scholarly journals Modelling of the fuel injection of medium speed marine diesel engines

2017 ◽  
Vol 170 (3) ◽  
pp. 139-146
Author(s):  
Jan MONIETA
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Working Cycle ◽  
Fuel Flow ◽  
Injection Pump ◽  
Medium Speed ◽  
Engine Cylinder ◽  
Crank Angle ◽  
Marine Diesel ◽  
Mathematical Relationships

The article presents the stages of fuel injection modeling of the four-stroke marine diesel engines as a set of functional blocks the of the fuel waves flow. The elaborated model includes the values of changing pressures in the combustion chamber and the course of changes of the pressure in spaces of the injection pump, injection pipe and the injector. Linear and local losses, as well as the conditions for the functioning were taken into account in stages of the fuel flow. The influence of different values of the engine load on the pressure course of the in individual spaces of injection apparatus and in the engine cylinder during the working cycle depending on the crank angle of rotation of the crankshaft have been simulated. The mathematical relationships were selected and the structural and experimental data are used, allowing the calculation of the parameters of interest for the simulated process.

scholarly journals Tribology in Marine Diesel Engines

2021 ◽  
Author(s):  
Sung-Ho Hong
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Tribological Performance ◽  
Engine Room ◽  
Medium Speed ◽  
Marine Engines ◽  
Marine Diesel ◽  
Power Outputs ◽  
Engine Components

This chapter deals with the tribology of marine diesel engines. Several types of diesel engines have been installed and used in the engine room of marine ships. Some of them, used for propulsion, operate at low-speed in a two-stroke combustion process in conjunction with propellers. Four-stroke engines are used for power generation and operates at medium-speed. In general, two or more four-stroke engines, including spares, are installed in the large ships. Tribological problems are important issue in the respect of reliability in the marine diesel engines, and there are many tribological engine components including bearings, pistons, fuel injection pumps and rollers. Moreover, the marine engines have lubricant problems such as lacquering. Improvements to the tribological performance of marine engine components, and lubricants can provide reduced oil and fuel consumption, improved durability, increased engines power outputs and maintenance. Therefore, this chapter shows better designs and methods in order to improve the tribological problem in the marine diesel engines.

scholarly journals Влияние износа плунжерных пар топливных насосов высокого давления на эксплуатационные показатели судовых дизелей

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
Keyword(s):  
High Pressure ◽  
Wear Resistance ◽  
Diesel Engines ◽  
Composite Coatings ◽  
Gas Temperature ◽  
Fuel Supply ◽  
Injection Pump ◽  
Medium Speed ◽  
Marine Diesel ◽  
Pump Plunger

Представлен обзор авторских исследований повышения долговечности плунжерных пар топливных насосов высокого давления (ТНВД) судовых дизелей и влияния их износа на эксплуатационные показатели двигателей, выполненных с 1990 по 2020 г., Уточнены факторы, влияющие на ресурсные показатели плунжерных пар ТНВД судовых мало- и среднеоборотных двигателей. Определены методы и возможности оценки износных показателей топливной аппаратуры. Приведен сравнительный анализ ресурсных возможностей плунжерных пар, восстановленных различными методами, и новых пар, изготовленных ведущими дизелестроительными фирмами, а также анализ влияния износов плунжерных пар топливных насосов высокого давления на эксплуатационные показатели судовых дизелей. Показано, что по мере изнашивания плунжерных пар ТНВД судовых средне- и малооборотных дизелей уменьшается цикловая подача топлива вследствие его протечек, при этом возрастает температура отходящих газов, что часто приводит к аварийным ситуациям. Для повышения эффективности эксплуатации и надежности дизелей нами разработана перспективная технология упрочнения, позволяющая увеличить износостойкость плунжерных пар ТНВД. Впервые показано, что плунжерные пары ТНВД, восстановленные нанесением износостойких хромовых покрытий, успешно конкурируют с серийными (плунжерами без покрытия), а в случае нанесения композиционных покрытий (хром-металлокерамика) – обеспечивают значительно большую износостойкость. Динамическая гидроплотность пар и соответственно цикловая подача топлива плунжерных пар с износостойким покрытием плунжера остается практически неизменной в течение более длительного времени (период стабильной динамической гидроплотности в среднем в 2–3 раза дольше, чем для пар без покрытия). Ключевые слова: дизель, плунжерная пара, износ, отказ, цикловая подача топлива, температура отходящих газов, хром-металлокерамическое покрытие An overview of the author's studies focused on increasing the durability of plunger pairs of highpressure fuel pumps of marine diesel engines and the effect of their wear on engine performance is presented, made from 1990 to 2020. The factors affecting the resource indicators of the plunger pairs of high-pressure fuel pumps of marine low- and medium-speed engines have been clarified. Methods and possibilities for assessing wear indicators of fuel equipment are determined. A comparative analysis of the resource capabilities of plunger pairs, restored by various methods, and new pairs, manufactured by leading diesel-building companies, as well as an analysis of the effect of wear of plunger pairs of high-pressure fuel pumps on the performance of marine diesel engines is presented. It is shown that as the plunger pairs of high-pressure fuel pumps of marine medium- and low-speed diesel engines wear out, the cycle fuel supply decreases due to its leaks, while the temperature of the exhaust gases rises, which often leads to emergency situations. To increase the efficiency of operation and reliability of diesel engines, we have developed a promising hardening technology, which makes it possible to increase the wear resistance of the injection pump plunger pairs. It has been shown for the first time that high-pressure fuel pump plunger pairs, restored by applying wearresistant chromium coatings, successfully compete with serial (uncoated plungers), and in the case of applying composite coatings (chromium + cermet), they provide significantly higher wear resistance. The dynamic hydraulic density of the steam and, accordingly, the cyclic fuel supply of plunger pairs with a wear-resistant plunger coating remains practically unchanged for a longer time (the period of stable dynamic hydraulic density is on average 2–3 times longer than for uncoated steam). The conditions of operation of precision parts of the fuel equipment of marine low and medium speed engines are described. The factors influencing the service life of the plunger pairs are given. Methods and possibilities for assessing the wear indicators of fuel equipment are determined. Keywords: diesel, plunger pair, wear, failure, cyclic fuel supply, exhaust gas temperature, cover

scholarly journals APPLICABILITY STUDY OF THE FIBER-OPTIC GYRO IN PISTON ENGINES DIAGNOSING PROCESS

2014 ◽  
Vol 46 (1) ◽  
pp. 40-50
Author(s):  
Tomasz Lus ◽  
Marek Łutowicz ◽  
Dominika Cuper
Keyword(s):  
Diesel Engines ◽  
Rotation Speed ◽  
Angular Speed ◽  
Naval Academy ◽  
Medium Speed ◽  
Engine Cylinder ◽  
Diagnostic Decision ◽  
Marine Diesel ◽  
The Difference ◽  
The One

The Polish Naval Academy has been involved in marine reciprocating combustion engines indication tests for many years. Results of researches aiming to diagnostic using of measurement of engine crankshaft unsteady angular speed are presented in the paper. Up to now, adequate accuracy of angular speed measurement had not been achieved to make proper diagnostic decision. Commercially, measurement of unsteady rotation speed has been used only in MAPEX –TV system (Torsional Vibration detector) dedicated to SULZER engines, which can detect only the one engine cylinder switch out of work without any mistakes. For several years, mostly in navigation, more often are used optic gyroscopes which work on the base of Sagnac effect, assuring angular speed measurements with resolution of 0.001o/h. Such resolution is too high than needed in piston engines diagnostic, but range of measured rotation speed is much much lower than rpm of medium-or low-speed marine diesel engines. In scope of conducted research it was decided to build a model of Sagnac interferometer prepared to measure of instantaneous angular speed in range adequate to medium speed marine diesel engines. At rotational crankshaft speed equal 750 rpm 1mV change in output voltage had been achieved for the difference of 0,4 o/sec of rotational speed. Time of measurement is equal the time which need light ray to go through distance of 100 m fibber-optic line. In practice this method do not introduce any significant phase shifts and does not limit the number of samples per revolution.

scholarly journals Marine diesel engines operating cycle simulation for diagnostics issues

2021 ◽  
Vol 61 (3) ◽  
pp. 435-447
Author(s):  
Dmytro S. Minchev ◽  
Roman A. Varbanets ◽  
Nadiya I. Alexandrovskaya ◽  
Ludmila V. Pisintsaly
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Maximum Pressure ◽  
Compression Pressure ◽  
Operating Cycle ◽  
Engine Operation ◽  
Cycle Simulation ◽  
Engine Cylinder ◽  
Marine Diesel ◽  
On Line

The ongoing monitoring of marine diesel engines helps to detect the deviations of its parameters early and prevent major failures. But the experimental diagnostics data are generally limited, so frequently, it isn’t possible to get all the necessary information to make a clear decision. The mathematical simulation could be used to clarify the experimental data and to provide a deeper understanding of engine conditions. In this paper, the MAN 6L80MCE marine diesel engine of “Father S” bulk carrier diagnostics issues are considered. The diagnostics data were collected with DEPAS Handy equipment and present the information about indicated processes by every engine cylinder. The on-line resource Blitz-PRO was used for the simulation of the engine operation and helped to prove that the variation in exhaust valve’s closing timing is responsible for the observed compression pressure difference, while the irregularity in fuel injection causes the considerable difference in the maximum pressure.

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