylinder-piston group of a marine engine on different parameters of the studied lubricants are shown. The wear rate of experimental samples in conditions of variable characteristics of lubricants has been studied. According to the tribological studies of lubricants and structural materials, the tribological rating of lubricating compositions containing M16G2CS marine engine oil as a base and a layered friction modifier - molybdenum diselenide as a tribologically active additive was built. The test tool for the antiwear ability of lubricants is a friction machine of an original design with abraded samples according to the “ball-cylinder” contact scheme. Mechanical mixing of the lubricating medium of “oil + additive” type on the RPU-0.8-55A rotary-pulsating unit was one of the variable parameters in the tests. The tribological efficiency of the studied antiwear additive varies depending on the type of mixing of the additive solution before adding to the base lubricating oil and makes 13-54% (the difference in the diameter of the wear spot of the sample) for mechanical mixing, and for rotary-pulsation mixing - 45-56%.

Simulation Model of Selective Assembly of the Conrod-Piston Group Unit of Internal Combustion Engines, Taking into Account Measurement Errors During Sorting

The process of selective assembly of the conrod-piston group of an internal combustion engine, which provides the required accuracy of the connections, is considered. The functioning of a unit consisting of three main elements is described, the scheme of the assembly set-making is shown. The simulation model of a one-parameter selective assembly of three elements has been modernized by taking into account measurement errors arising from sorting into size groups. The modeling of the assembly process of the unit for a specific engine model has been carried out. A dependence is obtained that connects the required output indicator of the technological process with the parameter of the measurement quality. This research will allow solving the metrological problem associated with the choice of the optimal accuracy of measuring equipment under technical and economic constraints.

Normalization of the permissible error in measuring the mass when controlling the parts of the connecting rod-piston group

The problems related to the standardization of the error in the mass measurements when dividing products into groups and picking according to the difference in mass are considered. On the basis of the theory of probabilities and the basic provisions of metrology, a dependence is obtained to determine the error of the mass difference. Recommendations are given for improving the metrological support of indirect measurements of the mass difference, a formula is determined for calculating the normalized values of errors depending on the tolerances for the mass difference, and criteria for choosing measuring instruments for controlling the mass difference of parts at the stage of completing the connecting rod-piston group during the production and repair of engines are considered. The measurement error is estimated when using preassembly selection of parts by weight. Keywords: quality of measurements, mass measurements, mass difference, indirect measurements, choice of measuring instruments, permissible measurement error, complete set of connecting rod and piston group. [email protected]

Influence of cavitation on the working surfaces of the cylinder&piston group of a diesel engine during maintenance

It is established, that the destruction of carbon deposits when the engine is running on a water-fuel emulsion occurs due to the phenomenon of micro-impact of emulsified fuel droplets, the evaporation rate of which depends on their diameter, pressure and amplitude of the gaseous medium. As a result of the removal of carbon deposits in the engines, there is an increase in the average compression value for the engine cylinders by 8 % and the engine power by 11 %, as well as a decrease in the specific fuel consumption by 10 % and the smoke of the exhaust gases by 16 %. Keywords: engine, water-fuel emulsion, micro-impact, emulsified fuel, compression. [email protected]

Constructive possibilities of increasing the tightness and wear resistance of the cylinder-piston group of the internal combustion engine

The processes of wear of the tribocouplings of the cylinderpiston group (CPG) of the internal combustion engine are investigated. Design solutions are developed that increase the tightness and wear resistance of the CPG parts. Keywords: cylinder-piston group, internal combustion engine, wear, tightness, wear resistance, running-in. [email protected]