• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.351-353
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• 2007

해양온도차를 이용한 냉난방 시스템의 도입을 위한 해상 및 기상 실측을 통한 자원조사 및 시스템에 관한 기술적인 내용을 기술한다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.40 no.8
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• pp.37-47
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• 2011

해양온도차를 이용한 해수온도차냉난방시스템의 해외사례 및 국내사례를 중심으로 설명하고, 가까운 미래의 신에너지인 해양온도차발전의 원리 및 해외사례를 소개하고자 한다.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.8
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• pp.1036-1042
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• 2012

This paper describes an analysis on exergy efficiency of R744 OTEC power system to optimize the design for the operating parameters of this system. The operating parameters considered in this study include subcooling and superheating degree, evaporation and condensation temperature, and turbine and pump efficiency, respectively. The main results are summarized as follows : As the evaporation temperature, superheating degree, and turbine and pump efficiency of R744 OTEC power system increases, the exergy efficiency of this system increases, respectively. But condensation temperature and subcooling degree of R744 OTEC power system increases, the exergy efficiency of this system decreases, respectively. The effect of evaporation temperature and pump efficiency on R744 OTEC power system is the largest and the lowest among operation parameters, respectively. Therefore, the refrigerant temperature in the evaporator must be closely to the surface seawater temperature to enhance the exergy efficiency of R744 OTEC power system.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.5
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• pp.580-585
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• 2012

In this paper, the cycle performance analysis for condensation and evaporation capacity, total work and efficiency of ocean thermal energy conversion power system using R744 ($CO_2$) is presented to offer the basic design data for the operating parameters of this system. The operating parameters considered in this study include superheating and subcooling degree, evaporation and condensation temperature, pump and turbine efficiency. The main results were summarized as follows : The evaporation capacity of R744 increases with superheating and subcooling degree, but decreases with the increasing condensation temperature. The total work increases with superheating and subcooling degree of R744, but decreases with the increasing evaporating temperature. And, the efficiency increases with subcooling and superheating degree, but decreases with the increasing condensation temperature. Therefore, superheating and subcooling degree, evaporation and condensation temperature and pump and turbine efficiency of R744 OTEC power system have an effect on the evaporation and condensation capacity, total work and efficiency of this system. With a thorough grasp of these effect, it is necessary to design the OTEC power cycle using R744.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.567-575
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• 1999

This study found potential ability to generate electric power using difference in water temperature between sea surface water and deep water in the East Sea which includes the East Sea Proper Water with the temperature less than 1$^{\circ}C$ throughout a year without seasonal variation. To quantify the difference in water temperature between sea surface water and deep water in the East Sea. We computed the annual mean ($^{\circ}C$), the annual amplitude ($^{\circ}C$), the annual phase (degree) and the duration time which showed more than 15$^{\circ}C$ temperature difference from the water temperature data using Harmonic analysis during 1961~1997. The best place for generating electric power in the East Sea seems to be the eastward ocean areas (36$^{\circ}$ 05'N, 129$^{\circ}$ 48'E~36$^{\circ}$ 05'N, 130$^{\circ}$ 00E'E) from Pohang city. The annual mean of the difference in water temperature between sea surface water and 500 m depth was 24$^{\circ}$C at the place to generate electric power in August according to the data of 1961~1997. the maximum duration periods with more than 15$^{\circ}C$ temperature difference were 215 days (5/5-12/10) a year in the place mentioned electricity with a stable plan. In the East Sea coastal areas of the Korean peninsula, the average minimum depth to reach the East Sea Proper Water from surface water is 300 m and fluctuates between 250 m and 350 m throughout a year. Further studies could be needed for the utilization of cold water, such as the East Sea Proper Water for energy conversion.

• 월간 기계설비
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• s.239
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• pp.44-49
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• 2010

국토해양부는 최근 신재생 에너지원으로 주목받고 있는 해양에너지 개발의 일환으로 "해양심층수를 활용한 냉난방 및 온도차 발전기술 개발"에 착수한다고 밝혔다. 이에 따라 그동안 고품질 생수, 식품, 농 수산업 등 주로 산업적 용도로 활용되었던 해양심층수가 앞으로는 신재생 에너지원으로 그 활용폭이 넓어질 전망이다.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.9
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• pp.1101-1105
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• 2014

Ocean Thermal Energy Conversion(OTEC) which uses the temperature difference between warm surface sea-water and cold deep sea-water to produce electric power is the promising technology. OTEC is able to be utilized as the $CO_2$ reducing technology by using the consistent temperature differential, while the system efficiency is very low. Thus, the design and development of a efficient turbine is essential to improve the system efficiency for OTEC. In this study, a 100kW-class radial inflow turbine using R32 was designed for OTEC and this turbine's performance was estimated by analysis of CFD. According as the simulation results, turbine's geometry was corrected. The radial inflow turbine satisfying the requirements is designed by the repeated attempts.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.239-239
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• 2010

해양에서 물리적 에너지원으로는 조류, 조력, 파력, 해양온도차에너지(Ocean Thermal Energy : OTE)가 있으며, OTE 개발을 위해서는 우선 부존 자원량 파악과 개발적지 선정이 선행되어야 한다. 이를 위해 대상해역의 표층과 심층간의 수온차이 값(${\Delta}T$)에 대한 연중출현확률의 산정이 필요하다. 본 연구에서는 이러한 ${\Delta}T$의 연중출현확률을 산정하기 위해 남해 해역을 대상으로 47년간(1961~2007) 격월 별(2, 4, 6, 8, 10, 12월)로 관측된 93개 정점의 정선해양관측자료(국립수산과학원)를 사용하였다. ${\Delta}T$값을 정량화 하고자 정점 별 ${\Delta}T$(> $5^{\circ}C$, > $10^{\circ}C$, > $15^{\circ}C$)의 연중출현확률을 빈도분석과 조화분석 방법을 사용하여 계산하고 이를 공간적으로 광역적 규모와 지역적 규모에서 두 방법의 장단점을 비교, 분석 하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.4
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• pp.470-476
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• 2010

The thermodynamic performance of closed ocean thermal energy conversion (OTEC) cycle with 1 MW gross power was evaluated to obtain the basic data for the optimal design of OTEC. The basic thermodynamic model for OTEC is Rankine cycle and the thermal effluent from power plant was used for the heat source of evaporator. The cycle performance such as efficiency, heat exchanger capacity, etc. was analyzed on the temperature variation of thermal effluent. The saturated pressure of evaporator increased with respect to the increase of thermal effluent temperature, so the cycle efficiency increased and necessary capacity of evaporator and condenser decreased under 1 MW gross power. As the thermal effluent temperature increases about $15^{\circ}C$, the cycle efficiency increased approximately 44%. So, it was revealed that thermal effluent from power plant is important heat source for OTEC plant. Also, if there is an available waste heat, it can be transferred heat to the working fluid form the evaporator through heat exchanger and cycle efficiency will be increased.

• Journal of the Korean Association of Geographic Information Studies
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• v.1 no.2
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• pp.44-55
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• 1998

This study was carried out to investigate the feasibility of OTEC(Ocean Thermal Energy Conversion) operation, in the East Sea of Korea. Accumulated cruise data of NFRDI (National Fisheries Research and Development Institute) over the period 1966~1995 were used to locate appropriate spot by season as well as by latitude which would show the difference at least $15^{\circ}C$ or more between the surface layer and each depth of 50, 100, 150, 200, 250, 300, 400 and 500m. Our results showed that the coastal areas of Pohang city met the requirement of more than $20^{\circ}C$ difference for OTEC plant from August to October. In contrast, in case that $15^{\circ}C$ would be possible thermal difference to operate OTEC plant, most coastal areas in the East Sea including Pohang from June to December are potential candidates for this future energy source. Therefore, we present in this paper the first option to locate the best place for OTEC plant operation using Geographical Information System (GIS), which is currently used for multi-dimensional space analysis.