Multi-Field Coupling Modeling and Analysis for Cylinder Liner of Slow Speed Two Stroke Marine Diesel Engine

2014 ◽  
Vol 1070-1072 ◽  
pp. 1856-1860
Author(s):  
Hui Xing ◽  
Lei Guo ◽  
Ji Wu

To predict accurately the stress and deformation of combustion chamber components of large slow speed two stroke marine diesel engines, based on AVL Fire and ANSYS Workbench software, multi-field coupling modeling and analysis technology was employed to carry out the strength analysis for combustion chamber components of crosshead type marine diesel engine. The boundary conditions, i.e., the temperature field distribution, the mean temperature and the mean heat transfer coefficient are obtained firstly. Then the strength analysis for cylinder liner of crosshead type marine diesel engine under the thermal loads, mechanical loads and thermal mechanical coupled loads was conducted. The results show that the strength meets the design requirement and the stress concentration and the deformation of the cylinder liner were mainly dependent on the thermal load.

Author(s):  
Nader R. Ammar

Marine diesel engines are facing challenges to cope with the emission-reduction regulations set by the international maritime organization (IMO). Hydrogen fuel is one of the alternative fuels which can be used to reduce the exhaust gas emissions from ships. The current paper investigates the effect of using diesel-hydrogen dual fuels on the environmental, energetic and exergetic performance parameters of slow speed marine diesel engine. The investigation is performed using Engineering Equation Solver (EES) software package. As a case study, slow speed diesel engine has been investigated. The results obtained revealed that the energetic and exergetic parameters are influenced by engine load and hydrogen substitution percent. The exergy efficiency is increased by 3.65%, 8.20%, 13.99%, and 21.7% for the hydrogen substitution percentages of 10%, 20%, 30%, and 40%, respectively compared with the diesel engine at full load. Environmentally, CO and CO2 emissions are reduced and NOx emissions are increased as the hydrogen energy content increases. Dual fuel engine with input hydrogen energy fractions of 10% and 20% will comply with the required NOx emission regulations set by IMO after using selective catalytic reduction (SCR) system. It will comply with the required regulations with relative percentages of 96.4% and 98.4%, respectively.


Author(s):  
Б.И. Руднев ◽  
О.В. Повалихина

Температура пламени и степень черноты определяют его собственное излучение. Однако оценка указанных параметров на стадии проектирования судовых дизелей представляет собой трудную и еще пока нерешенную проблему. Последнее обусловливается сложностью достоверного математического моделирования процесса сгорания топлива в дизельных двигателях и весьма высокой стоимостью экспериментальных исследований в этой области. Целью данной статьи является разработка расчетно-экспериментального метода определения параметров излучения пламени в камере сгорания судового дизеля 6 ЧН 24/36. Показано, что оценка величины температуры пламени в камере сгорания в функции угла поворота коленчатого вала может быть выполнена по температуре газов, найденной из экспериментальной или расчетной индикаторной диаграммы и специального параметра. Последний определяется на основании зависимости, полученной путем обобщения экспериментальных данных по измерениям температуры пламени на ряде дизельных двигателей. Представлены результаты по температуре пламени для судового дизеля 6 ЧН 24/36, полученные с использованием разработанного расчетно-экспериментального метода. Установлено, что с ростом нагрузки температура пламени возрастает. При этом в диапазоне изменения нагрузки дизеля от 50% до 100% от номинальной мощности увеличение температуры пламени примерно в два раза превышает увеличение температуры газов. Использование полученных результатов для оценки собственных потоков излучения пламени в камере сгорания судового дизеля 6 ЧН 24/36 и сопоставление их с известными экспериментальными данными показало сходимость в пределах 10 – 15%. The flame temperature and radiating power are determined with its own radiation. However, the assessment of these parameters at the design stage of marine diesel engines is a complicated and still unsolved problem. The latter is due to the complexity of reliable mathematical modeling of the fuel combustion process in diesel engines and the very high cost of experimental research in this area. The purpose of this article is to develop a computational and experimental method for determining the parameters of flame radiation in the combustion chamber of marine diesel engine 6 ChN 24/36. It is shown that the estimation of the value of flame temperature in the combustion chamber as a function of the crankshaft rotation angle can be performed using the gas temperature found from the experimental or calculated indicator diagram and a special parameter. The latter is determined on the basis of the dependence obtained by generalizing experimental data of the flame temperature measurements at a number of diesel engines. The results on the flame temperature for marine diesel engine 6 ChN 24/36, obtained using the developed computational and experimental method, are presented. It has been found that the flame temperature increases with increasing load. At the same time, in the range of diesel load variation from 50% to 100% of the nominal power, an increase in the flame temperature is approximately twice more than an increase in the gas temperature. The use of the results obtained to assess the intrinsic fluxes of flame radiation in the combustion chamber of marine diesel engine 6 ChN 24/36 and their comparison with the known experimental data showed the convergence within 10 - 15%.


2012 ◽  
Vol 2 (4) ◽  
pp. 239-243
Author(s):  
Jae-Hyun Jeong ◽  
Jong-Sun Kim ◽  
Yeon-Chang Lee ◽  
Sung-Yul Lee ◽  
Kyung-Man Moon ◽  
...  

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