scholarly journals Analysis of mechanical energy losses in marine diesels

2021 ◽  
Vol 5 (2(61)) ◽  
pp. 26-32
Author(s):  
Sergii Sagin ◽  
Volodymyr Madey ◽  
Tymur Stoliaryk

The object of research is marine diesel engine oils, which provide lubrication, cooling and separation of friction surfaces. The subject of the research is the process of ensuring minimum mechanical losses in marine diesel engines. A problematic point in ensuring the lubrication of the cylinder-piston group and motion bearings is the lack of analytical and experimental studies that establish the relationship between the structural characteristics of engine oils and mechanical losses arising in marine internal combustion engines. The degree of orientational ordering of molecules and the thickness of the boundary lubricating layer are considered as the structural characteristics of engine oils. The determination of these values was carried out using the optical method based on the anisotropy of the light absorption coefficient by the boundary lubricant layer and the isotropic volume of the liquid (engine oil). The assessment of the level of mechanical losses arising in marine diesel engines was carried out according to an indirect indicator – the overshoot of the rotational speed and the time to reach the steady state of operation in the event of a change in load. It has been experimentally established that for engine oils used in marine internal combustion engines, the thickness of the boundary layer can be 15–17.5 µm. Motor oils, which are characterized by a higher ordering of molecules and a thickness of the boundary lubricant layer, ensure the flow of transient dynamic processes with less overshoot and a shorter transient time. This ensures the level of minimal mechanical losses occurring in marine diesel engines. The technology for determining the structural characteristics of engine oils can be used for any type and grade of oil (mineral or synthetic; high or low viscosity; used in both circulating and cylinder lubrication systems). The method of indirect assessment of mechanical losses of marine diesel engines can be used for any types of internal combustion engines of ships of sea and river transport (low-, medium- and high-speed; as well as performing the functions of both main and auxiliary engines).

Author(s):  
Gennadiy Petrovich Kicha ◽  
Liudmila Anatolievna Semeniuk

The article gives analysis of the advantages and disadvantages of cleaning engine oil in internal combustion engines by filtration and centrifugation. The principles of increasing the efficiency of fine oil purification by combining these methods are formulated. The scheme of a perspective system for fine cleaning of engine oil is presented, which most fully realizes the advantages of full-flow filtration and centrifugation for a two-circuit lubrication system of forced internal combustion engines. The operating conditions of diesel engines are shown, under which the advantages of filtration and centrifugation can be realized to the full. The indices for the specific productivity index and capacity of the centrifugal cleaner are calculated, contributing to the attainment of the minimum wear rate of the engine parts and the maximum service life of the filter elements. Prospects for the application of a full-flow fine engine oil purification system in forced engines with a sequential connection of purification units with different principles of separation of complex heterogeneous polydisperse systems, which include the products of contamination of lubrication systems, are outlined. Particularly effective is the use of the developed combined fine-cleaning system in marine diesel engines with increased rotational speed, operating on screw characteristics. The results of motor tests in the ship's trunk boosted diesels of the new combined lubrication oil fine cleaning system are reported. The results of operational tests in the marine diesel engine ДД108 (8ЧСПН 18/22) of a combined engine oil purification system have been analyzed, which combine the advantages of a full-flow filter and a centrifuge with a discharge head connected in series. The parameters of efficient regular and experienced combined engine oil cleaning system are compared with the effect on aging, wear and varnish and lacquer formation of a diesel engine.


2018 ◽  
Vol 7 (4.3) ◽  
pp. 162 ◽  
Author(s):  
Oleksandr Babanin ◽  
Oleksandr Butskiy ◽  
Oleksandr Kovalenko ◽  
Maksym Maksimov

The questions of application of synthetic materials as filtering, in oil systems of internal combustion engines are considered in the article. In existing oil systems, diesel engines of internal combustion use filtering elements that provide limited protection of oil systems from particles of potentially dangerous dimensions and, therefore, wear. They are not designed to work for a long service life with the higher level of oil purity required at the present time. The urgency of these issues is caused by the need to improve the quality of engine oil cleaning and, as a consequence, to increase the reliability of the engine. The use of filter elements made of porous, fibrous polypropylene is proposed. Which, according to the results of the experiment, will allow to extend the service life of the filter elements and improve the quality of their operation. 


Author(s):  
Толмачев ◽  
D. Tolmachev ◽  
Голубенко ◽  
Natalya Golubenko

The article describes some of chemmotology processes in systems: engine oil – elements of internal combustion engines. Motor oil is regarded as an important element in the construction of an internal combustion engine, and it is necessary to make quantitative description of its condition which changing over time for its operability forecasting. In connection with the increasing number of vehicles with gas engines, the topics of necessity of special engine oils use for the gas internal combustion engine and of monitoring of their quality indicators are mentioned


Author(s):  
Mikhail Sergeevich Kurlenko ◽  
Alexander Aleksandrovich Budin ◽  
Aleksandr Dorokhov ◽  
Nikolay Vasilievich Selivanov

The need in research works on improving working process of internal combustion engines requires analyzing parameters of operation cycle. The aim of the study is to create a generalized technique for calculating the high-speed cycle diesel engines under different ways of working processes based on well-researched and reliable methodology based on using dependencies containing the general parameters of the engine performance. With the development of technology, particularly, engine manufacturing and evolution of engineering thought, by combining and add-on workflow operationalization of internal combustion engines there was received a reliable Grinevetskiy-Mazing technique of engineering calculations as a general system. Professor V.I. Grinevetskiy in his thermal design offered a pre-set temperature of residual gases Т г and cylinder filling factor ηN and gave formulas to calculate the starting compression temperature coefficient γг. The follower of V.I. Grinevetskiy, E.K. Mazing offered to evaluate the temperature of residual gases Т г and residual gas coefficient γг, and to calculate temperature of starting pressure Та and filling coefficient ηN introducing value of temperature Т′ 0 (air wormed by cylinder walls) into Grinevetskiy equation system. Today there are various software analytical complexes with different capacity (number of integrated functions), assignment (analysis, diagnostics, check calculation, design etc.), as well as basic method of calculation, which is the basic principle of the whole logic complex. Grinevetskiy-Mazing technique that has passed evolution of specifications and complements made in the course of time forms the basis of calculating method of operation cycle of marine diesel engines.


2021 ◽  
pp. 146808742110129
Author(s):  
Hidemi Ogihara ◽  
Takumi Iwata ◽  
Yuji Mihara ◽  
Makoto Kano

Internal combustion engines have been improved markedly in recent years through efforts to conserve resources, reduce emissions and improve fuel efficiency. In this regard, the authors have been working to reduce friction and improve the seizure properties of the crankshaft main journal and main bearing. These mechanical components of internal combustion engines incur large friction losses. In order to reduce friction, journals have been coated with a diamond-like carbon (DLC) coating, which has been reported to reduce friction in the fluid lubrication regime in recent years. Another current issue of journals and bearings is the need to improve seizure resistance. Therefore, these properties were evaluated for material combinations of aluminium alloy bearings and DLC-coated journals, which have low affinity. The results revealed that friction was reduced under a fluid lubrication regime and seizure resistance was improved under a mixed lubrication regime.


2020 ◽  
pp. 10-16
Author(s):  
S.A. Belov ◽  
I.V. Busin

The article reviews four existing technologies for replacing engine oil and a method for determining its suitability for improving economic efficiency. It is established that the oil is replaced according to the need in accordance with the defect indicators. This technology of oil condition is characterized by a more complete use of its resource. The frequency of replacement is determined by the indicators of condition, which is monitored by special sensors built into the engine lubrication system. However, the difficulty of using this technology is due to the lack of high-quality devices for monitoring the state of running engine oil in the engine.


2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Mohamed Kamal Ahmed Ali ◽  
Hou Xianjun

AbstractThe friction between two sliding surfaces is probably one of the oldest problems in mechanics. Frictional losses in any I.C. engine vary between 17% and 19% of the total indicated horse power. The performance of internal combustion engines in terms of frictional power loss, fuel consumption, oil consumption, and harmful exhaust emissions is closely related to the friction force and wear between moving parts of the engine such as piston assembly, valve train, and bearings. To solve this problem, most modern research in the area of Nanotribology (Nanolubricants) aims to improve surface properties, reduce frictional power losses, increase engine efficiency, and reduce consumed fuel and cost of maintenance. Nanolubricants contain different nanoparticles such as Cu, CuO, TiO


2019 ◽  
Vol 287 ◽  
pp. 06005
Author(s):  
Aliaksandar Ilyushchanka ◽  
Vyacheslav Kaptsevich ◽  
Valeria Korneeva ◽  
Ruslan Kusin ◽  
Igar Zakreuski ◽  
...  

The article discusses the use of powder filter materials (PFM) for cleaning engine oil when running-in internal combustion engines (ICE) of agricultural vehicles at motor repair enterprises. The results of comparative tests of powder, paper and net filter elements (FE) are presented. The design of the equipment for cleaning engine oil during and after run-in the engine is proposed.


2005 ◽  
Vol 127 (1) ◽  
pp. 206-212
Author(s):  
T. Icoz ◽  
Z. Dursunkaya

Blowback of engine oil suspended in combustion gases, when the gas flows from the piston second land back into the combustion chamber, is believed to contribute to oil consumption and hydrocarbon emissions in internal combustion engines. Oil accumulation in the region between top and second compression rings is a factor that influences this phenomenon. The effects of individual parameters, such as oil film thickness and viscosity, however, have still not been understood. The present study was aimed at constructing an experimental setup to study the effect of oil film thickness on oil accumulation in the second land of internal combustion engines. Due to the inherent difficulties of experimentation on production engines, a modeled piston-cylinder assembly was constructed. Total oil accumulation in the modeled second land after a single piston stroke was measured and compared to oil consumption in operating engines.


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