• 한국수산과학회지
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• 제30권6호
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• pp.929-935
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• 1997

The total energy of fish movement and the maximum burst swimming speed were estimated and formulated in accordance with body length and water temperature for several species in fisheries by empirical methods and also by using published results. Under the assumption of swimming energy reserve of a fish at the initial rest state, the swimming endurance of fish with different body lengths, swimming speeds and angular velocity was calculated using the relevant equations under similar conditions in tank experiments as well as natural conditions in field. Relative swimming energy efficiency or the transition swimming speed between red and white muscle for energy consumption was represented as a trigonometric function of swimming speed ratio. Therefore, this model does closely approach the actual swimming abilities and their limits especially in relation to the fishing gear operation and allow for the greater vitality of the wild fish in the fields.

• Fisheries and Aquatic Sciences
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• 제24권11호
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• pp.341-350
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• 2021

The energy production of offshore wind farms plays an important role in expanding renewable energy. However, the development of offshore wind farms faces many challenges due to its incompatibility with marine environments and its social acceptability among the local community. In this study, we reviewed the marine environmental impact assessment status of offshore wind farm development projects for 2012-2019 in South Korea. A total of nine projects were selected for this study, all of which experienced considerable conflict with local fisheries resources. To appropriately respond to the underlying challenges faced by offshore wind farm development and in order to better support decision-making for future impact assessment, our findings identified: i) a need for adequate preliminary investigation and technical examination of fisheries resources; ii) a need to assess and estimate the impact of underwater noise, vibration, and electromagnetic waves on fisheries resources during wind farm construction and operation; and iii) a need for a bottom-up approach that allows for communication with local stakeholders and policy-makers to guarantee the local acceptability of the development.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2022년도 추계학술대회
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• pp.160-161
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• 2022

Hydrogen is bridge fuel with high energy content and environmentally friendly to satisfy the stringent IMO regulation relating to greenhouse gas (GHG) emissions. There is growing interest in hydrogen in numerous nations and regions illustrated by an extensive range of research and development in technology. Regarding maritime applications, researchers have recognized the utilization of hydrogen as a fuel for fuel cells, a device that converts the chemical energy of the fuel to electrical energy. Solid oxide fuel cell (SOFC), with high working temperature, is easy to combine with the waste heat recovery cycles/devices to increase output power and thermodynamic performances as well. Furthermore, the cold energy from liquid hydrogen supplied to SOFC can also be used to generate more power. In this study, we proposed a SOFC integrated system with the idea of combining the waste heat recovery from the SOFC exhaust stream and cold energy utilization from LH₂. The designation is aimed to target small-scale vessel which uses electric propulsion for short distances voyage.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2021년도 추계학술대회
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• pp.132-133
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• 2021

In recent years, energy harvesting from natural sources and waste heat has been attracting more attention from researchers in response to ever-growing energy demands, high energy prices, and climate-change-mitigation purposes. It is also an important step towards future sustainable energy usages. In thermal dynamic cycles, expanders are playing as the most important equipment for waste heat recovery and energy harvesting as well. As a kind of expander, the bladeless turbine has a promising future and more widely using owning its advantages on relatively long life, good off-design performance, easy operation cleaning and maintenance, a simple structure, no blade corrosion, and low manufacturing costs. There are numerous studies about using the Tesla Turbine as a key technology for energy harvesting in a wide range of applications and conditions. They are presented to help identify technologies that have sufficient potential for applicating to our life and marine industrial engineering. This review paper, initially, presents an overview of current studies both theoretical and experimental of Tesla Turbine usage for waste heat recovery alongside its challenges and investigation on the effect of its configuration, working fluid selection as well. To conclude, future perspectives besides possible ways of transforming waste heat energy to electricity or work, which leads to circular energy, are discussed. The ambition of this paper is to act as a first-hand reference, through the well-defined possible directions, to the young researchers and senior scientists.

• Advances in Energy Research
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• 제6권2호
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• pp.103-129
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• 2019

While global demand for energy increases annually, at the same time the demand for carbon-free, sulphur-free and NO_x-free energy sources grows considerably. This state poses a challenge in the research for newer sources like biomass and shale gas as well as renewable energy resources such as solar, wind, geothermal and hydraulic energy. Although wave energy also is a form of renewable energy it has not fully been exploited technically and economically so far. This study tries to explain those reasons in which it is beyond doubt that the demand for wave energy will soon increase as fossil energy resources are depleted and environmental concerns gain more importance. The electrical energy supplied to the grid shall be produced from wave energy whose conversion devices can basically work according to three different systems. i. Systems that exploit the motions or shape deformations of their mechanisms involved, being driven by the energy of passing waves. ii. Systems that exploit the weight of the seawater stored in a reservoir or the changes of water pressure by the oscillations of wave height, iii. Systems that convert the wave motions into air flow. One of the aims of this study is to present the classification deficits of the wave energy converters (WECs) of the "wave developers" prepared by the European Marine Energy Center, which were to be reclassified. Furthermore, a new classification of all WECs listed by the European Marine Energy Center was arranged independently. The other aim of the study is to assess the technological state of the art of these WECs designed and/or produced, to obtain an overview on them.

• 한국해양환경ㆍ에너지학회지
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• 제7권3호
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• pp.111-115
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• 2004

본고에서는 해양생명공학 측면에서 조망한 해양환경공학의 학문적 성격 및 학회의 발전방향을 기술하고자 한다. 먼저 해양생명공학 및 해양환경공학의 정의 및 특성을 살펴보고 미국의 환경연구에 대한 거시적 경향, 해양생명공학관점에서의 해양환경공학분야의 학문적 방향에 대하여 기술하였다. 또한 국내 해양환경공학 연구의 현황을 조망하여 향후 발전방향을 제언하고, 현 문제점 및 해결방안 제시를 통한 해양환경공학회의 향후 진로에 대한 의견을 제시하고자 한다.

• 한국토양비료학회지
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• 제45권2호
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• pp.156-161
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• 2012

Marine biomass is considered an important substrate for anaerobic digestion to recovery energy i.e. methane. Nevertheless, marine biomass has attracted little attention by researchers compared to terrestrial feedstock for anaerobic digestion. In this study, biochemical methane potential (BMP) test was used to evaluate generation of renewable energy from starfish. A cumulative biogas yield of $748{\pm}67mL\;g^{-1}VS^{-1}$ was obtained after 60 days of digestion. The cumulative methane yield of $486{\pm}28mL\;CH_4\;g^{-1}VS^{-1}$ was obtained after 60 days of digestion. The methane content of the biogas was approximately 70%. The calculated data applying the modified Gompertz equation for the cumulative $CH_4$ production showed good correlation with the experimental result obtained from this batch study. Since the result obtained from this study is comparable to results with other substrates, marine biomass can be co-digested with food waste or swine wastewater to produce $CH_4$ gas that will help to reduce the gap in global energy demand.

• 한국해양환경ㆍ에너지학회지
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• 제18권3호
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• pp.179-188
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• 2015

본 연구는 연안 육역 및 해역에서 일어나고 있는 해양 신재생에너지 개발계획 및 추진사업을 분석하고, 해양환경 및 생태계와 관련된 중점평가사항을 진단하여 효율적인 스코핑(Scoping) 방안과 정책제언을 제시하였다. 주요한 사업유형으로는 공유수면에는 조력, 해상풍력 및 파력발전이 많았으며, 연안 육역에는 태양광발전사업이 주로 계획되었다. 조력발전 등 대규모 개발사업 추진 시, 상위계획에 따른 전략환경영향평가(SEA)와 공유수면매립기본계획 등 사전평가단계에서는 입지의 타당성과 계획의 적정성 측면에서 연안관리지역계획에 따른 용도구역 등 다른 계획과의 조화, 실질적인 대안분석, 그리고 해양수산 규제지역 분포와 어장이용 등 기 해양공간계획과의 상호 연관성 진단 등이 중요하다. 또한, 해역이용협의나 환경영향평가 등 실시단계에서의 구체적인 평가에서는 사업유형별로 중점평가사항에 대한 철저한 진단, 실효적인 사후모니터링 및 저감방안의 제시가 핵심으로 고려되어야 할 것이다. 특히, 순수하게 해양공간에서 일어나는 에너지발전사업일 경우에는 해양공간계획 방향과 연계되는 사전평가방안 도입 및 통합 "해양환경영향평가" 체제로의 전환 등 해양수산부가 주도하는 평가제도의 개선방안이 필요할 것으로 판단된다.

• Journal of Advanced Marine Engineering and Technology
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• 제32권8호
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• pp.1157-1163
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• 2008

Fuel represents a significant portion of the operating costs of voyages of the vessel. Under this situation, dramatic increase in fuel price caused a problem that earnings of ship becomes decreased seriously. Pumps in a cooling system of the vessel are often operated inefficiently. The reasons will vary from process to process and application to application. Inefficiency of pumps is one of the reason for making the cost of operating the vessel increased. This paper suggests energy-effective cooling system that controls sea water pumps with inverters to reduce energy consumption in vessel by conducting simulation with LabVIEW. Results shows that electric energy consumption of pumps are significantly deceased. If this energy-effective cooling system is applied to other systems which need cooling, it could be useful in reducing electric energy wastage.

• Journal of Advanced Marine Engineering and Technology
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• 제40권8호
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• pp.704-709
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• 2016

Wave energy generation systems can be divided into oscillating water chamber type, over topping device type and wave activating body type. The wave activating body type converts wave energy to kinetic energy, and the power generation amount increases as the motion of an activating body increases. In this paper, the wave energy convertor consists of a main body, which has an H-shape, and the activating body. These are connected by a bar-type bridge. By the incident wave, when the activating body moves with vertical motion this motion is consequently converted into rotational motion. The twisting moment and angular velocity at a shaft of convertor are calculated according to various conditions of the incident wave and the shape of the activating body. This can be used as a basic idea for determining the design of wave activating body type convertor.