Wyniki wyszukiwania - BazTech

1

Modelling ships main and auxiliary engine powers with regression-based machine learning algorithms

Okumuş Fatih, Ekmekçioğlu Araks, Kara Selin Soner

Polish Maritime Research

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2021

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nr 1

83--96

EN

Based on data from seven different ship types, this paper provides mathematical relationships that allow us to estimate the main and auxiliary engine power of new ships. With these mathematical relationships we can estimate the power of the engine based on the ship’s length (L), gross tonnage (GT) and age. We developed these approaches using simple linear regression, polynomial regression, K-nearest neighbours (KNN) regression and gradient boosting machine (GBM) regression algorithms. The relationships presented here have a practical application: during the pre-parametric design of new ships, our mathematical relationships can be used to estimate the power of the engines so that more environmentally friendly ships may be built. In addition, with the machine learning methodology, the prediction of the main engine (ME) and auxiliary engine (AE) powers used in the numerical calculation of ship-based emissions provides data for researchers working on emission calculations. We conclude that the GBM regression algorithm provides more accurate solutions to estimate the main and auxiliary engine power of a ship than other algorithms used in the study.

2

Plasma technology to remove NOx from off-gases

Pawelec Andrzej, Chmielewski Andrzej G., Sun Yongxia, Bułka Sylwester, Torims Toms, Pikurs Guntis, Mattausch Gösta

Nukleonika

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2021

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Vol. 66, No. 4

227--231

EN

Operation of marine diesel engines causes signifi cant emission of sulphur and nitrogen oxides. It was noticed worldwide and the regulations concerning harmful emissions were introduced. There were several solutions elaborated; however, emission control for both SOx and NOx requires two distinctive processes realized in separated devices, which is problematic due to limited space on ship board and high overall costs. Therefore, the electron beam flue gas treatment (EBFGT) process was adopted to ensure the abatement of the problem of marine diesel off-gases. This novel solution combines two main processes: fi rst the fl ue gas is irradiated with electron beam where NO and SO2 are oxidized; the second stage is wet scrubbing to remove both pollutants with high efficiency. Laboratory tests showed that this process could be effectively applied to remove SO2 and NOx from diesel engine off-gases. Different compositions of absorbing solution with three different oxidants (NaClO, NaClO2 and NaClO3) were tested. The highest NOx removal efficiency (>96%) was obtained when seawater-NaClO2-NaOH was used as scrubber solution at 10.9 kGy dose. The process was further tested in real maritime conditions at Riga shipyard, Latvia. More than 45% NOx was removed at a 5.5 kGy dose, corresponding to 4800 Nm3 /h off-gases arising from ship emission. The operation of the plant was the first case of examination of the hybrid electron beam technology in real conditions. Taking into account the experiment conditions, good agreement was obtained with laboratory tests. The results obtained in Riga shipyard provided valuable information for the application of this technology for control of large cargo ship emission.

3

Thermo-economic analysis and environmental aspects of absorption refrigeration unit operation onboard marine vehicles: RO- PAX vessel case study

Ammar N. R., Sediek I. S.

Polish Maritime Research

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2018

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nr 3

94--103

EN

Marine diesel engines lose a huge amount of fuel heat content in the form of exhaust gas and jacket cooling water, especially onboard high-powered marine vehicles such as Ro-Pax ships. In this paper, the possibility of using the waste heat of marine diesel engines as a source of heat for air conditioning absorption system is investigated. The thermodynamic analysis, in addition to the environmental and economic analysis of the air condition absorption cycle operated with two heat sources using lithium bromide as absorbent, are performed using the Engineering Equation Solver (EES) software. The last 10 years have seen a steady growth in the passenger ferry and Ro-Pax market, with particularly strong growth in passenger numbers. As a case study, a Ro-Pax vessel operating in the Red Sea area is considered, regarding the profitability of using air conditioning absorption system. The results show specific economic benefits of the jacket cooling water operated absorption refrigeration unit (ARU) over the exhaust gas operated unit, with annual costs of capital money recovery of 51,870 $/year and 54,836 $/year, respectively. Environmentally, applying an ARU machine during cruising will reduce fuel consumption by 104 ton/year. This, in turn, will result in reducing NOx, SOx, and CO2 emissions with cost-effectiveness of 7.73 $/kg, 20.39 $/kg, and 0.13 $/kg, respectively.

4

Techno-economic approach to solar energy systems onboard marine vehicles

Salem A. A., Seddiek I. S.

Polish Maritime Research

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2016

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nr 3

64--71

EN

The world is facing the challenge of continuously increasing energy consumption. At the same time, the energy resources are getting scarcer. Despite a sudden significant drop of fuel prices worldwide, research activities that focus on reducing the dependence on fossil fuels as a traditional source of energy still have the preference in the field of shipping industry. The use of clean and renewable energies, such as solar energy for instance, is proposed as a method to improve the ship efficiency. Ships can get the benefits from solar energy due to the fact that most of their upper decks are always exposed to the Sun, especially in sunny water regions. The present paper discusses the effectiveness and challenges of installing solar panels for auxiliary power production on board a ship. As a case study, the research evaluates both economic and environmental benefits resulting from implementing such concept aboard a research vessel.

5

Legal aspects of low-emission shipping in the light of provisions of “sulphur directive” adopted by the European Union

Madejska B.

Polish Maritime Research

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2013

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nr 4

87--94

EN

Shipping emits a variety of air pollutants: sulphur dioxide (SOx), nitrogen oxides (NOx ), carbon dioxide (CO2 ) and particulate matter PM. Air pollutant emissions from maritime transport can be transported over long distances and thus increasingly contribute to air quality problems. Key environmental regulations (international and European) coming into force in this decade address emissions of SOx , NOx , CO2 and PM to control and limit their impact in the atmosphere. In the European Union, accordingly to the legal regulations, in the sulphur emission control areas the required SOx content of fuel will be reduced from 1.5 % to 0.1 % beginning January 2015. Globally, from 2020 onwards, ships operating in all other European Sea areas will have to use fuels with sulphur content of 0.5 % or less.