scholarly journals Changes in the kinematic viscosity of engine oil during the operation of marine diesel engines

2021 ◽  
Vol 2131 (3) ◽  
pp. 032060
Author(s):  
V Zhukov ◽  
O Melnik ◽  
E Khmelevskaya
Keyword(s):  
Diesel Engines ◽  
Kinematic Viscosity ◽  
Environmental Safety ◽  
Engine Oil ◽  
Engine Oils ◽  
Marine Diesel ◽  
Required Quality

Abstract A prerequisite for the long-term and safe operation of marine diesel engines is the high quality of operational materials, which include engine oils and coolants. The required quality of operational materials is ensured by the introduction of additives into their composition, which are now increasingly used as nanoparticles. During operation, as a result of the destruction of additives, the operational properties of coolants and engine oils deteriorate. The conducted studies allowed us to evaluate the change in the lubricating ability of engine oils of two brands that are used in marine diesels during operation. As a characteristic of the lubricating ability of the oil, its kinematic viscosity was used. The experimental determination of the kinematic viscosity of engine oil samples having different periods of operation, and the subsequent mathematical processing of the experimental results made it possible to determine the dependencies characterizing the change in the kinematic viscosity of engine oil during its operation. The research results confirm the possibility of scientific justification for extending the use of marine diesel engine oils, which reduces operating costs and increases the environmental safety of marine diesel engines.

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
Keyword(s):  
Diesel Engines ◽  
Internal Combustion Engines ◽  
Structural Characteristics ◽  
Internal Combustion ◽  
Engine Oil ◽  
Lubricant Layer ◽  
Combustion Engines ◽  
Engine Oils ◽  
Boundary Lubricant ◽  
Marine Diesel

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).

Increasing the durability of the coupling "crankshaft neck – bearing liner" by applying nanocomposite additives to the engine oils of marine medium-speed diesel engines

2021 ◽  
pp. 93-100
Author(s):  
Л.Б. Леонтьев ◽  
Н.П. Шапкин ◽  
А.Л. Леонтьев ◽  
В.Н. Макаров ◽  
А.В. Арон
Keyword(s):  
Wear Resistance ◽  
Diesel Engines ◽  
Operating Conditions ◽  
Inorganic Materials ◽  
Engine Oil ◽  
High Wear Resistance ◽  
Medium Speed ◽  
Marine Diesel ◽  
Optimal Material ◽  
Technical Operation

Повышение долговечности трибосопряжений судовых дизелей, определяющих их ресурс, представляет собой актуальнейшую проблему, обусловленную как безопасностью мореплавания, так и экономическими факторами. Основной причиной отказов коленчатых валов двигателей, определяющих необходимость капитального ремонта, является износ шеек. Решение проблемы повышения износостойкости и, соответственно, долговечности связано с применением трибоактивных присадок в смазку. Несмотря на глубокие и обстоятельные исследования в области применения органо-неорганических материалов для использования в качестве присадок в моторное масло для повышения долговечности трибоузлов осуществить выбор оптимального материала для конкретных условий практически невозможно, так как исследования выполнены для различных условий эксплуатации и по различным методикам. Цель работы – разработка триботехнической присадки к моторным маслам, обеспечивающей повышение надежности и эффективности технической эксплуатации судовыхсреднеоборотных дизелей путем формирования тонкопленочного металлокерамического покрытия на поверхностях трения стальных деталей трибоузлов, позволяющего получить оптимальный комплекс параметров материала износостойкого покрытия. В работе представлены исследования эксплуатационных свойств присадок в моторное масло 17 органо-неорганических триботехнических материалов 4 групп — природные и искусственные полимеры, из которых были изготовлены свыше 20 композиций и композитов. Установлено, что наиболее перспективным является использование нанокомпозитов на основе вермикулита, модифицированного кислотой, в качестве присадок в моторное масло, так как они обладают минимальными коэффициентом трения при граничной смазке (0,007–0,014) а также высокой износостойкостью стали 40Х и обеспечивают минимальную величину скорости изнашивания вкладыша подшипника, благодаря чему повышается ресурс трибосопряжения более, чем в 3 раза, и соответственно снижаются эксплуатационные расходы. Increasing the durability of the tribo-couplings of marine diesel engines, which determine their resource, is an urgent problem due to both the safety of navigation and economic factors. The main reason for engine crankshafts failures, which determine the need for major repairs, is the wear of the necks. The solution to the problem of increasing wear resistance and, accordingly, durability is associated with the use of triboactive additives in the lubricant. Despite in-depth and thorough research in the field of application of organo-inorganic materials for use as additives in engine oil to increase the durability of tribo-nodes, it is almost impossible to choose the optimal material for specific conditions, since the studies were carried out for various operating conditions and according to various methods. The purpose of the work is to develop a tribotechnical additive to motor oils that provides an increase in the reliability and efficiency of technical operation of medium-speed marine diesel engines by forming a thin-film metal-ceramic coating on the friction surfaces of steel parts of tribo-nodes, which allows to obtain an optimal set of parameters of the wear-resistant coating material. The paper presents studies of the operational properties of additives in engine oil of 17 organo-inorganic tribotechnical materials of 4 groups — natural and artificial polymers, from which more than 20 compositions and composites were made. It has been established that the most promising is the use of nanocomposites based on vermiculite modified with acid as additives in engine oil, since they have a minimum coefficient of friction with boundary lubrication (0.007-0.014) as well as high wear resistance of 40X steel and provide a minimum wear rate of the bearing liner, thereby increasing the tribo-tension life by more than 3 times, and, accordingly, operating costs are reduced.

Determination of Long-Term Stability and Quality of HT-PEM MEAs

2018 ◽  
Vol 86 (13) ◽  
pp. 301-314
Author(s):  
Maren Rastedt ◽  
Julian Büsselmann ◽  
Tomas Klicpera ◽  
Karsten Reinwald ◽  
Nadine Pilinski ◽  
...  
Keyword(s):  
Term Stability ◽  
Long Term Stability

scholarly journals Study on the Prospects of Use the Group D Engine Oil in Locomotive Diesel Engines

2018 ◽  
Vol 7 (4.3) ◽  
pp. 47
Author(s):  
Andrii Кravets ◽  
Andrii Yеvtushenko ◽  
Andrii Pogrebnyak ◽  
Yevhenii Romanovych ◽  
Heorhii Afanasov
Keyword(s):  
Diesel Engines ◽  
Wear Test ◽  
Engine Oil ◽  
Test Machine ◽  
Group V ◽  
Engine Oils ◽  
Oil Fuel ◽  
Continuous Use ◽  
Group D ◽  
Locomotive Diesel

It was suggested to use group D engine oil with advanced properties instead of group V and G engine oils, which are used in locomotive diesel engines today, to improve the performance of the Ukrainian locomotive fleet of railways.A series of comparative laboratory studies of these oil groups was conducted to substantiate this suggestion which proved better lubrication and tribological performance of group D engine oil and allowed its performance tests.Tests conducted on diesel 5D49 for mileage of more then 100,000 km have demonstrated the advantages of group D oils, such as more stable viscosity, neutralizing ,washing and other properties. Studies on the four-ball wear test machine proved better anti-wear, anti-scoring and anti-friction properties of group D engine oil, which appear even after the continuous use of oils in locomotive diesels. Decrease in burning loss of engine oil was recorded, resulting in the decrease of oil fuel consumption for group D by 30-60% vs. the group G oil.According to the results of performance tests, group D engine oil has been recommended for the use in 5D49 locomotive diesels and some advice on its future implementation have been provided.  

scholarly journals Determination of inundation areas within karst poljes and intermittent lakes for the purposes of ephemeral flood mapping

2020 ◽  
Author(s):  
Nataša Ravbar ◽  
Cyril Mayaud ◽  
Matej Blatnik ◽  
Metka Petrič
Keyword(s):  
Environmental Changes ◽  
Stagnant Water ◽  
Karst Environment ◽  
Karst Areas ◽  
Special Challenge ◽  
National Networks ◽  
Specific Definition

AbstractThe karst environment presents a special challenge when it comes to identifying groundwater/surface-water interactions. Existing definitions of areas of regular flooding in karst regions are too general and lack a measurable approach for the determination of flood-liable land. This paper proposes a means of specific definition and quantitative determination of intermittently flooded karst areas, which takes into account the extent, duration and frequency of flooding, and includes the identification of data sources and processing methods. The procedure, involving spatial layers, was developed using a pilot area and tested in three additional areas in Slovenia. The derived definition determines that flood-liable land within karst poljes and intermittent lakes comprise areas where stagnant water or stream overflow is present for at least 10 days/year over a period of 30 years, and these waters have direct contact with groundwater. The results show that the proposed procedure is applicable to areas with different geomorphological settings and to areas where the quantity and quality of available data vary. The study is an example of the practical application of knowledge on karst, as the findings can be used for short-term purposes (mapping flood areas, determination of habitats) and long-term purposes (study of impacts of environmental changes). Attention should be drawn to the lack of available data and the fact that the national networks of hydrological observatories are often too sparse for this purpose. This study raises awareness of these shortcomings and improves the planning or expansion of such a network in collaboration with experts.

scholarly journals Research on the relative productivity of a drum mill type SAG 8.5×5.3

2020 ◽  
Vol 168 ◽  
pp. 00012
Author(s):  
Ivan Minin
Keyword(s):  
Energy Consumption ◽  
Control Parameters ◽  
Operational Mode ◽  
Operational Parameters ◽  
Technological Parameters ◽  
Expected Performance ◽  
Relative Productivity ◽  
Required Quality

The determination of the optimal operational mode of drum mills can be assessed by different criteria. The most important of them can be formulated as follows: “To be specified and established the values of the mill operational parameters regarding to which it is possible to be provided the user’s expected performance at the required quality of the final product and the same to be achieved at minimal energy consumption”. For the fulfillment of this condition, there has to be determined the laws of productivity variation, the final product quality and the energy consumption in function of the adequately chosen representative control parameters of the mill. There are obtained mathematical models, describing the most important technological parameters of the machine and are made conclusions about the factors influencing on them.

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

2021 ◽  
Vol 2021 (4) ◽  
pp. 62-74
Author(s):  
Vasiliy Aleksandrovich Chanchikov ◽  
Ivan Nikolaevich Guzhvenko ◽  
Alexandr Ivanovich Andreev ◽  
Marina Aleksandrovna Shulimova ◽  
Sergey Aleksandrovich Svekolnykov
Keyword(s):  
Diesel Engines ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Mechanical Mixing ◽  
Friction Modifier ◽  
Marine Engine ◽  
Piston Group ◽  
Molybdenum Diselenide ◽  
Marine Diesel ◽  
Cylinder Piston

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%.

Left renal vein stenting: indications, disputable points, immediate and long-term results

2021 ◽  
Vol 22 (1) ◽  
pp. 28-37
Author(s):  
A. Е. Vasiliev ◽  
О. В. Zhukov ◽  
V. Е. Sinitsyn ◽  
A. N. Sulima
Keyword(s):  
Renal Vein ◽  
Left Renal Vein ◽  
Clinical Manifestations ◽  
Long Term Results ◽  
Technical Performance ◽  
Significant Compression

The article presents the results of stenting of the left renal vein in 35 patients with proven hemodynamically significant compression of the vein in “aorto-mesenteric tweezers”. Clinical manifestations of lesions of the left renal vein are very diverse, and pathogenetic mechanisms remain not fully understood. Therefore, the determination of indications for stenting and perfect technical performance are predictors of success in the near and long-term periods of postoperative follow-up. Our experience in stenting the left renal vein demonstrates the possibility of achieving intraoperative technical success in 100 % of cases, as well as a significant improvement in the quality of life in most patients after endovascular intervention, due to a significant reduction in the clinical manifestations of the pathological phenomenon. 

scholarly journals Characterization of PM10 Sampled on the Top of a Former Mining Tower by the High-Volume Wind Direction-Dependent Sampler Using INNA

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Irena Pavlíková ◽  
Daniel Hladký ◽  
Oldřich Motyka ◽  
Konstantin N. Vergel ◽  
Ludmila P. Strelkova ◽  
...  
Keyword(s):  
Winter Season ◽  
Ground Level ◽  
High Volume ◽  
Limit Values ◽  
Health Quality ◽  
Health Quality Of Life

The PM10 concentrations in the studied region (Ostravsko-karvinská agglomeration, Czech Republic) exceed air pollution limit values in the long-term and pose a significant problem for human health, quality of life and the environment. In order to characterize the pollution in the region and identify the pollution origin, Instrumental Neutron Activation Analysis (INAA) was employed for determination of 34 elements in PM10 samples collected at a height of 90 m above ground level. From April 2018 to March 2019, 111 PM10 samples from eight basic wind directions and calm and two smog situations were sampled. The elemental composition significantly varied depending on season and sampling conditions. The contribution of three important industrial sources (iron and steelworks, cement works) was identified, and the long-range cross-border transport representing the pollution from the Polish domestic boilers confirmed the most important pollution inflow during the winter season.

scholarly journals Выбор индекса производительности центробежного сепаратора для комбинированных маслоочистительных комплексов судовых тронковых дизелей

2020 ◽  
Vol 45 (4) ◽  
Author(s):  
Keyword(s):  
Diesel Engines ◽  
Performance Index ◽  
High Speed ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Lubrication System ◽  
Centrifugal Separator ◽  
Resource Saving ◽  
Marine Diesel ◽  
Engine Wear

Показана перспективность комбинированной очистки моторного масла в судовых тронковых дизелях с использованием саморегенерирующихся фильтров и сепараторов. Этот метод очистки особенно эффективен для форсированных высокоавтоматизированных двигателей с низким угаром масла, работающих на высоковязких остаточных топливах. Обосновывается важность надежной защиты подшипников двигателя от абразивного изнашивания полнопоточным фильтрованием масла. Центробежный сепаратор, работающий по байпасной схеме, эффективно удаляет из системы смазки мелкодисперсную фазу нерастворимых загрязнений, что обеспечивает функционирование и повышает автономность саморегенерирующегося фильтра, а также замедляет старение смазочного масла. Доказывается необходимость подбора сепаратора по удельному индексу производительности, обеспечивающему ресурсосберегающее маслоиспользование в системе «дизель–топливо–масло– очистка». Новизна экспериментального моделирования эффективности этой системы состоит в оценке с помощью лабораторной моторной установки трибологических показателей отработавшего в судовом дизеле смазочного масла, отражающих взаимодействие звеньев рассматриваемой системы, и установлении их связи с изнашиванием двигателя. Эффективность системы идентифицирована по критерию изнашивания дизеля, что позволяет использовать ее расчетно-экспериментальную модель для определения параметров центробежного сепаратора – с тем, чтобы он удовлетворял требованиям рассматриваемых взаимодействующих звеньев. Модель трансформирована в выражение для расчета удельного, приходящегося на единицу мощности двигателя индекса производительности сепаратора, обеспечивающего минимальное изнашивание двигателя, бессменную работу смазочного масла и автономный срок службы саморегенерирующегося фильтра не менее 3 тыс. ч. Полученные рекомендации по подбору сепаратора в системе смазки двигателя с полной реализацией достоинств автоматизированной тонкой очистки моторного масла комбинированием фильтрования и центрифугирования применимы для судовых дизелей средней и повышенной частоты вращения мощностью до 20 тыс. кВт. Ключевые слова: ресурсосберегающее маслоиспользование, саморегенерирующийся фильтр, центробежный сепаратор, изнашивание дизеля, комбинированная очистка масла, смазочная система, индекс производительности сепаратора, оптимизация сепарирования масла The prospects of combined cleaning of engine oil in ship trunk diesel engines using self-regenerating filters and separators are shown. This cleaning method is especially effective for high-powered, highly automated engines with low oil waste, operating on high-viscosity residual fuels. The importance of reliable protection of engine bearings from abrasive wear by full-flow oil filtration is substantiated. The centrifugal separator, operating according to the bypass scheme, effectively removes the finely dispersed phase of insoluble contaminants from the lubrication system, which ensures the functioning and increases the autonomy of the self-regenerating filter, and also slows down the aging of the lubricating oil. The necessity of selecting a separator according to the specific performance index, which ensures resource-saving oil use in the “dieselfuel-oil-cleaning” system, is proved. The novelty of the experimental modeling of the efficiency of this system consists in evaluating the tribological indicators of the lubricating oil used in a marine diesel engine, reflecting the interaction of the links under consideration, on a laboratory motor unit, and establishing their connection with engine wear. The efficiency of the presented system is identified by the criterion of diesel wear, which makes it possible to use its computational and experimental model to determine the parameters of a centrifugal separator so that it meets the requirements of the considered interacting links. The model has been transformed into an expression for calculating the specific index of the separator performance per unit of engine power, which ensures minimum engine wear, permanent operation of the lubricating oil and an autonomous service life of a self-regenerating filter of at least 3 thousand hours. Full realization of the advantages of automated fine cleaning of engine oil by combining filtration and centrifugation, are applicable for marine diesel engines of medium and high speed with a capacity of up to 20 thousand kW. Keywords: resource-saving oil use, self-regenerating filter, centrifugal separator, diesel wear, combined oil purification, lubrication system, separator performance index, optimization of oil separation

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