Journal of Marine Science and Engineering

14 pages, 2823 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Numerical Analysis of NOx Reduction Using Ammonia Injection and Comparison with Water Injection

by María Isabel Lamas Galdo, Laura Castro-Santos and Carlos G. Rodriguez Vidal

J. Mar. Sci. Eng. 2020, 8(2), 109; https://doi.org/10.3390/jmse8020109 - 11 Feb 2020

Cited by 33 | Viewed by 4896

This work analyzes NO_x reduction in a marine diesel engine using ammonia injection directly into the cylinder and compares this procedure with water injection. A numerical model based on the so-called inert species method was applied. It was verified that ammonia injection [...] Read more.

This work analyzes NO_x reduction in a marine diesel engine using ammonia injection directly into the cylinder and compares this procedure with water injection. A numerical model based on the so-called inert species method was applied. It was verified that ammonia injection can provide almost 80% NO_x reduction for the conditions analyzed. Furthermore, it was found that the effectiveness of the chemical effect using ammonia is extremely dependent on the injection timing. The optimum NO_x reduction was obtained when ammonia is injected during the expansion stroke, while the optimum injection timing using water is near top dead center. Chemical, thermal, and dilution effects of both ammonia and water injection were compared. The chemical effect was dominant in the case of ammonia injection. On the other hand, water injection reduces NO_x through dilution and, more significantly, through a thermal effect. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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33 pages, 68713 KiB

Open AccessArticle

Development of a Marine Two-Stroke Diesel Engine MVEM with In-Cylinder Pressure Trace Predictive Capability and a Novel Compressor Model

by Haosheng Shen, Jundong Zhang, Baicheng Yang and Baozhu Jia

J. Mar. Sci. Eng. 2020, 8(3), 204; https://doi.org/10.3390/jmse8030204 - 16 Mar 2020

Cited by 12 | Viewed by 5994

Abstract

In this article, to meet the requirements of marine engine room simulator on both the simulation speed and simulation accuracy, a mean value engine model (MVEM) for the 7S80ME-C9.2 marine two-stroke diesel engine was developed and validated in the MATLAB/Simulink environment. In consideration [...] Read more.

In this article, to meet the requirements of marine engine room simulator on both the simulation speed and simulation accuracy, a mean value engine model (MVEM) for the 7S80ME-C9.2 marine two-stroke diesel engine was developed and validated in the MATLAB/Simulink environment. In consideration of the significant influence of turbocharger compressor on both the engine steady state performance and transient response, a novel compressor model (mass flow rate and isentropic efficiency model) based on a previous study carried out by the first author was proposed with the aim of achieving satisfactory simulation accuracy within the whole engine operating envelope. The predictive and extrapolative capability of the proposed compressor model was validated by carrying out simulation experiments and analyzing the simulation results under steady state condition and during transient process. To make the traditional MVEM capable of predicting in-cylinder pressure trace, the cylinder pressure analytic model proposed by Eriksson and Andersson for the four-stroke SI (spark ignition) engine was adapted to the 7S80ME-C9.2 marine two-stroke diesel engine based on the characteristic of in-cylinder pressure trace of this type of engine and then coupled to the MVEM developed in this paper. Since there is no need to solve any differential equation as it is done in the 0-D model, the advantage of MVEM in running speed is not impaired. For achieving satisfactory simulation accuracy by using the analytic model, the model parameters were calibrated elaborately by using engine measured data and a 0-D model and the relevant tuning procedure was discussed in detail. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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21 pages, 1253 KiB

Open AccessArticle

Optimization of the Emissions Profile of a Marine Propulsion System Using a Shaft Generator with Optimum Tracking-Based Control Scheme

by Joel R. Perez and Carlos A. Reusser

J. Mar. Sci. Eng. 2020, 8(3), 221; https://doi.org/10.3390/jmse8030221 - 20 Mar 2020

Cited by 13 | Viewed by 4500

Abstract

Nowadays, marine propulsion systems based on thermal machines that operate under the diesel cycle have positioned themselves as one of the main options for this type of applications. The main comparative advantages of diesel engines, compared to other propulsion systems based on thermal [...] Read more.

Nowadays, marine propulsion systems based on thermal machines that operate under the diesel cycle have positioned themselves as one of the main options for this type of applications. The main comparative advantages of diesel engines, compared to other propulsion systems based on thermal cycle engines, are the low specific fuel consumption of residual fuels, and their higher thermal efficiency. However, its main disadvantage lies in the emissions produced by the combustion of the residual fuels, such as carbon dioxide (CO₂), sulfur oxide (SO_x), and nitrogen oxide (NO_x). These emissions are directly related to the operating conditions of the propulsion system. Over the last decade, the International Maritime Organization (IMO) has adopted a series of regulations to reduce CO₂ emissions based on the introduction of an Energy Efficiency Design Index (EEDI) and an Energy Efficiency Operational Indicator (EEOI). In this context, adding a Shaft Generator (SG) to the propulsion system favoring lower EEDI and EEOI values. The present work proposes a selective control system and optimization scheme that allows operating the shaft generator in Power Take Off (PTO) or Power Take In (PTI) mode, ensuring that the main engine operates, always, at the optimum fuel efficiency point, thus ensuring minimum CO₂ emissions. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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21 pages, 1882 KiB

Open AccessArticle

Effects of Marine Exhaust Gas Scrubbers on Gas and Particle Emissions

by Hulda Winnes, Erik Fridell and Jana Moldanová

J. Mar. Sci. Eng. 2020, 8(4), 299; https://doi.org/10.3390/jmse8040299 - 24 Apr 2020

Cited by 65 | Viewed by 7222

Abstract

There is an increase in installations of exhaust gas scrubbers on ships following international regulations on sulphur content in marine fuel from 2020. We have conducted emission measurements on a four-stroke marine engine using low sulphur fuel oil (LSFO) and heavy fuel oil [...] Read more.

There is an increase in installations of exhaust gas scrubbers on ships following international regulations on sulphur content in marine fuel from 2020. We have conducted emission measurements on a four-stroke marine engine using low sulphur fuel oil (LSFO) and heavy fuel oil (HFO) at different steady state engine loads. For the HFO the exhaust was probed upstream and downstream of an exhaust gas scrubber. While sulphur dioxide was removed with high efficiency in the scrubber, the measurements of particle emissions indicate lower emissions at the use of LSFO than downstream of the scrubber. The scrubber removes between 32% and 43% of the particle mass from the exhaust at the HFO tests upstream and downstream of the scrubber, but levels equivalent to those in LSFO exhaust are not reached. Decreases in the emissions of polycyclic aromatic hydrocarbons (PAH-16) and particulate matter as black carbon, organic carbon and elemental carbon, over the scrubber were observed for a majority of the trials, although emissions at LSFO use were consistently lower at comparable engine power. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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11 pages, 7412 KiB

Open AccessFeature PaperArticle

Reduction of the Gaseous Emissions in the Marine Diesel Engine Using Biodiesel Mixtures

by Michal Puškár, Melichar Kopas, Dušan Sabadka, Marek Kliment and Marieta Šoltésová

J. Mar. Sci. Eng. 2020, 8(5), 330; https://doi.org/10.3390/jmse8050330 - 8 May 2020

Cited by 23 | Viewed by 3106

Abstract

Taking into consideration the quality of air, it is necessary to ensure a continued reduction of the gaseous emissions that are produced by the maritime transport. The most effective solution of this serious worldwide problem is application of a suitable fuel mixture, which [...] Read more.

Taking into consideration the quality of air, it is necessary to ensure a continued reduction of the gaseous emissions that are produced by the maritime transport. The most effective solution of this serious worldwide problem is application of a suitable fuel mixture, which contains a bio-component, i.e. the biofuel. The presented scientific study is focused on influence of the biofuels on production of the gaseous emissions in the case of a diesel auxiliary engine, which is used in the ship transport. There were created various fuel mixtures with different content of the bio-component in order to investigate their emission characteristics. The individual experimental measurements were performed at the different engine loading levels and using a variable engine speed spectrum. The obtained results demonstrated a significant influence of the fuel mixtures on the whole combustion process, on the heat release process, on the pressure time behaviour as well as on the engine emission characteristics. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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12 pages, 4178 KiB

Open AccessArticle

Effective Mistuning Identification Method of Integrated Bladed Discs of Marine Engine Turbochargers

by Václav Píštěk, Pavel Kučera, Oleksij Fomin and Alyona Lovska

J. Mar. Sci. Eng. 2020, 8(5), 379; https://doi.org/10.3390/jmse8050379 - 25 May 2020

Cited by 35 | Viewed by 3172

Abstract

Radial turbine and compressor wheels form essential cornerstones of modern internal combustion engines in terms of economy, efficiency and, in particular, environmental compatibility. As a result of the introduction of exhaust gas turbochargers in the extremely important global market for diesel engines, higher [...] Read more.

Radial turbine and compressor wheels form essential cornerstones of modern internal combustion engines in terms of economy, efficiency and, in particular, environmental compatibility. As a result of the introduction of exhaust gas turbochargers in the extremely important global market for diesel engines, higher engine efficiencies are possible, which in turn reduce fuel consumption. The associated reduced exhaust emissions can answer questions that results from environmentally relevant aspects of the engine development. In shipping, the international Maritime Organisation (IMO) prescribes the step-by-step reduction of nitrogen oxide and other types of emissions. To reduce these emissions, various systems are being developed, in which turbochargers are an important part. The requirements for the reliability and service life of turbochargers are constantly increasing. Turbocharger blade vibration is one of the most important problems to be solved when designing the rotors. In the case of real rotors, so-called mistuning arises, which is a slight deviation of the properties of the individual blades from the design parameters. The article deals with an effective method of mistuning identification for cases of integrated bladed discs of marine engine turbochargers. Unlike approaches that use costly scanning laser Doppler vibrometers, this method is based on using only a simple laser vibrometer in combination with a computational model of the integrated bladed disc. The added value of this method is, in particular, a significant reduction in the cost of laboratory equipment and a reduction in the time required to obtain the results. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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11 pages, 1584 KiB

Open AccessArticle

Research of the Effectiveness of Selected Methods of Reducing Toxic Exhaust Emissions of Marine Diesel Engines

by Kazimierz Witkowski

J. Mar. Sci. Eng. 2020, 8(6), 452; https://doi.org/10.3390/jmse8060452 - 20 Jun 2020

Cited by 11 | Viewed by 3626

Abstract

The article’s applications are very important, as it is only a dozen or so years since the current issues of protection of the atmosphere against emissions of toxic compounds from ships. The issue was discussed against the background of binding legal norms, including [...] Read more.

The article’s applications are very important, as it is only a dozen or so years since the current issues of protection of the atmosphere against emissions of toxic compounds from ships. The issue was discussed against the background of binding legal norms, including rules introduced by the IMO (International Maritime Organization) in the context of the MARPOL Convention (International Convention for the Prevention of Pollution from Ships), Annex VI, with the main goal to significantly strengthen the emission limits in light of technological improvements. Taking these standards into account, effective methods should be implemented to reduce toxic compounds’ emissions to the atmosphere, including nitrogen oxides NO_x and carbon dioxide CO₂. The purpose of the article was, based on the results of our own research, to indicate the impact of the effectiveness of selected methods on reducing the level of nitrogen oxides and carbon dioxide emitted by the marine engine. The laboratory tests were carried out with the use of the one-cylinder two stroke, crosshead supercharged diesel engine. Methods of reducing their emissions in the study were adopted, including supplying the engine with fuel mixtures of marine diesel oil (MDO) and rapeseed oil ester (RME)-(MDO/RME mixtures) and changing the fuel injection parameters and the advance angles of fuel injection. The supply of the engine during the tests and the mixtures of marine diesel oil (MDO) and rape oil esters (RMEs) caused a clear drop in emissions of nitrogen oxides and carbon dioxide, particularly for a higher engine load, as has been shown. The decrease of the injection advance angle unambiguously makes the NO_x content in exhaust gas lower. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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23 pages, 5245 KiB

Open AccessArticle

Fuel Consumption and Emissions of Ocean-Going Cargo Ship with Hybrid Propulsion and Different Fuels over Voyage

by Congbiao Sui, Peter de Vos, Douwe Stapersma, Klaas Visser and Yu Ding

J. Mar. Sci. Eng. 2020, 8(8), 588; https://doi.org/10.3390/jmse8080588 - 6 Aug 2020

Cited by 66 | Viewed by 10239

Abstract

Hybrid propulsion and using liquefied natural gas (LNG) as the alternative fuel have been applied on automobiles and some small ships, but research investigating the fuel consumption and emissions over the total voyage of ocean-going cargo ships with a hybrid propulsion and different [...] Read more.

Hybrid propulsion and using liquefied natural gas (LNG) as the alternative fuel have been applied on automobiles and some small ships, but research investigating the fuel consumption and emissions over the total voyage of ocean-going cargo ships with a hybrid propulsion and different fuels is limited. This paper tries to fill the knowledge gap by investigating the influence of the ship mission profile, propulsion modes and effects of different fuels on the fuel consumption and emissions of the ship over the whole voyage, including transit in open sea and manoeuvring in close-to-port areas. Results show that propulsion control and electric power generation modes have a notable influence on the ship’s fuel consumption and emissions during the voyage. During close-to-port manoeuvres, propelling the ship in power-take-in (PTI) mode and generating the electric power by auxiliary engines rather than the main engine will reduce the local NOx and HC (hydrocarbons) emissions significantly. Sailing the ship on LNG will reduce the fuel consumption, CO₂ and NOx emissions notably while producing higher HC emissions than traditional fuels. The hybridisation of the ship propulsion and using LNG together with ship voyage optimisation, considering the ship mission, ship operations and sea conditions, will improve the ship’s fuel consumption and emissions over the whole voyage significantly. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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17 pages, 22720 KiB

Open AccessArticle

Electronic Constant Twist Angle Control System Suitable for Torsional Vibration Tuning of Propulsion Systems

by Jaroslav Homišin, Peter Kaššay, Matej Urbanský, Michal Puškár, Robert Grega and Jozef Krajňák

J. Mar. Sci. Eng. 2020, 8(9), 721; https://doi.org/10.3390/jmse8090721 - 18 Sep 2020

Cited by 10 | Viewed by 2791

Abstract

Currently, great emphasis on reducing energy consumption and harmful emissions of internal combustion engines is placed. Current control technology allows us to customize the operating mode according to the currently required output parameters, while the tuning of mechanical systems in terms of torsional [...] Read more.

Currently, great emphasis on reducing energy consumption and harmful emissions of internal combustion engines is placed. Current control technology allows us to customize the operating mode according to the currently required output parameters, while the tuning of mechanical systems in terms of torsional vibration is often ignored. This article deals with a semi-active torsional vibroisolation system using pneumatic flexible shaft coupling with constant twist angle control. This system is suitable, as it is specially designed, for the tuning of mechanical systems where the load torque has fan characteristics (fans, ship propellers, pumps). The main goal of this research is to verify the ability of an electronic control system developed by us to maintain the pre-set constant twist angle of the used pneumatic flexible shaft coupling during operation. The constant twist angle control function was tested on a laboratory torsional oscillating mechanical system. Presented results show that the proposed electronic control system meets the requirements for its function, namely that it can achieve, sufficiently accurately and quickly, the desired constant twist angle of the pneumatic flexible shaft coupling. It is possible to assume that the presented system will increase the technical level of the equipment where it will be applied. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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14 pages, 799 KiB

Open AccessArticle

Optimization of a Multiple Injection System in a Marine Diesel Engine through a Multiple-Criteria Decision-Making Approach

by Maria Isabel Lamas, Laura Castro-Santos and Carlos G. Rodriguez

J. Mar. Sci. Eng. 2020, 8(11), 946; https://doi.org/10.3390/jmse8110946 - 20 Nov 2020

Cited by 16 | Viewed by 2532

Abstract

In this work, a numerical model was developed to analyze the performance and emissions of a marine diesel engine, the Wärtsilä 6L 46. This model was validated using experimental measurements and was employed to analyze several pre-injection parameters such as pre-injection rate, duration, [...] Read more.

In this work, a numerical model was developed to analyze the performance and emissions of a marine diesel engine, the Wärtsilä 6L 46. This model was validated using experimental measurements and was employed to analyze several pre-injection parameters such as pre-injection rate, duration, and starting instant. The modification of these parameters may lead to opposite effects on consumption and/or emissions of nitrogen oxides (NO_x), carbon monoxide (CO), and hydrocarbons (HC). According to this, the main goal of the present work is to employ a multiple-criteria decision-making (MCDM) approach to characterize the most appropriate injection pattern. Since determining the criteria weights significantly influences the overall result of a MCDM problem, a subjective weighting method was compared with four objective weighting methods: entropy, CRITIC (CRiteria Importance Through Intercriteria Correlation), variance, and standard deviation. The results showed the importance of subjectivism over objectivism in MCDM analyses. The CRITIC, variance, and standard deviation methods assigned more importance to NO_x emissions and provided similar results. Nevertheless, the entropy method assigned more importance to consumption and provided a different injection pattern. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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13 pages, 2723 KiB

Open AccessArticle

One-Dimensional Gas Flow Analysis of the Intake and Exhaust System of a Single Cylinder Diesel Engine

by Kyong-Hyon Kim and Kyeong-Ju Kong

J. Mar. Sci. Eng. 2020, 8(12), 1036; https://doi.org/10.3390/jmse8121036 - 20 Dec 2020

Cited by 9 | Viewed by 4360

Abstract

In order to design a diesel engine system and to predict its performance, it is necessary to analyze the gas flow of the intake and exhaust system. Gas flow analysis in a three-dimensional (3D) format needs a high-resolution workstation and an enormous amount [...] Read more.

In order to design a diesel engine system and to predict its performance, it is necessary to analyze the gas flow of the intake and exhaust system. Gas flow analysis in a three-dimensional (3D) format needs a high-resolution workstation and an enormous amount of time for analysis. Calculation using the method of characteristics (MOC), which is a gas flow analysis in a one-dimensional (1D) format, has a fast calculation time and can be analyzed with a low-resolution workstation. However, there is a problem with poor accuracy in certain areas. It was assumed that the reason was that 1D could not implement the shape. The error that occurs in the shape of the bent pipe used in the intake and exhaust ports of the diesel engine was analyzed and to find a solution to the low accuracy, the results of the experiment and 1D analysis were compared. The discharge coefficient was calculated using the average mass flow rate, and as a result of applying it, the accuracy was improved for the maximum negative pressure by 0.56–1.93% and the maximum pressure by 3.11–7.86% among the intake pipe pressure results. The difference in phase of the exhaust pipe pressure did not improve. It is considered as a limitation of 1D analysis that does not improve even by applying the discharge coefficient. In the future, we intend to implement a bent pipe that cannot be realized in 1D using a 3D format and to prepare a method to supplement the reliability by using 1D–3D coupling. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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12 pages, 1450 KiB

Open AccessArticle

Performance and Regeneration of Methane Oxidation Catalyst for LNG Ships

by Kati Lehtoranta, Päivi Koponen, Hannu Vesala, Kauko Kallinen and Teuvo Maunula

J. Mar. Sci. Eng. 2021, 9(2), 111; https://doi.org/10.3390/jmse9020111 - 22 Jan 2021

Cited by 26 | Viewed by 4522

Abstract

Liquefied natural gas (LNG) use as marine fuel is increasing. Switching diesel to LNG in ships significantly reduces air pollutants but the methane slip from gas engines can in the worst case outweigh the CO₂ decrease with an unintended effect on climate. [...] Read more.

Liquefied natural gas (LNG) use as marine fuel is increasing. Switching diesel to LNG in ships significantly reduces air pollutants but the methane slip from gas engines can in the worst case outweigh the CO₂ decrease with an unintended effect on climate. In this study, a methane oxidation catalyst (MOC) is investigated with engine experiments in lean-burn conditions. Since the highly efficient catalyst needed to oxidize methane is very sensitive to sulfur poisoning a regeneration using stoichiometric conditions was studied to reactivate the catalyst. In addition, the effect of a special sulfur trap to protect the MOC and ensure long-term performance for methane oxidation was studied. MOC was found to decrease the methane emission up to 70–80% at the exhaust temperature of 550 degrees. This efficiency decreased within time, but the regeneration done once a day was found to recover the efficiency. Moreover, the sulfur trap studied with MOC was shown to protect the MOC against sulfur poisoning to some extent. These results give indication of the possible use of MOC in LNG ships to control methane slip emissions. Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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2 pages, 187 KiB

Open AccessEditorial

Marine Engines Performance and Emissions

by María Isabel Lamas Galdo

J. Mar. Sci. Eng. 2021, 9(3), 280; https://doi.org/10.3390/jmse9030280 - 5 Mar 2021

Cited by 5 | Viewed by 1983

Abstract

Marine engines are key components in most ships [...] Full article

(This article belongs to the Special Issue Marine Engines Performance and Emissions)

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