• Journal of Advanced Marine Engineering and Technology
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• v.27 no.7
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• pp.832-838
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• 2003

IMO NOx levels are generally possible to meet by means of primary on-engine measures. Nevertheless further significant follow-on reductions are likely to require a secondary after-treatment technique. SCR system is currently the only available technology proven at full scale to meet the 90% NOx reduction levels. Accordingly, maybe the use of an SCR system on board ship provides the solution to minimize this primary pollutant without increasing fuel consumption. In order to develop a practical SCR system for marine application on board ship, a primary SCR system using urea was made. The SCR system was set up on the ship. employed a two-stroke diesel engine as a main propulsion. which is a training ship in KMU (Korea Maritime Univ.). The purpose of this paper is to report the results about the basic effects of the above system parameters which is investigated from practical application through its trial use. The degree of NOx removal depends on some parameters. such as the amount of urea solution added, space velocity. reaction gas temperature and activity of catalyst. The preliminary results from trial run are presented.

• Particle and aerosol research
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• v.19 no.4
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• pp.101-110
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• 2023

In order to reduce particulate matters (PM) from marine diesel engines, we developed novel electrostatic diesel particulate matter filtration system. Electrostatic diesel particulate filtration (DPF) system consists of electrostatic charger and filtration part. The electrostatic charger and filtration part are composed of a metal discharge electrode and a metal fiber filter (porosity: 68.1-86.1%), respectively. In the electrostatic charger part, diesel soot particles are reduced by electrostatic force. The filtration part after electrostatic charger part reduces diesel soot particles through inertial and diffusion forces. The filtration efficiency of electrostatic DPF system was examined through the experiments using engine dynamometer system (300 kW) and ship (200 kW). The PM reduction efficiencies due to inertial and electrostatic forces showed about 70-75% and 80-90%, respectively, according to the RPM of the engine. The differential pressure of the electrostatic DPF system applied to the ship was about 1-9 mbar, which was less than the allowable differential pressure for ship engines in South Korea (100 mbar). The results show that the electrostatic DPF system is suitable for application to the PM reduction emitted from ships.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.151-152
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• 2012

Collectors connected to diesel engine exhaust pipe for application of PM reduction facilities which was used to reduce PM from the exhaust gas produced from ship, Filtration performance of PM was tested. In this system, it was confirmed that the bag house can remove over 90 percent of PM from a lot of high temperature and high pressure gases produced in diesel engine. The results obtained from performance test show the potential possibility for commercialization of ceramic filter collectors which is applied to reduction facilities of flue gas produced from a diesel engine on the ship.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.3
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• pp.705-715
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• 2013

This Paper presented the reduction methods of $CO_2$ emission from ships during voyage. In order to decrease $CO_2$ emission during voyage the equation was established and conducted the study about the relationship between ship speed, the propulsive efficiency and its $CO_2$ production. The results obtained from the examinations are as follows : 1. $CO_2$ emission from sailing ships can be decreased by reducing specific fuel oil consumption of main diesel engine, coefficient of total resistance and ship speed and also by increasing propeller efficiency. 2. Diesel-electric propulsion system is more effective than diesel-mechanical system to decrease the level of $CO_2$ emission during long voyage. 3. Good condition of ship's hull surface, rudder and propeller's surface can decrease the quantity of fuel oil and $CO_2$ emission by reducing the resistance of ship that can rise the propeller efficiency 4. $CO_2$ emitted from ships can be decreased in a global scale by giving attention to the synthetic transport efficiency.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.12
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• pp.815-821
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• 2015

Maritime safety has been more critical recently due to the occurrence of shipboard accidents involving prime movers. As such, the propulsion shafting design and construction plays a vital role in the safe operation of the vessel other than focusing on being cost-efficient. Smaller vessels propulsion shafting system normally install high speed four-stroke diesel engine with reduction gear for propulsion efficiency. Due to higher cylinder combustion pressures, flexible couplings are employed to reduce the increased vibratory torque. In this paper, an actual vibration measurement and theoretical analysis was carried out on a propulsion shafting with V18.3L engine installed on small car-ferry and revealed higher torsional vibration. Hence, a rubber-block type flexible coupling was installed to attenuate the transmitted vibratory torque. Considering the flexible coupling application factor, reduction gear stability due to torque variation was analyzed in accordance with IACS(International Association of Classification Societies) M56 and the results are presented herein.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1808-1817
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• 2017

Duties required for naval ship such as anti-submarine, anti-ship, and supply, etc are diversified, so the ECS (Enfineering Control System) is required for executing the mission effectively. The ECS monitors and controls the propulsion system in order that naval ship can perform the mission. As the in-country development of ECS is progressed, a test system for ECS is needed, and a naval ship propulsion system simulator based on CODOG was developed on this study. The naval ship propulsion system simulator based on CODOG which is divided into gas turbine model, diesel engine model, reduction gear model and controllable pitch propeller model, simulates to feedback of control commands of ECS. As a result of the experiment, it is able to confirm speed, torque and power, etc. of the gas turbine, diesel engine and shaft according to ECS propulsion mode.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.3
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• pp.451-458
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• 2022

In Korea, five major ports have been designated as sulfur oxide emission control areas to reduce air pollutant emissions, in accordance with Article 10 of the "Special Act on Port Air Quality" and Article 32 of the "Ship Pollution Prevention Regulations". As regulations against vessel-originated air pollutants (such as PM, CO2, NOx, and SOx) have been strengthened, the Ministry of Oceans and Fisheries(MOF) enacted rules that newly built public ships should adopt eco-friendly propulsion systems. However, particularly in diesel-electric hybrid propulsion systems,the demand for precise control schemes continues to grow as the fuel saving rate significantly varies depending on the control strategy applied. The conventional Power Take In-Power Take Off(PTI - PTO) mode control adopts a rule-based strategy, but this strategy is applied only in the low-load range and PTI mode; thus, an additional method is required to determine the optimal fuel consumption point. The proposed control method is designed to optimize fuel consumption by applying the equivalent consumption minimization strategy(ECMS) to the PTI - PTO mode by considering the characteristics of the specific fuel oil consumption(SFOC) of the engine in a diesel-electric hybrid propulsion system. To apply this method, a specific fishing vessel model operating on the Korean coast was selected to simulate the load operation environment of the ship. In this study, a 10.2% reduction was achieved in the MATLAB/SimDrive and SimElectric simulation by comparing the fuel consumption and CO2 emissions of the ship to which the conventional rule-based strategy was applied and that to which the ECMS was applied.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.5
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• pp.407-413
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• 2014

The diesel engine and reduction gear combination is one of the common propulsion system in a naval vessel. Since the diesel engine has torsional vibration caused by reciprocating motion of the mass and gas pressure force of the cylinder, high cycle torsional fatigue can be occurred. Therefore, ROK navy restricts the maximum stress of the propulsion shaft according to MIL G 17859D. In this paper, the root cause for the failure of the diesel engine and reduction gear connecting shaft occurred in typical naval vessel is investigated based on the measured bending and torsional moment according to MIL G 17859D procedure.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.642-652
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• 2018

• Clean Technology
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• v.25 no.2
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• pp.153-160
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• 2019

As air pollution becomes more serious due to the increased number of diesel vessel operations, ship regulations on harmful emissions strengthen. Therefore, the development of a diesel exhaust after-treatment system for ships is required, and the higher the flow uniformity of the exhaust treatment system, the higher the treatment efficiency. With the computer software ANSYS Fluent, pressure drop and flow uniformity were used in this study to simulate flow rate with and without a baffle in both a Diesel Oxidation Catalyst (DOC) and Diesel Particulate Filter (DPF) system. The system pressure drop was found to be 38 to 40 mbar in the existing system condition, and the flow uniformity was approximately 84 to 92% at the inlet and outlet of the DOC. When the baffle was installed inside the system, the pressure increased and the flow uniformity was lowered due to an increase in flow rate. When the exhaust gas flow was reduced by 50% from $7,548kg\;h^{-1}$ to $3,772kg\;h^{-1}$, the flow uniformity at the inlet and outlet of the DOC increased by approximately 1 to 3% due to the low flow rate. In the case of DPF, the flow uniformity of exhaust gas was 98 to 99% because the uneven flow proceeded after uniformly flowing from the DOC.