scholarly journals Development of Management System for Marine Diesel Engines - Influence of Data Sampling Interval on Calculation Error of Indicated Mean Effective Pressure (IMEP)

2009 ◽  
Vol 44 (4) ◽  
pp. 635-640
Author(s):  
Sumito Nishio ◽  
Masahiro Sakai ◽  
Kazuo Tsuchiya, ◽  
Koichi Hirata ◽  
Tomoyuki Shigeji Tsukahara
1980 ◽  
Vol 102 (4) ◽  
pp. 827-835 ◽  
Author(s):  
T. Azuma ◽  
Y. Tokunaga ◽  
T. Yura

The constant pressure turbo-charge system has now been increasingly adopted for marine diesel engines because of its higher thermal efficiency in the range of higher mean effective pressure. However, it seems that there has been no paper published on the exhaust gas pulsation of this sytem. In this study, a gas flow model of the constant pressure turbo-charged diesel engines was assumed as a basic and fundamental one, and an investigation was made of it. As a result, some characteristics of the exhaust gas pulsation of this system have been clarified and a mathematical simulation system has been established. It must be emphasized that the filling and emptying method which neglects wave propagation cannot simulate the pulsation, although it can simulate the average exhaust gas pressure and temperature of this system.


1983 ◽  
Vol 105 (3) ◽  
pp. 697-711 ◽  
Author(s):  
T. Azuma ◽  
T. Yura ◽  
Y. Tokunaga

The constant pressure turbocharge system is widely used in marine diesel engines because of its high thermal efficiency. This study has been made to establish a simulation system for exhaust gas pulsation of the constant pressure turbocharge system and to clarify its characteristics. The previous paper reported that the pressure fluctuations measured on test units and some engines agreed very well with those simulated by the scheme developed in this study. The study used the characteristic method for solving the differential equations of unsteady flow. This report will first discuss the high thermal efficiency of this turbocharge system in the range of high mean effective pressure, then it will show the advantages of the two-step Lax-Wendroff’s method in solving the unsteady flow equations in comparison with the characteristic method. Furthermore, it will present some characteristics of the pulsation and the unique pulsation resonance in this turbocharge system.


1990 ◽  
Vol 27 (04) ◽  
pp. 237-249
Author(s):  
Anastassios N. Perakis ◽  
Bahadir Inozu

Some essential steps for the application of reliability, availability, and maintainability (RAM) techniques to marine diesel engines are presented. The paper begins with a summary of the basic concepts of reliability engineering, followed by a survey of the relevant literature on RAM applications to the marine industry and to marine diesel engines in particular. Next, the results of an informal survey of the reliability, maintenance, and replacement practices of Great Lakes operators are presented. Finally, the first two steps for a RAM application, failure modes and effects analysis and fault tree analysis, are introduced and applied for a prototype Colt-Pielstick marine diesel engine.


2015 ◽  
Author(s):  
Jerry Ng ◽  
Kaisa Honkanen

Emulsified fuel technology has been developed since the early 1980’s to the improve combustion efficiency of marine diesel engines by creating a secondary atomization effect after the initial fuel injection. The main challenge is to measure the improved sfoc of ships accurately and reliably. This paper presents a proposed method to measure the sfoc accurately and reliably to the order of 1%. Electronic governor also poses new challenge to measuring the sfoc of ships burning emulsified fuel. Meanwhile, fuel types supplied to ship owners are of increased varying properties although still complying to ISO8217 standard. This paper describes the innovations in emulsified fuel technology that were developed to meet these challenges.


Author(s):  
Л.Б. Леонтьев ◽  
Н.П. Шапкин ◽  
А.Л. Леонтьев ◽  
В.Н. Макаров ◽  
А.В. Арон

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.


2012 ◽  
Vol 60 (1) ◽  
Author(s):  
Mohamed Nazul Ismail ◽  
Yazrina Yahya ◽  
Muriati Mukhtar

The purpose of this study is to identify the value co-creation of a Learning Management System. Data were collected through a Laddering Technique based on Means-End Chain Theory, Service Dominant Logic and Rokeach Value List (1973). Value co-creation elements are important to identify the critical feature during the design process of the Learning Management System. A number of 30 respondents were selected using purposive data sampling technique. This is a case study based on Sistem Pengurusan Pengajaran dan Pembelajaran Interaktif, UKM (SPIN). Research findings listed six value co-creation elements consists of self directed, capability, intellectual, ambitious (hardworking), responsibility and helpful. The findings were shown in an implication matrix and Value Hierarchy Map (VHM). Significant of the study is to help identify co-creation value based on critical features such as Lecture Notes, Annoucement and Course Profile. These critical features are able to provide great impact on the success of a Learning Management System. The research findings could be developed into a generic model of value co-creation model. Keywords: Laddering technique; learning management system; value co-creation; means-end theory;servic dominant logic Kajian ini bertujuan untuk mengenal pasti nilai cipta-sama dari sebuah sistem pengurusan pembelajaran. Data diperoleh melalui Teknik Laddering berlandaskan Teori Means-End, Service Dominant Logic dan Senarai Nilai Rokeach(1973). Elemen nilai cipta-sama ini penting dalam mengenal pasti fitur kritikal semasa proses mereka bentuk sistem pengurusan pembelajaran yang berjaya. Seramai 30 orang responden dipilih melalui teknik persampelan bertujuan. Reka bentuk kajian ini berasaskan kajian kes dengan menjadikan Sistem Pengurusan Pengajaran dan Pembelajaran Interaktif, UKM (SPIN) sebagai medium kajian. Dapatan kajian ini menyenaraikan 6 elemen nilai cipta-sama iaitu kawalan kendiri, berkebolehan, intelektual, cita-cita (kesungguhan), tanggungjawab dan saling bantu. Hasil kajian ini dipaparkan dalam bentuk matrik implikasi dan Rajah Hirarki Nilai (RHN). Sumbangan daripada kajian ini dapat membantu mengenal pasti elemen nilai cipta-sama yang diwakili oleh fitur kritikal seperti Lecture Notes, Annoucement dan Course Profile. Fitur kritikal ini berupaya memberi impak besar terhadap kejayaan sesebuah sistem pengurusan pembelajaran. Hasil kajian ini penting untuk dikembangkan sehingga terbina model generik berasaskan nilai cipta-sama. Kata kunci: Teknik laddering; sistem pengurusan pembelajaran; nilai cipta-sama; teori means-end; service dominant logic


2020 ◽  
Vol 08 (08) ◽  
pp. 36-44
Author(s):  
Zhengyang Qi ◽  
Yunsong Qi ◽  
Guangpeng Hu

Author(s):  
Nikolai Sergeevich Molokov ◽  
Gennadiy Petrovich Kicha ◽  
Andrei Veniaminovich Nadezkin

The article considers the rationality of combined lubricating oil cleaning system in the automatically operated marine diesel engines. The system includes a self-recovering filter and a self-cleaning centrifugal purifier. This combination is found to obtain resource-saving oil using coupled with minimum engine wear and increased reliability. The full-flow filtration of oil in a die-sel engine lubricating system is necessary to protect its friction couples (bearings) from abrasive wear. Centrifugal separation contributes deep oil purification i.e. removal of insoluble impurities reducing lubricating oil service life. By means of experimental simulation there has been found a minimum value of centrifugal purifier capacity index, when engine wear reaches the lowest level and keeps stable. The dependence of engine wear on the fuel quality and centrifugal purification intensity represented by centrifugal purifier capacity index is displayed. The adequacy variance was calculated, the adequacy of the found model being checked by using Fisher criterion. The experimental design and processing of the results have been carried out using orthogonal central composite plan of the second order. Specificity of polynomial when all the points of extremum show the minimum value of engine wear was presented. The model is designed to select the proper oil purifier for forced marine diesel engines with average and increased revolutions.


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