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

2021 ◽  
Vol 2131 (2) ◽  
pp. 022064
Author(s):  
A Nikitin ◽  
V Poberezhnyy

Abstract 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.


Author(s):  
A.V. Golenishev ◽  
A.V. Nadezkin ◽  
M.E. Starchenko

Рассматриваются подходы по определению пороговых значений концентрации продуктов износа в отработанном цилиндровом масле, характеризующие переход объекта диагностирования судового крейцкопфного дизеля из одного технического состояния в другое. Показано, что существующие методики не учитывают индивидуальные особенности и техническое состояние деталей цилиндропоршневой группы. Предложено для решения задачи их трибодиагностики использовать разработанную имитационную модель, позволяющую провести моделирование процесса изнашивания цилиндровой втулки и поршневых колец судового дизеля и на основании полученных расчетов определить концентрацию продуктов износа поступивших в отработанное цилиндровое масло при различной скорости изнашивания трущихся деталей. Данные о фактической концентрации продуктов износа в отработанном цилиндровом масле в дальнейшем соотносятся с результатами моделирования, что позволяет оценить техническое состояние деталей цилиндропоршневой группы двигателя. Представлены результаты моделирования по определению пороговых значений концентрации продуктов износа в отработанном цилиндровом масле, характеризующее переход судового дизеля из исправного в несправное техническое состояние. Даны практические рекомендации по выбору пороговых значений содержания продуктов износа в отработанном цилиндровом масле для различных типов судовых крейцкопфных дизелей и условий их эксплуатации.The article examines approaches to determine the threshold values of the concentration of wear debris in used cylinder oil that characterize the transition of a ship crosshead diesel engine unit under test from one technical condition to another. It is shown that the existing methods do not take into account the individual characteristics and technical condition of the parts of the cylinder-piston group. To solve the problem of tribodiagnostics, it is proposed to use the developed simulation model, which allows modeling the wear process of the cylinder bushing and piston rings of a marine diesel engine and, based on the obtained results, determining the concentration of wear products issued in the used cylinder oil at different wear rates of the moving parts. The data on the actual concentration of wear products in the used cylinder oil are subsequently correlated with the simulation model results, which makes it possible to evaluate the technical condition of the parts of the engine cylinder-piston group. The article presents the results of modeling of threshold values determination of the concentration of wear products in used cylinder oil, that measure the transition of a marine diesel engine from a working condition to a malfunctioning technical condition. Practical recommendations are given on choosing threshold values for the concentration of wear products in used cylinder oil for various types of marine crosshead diesel engines and their operating conditions.



2021 ◽  
Vol 2131 (5) ◽  
pp. 052058
Author(s):  
O Roslyakova ◽  
V Zaitsev ◽  
D Panov

Abstract Nowadays, a lot is paid to environmental protection issues, including those related to reducing emissions from ships of the sea and river fleet, which is reflected in many works. Constant control over the content of harmful emissions in the environment forces us to deal with the issues of reducing emissions from diesel engines at the design stages and during operation. The solution to this problem allows us to consider 2 directions: constructional and the use of special equipment for capture and neutralization. In the best case, a combined method can be used, i.e. constructional with the use of capturing equipment for harmful components in diesel exhaust gases. This paper presents an analysis of the influence of various factors that reduce the load on the atmospheric air from nitrogen oxides of marine diesel engines, namely, from the operating settings of the diesel engine and its wear. On the ships of the river fleet, diesel engines are used with various mixture formation with volumetric, volumetric-film, vortex mixture formation. The leader in the listed group is the volumetric mixture engines. The paper provides an assessment of the research carried out to analyze various methods of influencing the working process of a diesel engine - the type of mixture formation, wear of the cylinder sleeve in order to determine their influence on the formation of NOx emissions.



2021 ◽  
Vol 264 ◽  
pp. 04061
Author(s):  
Mukhammad Valiev ◽  
Khusan Kosimov

The reliability of locomotive diesel engines largely depends on a timely and objective assessment of the technical condition of its equipment during operation. The article proposes a technique for the integral assessment of the technical state of the quality of the working process in a diesel cylinder using on-board diagnostics.



2018 ◽  
Vol 22 (1) ◽  
pp. 18-26
Author(s):  
E. V. Ageev ◽  
A. V. Shcherbakov ◽  
YU. G. Alekhin ◽  
S. A. Grаshcow

Car engine is the most complex and important unit of a car. A lot of technical, economic and environmental automobile performance depend on it. Therefore, the development of advanced methods for diagnosing the technical state of engine mechanisms and systems is of great practical importance. The most part and labor intensity of the total number of malfunctions accounts for the cylinder-piston group (GPG). The purpose of this work was to increase the informative value of the process of diagnosing the engines of VAZ front-wheel drive vehicles by using technical endoscopy. To obtain information about the level of technical condition, it is not advisable to disassemble a unit or assembly in a good operation condition, since, first, it is associated with considerable labor costs, and second, and what is important, each disassembly and change of the mutual position of the used parts leads to the reduction of the residual life by 30 - 40%. Using a technical endoscope to obtain information about the technical state of the GPG provides unique opportunities for visual diagnostics. Due to the use of a technical endoscope, it became for the first time possible to proceed while diagnosing internal combustion engine GPG to the evaluation of design parameters of the technical state, such as: the state of the hone net, grooves, scoring, scratches, which could only be performed before by automobile disassembly. In general, technical endoscopy increases the informative value of the process of cylinder-piston group diagnosing. The use of a technical endoscope reveals unique possibilities for an operative assessment of the technical condition of the object being diagnosed in order to shorten the time of detection and subsequent elimination of malfunctions.



2020 ◽  
Author(s):  
Alexandr Gritsenko ◽  
Vladimir Shepelev ◽  
Sergey Baryshnikov

Abstract To increase the diagnostic efficiency, significantly reduce the unproductive time, and mainly increase the reliability and accuracy, we propose a new method and tools implementing it - an oscillographic method for monitoring the pressure and phase parameters during the dynamic change in the operating parameters. The proposed work is aimed at improving the internal combustion engine (ICE) performance by timely diagnosing the cylinder-piston group (CPG) and its maintenance based on the diagnostic results. The scientific novelty of the work lies in the establishment of the interconnection of the CPG parameters obtained in the test modes of the ICE operation, allowing us to justify the diagnostic modes and their limiting values; the development of diagnostic methods and tools allowing us to justify the test modes for diagnosing the ICE CPG; the experimental data, which revealed that the instantaneous pressure signal in the combustion chamber is a sensitive diagnostic sign, which reflects the technical condition of the ICE CPG and its elements; the results of the experimental studies of diagnosing the ICE CPG in test modes. The results of the experimental work were compared with the results of theoretical modeling, the convergence between them was 97–99%. The production validation of the new method demonstrated the reliability within 0.92–0.97.



Author(s):  
Roman Vladimirovich Gorshkov

The paper considers one of the promising ways to influence the heat transfer in the cooling system of a cylinder-piston group, which is to improve physical properties of coolants. It has been stated that the development of nanotechnology has recently made it possible to significantly increase the thermal conductivity coefficient of base coolant - an aqueous solution of ethylene glycol due to its modification by high-conductive solid multigraphene nanoparticles. The resulting stable two-phase suspensions based on the base coolant and particles of the solid phase are called nanofluids. To evaluate the increase in heat transfer at the “wall-coolant” boundary and the decrease of temperature of this wall when applying nanofluid in the engine cooling system as compared to the base fluid, an experimental setup was developed for simulating the flow of coolant in the annular channel of the cooling cavity of the cylinder liner and the conditions determining the heat transfer in its cooling cavity. As a result of conducting a series of experiments under similar test conditions, a significant increase in the heat transfer coefficient was found at the boundary of the “liner wall-liquid” due to the use of nanofluids with highly heat-conducting multigraphene nanoparticles compared to the base fluid. This led to a decrease in the temperature of the cylinder liner. Reducing the temperature of the heat-loaded engine parts allows to increase the reliability of the promising and forced diesel engines, to increase the degree of boosting at the average effective pressure while maintaining the permissible temperature level of the parts of the cylinder-piston group. Intensification of heat transfer at the “wall-liquid” interface contributes to an increase in the thermal efficiency of various heat exchangers as part of an internal combustion engine associated with the main circuit of the cooling system.



2019 ◽  
Vol 177 (2) ◽  
pp. 139-144
Author(s):  
Tomasz KNIAZIEWICZ ◽  
Marcin ZACHAREWICZ

The paper presents an innovative method for assessing technical condition of a marine diesel engine that drives synchronous generator. It is based on the measurement and analysis of generators phase-to-phase voltage. Additionally, it requires the measurement of a pseudoperiodic signal [3] with a period equal to duration of engines working cycle. The basis for developing method was the assumption that rotational speed fluctuations of an engines crankshaft (and also the generator) depend on a course of a working process carried out in it. The generators phase-to-phase voltage is directly dependent on a rotational speed fluctuation of its rotor. It must therefore be possible to assess a course of a working process of an engine based on a voltage waveform of a synchronous generator that cooperates ogether.



Author(s):  
Vasiliy Aleksandrovich Chanchikov ◽  
Ivan Nikolaevich Guzhvenko ◽  
Alexandr Ivanovich Andreev ◽  
Marina Aleksandrovna Shulimova ◽  
Sergey Aleksandrovich Svekolnykov

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%.



2021 ◽  
Vol 13 (1) ◽  
pp. 133-139
Author(s):  
Iryna Sarayevа ◽  
◽  
Alexander Khrulev ◽  
Oleksandr Vorobiov ◽  
◽  
...  

Informative dampers and installation methods do not dose the speed, accurately distinguish the nature of the injustice of the cylinder-piston group and check the tightness of the valves of the single-stage model of the engine, which allows a preliminary quality assessment in the production assessment. . During the inspection, the activity of the "black box" is checked for unknown structural elements, the initial diagnostic obligations that affect. The nomenclature of structural parameters that are checked is determined in accordance with existing standards. Based on the advanced model development method produced by the technical condition of the cylinder-piston group and the sealed valve of the engine, model, detailed dosing, statistical information, machines, machines, machines, machines, machines, machines, machines, machines and equipment. first, to localize the unevenness of the cylinder-piston group and the tightness of the engine valve, and secondly, to formally process the process of automated technical diagnosis; thirdly, it will provide a high rate of indiscriminate diagnosis. To assess the sensitivity of the diagnostic value as a random variable, it is proposed to evaluate not the relative change in the limit and nominal value of the controller, the relative change in the average value of the random variable within the allowable value. The diagnostic parameter is considered stable if the condition under which the absolute maximum value from the average value does not exceed "three sigma" is fulfilled. Informative in consideration is the diagnostic parameter in which the ratio of the difference between the average significant value of the random control in good and faulty state of the object to the difference of standard deviations exceeds one. Expert assessment of the technical condition of the road vehicle is associated with the determination of diagnostic parameters, structural parameters, as well as the reasons that caused the change of these parameters.



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