• 해양환경안전학회지
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• 제27권7호
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• pp.1067-1073
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• 2021

선박으로부터 발생하는 온실가스 배출을 저감하기 위한 규제가 점차 강화되고 있다. 현존선에서도 EEXI(Energy Efficiency Existing Index)가 도입되었으며 이와 같은 온실가스 배출 감축목표를 달성하기 위해 다양한 연구가 진행되고 있다. 본 연구에서는 국제항해에 종사하는 현존선 중 자동차운반선에 태양광 발전시스템을 적용하여 연료유 사용량을 줄임으로써 온실가스 배출이 저감될 수 있는 시스템을 제안하였다. 제안된 태양광 발전시스템은 태양광 모듈, 에너지저장시스템, 전력변환장치 등으로 구성되었으며, 본 시스템의 적용 가능성을 확인하기 위해 전력전자프로그램을 통해 시스템을 모델링하였으며, 시뮬레이션을 실시하였다. 또한, 실제 선박에 적용하기 위한 타당성 검증을 위해 경제성 분석을 실시하였으며, 약 11년 이후 경제성 부분에서도 유의미한 결과가 도출됨을 확인할 수 있었다.

• 한국해양공학회지
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• 제37권5호
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• pp.205-214
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• 2023

As the regulations on greenhouse gas emissions at sea become strict, efforts are being made to minimize environmental pollutants emitted from fossil fuels used by ships. Considering the large sizes of ships in conjunction with securing stable supplies of environment-friendly energy, interest in nuclear energy to power ships has been increasing. In this study, the neutron irradiation that occurs during the nuclear reactor operation and its effect on the structural responses of the stiffened-plate structures are investigated. This is done by changing the material properties of DH36 steel according to the research findings on the neutron-irradiated steels and then performing the structural response analyses of the structures using analytical and finite-element numerical solutions. Results reveal the influence of neutron irradiation on the structural responses of the structures. It is shown that both the strength and stiffness of the structures are affected by the neutron-irradiation phenomenon as their maximum flexural stress and deflection are increased with the increase in the amount of neutron irradiation. This implies that strength and stiffness need to be considered in the design of ships equipped with marine nuclear reactors.

• 대한조선학회논문집
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• 제61권1호
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• pp.19-28
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• 2024

Environmental regulations are becoming more stringent in response to climate change, especially concerning marine pollution caused by ship emissions. Large ships are adjusting by integrating technologies to reduce pollutant emissions and transitioning to eco-friendly fuels such as low-sulfur oil and LNG. However, small ships face space constraints for installing LNG propulsion systems and the risk of power depletion with pure electric propulsion. Consequently, there's growing interest in researching hybrid propulsion methods that combine electricity and diesel for smaller vessels. Hybrid propulsion systems utilize diverse energy sources, requiring an effective method for evaluating their efficiency. This study proposes employing Bond graph modeling to comprehensively analyze energy dynamics within hybrid propulsion systems, facilitating better understanding and optimization of their efficiency. Modeling of the ship's energy system using Bond graphs will be able to provide a framework for integrating various energy sources and evaluating their effects.

• Journal of Advanced Marine Engineering and Technology
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• 제17권4호
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• pp.49-62
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• 1993

It has been a principle research topic on the diesel engine development to increase the efficiency and the performance of engine to satisfy the user's needs for high reliability and durability. However, recently with the worldwide concerns at the global climate change and environmental protection, the main target in the diesel engine research has been changed to solve the exhaust emission problem in order to satisfy the strict emission regulations. To reduce the pollutant for the diesel engine, the researchs on the combustion chamber is the most important and has to be performed first of all. The diesel fuel injection system plays major role to air-fuel mixing process and influences engine output, themal efficiency, reliability, noise, and emissions. The experimental studies were conducted by varying the various parametric conditions and the results were campared with the computation and calculated results by using the fuel injection simulation program developed during previous research. From the experiments, the matching technique of a fuel injection pump and nozzle was conducted to understand under the various parametric conditions. Also, the relations between needle lift and wave propagation characteristics in high pressure pipe were examined. The basic design data from the experimentations and computation works would be applied to actual design works of diesel fuel injection system.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.580-586
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• 2023

Diversified fuel types such as methanol, hydrogen, liquefied natural gas, ammonia, biofuels, have been come to fore in consideration of the limitations, regulations, environmental perception and efficient use of resources on maritime sector. NE is described as a substantial alternative energy source on the marine vessels in the sense of de-carbonization and fuel efficiency activities carried out by IMO. Although NPVs have been constructed for the merchant, navy and supply fields over the years, their numbers are few and working ranges are quite limited. NE generation techniques, reactor types, safety and security issues in case of any leakage or radiation pollution are analyzed and comparisons are performed between fossil-based fueled and NP based on icebreakers. The comparison are conducted on the basis of dimensions, resistances and operational competences by the VIKOR. NP icebreakers operated in recent years occupy a notable position in the ranking, although fossil fueled ones are most prevalent. Consequently, refueling period and emissions are the principal benefits of NPVs. Nevertheless, the use of such systems on marine vessels especially for merchant ships may come to the fore when all concerns in terms of safety, security and society are resolved since the slightest mistake can have irreversible consequences.

• Journal of Advanced Marine Engineering and Technology
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• 제39권10호
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• pp.1054-1061
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• 2015

The International Maritime Organization (IMO) has been regulating emissions by making mandatory the compliance with institutions aimed at protecting air quality such as the Energy Efficiency Design Index (EEDI), Ship Energy Efficiency Management Plan (SEEMP) and Tier III. Under the circumstances, one of the response measures considered to be the most feasible is the replacement of existing marine fuel with Liquefied Natural Gas (LNG). The industry has been preemptively building infrastructure and developing and spreading engine technology to enable the use of LNG-fueled ships. The IMO, in turn, recently adopted the International Code of Safety for Ships Using Gases or Other Low-Flash-Point Fuels (IGF Code) as an institutional measure. Thus, it is required to comply with regulations on safety-related design and systems focused on response against potential risk for LNG-fueled ships, in which low-flash-point fuel is handled in the engine room. Especially, the Standards of Training, Certification and Watchkeeping (STCW) Convention was amended accordingly. It has adopted the qualification and training requirements for seafarers who are to provide service aboard ships subject to the IGF Code exemplified by LNG-fueled ships. The expansion in the use of LNG-fueled ships and relevant facilities in fact is expected to increase demand for talents. Thus, the time is ripe to develop methods to set up appropriate STCW training courses for seafarers who board ships subject to the IGF Code. In this study, the STCW Convention and existing STCW training courses applied to seafarers offering service aboard ships subject to the IGF Code are reviewed. The results were reflected to propose ways to design new STCW training courses needed for ships subject to the IGF Code and to identify and improve insufficiencies of the STCW Convention in relation to the IGF Code.

• Journal of Advanced Marine Engineering and Technology
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• 제41권3호
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• pp.245-250
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• 2017

전 세계적으로 온실가스 및 대기 오염물질 배출 저감을 위한 환경 규제가 강화되고 있고, 그에 따라 여러 가지 대책들이 마련되고 있다. 또한 환경오염 최소화와 더불어 효과적이고 합리적인 에너지 절감 방법에 대한 필요성이 점차 커지고 있는 실정이다. 선박 분야의 경우에는 친환경 선박 개발이 활발히 연구되고 있으며 배기가스 배출저감, 대체 연료 개발, 새로운 추진 방식의 선박 등이 이러한 연구 범주에 속한다. 본 논문에서는 하이브리드 전기추진선박에 대한 기본 개념을 제시하고, 선박 운전환경 분석에 따른 하이브리드 전기추진선박의 전력공급 시스템 배터리 단독 운전, 발전기 단독 운전 및 전 출력 운전 모드로 구성하고 각 운전 모드별 속도, 전류, 전압 및 출력 특성을 분석하였다.

• 해양환경안전학회지
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• 제28권7호
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• pp.1238-1243
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• 2022

국제해사기구(IMO)를 필두로하여 국제적으로 선박에 대한 배출가스 규정을 강화하고 있으며, 대한민국 정부도 온실가스 감축을 위한 기본 로드맵을 설정하는 등 배출가스 저감을 위한 대책 마련이 절실한 상황이다. 또한, 국내 연안을 항해하는 선박에서 배출되는 온실가스 배출량 중 90.6%를 차지하고 있는 어선에 적용가능한 효율적이고 배출가스량이 감소가능한 새로운 추진시스템의 도입이 절실하다. 본 연구에서는 국내 연안어선에 적용가능한 전기복합 추진시스템을 제안하고, 전기복합 추진시스템이 적용가능한 대상선박을 선정하였다. 선정된 기존 대상어선에 탑재된 추진시스템과 비교하여 개발된 전기복합 추진시스템을 적용할 경우 발생할 수 있는 예상 연료소모량을 비교하기 위한 시뮬레이션 시스템을 Matlab/Simulink를 이용하여 구성하였다. 시뮬레이션을 통해 기계식 추진시스템, 전기복합 추진시스템(배터리 육상충전을 하지 않은 경우, 육상충전을 한 경우)간의 연료소모량 결과를 확인하였으며 전기복합 추진시스템을 적용하는 경우 약 13%, 16%의 연료소모량이 감소될 수 있는 것을 보여주는 결과를 확인하였다.

• 한국해양환경ㆍ에너지학회지
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• 제8권4호
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• pp.203-212
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• 2005

온실기체의 인위적 배출은 지구온난화를 유발하여 해수면 상승, 극 기상 등 전 세계에서 피해가 증가하고 있다. 특히, 지구온난화 기여도가 가장 높은 온실기체 중 이산화탄소($CO_2$)는 주로 화석연료의 사용 공정에서 발생하는 폐기물이다. 대기 중의 이산화탄소의 농도 증가는 표층 해양을 산성화시켜 표층해양 생태계, 나아가서는 지구 전체 생태계에 악영향을 미치게 될 것으로 보인다. 이산화탄소 배출량을 줄이기 위해서 에너지 효율을 높이거나 대체 에너지를 이용하는 등의 완화 기술이 동원 되고 있다. 그러나 현재 세계 에너지 수요의 약 85%가 화석연료로 충당되고 있기 때문에, 화석연료 이외의 대체 에너지원으로 급격히 전환한다면 세계 경제에 엄청난 충격이 올 것이다. 다행히도 최근 이산화탄소를 포집하여 지질구조에 격리하는 기술이 개발단계를 지나 실용화단계로 성숙하였다. 이 방안으로 단기간에 온실기체의 대기로의 배출량을 대규모로 줄일 수 있다(이상 2005년 런던협약 과학그룹회의록에서 발췌). 우리나라의 경우는 이산화탄소를 격리시킬 수 있는 장소는 육상면적이 작고 인구 밀도가 높아서 육상보다는 해양저지질구조가 선호될 수밖에 없을 것으로 보인다. 해양 이용은 해양의 특성상 런던협약 등의 국제적인 규제를 받게 된다. 본고는 해저 지질 구조에 대한 이산화탄소의 격리 관련 기술 및 제도의 국제동향을 우리나라 입장에서 예비적으로 검토하였다.

• 한국해양공학회지
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• 제37권2호
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• pp.58-67
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• 2023

While extensive research is being conducted to reduce greenhouse gases in industrial fields, the International Maritime Organization (IMO) has implemented regulations to actively reduce CO₂ emissions from ships, such as energy efficiency design index (EEDI), energy efficiency existing ship index (EEXI), energy efficiency operational indicator (EEOI), and carbon intensity indicator (CII). These regulations play an important role for the design and operation of ships. However, the calculation of the index and indicator might be complex depending on the types and size of the ship. Here, to calculate the EEDI of two target vessels, first, the ships were set as Deadweight (DWT) 50K container and 300K very large crude-oil carrier (VLCC) considering the type and size of those ships along with the engine types and power. Equations and parameters from the marine pollution treaty (MARPOL) Annex VI, IMO marine environment protection committee (MEPC) resolution were used to estimate the EEDI and their changes. Technical measures were subsequently applied to satisfy the IMO regulations, such as reducing speed, energy saving devices (ESD), and onboard CO₂ capture system. Process simulation model using Aspen Plus v10 was developed for the onboard CO₂ capture system. The obtained results suggested that the fuel change from Marine diesel oil (MDO) to liquefied natural gas (LNG) was the most effective way to reduce EEDI, considering the limited supply of the alternative clean fuels. Decreasing ship speed was the next effective option to meet the regulation until Phase 4. In case of container, the attained EEDI while converting fuel from Diesel oil (DO) to LNG was reduced by 27.35%. With speed reduction, the EEDI was improved by 21.76% of the EEDI based on DO. Pertaining to VLCC, 27.31% and 22.10% improvements were observed, which were comparable to those for the container. However, for both vessels, additional measure is required to meet Phase 5, demanding the reduction of 70%. Therefore, onboard CO₂ capture system was designed for both KCS (Korea Research Institute of Ships & Ocean Engineering (KRISO) container ship) and KVLCC2 (KRISO VLCC) to meet the Phase 5 standard in the process simulation. The absorber column was designed with a diameter of 1.2-3.5 m and height of 11.3 m. The stripper column was 0.6-1.5 m in diameter and 8.8-9.6 m in height. The obtained results suggested that a combination of ESD, speed reduction, and fuel change was effective for reducing the EEDI; and onboard CO₂ capture system may be required for Phase 5.