• Journal of Advanced Marine Engineering and Technology
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• 제25권6호
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• pp.1317-1323
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• 2001

The circumstance is giving the blow against fishermen with the incoming-decreasing and the difficulty of crew's supply & demand and management. In addition, the depression of the external situation like the departure of WTO system and the plan of EEZ proclaim is forcing fishery into improving their fishing condition. By this international and domestic circumstance, development of the sea water cooling apparatus for fish hold storage is demanded sincerely. First of all, we Investigated load characteristics which based on development of sea water cooling system and optimum fish hold storage. The experimental results is as follows. In creasing the speed of compressor and mass blew rate of refrigerant, the temperature of NaCl solution is low. And the load characteristics experiment on fish hold storage outlet is as fellows. As time goes by, increasing the mass flow rate of NaCl solution, temperature difference between inlet and outlet is small in a model of fish hold storage. These results provide many useful informations applicable to an actual design of sea water cooling system and optimum fish hold storage.

• Journal of Mechanical Science and Technology
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• 제18권5호
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• pp.820-829
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• 2004

The In-Containment Refueling Water Storage Tank (IRWST), one of the design improvements applied to the APR -1400, has a function to condense the high enthalpy fluid discharged from the Reactor Coolant System (RCS). The condensation of discharged fluid by the tank water drives the tank temperature high and causes oscillatory condensation. Also if the tank cooling water temperature approaches the saturated state, the steam bubble may escape from the water uncondensed. These oscillatory condensation and bubble escape would burden the undue load to the tank structure, pressurize the tank, and degrade its intended function. For these reasons simple analytical modeling and experimental works were performed in order to predict exact tank temperature distribution and to find the effective cooling method to keep the tank temperature below the bubble escape limit (93.3$^{\circ}C$), which was experimentally proven by other researchers. Both the analytical model and experimental results show that the temperature distributions are horizontally stratified. Particularly, the hot liquid produced by the condensation around the sparger holes goes up straight like a thermal plume. Also, the momentum of the discharged fluid is not so strong to interrupt this horizontal thermal stratification significantly. Therefore the layout and shape of sparger is not so important as long as the location of the sparger hole is sufficiently close to the bottom of the tank. Finally, for the effective tank cooling it is recommended that the locations of the discharge and intake lines of the cooling system be cautiously selected considering the temperature distribution, the water level change, and the cooling effectiveness.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.1279-1284
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• 2008

The alternative energy has lately attracted considerable attention due to the high oil price and environment problem. Deep sea water that is one of the natural energy sources should be getting popular continually to reduce the environment problem. In this study, cooling system of deep sea water using heat exchangers of two hotels where is located in near Hae-undae Bay has been analyzed on the quantity of electricity comparison between existing cooling system and deep seawater cooling system. As shortly, the results of study showed that the first building approximately saves 370 millions won per year, also the second building saves 248 millions won per year. It means that the cooling system by using deep sea water has great worth to reduce the ratio of fossil fuel.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.893-898
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• 2014

Recently, the interior permanent synchronous motor (IPMSM) has been applied to an integrated starter and generator (ISG) for hybrid electric vehicles. In the design of such a motor, thermal analysis is necessary to maximize the power density because the loss is proportional to the power of a motor. Therefore, a cooling device as a heat sink is required internally. Generally, a cooling system designed with a water jacket structure is widely used for electric motors because it has advantages of simple structure and cooling effectiveness. An effective approach to analyze an electric machine with a water jacket is a thermal equivalent network. This network is composed of thermal resistance, a heat source, and thermal capacitance that consider the conduction, convection, and radiation. In particular, modeling of the cooling channel in a network is challenging owing to the flow of the coolant. In this paper, temperature prediction using a thermal equivalent network is performed in an ISG that has a water cooled system. Then, an experiment is conducted to verify the thermal equivalent network.

• 한국산학기술학회논문지
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• 제9권3호
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• pp.599-604
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• 2008

본 연구에서는 냉방운전 시에 팬코일 유닛에 사용되는 핀-관 열교환기의 공기측 열전달 능력과 압력강하를 실험을 통하여 조사하였다. 실험을 위하여 칼로리미터와 항온수조를 이용하였다. 사용된 핀은 슬릿핀이며 5종 열교환기에 대해 배관회로와 실험조건을 변화하면서 실험하였다. 공기-물 정격유량에서의 냉방능력은 열교환기 공급 물온도가 낮은 조건이 우수하였으며, 배관회로에 따른 냉방능력은 배관 내 물흐름이 U형보다 ㄹ형인 경우에 더 크게 나타났다. 물유량이 증가할수록 냉방능력은 일정비율로 증가하였으며, 열교환기 공급 물 온도가 낮을 때 우수하였다. 공급 물 온도가 낮은 조건에서 많은 응축수가 생성되어 공기측 압력강하는 크게 나타났다.

• 한국기계가공학회지
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• 제18권6호
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• pp.55-61
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• 2019

The purpose of this study was to numerically analyze the heat flow characteristics of an automotive radiator. Heat flow analyses were conducted on the cooling water and outdoor air of the radiator, as well as the temperature distribution of the cooling water after heat transfer. The results of the study revealed that neither heat transfer nor radiator volume was affected by the position of the inlet of cooling water. However, temperature distribution was affected by the position of both the inlet and outlet. In case of heat transfer, three models underwent about 158 kW of heat transfer. The difference in cooling water temperature was about $10^{\circ}C$. In case of pressure drop, the core external air side was reduced to about 1,375 Pa, and the internal cooling water side about 14,570 Pa.

• 설비공학논문집
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• 제4권4호
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• pp.263-276
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• 1992

The transmission current in a power cable is determined under the condition of separate pipe cooling. To this end, the thermal analysis is conducted with the standard condition of separate pipe cooling system, which constitutes one of the underground power transmission system. The changes of transmission current in a power cable with respect to the variation of temperatures and flow rates of inlet cooling water as well as the cooling spans are also determined. As a consequnce, the corresponding transmission current is shown to vary within allowable limit, resulting in the linear variation of the current for most of the cable routes. The abrupt changes of current, however, for the given flow rate of inlet cooling water in some cooling span lead to the adverse effects on the smooth current transmission within the underground power transmission system. In practice, it is expected that the desinging of the separate pipe cooling system in conjunction with the evaluation of system capacity should take into account the effects of design condition on the inlet cooling flow rate.

• 한국추진공학회지
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• 제20권2호
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• pp.1-10
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• 2016

고성능 고체 입자 연소를 위해 제안된, 로켓 엔진 기술이 접목된 연소실이 기존 연구를 통해 제시되었고, 본 연구에서는 연소실 벽면의 냉각해석을 수행하였다. 실제 연소실 제작에 앞서 연소율과 함께 냉각성능을 평가하기 위한 수치해석을 수행하였다. 연소실 벽면을 냉각하는 방식중 수냉각 방법을 적용하였고, 연소해석을 수행하여 선정한 냉각유량의 적정성을 검증하였다. 그리고 수냉각과 병행하여 공기 막냉각 방법을 이용한 복합냉각 방식을 적용한 수치해석 연구를 수행하였다. 해석 결과, 공기 막냉각만을 적용한 방식보다 막냉각과 수냉각을 복합적으로 적용한 냉각 방식이 더 우수한 냉각성능을 보였으며, 적용 가능한 범위의 냉각 유량을 산출하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1146_1147
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• 2009

This experiment is significant because we can provide information by measuring effect of energy saving for whom plan to install a geothermal heat & cooling system. The result shows geothemal system can save about 50% of energy(heating : 35%, cooling : 60%) and we verified that when using curtain can help saving 4~12% of energy additionally.

• 오토저널
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• 제5권1호
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• pp.89-93
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• 1983

This paper describes on experimental investigation into the heat dissipation of Diesel engine, placing emphasis on the variations of compression ratio and cooling water temperature. The engine used for this test was a vertical single-cylinder four-cycle type, having a direct injection. Engine performance and heat transfer rates was tested under the compression ratio 14.3 and 17.4. In this study, the results showed that output and transfer rates of engine decrease in accordance with the decrease of compression ratio. The effect of cooling water temperature and injection delay of fuel on the heat dissipation brings about the decrease of heat transfer rates from cylinder to cooling water.