scholarly journals Method for assessing the technical condition of marine diesel engine driving the synchronous generator

2019 ◽  
Vol 177 (2) ◽  
pp. 139-144
Author(s):  
Tomasz KNIAZIEWICZ ◽  
Marcin ZACHAREWICZ

The paper presents an innovative method for assessing technical condition of a marine diesel engine that drives synchronous generator. It is based on the measurement and analysis of generators phase-to-phase voltage. Additionally, it requires the measurement of a pseudoperiodic signal [3] with a period equal to duration of engines working cycle. The basis for developing method was the assumption that rotational speed fluctuations of an engines crankshaft (and also the generator) depend on a course of a working process carried out in it. The generators phase-to-phase voltage is directly dependent on a rotational speed fluctuation of its rotor. It must therefore be possible to assess a course of a working process of an engine based on a voltage waveform of a synchronous generator that cooperates ogether.

2015 ◽  
Vol 236 ◽  
pp. 212-219
Author(s):  
Aleksy Cwalina ◽  
Tomasz Kniaziewicz ◽  
Marcin Zacharewicz

In the paper the first phase of a mathematical model construction of processes occurring in the cylinder during the working cycle of marine internal combustion engine is presented. The physical model of the mechanical and thermodynamic processes taking place when marine diesel engine drives a synchronous generator is described. In addition, assumptions of the mathematical model developed for marine engine diagnostics are discussed. The input parameters of the model and some simplifying assumptions have been presented. In parallel with the mathematical model, a computer program was created to facilitate carrying out the calculations. Descriptions of the mathematical model and a computer program are illustrated by means of graphs of selected parameters of combustion engine as a function of rotation angle of the crankshaft.


Author(s):  
A.V. Golenishev ◽  
A.V. Nadezkin ◽  
M.E. Starchenko

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.


Naše more ◽  
2021 ◽  
Vol 68 (2) ◽  
pp. 65-73
Author(s):  
Do Duc Luu ◽  
◽  
Nguyen Quang Vinh

After a long period of use, some important technical parameters of the main marine diesel engines (MDE) gradually become worse, such as the turbine speed, intake pressure, exhaust temperature, engine power, and specific fuel oil consumption (SFOC). This paper studies the affections of the turbine nozzle cross-sectional area (AT) to MDE and presents a method of AT adjustment to improve the performances of MDE. A mathematical model of an engine was built based on the existent engine construction and the theory of the diesel engine working cycle and the simulation was programmed by Matlab/Simulink. This simulation model accuracy was evaluated through the comparison of simulation results and experimental data of the MDE. The accuracy testing results were acceptable (within 5%). The influences of AT on the engine working parameters and the finding optimization point were conducted by using the simulation program to study. The predicted optimization point of the nozzle was used to improve the engine’s performances on board. The integration of the simulation and experiment studies showed its effectiveness in the practical application of the marine diesel engine field.


2021 ◽  
Vol 2131 (5) ◽  
pp. 052058
Author(s):  
O Roslyakova ◽  
V Zaitsev ◽  
D Panov

Abstract Nowadays, a lot is paid to environmental protection issues, including those related to reducing emissions from ships of the sea and river fleet, which is reflected in many works. Constant control over the content of harmful emissions in the environment forces us to deal with the issues of reducing emissions from diesel engines at the design stages and during operation. The solution to this problem allows us to consider 2 directions: constructional and the use of special equipment for capture and neutralization. In the best case, a combined method can be used, i.e. constructional with the use of capturing equipment for harmful components in diesel exhaust gases. This paper presents an analysis of the influence of various factors that reduce the load on the atmospheric air from nitrogen oxides of marine diesel engines, namely, from the operating settings of the diesel engine and its wear. On the ships of the river fleet, diesel engines are used with various mixture formation with volumetric, volumetric-film, vortex mixture formation. The leader in the listed group is the volumetric mixture engines. The paper provides an assessment of the research carried out to analyze various methods of influencing the working process of a diesel engine - the type of mixture formation, wear of the cylinder sleeve in order to determine their influence on the formation of NOx emissions.


2017 ◽  
Vol 6 (2) ◽  
pp. 93-108
Author(s):  
Andrzej Grządziela ◽  
Agata Załęska-Fornal ◽  
Marcin Kluczyk

The paper presents the results of simulation of marine diesel engine fuel injector malfunction and its effects on engine vibration. The work includes the analysis of the engine internal forces and their mathematical models. Simplifications are proposed to allow analyzing the system in one degree of freedom. The results of vibration simulations for the model with efficient fuel system and improperly adjusted injector are also presented. The comparison of simulation results with vibration measurements on the engine was also performed, the diagnostic model was identified and simulation errors were calculated. The complexity of other internal and external interactions is the subject of other studies by the authors. The paper analyzes only the effects of energy dissipation - vibration as a symptom of changes in the technical condition.


2020 ◽  
Vol 181 (2) ◽  
pp. 40-45
Author(s):  
Tomasz KNIAZIEWICZ ◽  
Marcin ZACHAREWICZ

The article presents a mathematical model of a marine diesel engine developed for the needs of the research on the innovative method of evaluating technical condition of a marine engine. Basic assumptions of the method under development have also been included. The main focus has been directed on the evaluation of adequacy of a mathematical model of a marine diesel engine proposed in this article. In addition, measures of adequacy for the needs of the conducted research have also been presented. A comparison of the results of empirical and modeling research was presented. Finally, the article shows results from the conducted research followed by conclusions.


2019 ◽  
Vol 177 (2) ◽  
pp. 122-126
Author(s):  
Rafał KRAKOWSKI

In the article, the concept of technical diagnostics in relation to marine engines was characterized. The compression ignition piston engine was presented as a diagnostic object. The next part of the article discusses the composition of exhaust gases with particular emphasis on compounds harmful to the environment. The available test methods for exhaust composition are also briefly described by means indication of the engine and exhaust gas analyzer. The reduction of emission of harmful compounds in the exhaust gases is also described in the article. The main part of the article presents the research object, i.e. the marine diesel engine piston and the exhaust gases analyzer, as well as tests carried out. The tests were performed for the engine in working order and inefficient condition in order to compare them with the simulated damages of injection pump and turbocharger. The article was completed conclusions.


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