Wyniki wyszukiwania - BazTech

1

Estimating the main dimensions of the ship’s hull

Charchalis A.

Journal of KONES

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2018

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Vol. 25, No. 2

75--80

EN

Preliminary ship owner's assumptions for new ship consist of deadweight, speed-shipping line and others. Taking it as a base, in early stage of design one has to select propulsion type. This goal needs definition of principal dimensions of a vessel, which are the base for further calculations of hull’s resistance and evaluation of necessary power of main engine to fulfil shipping requirements. Selection of main dimensions of vessel is limited by rules regarding buoyancy, stability, hull strength, manoeuvring capability, and limitations related to seaways or harbours characteristic. In this article is presented the methodology of calculation of principal parameters of a vessel, necessary for calculation of displacement in relation to vessel’s type, volumetric coefficients, Froude number, and others values affecting ship’s dimensions. It is about midship section coefficient, waterline coefficient, prismatic coefficient. Those values are necessary for calculation of hull resistance. In the article, are presented major constraints for designing of new vessels coming from ship-owner assumptions such as seafaring limitations. In the table is presented comparison of results of calculations above-mentioned values of three type of vessels representing same displacement. There are also presented different calculation methods of transverse midship section coefficient and wet area coefficient, for 3 types of vessels (container vessel, bulk carrier and tanker with displacement of 120000 t.

2

COGES as a future of marine propulsion plants

Cwilewicz R., Górski Z.

Zeszyty Naukowe Akademii Morskiej w Gdyni

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2014

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nr 84

5--13

EN

The paper presents results of analysis concerning type of seagoing ships propulsion plants concerning efficiency, kind of fuel used and influence of propulsion plant operation on marine environment. Application of innovatory combined turbine propulsion plants where gas turbines are thermodynamically connected with steam turbines allows achievement of high efficiency about 60%. Modern design of turbines and using natural gas as a fuel are very important. Gas fuel is characterised by lowered harmfulness for environment than traditional heavy fuel oil. Particularly gas fuel does not contain sulphur and gas fuel exhaust gases are free of solid particles. Additionally calorific value of gas fuel is 25% higher than heavy fuel oil thus the amount of exhaust gases and carbon dioxide emitted to atmosphere are reduced.

3

Designing constraints in evaluation of ship propulsion power

Charchalis A.

Journal of KONES

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2013

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Vol. 20, No. 1

29--34

EN

Preliminary ship owners' assumptions for new ship consist of deadweight (for container vessel load capacity TEU), speed shipping line and others. Taking it as a base, in early stage of design one has to select propulsion type. This goal needs definition of principal dimensions of a vessel, which are the base for further calculations of hull’s resistance and evaluation of necessary power of main engine (engines) to fulfil shipping requirements. Selection of main dimensions of vessel is limited by rules regarding buoyancy, stability, hull strength, manoeuvring capability, and limitations related to seaways or harbours characteristic. In this paper is presented the methodology of calculation of principal parameters of a vessel, necessary for calculation of displacement in relation to vessel’s type, volumetric coefficients, Froude number, and others values affecting ship’s dimensions. It is about midship section coefficient, waterline coefficient, prismatic coefficients and hull feature and area coefficients. Those values are necessary for calculation of hull resistance. In the table are presented comparison of results of calculations above mentioned values and movement resistance and propulsion power of three container vessels representing different load capacity and one bulk carrier. There are also presented different calculation methods of transverse midship section coefficient and wet area coefficient, for 5000TEU container vessel.

4

Design and operational aspects of diesel generators’ power and number for seagoing ships

Krefft J.

Journal of KONES

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2013

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Vol. 20, No. 4

193--199

EN

New chapter 4, added to Annex VI of MARPOL convention, put into effect regulations on the ships ‘energy efficiency. It makes mandatory since 1st January 2013 the so called Energy Efficiency Design Index (EEDI) for new ships and the Ship Energy Efficiency Management Plan (SEEMP) for new and existing vessels of 400 gt and above. There is a huge space to save the energy, improve the ships’ efficiency and reduce the GHG emissions for the sea going ships such as container carriers are. The aspects presented in the paper are based on the contemporary container vessels with the state of the art technology implemented to their design and operational stage. The estimation of the electric power and number of diesel generators with use of the statistical tools is the main aim of the paper. The container vessels fitted only with the diesel generators without any other type of electric generator unit are taken into account in the calculation process. The electric power equation has been determined, applying the multiple regression model with an absolute term, based on the ship’s parameters for the entire range of the container vessels’ load capacity TEU. It shown, the reefer containers RC and the main propulsion rating SMCR are the most important parameters statistically significant. It is calculated as well how the total ship’s electric power is very strictly dependent on the number of diesel generators installed on board. The reefer containers’ number and its assumed power considering the cargo type and the simultaneity coefficient are also presented in the article, as this impact the electric power demand. The different types of Power Management Systems for diesel generators load are discussed at the last stage of the paper.

5

Economizer selection method with reference to its reliability at preliminary design stage of seagoing vessels

Charchalis A., Kreft J.

Journal of KONES

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2011

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Vol. 18, No. 2

63-68

EN

The economizers are used for production of steam heating on en route ships. The economizers are producing steam in a heat exchange process from the ship's main engine exhaust gas. Products of the incomplete combustion of the heavy fuel oil remaining in engines, passing the boiler, collect on the heat exchange surface of the economizer. When the incorrect assumptions are made for the boiler operation conditions, the boiler steam capacity drops and fire and burning of the incomplete combustion products can occur in the economizer. To minimize combustion product quantity that collects on the boiler surface, the allowable exhaust gas pressure drop in the boiler should be taken into consideration, as well as the results from recommended exhaust gas flow velocity that is determined by main engine service load determined in the preliminary design phase of the ship. The remaining operating conditions are made in such a way to obtain high steam capacity of the boiler. It is essential at the design stage to take into consideration the future operating parameters of the combustion-steam-water installation, since these parameters depend on the choice of boiler and determined at the design stage production of steam. On the basis of operation parameters of contemporary container ships, an attempt was made to select economizer capacity in the preliminary design stage taking into consideration operation conditions of the propulsion system-steam installations unit in aspect of economizer reliability.

6

Estimation of main engine power of seagoing ship at preliminary design stage

Charchalis A., Krefft J.

Journal of KONES

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2010

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Vol. 17, No. 4

89-95

EN

Permanent growth of the container shipbuilding has led to the need of research - developing activities with references to design and ship building process. The requirements for the container vessels have been modified and changed compared with the ships built in the eighties of the past century. The ships capacity have been increased up to and even above 10 000 twenty feet containers (TEU) with the service speed above 25 knots. For such a giant sea going vessels with the overall length above 300 meters and draught above 10 meters the ship hull resistance characteristics have been modified. Those conditions bring to the situation where the propulsion power for the seagoing ships reached 80 MW. The estimation of the main engine power relation in the preliminary design stage is the main aim of the paper. The problem is such important as in that stage the most important design decisions with relatively low investment costs are determined. Moreover, the preliminary design stage distinguishes that the designer possesses just a few design parameters given by the ship owner of the future vessel. That is why the correct choice of the main engine power is difficult to determine. Determination of the main propulsion power impacts the electric and heat energy amount and the production way of both energy forms. The main engine equation has been determined based on the container ship's parameters for the entire range of container vessels load capacity (TEU). The values of the design parameters have came from author 's data base for the contemporary container vessels.

7

Economizer selection method with reference to its reliability at preliminary design stage of seagoing vessels

Charchalis A., Krefft J.

Journal of KONBiN

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2009

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No. 1-2 (9-10)

35-44

EN

The economizers are used for production of steam heating on en route ships. The economizers are producing steam in a heat exchange process from the ship's main engine exhaust gas. Products of the incomplete combustion of the heavy fuel oil remaining in engines, passing the boiler, collect on the heat exchange surface of the economizer. When the incorrect assumptions are made for the boiler operation conditions, the boiler steam capacity drops and fire and burning of the incomplete combustion products can occur in the economizer. To minimize combustion product quantity that collects on the boiler surface, the allowable exhaust gas pressure drop in the boiler should be taken into consideration, as well as the results from recommended exhaust gas flow velocity that is determined by main engine service load determined in the preliminary design phase of the ship. The remaining operating conditions are made in such a way to obtain high steam capacity of the boiler. It is essential at the design stage to take into consideration the future operating parameters of the combustion-steam-water installation, since these parameters depend on the choice of boiler and determined at the design stage production of steam. On the basis of operation parameters of contemporary container ships, an attempt was made to select economizer capacity in the preliminary design stage taking into consideration operation conditions of the propulsion system-steam installations unit in aspect of economizer reliability.

PL

Ekonomizery są stosowane do wytwarzania pary grzewczej podczas rejsów statków morskich. Para jest wytwarzana w procesie wymiany ciepła, którego nośnikiem są spaliny z głównych silników statku. Produkty niecałkowitego spalania ciężkiego oleju silnikowego (mazutu) pozostające w silniku po zakończeniu procesu spalania przechodzą następnie przez kocioł i gromadzą się na powierzchni wymiennika ciepła ekonomizera. Jeśli dla warunków pracy kotła zostaną przyjęte nieprawidłowe założenia, spada wydajność parowa układu, a w ekonomizerze może nastąpić zapalenie się produktów niecałkowitego spalania, prowadząc do pożaru. W celu zminimalizowania ilości produktów spalania, które zbierają się na powierzchni kotła, należy zawsze mieć na względzie dopuszczalny spadek ciśnienia gazów spalinowych, a także wyniki dla zalecanej prędkości przepływu spalin, która jest determinowana przez obciążenie robocze głównego silnika, określane w początkowej fazie projektowej każdego statku. Pozostałe warunki pracy są dobierane w taki sposób, aby osiągnąć wysoką wydajność parową projektowanego kotła. Istotne jest, aby jeszcze w fazie projektowej wziąć pod uwagę przyszłe parametry robocze układu spalinowo - parowo - wodnego, gdyż te parametry zależą od wyboru kotła i określają, już we wstępnej fazie projektowej, proces wytwarzania pary. Na podstawie parametrów roboczych współczesnych kontenerowców podjęto próbę wyboru zdolności produkcyjnej ekonomizera już we wstępnej fazie projektowania statku, biorąc pod uwagę warunki robocze układu napędowego oraz instalacji parowej w aspekcie niezawodności ekonomizera.