Digital evaluation of the accuracy and sensitivity of a mathematical model of a slow speed marine diesel engine

Author(s):  
Hristo Milushev
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.


2021 ◽  
Author(s):  
Marcin Zacharewicz ◽  
Tomasz Kniaziewicz

The paper presents the results of model and empirical tests conducted for a marine diesel engine fueled by a blend of n-butanol and diesel oil. The research were aimed at assessing the usefulness of the proprietary diesel engine model in conducting research on marine engines powered by alternative fuels to fossil fuels. The authors defined the measures of adequacy. On their basis, they assessed the adequacy of the mathematical model used. The analysis of the results of the conducted research showed that the developed mathematical model is sufficiently adequate. Therefore, both the mathematical model and the computer program based on it will be used in further work on supplying marine engines with mixtures of diesel oil and biocomponents.


1993 ◽  
Vol 28 (4) ◽  
pp. 286-293
Author(s):  
Tadahiro Kurosawa ◽  
Katsuharu Kobori ◽  
Kaname Tanaka ◽  
Yoshikazu Nagai

2015 ◽  
Vol 799-800 ◽  
pp. 870-875
Author(s):  
Sunarsih ◽  
Izzuddin Nur ◽  
Agoes Priyanto

As the vessel operates in the rough open seas, a marine diesel engine simulator which engine rotation is controlled to transmit through propeller shaft is a new methodology for the self-propulsion tests to track the fuel saving in a real time. Considering the circumstance, this paper presents the real time of marine diesel engine simulator system to track the real performance of a ship through computer-simulated model. A mathematical model of marine diesel engine and the propeller are used in the simulation to estimate fuel rate, engine rotating speed, thrust and torque of the propeller thus achieve the target vessel’s speed. The input and output are real time control system of fuel saving rate and propeller rotating speed representing the marine diesel engine characteristics. The self-propulsion test simulation results in calm water [7] were compared to validate the present marine diesel engine simulator. The present simulator then was used to evaluate the fuel saving by employing a new mathematical model of turbocharged marine diesel engine and was applied to a full scale target vessel. The control system developed will be beneficial for users as to analyze different condition of vessel’s speed to obtain better characteristics and hence optimize the fuel saving rate.


2012 ◽  
Vol 152-154 ◽  
pp. 1057-1062
Author(s):  
Guo Jin Chen ◽  
Zhang Ming Peng ◽  
Jian Guo Yang ◽  
Qiao Ying Huang

This paper establishes the mathematical model of the piston ring’s wearing capacity for the marine diesel engine, studies the influence of the piston ring’s axial motion and radial motion to the magnetic field’s output signal, computes and analyzes the corresponding relationships of the magnetoresistive sensor’s output and the piston ring’s wearing capacity, and does the on-board experiment on the oil tanker with the 6RTA52U diesel engine. Measuring actually the magnetoresistive sensor’s output corresponding to the piston ring’s wearing capacity of the marine diesel engine confirms the correctness for the mathematical model of the wearing capacity. The research conclusions lay the technical foundation for the online monitor of the piston ring’s wear.


2021 ◽  
Vol 28 (4) ◽  
pp. 63-87
Author(s):  
Mohammad Hossein Ghaemi

Abstract To analyse the behaviour of marine diesel engines in unsteady states for different purposes, for example to determine the fuel consumption or emissions level, to adjust the control strategy, to manage the maintenance, etc., a goal-based mathematical model that can be easily implemented for simulation is necessary. Such a model usually requires a wide range of operating data, measured on a test stand. This is a time-consuming process with high costs and the relevant data are not available publicly for a selected engine. The present paper delivers a rapid and relatively simple method for preparing a simulation model of a given marine diesel engine, based only on the widely available data in the project guides indicated for steady state conditions. After establishing the framework of the mathematical model, it describes how the parameters of the model can be adjusted for the simulation model and how the results can be verified as well. Conceptually, this is a trial and error method, but the presented case example makes clear how the parameters can be selected to reduce the number of trials and quickly determine the model parameters. The necessary descriptions are given through a case study, which is the MAN-B&W 8S65ME-C8 marine diesel engine. The engine is assumed to be connected to a constant pitch propeller. The presented mathematical model is a mean-value zero-dimensional type with seven state variables. The other variables of the engine are determined based on the state independent variables and the input value, which is the fuel rate. The paper can be used as a guideline to prepare a convenient mathematical model for simulation, with the minimum publicly available data.


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