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1

Research on the effect of low-sulphur marine fuels on the dynamic characteristics of a CI engine

Korczewski Zbigniew

Combustion Engines

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2023

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R. 62, nr 3

97--103

EN

The implementation of low-sulphur, so-called modified marine fuels into operation requires prior laboratory engine tests to assess the energy, emission and structural effects of their usage. This type of research are carried out on the test bed of a diesel engine as a small-scale physical model that reproduces the adequate design and process (parametric) features of a full-size marine engine. Their key stage is to determine the energy characteristics of the engine in the steady state of operation determined on the basis of the analysis of the developed indicator diagram and the dynamic characteristics of the transient processes from idling to the reference steady state of load - and vice versa. In this way, the basic diagnostic parameters of the fuel usable quality are determined: the rate of pressure increase in the cylinder and the average deceleration of the engine crankshaft within the strenuous transient process. This article presents representative results of this type of research carried out on six different, low-sulphur marine fuels used to feed marine engines.

2

Energy and emission quality ranking of newly produced low-sulphur marine fuels

Korczewski Zbigniew

Polish Maritime Research

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2022

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nr 4

77--87

EN

The article describes the methodology of engine tests on new types of low-sulphur marine fuels in laboratory conditions in order to conduct a comprehensive assessment of their suitability for powering full-size marine engines. The innovativeness of the proposed solution consists of adapting the laboratory Diesel Engine Test Bed to carry out experimental tests using residual and alternative fuels so that it is possible to imitate the real operating conditions of the ship engine. The main aim of the research program was to assess the energy efficiency of six different low-sulphur marine fuels and their impact on the chemical emissivity of engine exhaust gases and air pollution with toxic and harmful chemical compounds. In order to achieve the research purpose formulated in this way, it was necessary to: (1) equip the constructed laboratory stand with highly specialised measuring equipment and (2) develop a technology for determining diagnostic parameters representing the basis for developing a ranking of the energy and emission quality of the tested marine fuels according to the proposed physical model. The model distinguishes 10 diagnostic parameters that, after normalisation, form two subsets of evaluation parameters - stimulant and destimulant. Determining their values made it possible to estimate a synthetic variable, according to which all the tested fuels were adjusted in the order from the “best” to the “worst”, in accordance with the adopted qualitative criteria of such an assessment. The results of the laboratory tests show that among the considered fuels, i.e., MDO, MGO, RMD 80/L, RMD 80/S, RME 180, and RMG 380 type, the best solution is to use MDO distillate fuel to power full-size marine engines. However, taking into account its high purchase price, a rational alternative decision is to choose RMG 380 type residual fuel, which ranks second in the ranking of the functional quality of the tested marine fuels.

3

Program badań diagnostycznych modelu turbozespołu wiatrowego w małej skali

Korczewski Zbigniew

Journal of Polish CIMEEAC

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2022

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Vol. 17, no 1

58--65

PL

W artykule przybliżono wybrane problemy eksploatacyjne morskich turbozespołów wiatrowych uzasadniających podjęcie badań diagnostycznych na modelu w małej skali w zakresie identyfikacji symptomów i syndromów najczęściej występujących uszkodzeń ich układów mechanicznych. W zaproponowanym programie badań eksperymentalnych przyjęto koncepcję obserwacji realizowanych procesów energetycznych: podstawowych i towarzyszących, przy zastosowaniu metod tensometrycznych, optoelektronicznych, wibroakustycznych oraz termowizyjnych. Przedstawiono schemat ideowy budowanego stanowiska laboratoryjnego turbozespołu wiatrowego napędzanego generatorem strumienia powietrza (wiatru) o regulowanej wydajności. Przewiduje się możliwość faktycznego wprowadzania zmian w strukturze konstrukcyjnej turbozespołu, odwzorowujących znane i rozpoznawalne stany niezdatności eksploatacyjnej charakterystyczne dla konstrukcji morskich. Relacje diagnostyczne wyznaczane na drodze realizacji eksperymentów czynnych stanowić będą dane wejściowe dla systemu ekspertowego wspierającego proces wnioskowania o stanie technicznym testowanego turbozespołu wiatrowego. Istnieje możliwość przeniesienia wyników badań modelowych na obiekty rzeczywiste - pełnowymiarowe turbozespoły wiatrowe.

4

Test method for determining the chemical emissions of a marine diesel engine exhaust in operation

Korczewski Zbigniew

Polish Maritime Research

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2021

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nr 3

76--87

EN

The article briefly describes the problem of air pollution caused by sea-going ships and the resulting restrictions on the emission of toxic and harmful chemical compounds in the exhaust of marine engines, introduced by the International Maritime Organization (IMO) under the International Convention for the Prevention of Sea Pollution from Ships (MARPOL 73/78). Such emissions provide a significant metrological problem, not only for the owners of operating seagoing ships, but also for shipyards, maritime administration offices and environmental protection inspectors. For this reason, the article’s author is developing research issues related to the diagnosing the exhaust emissions of marine engines under operating conditions, i.e. with limited control (measurement) susceptibility. This is particularly important in the period of intensive implementation of a new category of marine fuel, so-called modified fuels with low sulphur content. As part of the problem, a computational model of the parameters characterising the exhaust emissions of a marine engine in operation is presented in this article. This model is based on the measurement of the engine’s control parameters, using a standard (stationary) measurement system and a portable diagnostic system, configured for the purpose of this research. Presented here are representative measurements and calculation results (both obtained by the author and provided by the manufacturer) from the chemical exhaust gas emissivity of one of the ship engines operated. These confirm the adequacy of the calculation model developed and the diagnostic effectiveness of the measuring equipment applied. The methodology developed for experimental testing may also be implemented for the operation of other types of marine engines, provided that the basic chemical composition of the fuel supply and the engine load characteristics and hourly fuel consumption are known. Moreover, there is the possibility of indicating the cylinders and measuring the chemical composition of exhaust gases in the high-temperature part of the exhaust duct.

5

Energy analysis of the propulsion shaft fatigue process in a rotating mechanical system part iii dimensional analysis

Korczewski Zbigniew, Marszałkowski Konrad

Polish Maritime Research

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2021

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nr 2

72--77

EN

This article presents the third and last part of the problem of diagnosing the fatigue of marine propulsion shafts in terms of energy with the use of the action function, undertaken by the authors. Even the most perfect physical models of real objects, observed under laboratory conditions and developed based on the results of their research, cannot be useful in diagnostics without properly transferring the obtained results to the scale of the real object. This paper presents the method of using dimensional analyses and the Buckingham theorem (the so-called π theorem) to determine the dimensionless numbers of the dynamic similarity of the physical model of the propulsion shaft and its real ship counterpart, which enable the transfer of the results of the research on the energy processes accompanying the ship propulsion shaft fatigue from the physical model to the real object.

6

Cel funkcjonowania, zadania i obszary badawcze Centrum Morskiej Energetyki Wiatrowej Politechniki Gdańskiej

Korczewski Zbigniew

Journal of Polish CIMEEAC

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2021

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Vol. 16, no 1

57--62

PL

W artykule przybliżono wybrane aspekty funkcjonowania Centrum Morskiej Energetyki Wiatrowej w Politechnice Gdańskiej. Scharakteryzowano główne zadania Centrum oraz wstępnie zdefiniowane obszary badawcze, w których specjalizują się naukowcy reprezentujący niemal wszystkie wydziały akademickie Uczelni (oprócz Wydziału Architektury). Przedstawiono kierunki działania Centrum w perspektywie kilku najbliższych lat, w wyniku których nastąpi weryfikacja i konieczne doprecyzowanie obszarów badawczych, zgodnie z oczekiwaniami inwestorów morskich farm wiatrowych budowanych w polskiej wyłącznie strefie ekonomicznej Morza Bałtyckiego.

7

Methodology for determining the elemental composition, as well as energy and ignition properties of the low-sulfur marine fuels

Korczewski Zbigniew

Combustion Engines

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2021

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R. 60, nr 3

96--102

EN

The key metrological issue of substance and energy balance in research engines is the precise determination of the elemental composition of the applied fuel and its net calorific value. This makes it possible to calculate the amount of heat brought with the fuel into the combustion chamber, as well as the amount and gas composition of the exhaust. However, to fully assess the energy quality of the fuel used, its ignition properties should also be estimated. They determine the combustion kinetics and, consequently, the course of gas pressure alterations and heat release in the cylinder, which have a direct impact on the indicated power and thermal efficiency of the engine. This article presents the methodology for carrying out this type of laboratory tests and their representative results concerning six different low-sulfur marine fuels used to feed marine engines at present. The considerations focus mainly on measurement technology, as well as the measuring apparatus applied today. Additionally some existing metrological difficulties that might be met were shortly described. The laboratory tests in question stand for the first stage of the program of testing a new kind of low-sulfur marine fuels in real operating conditions of a diesel engine, which was carried out at the Department of Ship Power Plants of the Gdańsk University of Technology.

8

Energy analysis of the propulsion shaft fatigue process in a rotating mechanical system. Part II. Identification studies – developing the fatigue durability model of a drive shaft

Korczewski Zbigniew, Marszałkowski Konrad

Polish Maritime Research

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2020

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nr 2

120--124

EN

The article presents a continuation of research carried out concerning identification of energy consequences of mechanical fatigue within a propeller shaft in a rotating mechanical system, while working under conditions of the loss of the required alignment of shaft lines. Experimental research was carried out on a physical model reflecting a full-sized real object: i.e., the propulsion system of the ship. It is proven, by means of an active experiment, that changes in propeller shaft deflection are reflected in the amount of dissipated kinetic energy of masses in rotational motion and the accumulated internal energy in its construction material. Adoption of a high-cycle fatigue syndrome, consisting of diagnostic symptoms determined from the action of the propeller shaft associated with the transformation of mechanical energy into work and heat, as well as with the generation of mechanical vibrations and elastic waves of acoustic emission, is proposed. To assess the diagnostic information quantity brought about by the defined features of propeller shaft fatigue, an experimental research program was developed and implemented, in which two statistical hypotheses are verified: the significance of the impact of the values enforcing the fatigue process, presented in the first part of the article, and the adequacy of the regression equation describing the fatigue durability of the propeller shaft in the energy aspect, constituting the second part of the article. This finally gives us the opportunity, after the appropriate translation of the model test results into full-sized real objects, to develop a methodology to diagnose marine propeller shaft fatigue in operating conditions. The third part of the article is devoted to this issue

9

Koncepcja diagnozowania gniazd zaworów cylindrowych silników okrętowych w eksploatacji

Korczewski Zbigniew

Journal of Polish CIMEEAC

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2020

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Vol. 15, no 1

62--70

PL

W artykule przybliżono fizykę uszkodzeń eksploatacyjnych zaworów cylindrowych silników okrętowych oraz technologię ich naprawy. Zaprezentowano system diagnozujący tego typu silników, który znajduje się na wyposażeniu bazy laboratoryjnej Katedry Siłowni Morskich i Lądowych WOiO PG. Umożliwia on przeprowadzenie kompleksowej oceny stanu technicznego przestrzeni roboczych silników zabudowanych w siłowni okrętowej w bieżącej eksploatacji. Zaproponowano schemat organizacji badań zaworów cylindrowych z wykorzystaniem posiadanego systemu diagnozującego dla potrzeb dokonania oceny skuteczności zaadaptowanej technologii naprawy gniazd zaworowych.

10

Przegląd działalności naukowo-dydaktycznej Katedry Siłowni Morskich i Lądowych Wydziału Oceanotechniki i Okrętownictwa Politechniki Gdańskiej

Korczewski Zbigniew

Journal of Polish CIMEEAC

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2019

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Vol. 14, no 1

7--20

PL

W artykule zaprezentowano profil statutowej działalności Katedry Siłowni Morskich i Lądowych Wydziału Oceanotechniki i Okrętownictwa Politechniki Gdańskiej w zakresie badań naukowych oraz dydaktyki. Przybliżono, specyfikę funkcjonowania Katedry, którą tradycyjnie charakteryzują bliskie związki z marynarką wojenną(początkowo niemiecką, a następnie polską), dla której zawsze stanowiła ważne zaplecze intelektualne i laboratoryjne, podczas realizacji podejmowanych zadań inwestycyjnych, modernizacyjnych i szkoleniowych. Miało to również swoje odzwierciedlenie w obsadzie stanowiska kierownika Katedry, które często powierzano profesorom wywodzącym się z korpusu oficerskiego marynarki wojennej. Omówiono zagadnienia naukowe, które są od lat rozwijane, w trzech zasadniczych kierunkach badawczych: projektowania, technologii wytwarzania i eksploatacji maszyn i urządzeń zabudowanych w siłowniach okrętowych i lądowych, a także w siłowniach różnego rodzaju obiektów oceanotechnicznych. W ostatnich dwóch dekadach wiodącym kierunkiem badań naukowych była diagnostyka techniczna silników okrętowych–tłokowych i turbinowych, głównie eksploatacyjna: cieplno-przepływowa i drganiowa, którą ostatnio rozszerzono o badania identyfikacyjne procesu emisji spalin. Projekty naukowo-badawcze, realizowane w tym zakresie od 2015 roku dotyczyły opracowania innowacyjnej metody suchej odsiarczania spalin silników okrętowych zasilanych paliwami pozostałościowymi, a także metody testowania modyfikowanych paliw żeglugowych w rzeczywistych warunkach pracy silnika Diesla. Stanowiska laboratoryjne, zaprojektowane i zbudowane w ramach projektów są sukcesywnie rozwijane i przystosowywane do nowych tematów badań naukowych, jak również dla potrzeb zajęć dydaktycznych. W artykule scharakteryzowano dodatkowo działalność dydaktyczną Katedry w zakresie prowadzonych na Wydziale kierunków studiów: „oceanotechnika”, „energetyka”, „transport”, „techniki geodezyjne w inżynierii” oraz uruchomionego w bieżącym roku akademickim: „inżynieria morska i brzegowa”. Aktualne obciążenie dydaktyczne nauczycieli akademickich Katedry wynosi 3350godzin(2500 godzin etatowych), co stanowi 12% ogólnej (sumarycznej) liczby godzin dydaktycznych realizowanych na Wydziale.

11

Thermal efficiency investigations on the self-ignition test engine fed with marine low sulfur diesel fuels

Korczewski Zbigniew

Combustion Engines

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2019

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R. 58, nr 3

15--19

EN

Within the article an issues of implementing the new kinds of marine diesel fuels into ships’ operation was described taking into account restrictions on the permissible sulphur content introduced by the International Maritime Organization. This is a new situation for ship owners and fuel producers, which forces the necessity to carry out laboratory research tests on especially adapted engine stands. How to elaborate the method enabling quality assessment of the self-ignition engine performance, considered in three categories: energy, emission and reliability, represents the key issue of the organization of such research. In the field of energy research, it is necessary to know the thermal efficiency of the engine as the basic comparative parameter applied in diagnostic analyzes and syntheses of sequentially tested marine diesel fuels. This type of scientific research has been worked out for two years in the Department of Marine and Land Power Plants of the Gdańsk University of Technology, as a part of the statutory activities conducted in cooperation with the Regional Fund for Environmental Protection in Gdansk and the LOTOS Group oil company. This article presents the algorithm and results of thermal efficiency calculations of the Farymann Diesel D10 test engine in the conditions of feeding with various low-sulfur marine diesel fuels: distillation and residual fuels. This parameters stands for one of ten diagnostic measures of the ranking of energy and emission quality of newly manufactured marine diesel fuels being built at the Department.

12

The method of energy-efficiency investigations of the newly produced marine fuels through an application of the laboratory diesel engine

Korczewski Zbigniew

New Trends in Production Engineering

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2018

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Vol. 1, Iss. 1

357--363

EN

The article deals with one of the scientific issue solved within frames of the research project financed by Voivodeship Fund for Environmental Protection and Water Management in Gdansk, namely, in particular, the method of energy investigations of the self-ignition engine in conditions of its supply with a non-standard (modified) marine fuel. The representative results of engine tests worked out on the especially built laboratory test bed have been presented. They aimed to elaborate energy profiles of a single-cylinder four-stroke Diesel engine in the form of Sankey diagrams of energy flows representing the most efficient and effective manner for the verification of a different kind of the modified marine fuels introduced on market. It is expected that the final results of the project will be interesting for their producers as well as the ship-owners of the operated ships, and also for the offices of sea administration as well as the inspectorates of environment protection.