scholarly journals Investigation on reducing NOx emission of medium-speed diesel engines.

1990 ◽  
Vol 69 (2) ◽  
pp. 100-106 ◽  
Author(s):  
Tateo NAGAI ◽  
Masayoshi KAWAKAMI
Keyword(s):  
Diesel Engines ◽  
Nox Emission ◽  
Medium Speed

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.

Experiments on Combustion of Heavy Fuels by Medium-Speed Diesel Engines

1987 ◽  
Author(s):  
Y. Itoh ◽  
M. Kawamoto ◽  
H. Fujiwara ◽  
M. Kawakami ◽  
T. Nagai
Keyword(s):  
Diesel Engines ◽  
Medium Speed ◽  
Heavy Fuels

Some Considerations in the Design of Polar Icebreakers

1972 ◽  
Vol 9 (01) ◽  
pp. 42-58
Author(s):  
J. Gordon German ◽  
C. F. Collins ◽  
A. R. Webster
Keyword(s):  
Diesel Engines ◽  
Gas Turbines ◽  
Design Features ◽  
Factors Affecting ◽  
Medium Speed ◽  
Hull Design ◽  
Ice Conditions ◽  
Hull Construction

This paper highlights some primary considerations in the design of polar icebreakers. Factors affecting determination of power-displacement relationships and the propulsion horsepower are discussed, as is the importance of clearly defining the manner in which the various ice conditions are to be handled. The authors deal briefly with hull construction aspects, outlining the general requirements for polar-class icebreakers, choice of parameters, and the principal hull design features of a proposed new Canadian polar icebreaker. Propulsion machinery options are discussed, including medium-speed diesel engines, aircraft and industrlal-type gas turbines, and combination systems.

Influence of the Indicator Channel and Indicator Valve on the Heat Release Characteristics of Medium Speed Marine Diesel Engines

2013 ◽  
Vol 588 ◽  
pp. 149-156 ◽  
Author(s):  
Stanisław Polanowski ◽  
Rafał Pawletko ◽  
Kazimierz Witkowski
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Diesel Engines ◽  
Diagnostic Information ◽  
Injection System ◽  
Indicator Diagram ◽  
Medium Speed ◽  
Marine Diesel ◽  
The Impact

Analysis of the indicator diagram is the basis of technical state evaluation of marine diesel engines. The indicator diagram contains a large amount of diagnostic information. A major problem for the diagnostic use of the indicator diagram is the pressure sensor location. Indicator channel and valve may introduce significant distortions in the resulting pressure. The paper presents results of research conducted on the medium speed laboratory engine Al 25/30. Pressure measurement (indication) was made by the sensor placed directly in the cylinder (instead of starting air valve), before the indicator valve (with special Kistler adapter) and on the indicator valve. Distortion of heat release characteristics for the sensor placed on the indicator valve is important, but it is estimated that diagnostic information is not erased. For medium speed engines is to be expected the use of a portable pressure sensors placed on the indicator valve. For this reason, further research is needed to assess the impact of channels and valves on different cylinders. During the research the course of heat release rate q and the heat released Q were determined. The curve of heat release rate q is a full equivalent to fuel injection pressure curve in the fuel pipes. It allows identification of the failure of the injection system. The curve of Q allows such determination and assessment of internal efficiency of the cylinder.

Internal EGR Systems for NOx Emission Reduction in Heavy-Duty Diesel Engines

2004 ◽  
Author(s):  
John Schwoerer ◽  
Sotir Dodi ◽  
Marty Fox ◽  
Shengqiang Huang ◽  
Zhou Yang
Keyword(s):  
Diesel Engines ◽  
Emission Reduction ◽  
Nox Emission ◽  
Heavy Duty ◽  
Heavy Duty Diesel
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