• Journal of IKEEE
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• v.25 no.3
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• pp.556-564
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• 2021

This paper presents trends of safety improvement technologies for an electric propulsion system of eco-friendly ships. As an effort to reduce a green house effect, demands for eco-friendly ships have been increased. An energy storage system (ESS) is one of key systems in an eco-friendly ship and a lithium-ion battery generally used in an ESS system due to its high power density and efficiency. However, a lithium-ion battery is considered as one of reasons for ESS fire hazard. Since a fire extinguishing facility is especially limited in the ocean, safety issue in an eco-friendly ship is important. In this paper, recent safety improvement technologies for traction motors, ESS batteries and structures for eco-friendly ships are presented.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.5
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• pp.358-366
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• 2023

Due to the International Maritime Organization's (IMO) environmental regulations on NOx and SOx, LNG-fueled eco-friendly ships are gaining attention worldwide, and various eco-friendly ships are being proposed and demanded for conversion to eco-friendly ships in Korea, as the eco-friendly ship law has recently been enforced. In this study, the initial basic design was performed to convert an existing Marine Gas Oil (MGO) fueled ship into an LNG-DF propulsion ship, targeting medium-sized ship, to select the fuel tank capacity and main dimensions and appropriate fuel ratio between the two fuels. In particular, Sustainable basic design method considering environmental impact were proposed by performing a Life Cycle Assessment (LCA) throughout the design process, and various design options were compared and analyzed to meet different design conditions by applying them.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.117-124
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• 2022

The International Maritime Organization (IMO) is tightening environmental regulations in the shipping sector to reduce air pollutants such as greenhouse gases emitted from ships. Meanwhile, the paradigm of the shipbuilding and shipping industries is shifting toward eco-friendly and high-efficiency ships worldwide. The Republic of Korea is also promoting a policy to expand the supply of eco-friendly ships from 2020 to disseminate them. In this article, a survey was conducted with 12 experts on the government's eco-friendly ship supply policy, and the priority of the policy was evaluated using the analytic hierarchy process (AHP). As a result of the comprehensive evaluation of the priorities for six priority tasks, "Securing the world's leading technology for future eco-friendly ships" for the development of carbon-free and low carbon ships was the highest. This study, which analyzed the importance of eco-friendly ship policies through AHP analysis, can be used as data to preemptively respond to international marine environmental regulations and to improve policy execution efficiency such as budget allocation and policy development regarding protecting national shipping and shipbuilding industries.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.207-214
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• 2023

Ships emit significant amounts of air pollution. To reduce ship emissions, the government has implemented the Eco-Friendly Ship Act to improve the marine air environment, under which the use of eco-friendly ships that use eco-friendly energy as a power source encouraged and technologies to reduce marine pollution are developed. Therefore, the revision of relevant laws and systems such as inspection and facility standards for the safe operation of eco-friendly ships is urgently needed, especially those for fishing vessels, which account for the majority of domestic coastal vessels. This study defines the core equipment for the application of electric complex propulsion systems to fishing boats and presents a minimum safety standard plan for the adoption and dissemination of eco-friendly fishing boats.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.52-52
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• 2017

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.96-96
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• 2017

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.216-219
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• 2021

In the Eco-Friendly Ship Act, the shaft generator is an equipment for eco-friendly ships. However, in order to apply the new technology in ships, high reliability is required, and the HILS (hardware in loop system) test is used as a verification method for this. Therefore, in this paper, a shaft generator is modeled and simulated for HILS test of a tugboat to which a shaft generator is applied. Through simulation, it was verified that the charging/discharging of the shaft generator operates according to the scenario.

• Journal of Ocean Engineering and Technology
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• v.35 no.1
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• pp.1-12
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• 2021

As increasing the international community's awareness of greenhouse gas reduction, the demand for eco-friendly ship fuel has accelerated recently. The fundamental aim of this study is to develop a new type of fully electrified ferry for passengers and cars considering Korean domestic coastal environmental conditions. Several technical difficulties are encountered in applying a fully electric propulsion system based on removable battery systems into a ship due to limitations imposed by the batteries' size and capacity. This paper reviews and analyzes marine environment regulations strengthened recently, technology trends related to fully electric propulsion vessels in each country, and Korean domestic coastal environments. We propose a new fully electrified car ferry design with a displacement of 400 t applied in Korea. It is powered by removable battery systems pre-charged in a safe inland charging station. The mobile battery system is developed to enable roll-on and roll-off using wheels. The characteristics of the ship motion are analyzed based on the weight and location of the battery systems. We expect our battery systems to be applicable to larger ships in the future.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.156-157
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• 2022

Currently, due to the increase in GHG emissions, the global weather phenomenon is constantly occurring, and each international organization is trying to reduce 온실가스 through various regulations to reduce GHG. To comply with the regulations, eco-friendly ships are currently being studied to reduce GHG. This paper models the fuel propulsion system of NH3 sofc fuel cell propulsion ship through the case study of eco-friendly ships, especially NH3 fuel cells, and provides information on how NH3 sofc fuel cell propulsion ships can benefit energy efficiency and decarbonization compared to existing FO vessels.

• Journal of Advanced Research in Ocean Engineering
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• v.4 no.3
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• pp.105-114
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• 2018

In the past, traditional methods of research on ship maneuvering performance were estimated in calm waters. However, the course-keeping ability and the maneuvering performance of a ship can be influenced by the presence of waves. Therefore, it is necessary to understand the maneuvering behavior of a ship in waves. In this study, the force acting on a moving ship and a rudder behind the model ship will be performed in regular waves in Changwon National University (CWNU). In addition, the prediction force acting on the rudder in calm waters was carried out and compared with those of Computational Fluid Dynamics (CFD). Model test in regular wave was performed to predict the force acting on the ship and the rudder behind the model ship in various wave directions. The effects of wavelength and wave direction on hydrodynamic forces acting on the ship hull versus rudder angle is discussed.