Analysis of the Lubrication Condition of a Crosshead Pin Bearing of a Large Marine Diesel Engine

2005 ◽  
Author(s):  
Sylvester Abanteriba
Keyword(s):  
Operating Conditions ◽  
Main Function ◽  
Connecting Rod ◽  
Operating Cycle ◽  
Lubrication Film ◽  
Normal Forces ◽  
Lubricating Film ◽  
Marine Diesel ◽  
Lubrication Condition ◽  
Low Levels

The main function of the crosshead bearing of a crosshead engine is to transmit the load from the connecting rod, which is directly attached to the piston of the engine, through a second rod to the guide shoe, which bears the entire crosshead. Apart from this function it enables the large normal forces, which are usually borne by the piston skirt in the case of a trunk piston engine, to be transmitted to the guide shoe from which it is subsequently transmitted to the rails along which the guide shoe glides. The dynamics of the crosshead bearing is such that the bearing pin is subjected to very low levels of incomplete rotation resembling that executed by a pendulum over a reduced arc. The bearing is also subjected to the load in only one direction. These operating conditions augur poorly for the formation of the hydrodynamic oil film necessary to support the imposed load. This type of bearing is therefore susceptible to considerable friction losses and significant wear as a result of lack of the capacity to generate lubrication film. This paper evaluates a model to determine the levels of achievable hydrodynamic film and the measures introduced to generate a hydrostatic squeeze lubricating film in the bearing as a result of the introduction of high pressure oil during part of the operating cycle of the engine.

Optimized control over modes of hydraulic percussion cutting heads of mining machines

2020 ◽  
pp. 95-104
Author(s):  
Yu. M. Smirnov ◽  
B. M. Kenzhin ◽  
N. S. Smakova ◽  
M. A. Zhurunova
Keyword(s):  
Time Derivative ◽  
Operating Conditions ◽  
Control Action ◽  
Main Function ◽  
Output Data ◽  
Working Cycle ◽  
Control Units ◽  
Action Change ◽  
Function Element ◽  
Service Factors

The main cause of the disagreement between the actual and calculated output data of hydraulic percussion mining machines is the erroneous feed of manipulation signals by the control units. For the maximal fitting of the calculated and actual figures, the continuous method of control action using the third time derivative of the law of motion of the main function element is accepted, namely, the accuracy. The mathematical models of control using displacement, velocity and acceleration are developed. The service factors of mining machines are found. Based on the theory of control and the mathematical logic theory, the logical circuits of formation of manipulation signals in each phase of the working cycle are developed. The main elements are converters, integrators and accumulators ensuring decomposition of elements of the logical circuits and further generation of appropriate control action. It is found that the simplest way is to generate the control action for acceleration of the key function element. For the developed circuits, it is recommended to use general charts of the control action change, implementable for a certain design of hydraulic percussion cutting heads in certain operating conditions.

Design and Performance of a Controlled Turbocharging System on Marine Diesel Engines

2006 ◽  
Author(s):  
Ioannis Vlaskos ◽  
Ennio Codan ◽  
Nikolaos Alexandrakis ◽  
George Papalambrou ◽  
Marios Ioannou ◽  
...  
Keyword(s):  
Steady State ◽  
Engine Performance ◽  
Operating Conditions ◽  
Electric Actuator ◽  
Engine Simulation ◽  
Engine Control System ◽  
Turbocharging System ◽  
Compressor Impeller ◽  
Marine Diesel ◽  
And Performance

The paper describes the design process for a controlled pulse turbocharging system (CPT) on a 5 cylinder 4-stroke marine engine and highlights the potential for improved engine performance as well as reduced smoke emissions under steady state and transient operating conditions, as offered by the following technologies: • controlled pulse turbocharging, • high pressure air injection onto the compressor impeller as well as into the air receiver, and • an electronic engine control system, including a hydraulic powered electric actuator. Calibrated engine simulation computer models based on the results of tests performed on the engine in its baseline configuration were used to design the CPT components. Various engine tests with CPT under steady state and transient operating conditions show the engine optimization process and how the above-mentioned technologies benefit engine behavior in both generator and propeller law operation.

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.

Introduction of the Taurus™ 65 Industrial Gas Turbine for Power Generation

2008 ◽  
Author(s):  
George Rocha ◽  
Simon Reynolds ◽  
Theresa Brown
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Electrical Power ◽  
Field Evaluation ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Liquid Fuels ◽  
Operating Cycle ◽  
Product Experience ◽  
Exhaust Heat

Solar Turbines Incorporated has combined proven technology and product experience to develop the new Taurus 65 gas turbine for industrial power generation applications. The single-shaft engine is designed to produce 6.3 megawatts of electrical power with a 33% thermal efficiency at ISO operating conditions. Selection of the final engine operating cycle was based on extensive aerodynamic-cycle studies to achieve optimum output performance with increased exhaust heat capacity for combined heat and power installations. The basic engine configuration features an enhanced version of the robust Centaur®50 air compressor coupled to a newly designed three-stage turbine similar to the Taurus 70 turbine design. Advanced cooling technology and materials are used in the dry, lean-premix annular combustor, consistent with Solar’s proven SoLoNOx™ combustion technology, capable of reducing pollutant emissions while operating on standard natural gas or diesel liquid fuels. Like the Titan™ 130 and Taurus 70 products, a traditional design philosophy has been applied in development of the Taurus 65 gas turbine by utilizing existing components, common technology and product experience to minimize risk, lower cost and maximize durability. A comprehensive factory test plan and extended field evaluation program was used to validate the design integrity and demonstrate product durability prior to full market introduction.

scholarly journals Методика для трибодиагностики судовых крейцкопфных дизелей на основе имитационного моделирования

2020 ◽  
Author(s):  
A.V. Golenishev ◽  
A.V. Nadezkin ◽  
M.E. Starchenko
Keyword(s):  
Diesel Engine ◽  
Simulation Model ◽  
Technical Condition ◽  
Operating Conditions ◽  
Marine Diesel Engine ◽  
Threshold Values ◽  
Piston Group ◽  
Marine Diesel ◽  
Cylinder Piston ◽  
Wear Products

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.

scholarly journals The influence of centrial forces on crankshaft bearing lubrication is in emergency modes of the engine of the car

2021 ◽  
Vol 12 (2) ◽  
pp. 112-121
Author(s):  
Oleksandr Khrulev ◽  
◽  
Olexii Saraiev ◽  
Iryna Saraieva ◽  
◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Operating Mode ◽  
Internal Combustion ◽  
Technical Condition ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Oil Supply ◽  
Technical Expert ◽  
The Difference

The analysis of the crankshaft bearing condition of the automotive internal combustion engines in the case of insufficiency and breakage of oil supply to them is carried out. It is noted that this fault is one of the most common causes of damage to rubbing pairs in operation. At the same time, the different groups of bearings are often damaged, which cannot be explained within the framework of existing models of plain bearing lubrication. The objective of the work is to develop a mathematical model of oil supply to connecting rod bearings in emergency mode, taking into account the characteristic features of the bearing design. The model also, depending on the nature of the damage, should help to determine and explain the causes of bearing failures if they occur in different modes when operating conditions are broken. A computational model has been developed that makes it possible to assess the effect of design differences in the features of oil supply and the action of the centrifugal forces during crankshaft rotation on the oil column in the lubrication hole where oil is supplied to the conrod bearing. Calculations of the change in time of the oil supply pressure to the connecting rod bearings for the various designs of the crankshaft lubrication holes have been performed. It is shown that, depending on the operating mode of the engine and its design, the oil pressure in front of the connecting rod bearings does not disappear immediately after oil supply failure to crankshaft. Moreover, the lower the crankshaft speed is, the longer the lubrication of the conrod bearings will continue. The calculation results are confirmed by the data of the expert studies of the engine technical condition, in which the crankshaft was wedged in the damaged main bearings was found in the absence of serious damage to the connecting rod ones. It has been found that such features of the damage correspond to an rapid breakage of the oil supply to the crankshaft in the case of such operational damage as the oil pump and pressure reducing valve failure, the oil filter seal and oil pan destruction, etc. The developed model explains the difference in lubrication conditions and in the damage feature to the main and connecting rod bearings in the emergency cases of the oil supply breakage, which are observed during operation, and helps to clarify the failure causes. This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines when the operating conditions are broken.

scholarly journals Fractographic Study of Marine Diesel Engine Connecting Rod Stud Bolt Crack

2021 ◽  
Vol 58 (4) ◽  
pp. 28-42
Author(s):  
K. Carjova ◽  
V. Priednieks ◽  
R. Klaucans ◽  
I. Irbe ◽  
A. Urbahs
Keyword(s):  
Fatigue Crack ◽  
Diesel Engine ◽  
Tensile Tests ◽  
Marine Diesel Engine ◽  
Connecting Rod ◽  
Worst Case ◽  
The People ◽  
Marine Diesel ◽  
Fatigue Rupture ◽  
Fatigue Crack Development

Abstract Failures of marine diesel engine components can lead to serious consequences for a vessel, cargo and the people on board a ship. These consequences can be financial losses, delay in delivery time or a threat to safety of the people on board. This is why it is necessary to learn about connecting rod bolt failures in order to prevent worst-case scenarios. This paper aims at determining the origin, velocity and the duration of fatigue crack development of a diesel alternator engine which suffered a significant failure of one of its mains, not long after a major overhaul had been completed and with less than 1000 running hours having elapsed. It was verified with fatigue rupture of one of the four connecting rod stud bolts. Tensile tests were performed in the remaining connecting rod bolts. During this procedure, another fatigue crack in an adjacent bolt was identified. The probable root case of damage, and at the end some final remarks are presented.

Thermodynamic Analysis and Working Fluid Optimization of a Combined ORC-VCC System Using Waste Heat From a Marine Diesel Engine

2014 ◽  
Author(s):  
Oumayma Bounefour ◽  
Ahmed Ouadha
Keyword(s):  
Thermodynamic Analysis ◽  
Waste Heat ◽  
Operating Conditions ◽  
Working Fluid ◽  
Vapor Compression ◽  
Marine Diesel ◽  
Vapor Compression Refrigeration ◽  
Propylene Yield ◽  
Fluid Optimization ◽  
Propane Butane

This paper examines through a thermodynamic analysis the feasibility of using waste heat from marine Diesel engines to drive a vapor compression refrigeration system. Several working fluids including propane, butane, isobutane and propylene are considered. Results showed that isobutane and Butane yield the highest performance, whereas propane and propylene yield negligible improvement compared to R134a for operating conditions considered.

Research on the intelligent generation method of MBD model 3D marking using predefined features

2020 ◽  
Vol 28 (3) ◽  
pp. 222-238
Author(s):  
Xuwen Jing ◽  
Mingming Tang ◽  
Jinfeng Liu ◽  
Honggen Zhou ◽  
Peng Zhao ◽  
...  
Keyword(s):  
Technological Innovation ◽  
Process Design ◽  
Connecting Rod ◽  
Association Model ◽  
Global Manufacturing ◽  
Modeling Problem ◽  
Marine Diesel ◽  
Expression Model ◽  
Product Manufacturing ◽  
Rapid Modeling

Model-based definition (MBD) carries out a technological innovation for global manufacturing, application of MBD technology plays an important supporting in process design, product manufacturing and other development activities, rapid creation of MBD models have become a key to reduce time and cost for enterprises. However, interactive dimensioning method has severely hampered the efficiency of MBD model creation. This paper mainly studies the dimensions intelligent marking method based on the predefined features to solve the rapid modeling problem of MBD model. Firstly, the expression model of dimensions metadata is established based on the feature identifier. Secondly, by establishing an association mechanism between the dimensions and the predefined feature, the “model-feature-dimensioning” association model is formed. Thirdly, through analysis of the dimensioning type, the intelligent dimensioning algorithm process is determined. Moreover, the completeness check of the dimensions is guaranteed during the marking process. Finally, taking the connecting rod and crankshaft of marine diesel as the research object, the effectiveness of this method is verified.

On-line determination of nitrite in wastewater treatment by use of a biosensor

2002 ◽  
Vol 45 (4-5) ◽  
pp. 69-76 ◽  
Author(s):  
M. Nielsen ◽  
N.P. Revsbech ◽  
L.H. Larsen ◽  
A. Lynggard-Jensen
Keyword(s):  
Activated Sludge ◽  
Mechanical Damage ◽  
Operating Conditions ◽  
Bacterial Populations ◽  
Operational Lifetime ◽  
On Line ◽  
Low Levels ◽  
In The Beginning

A newly developed biosensor for nitrite having a 90% response time of about 1 min was used to monitor nitrite concentration in activated sludge exposed to oxic/anoxic cycles. The NO2− biosensor contains bacteria that reduce NO2−, but not NO3−, to N2O that is subsequently monitored by a built-in electrochemical sensor. Nitrite plus nitrate (NOx−) was simultaneously monitored by a NOx− biosensor. The maximum operational lifetime of the NO2− biosensor was 6 weeks, but much longer lifetimes can be expected as malfunctioning by the 3 sensors used for longer periods was due to either mechanical damage or ineffective internal sterilization during the construction. Insufficiently sterilized sensors became sensitive also to NO3− after some time due to development of NO3−-reducing bacterial populations within the sensor. The fraction of NO2− as compared to NO3− in the activated sludge was very dependent on prehistory, actual loading, and aeration. During balanced operation with NH4+ being exhausted during the later parts of the aerobic cycle, NO2− increased in concentration up to about 50 μM during the early part of the aeration cycle until NH4+ became limiting. At that time the NO2− concentration decreased to low levels. Under some operating conditions a peak of NO2− also appeared in the beginning of the anoxic period. NO2− and NO3− were depleted simultaneously during the anoxic period.

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