• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.253-256
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• 2006

This paper shows the study on application of the law temperature energy in the deep seawater. Deep, cold seawater has long been recognized as a valuable ocean energy resource. Recently, research and experimentation has been conducted on energy systems using deep seawater: deep seawater air conditioning system, ice-making device, salt and fresh-water manufacturing system and the Spray freeze drying system for extracting valuable material of the deep seawater. They are technically and economically feasible today: once installed, the energy is inexhaustible and there are no adverse environmental impacts. Because of the economy of scale in the air conditioning system, the seawater A/C system is most appropriate for supplying multiple buildings or hotels in a coastal area.

• Journal of Power System Engineering
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• v.18 no.4
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• pp.29-35
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• 2014

Plate heat exchanger are being applied in the field of OTEC (ocean thermal energy conversion) and SWAC (seawater air conditioning) system. This study is to analyze numerically the heat transfer and pressure drop characteristics by using solid works flow simulation in order to offer optimum design data of plate heat exchanger. Plater heat exchanger proposed in this study is four types. The geometric design parameters of plate heat exchanger are a channel space, a flow orientation, a plate array, the flowrate of working fluid and so on. The main results for numerical analysis of plate heat exchangers are summarized as follows. Heat transfer performance for the channel space of 2.4 mm shows the highest value compared to other spaces. And, the Type 4 plate heat exchanger in Table 2 is the highest performance. From the pressure drop characteristics of plate heat exchanger, the channel space of 3.2 mm shows the lowest value. And Type 1 plate heat exchanger in Table 2 is the lowest pressure drop.

• Journal of Power System Engineering
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• v.21 no.2
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• pp.77-82
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• 2017

In the fishing boat, freshwater ice is loaded on the fishroom in advance and it is used for storage of fishes. However, it causes degradation of catches' freshness. Therefore, seawater ice machine on board is necessary for the fishing industry. In this study, seawater ice machine with drum type evaporator was manufactured, and the system was tested under various operating conditions having an influence on the COP and amount of ice produced. The main results are as follow : The COP of the system gets larger when the evaporation temperature and rotation speed of the drum in the evaporator increases. The most effective refrigerant is R22 and the value of the COP was 1.43 times higher than that of R404A. The amount of produced ice increases with respect to increment of the evaporation temperature, while that decreases with respect to increment of the evaporator drum rotation speed.

• Journal of Power System Engineering
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• v.20 no.2
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• pp.85-90
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• 2016

Coefficient of performance (COP) for two-stage compression system is investigated in this paper to develop seawater ice machine. The system performance is analyzed with respect to degrees of superheating and subcooling, condensing and evaporating temperatures, compression and mechanical efficiencies and mass flow ratio in an inter-cooler. The main results are summarized as follows : The COP of the system grows when the mass flow ratio, subcooling degree and evaporating temperature edge up. Contrariwise, the system performance descends in case that superheating degree and condensing temperature increase. The most effective factor for the COP is the mass flow rate ratio. Each refrigerant has different limitation for a value of the mass flow ratio in the inter-cooler because of difference in material property.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.23 no.5
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• pp.403-413
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• 1994

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.8
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• pp.883-890
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• 2005

The industrial growth and the raised living quality have led to the massive energy consumption. As a result. the polluted environment and the limited amount of energy resources emerged as serious problems to be resolved in 21st century. Especially, in the case of Korea whose imported energy dependency rate is 98.2$\%$ in 2003 and constantly increasing every rear. more than 24$\%$ of overall energy consumption is for housing and commercial use. In order to cope with the shortage of natural energy resources, it is inevitable to develop alternative sustainable energy resources including seawater heat. so that they can replace existing resources. The heat transfer air velocity 3.5 m/s is proper to consideration with the body the pipe size 200A is more suitable than look due to the air velocity quantify and the ratio of pipe surface area. And the error between experimental data with simulation is below 5.34$\%$ so the suggested equation for calculating heat transfer capacity can be used. Therefore out of many methods utilizing seawater heat. this work Presents the efficiency of using sea water heat as a resource for air-conditioners which can be converted from the outside air through the air-to-heat conversion tube . Consequently. this method provides pretty reasonable energy efficiency.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.12
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• pp.979-986
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• 2003

The performance characteristics of heating and cooling operation for a heat pump system using seawater heat source and exhaust energy are presented. The heat pump system is made of a waste heat recovery system and a vapor compression refrigeration system. The working fluid is R-22. The heat pump system COPs are measured during heating and cooling operation modes, and the resultant COPs were 9.7 and 7.9, respectively, which are three times higher than those of the heat pump itself. Therefore, the performance of the heat pump system using exhaust energy is excellent compared to that of a general heat pump. The experimental data can be effectively used for the design of the high efficient heat pump using a seawater heat source.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.60 no.2
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• pp.194-206
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• 2024

This study focuses on analyzing the energy-saving effects of the recirculation aquaculture system using seawater source heat pumps and solar power generation. Based on the thermal load analysis conducted using the transient system simulation tool, the annual energy consumption of the recirculation aquaculture system was analyzed and the energy-saving effects of utilizing the photovoltaic system was evaluated. When analyzing the heat load, the sea areas where the fish farms are located, the type of breeding tank, and the circulation rate of breeding water were taken into consideration. In addition, a method for determining the appropriate capacity for each operation time was examined when applying the energy storage system instead of the existing diesel generator as an emergency power, which is required to maintain the water temperature of breeding water during power outage. The results suggest that, among the four seas considered, Jeju should be estimated to achieve the highest energy-saving performance using the solar power generation, with approximately 45% energy savings.

• Journal of Power System Engineering
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• v.20 no.6
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• pp.87-92
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• 2016

This research dealt with performance characteristics of OTEC system applying an ejector and additional pump. Each system using five kinds of working fluids was analyzed, and primary parameters with respect to entrainment ratio were examined: Turbine gross power, evaporation capacity, pump work, efficiency and volume flow ratio. The primary results were as following. The efficiency of ejector-pump OTEC system was dependent on entrainment of the ejector. The degree of efficiency change was different from applied working fluid, and amount of pump work was turned out to be primary factor affected system efficiency. Meanwhile, optimized entrainment ratio was different from applied working fluid since their different vapor density. System efficiency at optimized entrainmet ratio of each working fluid was around 5%, showing minor difference each other.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.704-709
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• 2014

Plate heat exchanger is being applied in the field of marine plants and chemical industry, such as OTEC and SWAC equipment. The study aims to interpret the heat transfer and pressure drop characteristics of plate heat exchangers to determine the geometric design parameters such as the channel space. In this study, heat transfer performance was numerically studied with respect to the variation of channel spaces. The results from numerical analysis indicated that the j factor was linearly decreased with the flowrate of seawater over every cases. As the flowrate of water increased with respect to channel spaces, the j factor decreased linearly. And the f factor decreased linearly with the increase of flowrate. When the channel space is 2.8~3.2 mm and 3.2~3.2 mm, respectively, the area goodness factor of plate heat exchanger showed the highest performance.