MATHEMATICAL MODELLING OF FOUR STROKE DIESEL GENERATOR


Thesis Type: Postgraduate

Institution Of The Thesis: Yildiz Technical University, Naval Architecture and Maritime Faculty, Deparment of Naval Architecture and Marine Engineering, Turkey

Approval Date: 2018

Thesis Language: Turkish

Student: DİDEM GÜLŞEN KAYIŞOĞLU

Consultant: Aykut Safa

Abstract:

The industrialization process is one of the most basic parameters that allows the
continuous development of information and technology, with one of the most
important parameters of economic development from the past to the present day. The
increase in technological developments has gained momentum due to radical changes
in the industrialization process from the world past to the present day. Hence, the
measurement of the superiority of economic comparisons of developed countries in
terms of industry is now based on the development of technological structures.
The internal combustion engines examined in this thesis are; among the most
important inventions that have been invented from the past to the present day.
Internal combustion engines are frequently used in maritime, sea and railway
transport and in the industrial sector, and also contain very complex parameters from
engineering point of view.
For example; the most important equipments in the engine room must be firstly
operated and maintained under proper conditions so that failures that may result in
the failure or failure of a significant breakdown operation that may occur during the
dispatch of ship may occur in the main engine, generator or engine room. Working
with main engine and generator during operation; System components such as T / C
turbine, T / C compressor, lubrication and cooling systems, etc. are available. The

problems that may occur in these systems or components directly affect the dispatch
of the ship.
This thesis is a mathematical model of a four-stroke diesel engine; It involves modeling
the process from T / C compressor exhaust air through the air inlet to the outet of T / C
turbine exhaust gases from turbine wheels. In order to be able to carry out
calculations, it is assumed that the cylinder gases fit the ideal gas law and there are no
leaks or backflows. Based on the principle of conservation of mass and energy, the
modeling concept was created by using the single-zone thermodynamic model and the
Wiebe Burning Rate function on the temperature and pressure changes on the cylinder
gases (air, fuel, burnt gas) of the chemical energy contained in the fuel sprayed after
being taken into the air cylinder. T / C compressor, scavenge manifold, intake port, incylinder processes (compression, spray, ignition delay, combustion, expansion exhaust,
filler change), exhaust manifold, T / C turbine are modeled as separate subsystems.
The interworking of all these systems and components is modeled dynamically based
on the change in crankshaft angle.
The modeling was created and controlled on excel. The crank angle is taken as a
reference, the transition of the crank angle is provided and the whole system and the
subsystems are operated together by transferring data to one of the models included
in the system.
The diesel engine modeled; YANMAR 6EY22ALW Type is a six-cylinder four-stroke
diesel engine. Constant parameters such as cylinder diameter, stroke length, suction
port opening time, connecting rod length were taken from the engine technical
catalog. Values such as T / C compressor and scavenger manifold pressure values, time
of maximum pressure build up, T / C turbine information, number of revolutions and
fuel consumption in variable states are obtained by taking the test data of the variable
state of the engine. Variation of pressure and temperature values in cylinder, pressure
and temperature values of exhaust manifold, power generated by T / C Turbine, power
of scavenger manifold pressure and crankshaft power were calculated by operating
the created model at different loads. A change in the amount of fuel supplied to the
machine during the operation of the machine has led to a study in which changes to
the main engine can be monitored.