• 한국기계가공학회지
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• 제13권2호
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• pp.124-130
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• 2014

In a mass manufacturing system of optical fibers, the sufficient cooling of glass fibers freshly drawn from a draw furnace is essential, asinadequately cooled glass fibers can lead to poor resin coating on the fiber surface and possibly fiber breakage during the process. In order to improve fiber cooling at a high drawing speed, it is common to use a helium injection into a glass fiber cooling unit in spite of the high cost of the helium supply. The present numerical analysis carried out three-dimensional thermo-fluid computations of the cooling gas flow and heat transfer on moving glass fiber to determine the cooling performance of glass fiber cooling depending on the method of helium injection. The results showed that afront injection of helium is most effective compared to a uniform or rear injection for reducing air entrainment into the unit and thus cooling the glass fibers at a high fiber drawing speed. However, above a certain amount of injected helium, there was no more increase of the cooling effect regardless of the helium injection method.

• 대한기계학회논문집B
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• 제37권11호
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• pp.1047-1051
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• 2013

최신의 전투장갑차들은 통합형 공조장치를 선호하는 경향이 있음에도 불구하고 분리형 공조장치에 대한 필요성이 제기되고 있다. 본 연구에서는 특수목적용 장갑차량 및 군용규격이 요구되는 장갑차량의 냉방, 난방장치에 대한 연구로 상용 Fluent 를 이용한 유동해석을 통해 덕트 및 최적화 배치를 구현하였으며 실차을 통한 시험 수행으로 해석결과를 검증하고, 선정된 냉방 및 난방기의 유효성을 확인하였다. 기존 차량의 변경 모델이나 계열차량의 경우, 현재 선정된 모델의 부분 변경으로 가능하며, 차륜형 장갑차용으로 선정된 현재 모델의 유효성을 본 연구를 통해서 입증되었다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.263-268
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• 2008

In a residential complex case, the efficiency of land use are maximized, but a variation of external condition such as load in-equality, the increase in wind velocity and solar radiation by a height causes increasing energy in a building. Besides, because of increasing window size for a lighting and a view, it comes heating load in winter and cooling load in summer. A choice of cooling-system is important for this reason. Recently an internal high-rise residential complex installs an air-cooling system and operates individual heating. However, this study applies water-cooling used one public cooling-tower instead of an air-cooling system, also with an efficiency test of an air and a water-cooling system, consider an internal applicability.

• 한국수소및신에너지학회논문집
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• 제29권2호
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• pp.212-218
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• 2018

Li-ion battery system is regarded as one of the most potent power sources for electrified power-trains. For the Li-ion battery system to be widely adopted in automotive applications, the performance, safety, and cycle life issues need to be properly addressed. These issues are closely related to the thermal management of battery system. Especially, the effective cooling module design is the core part for the novel battery thermal management system development. In this paper, an experimental approach was carried out as a basic part of comprehensive battery thermal management research. The main goal of this paper is to present a comparison of two cooling systems (air cooling and phase change material (PCM) based cooling) of the unit 18650 battery module. The temperature rise with different battery discharge rate (c-rate) was mainly investigated and analyzed for two types of battery cooling systems. It is expected that this study can properly contribute to providing basic insights into the design of robust battery thermal management system for vehicular applications.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.249-256
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• 2009

The cooling technology of power conversion semiconductors in the propulsion system for the HEMU(High Electrical Multi Unit) are applied in water cooling method and phase change method such as the immersed type and the heat pipe type. This research designs and manufactures the water cooling system that could cool about heat load Q=2kW and performance tests to apply it by an electric power conversion semiconductors(IGBT) cooling technology. Experimental condition made change of a flow rate, an air velocity and a heat load to confirm operation characteristics of water cooling device, and when is heat load 2kW, air velocity 20 m/s, and water flow rate 7kg/s, it is about $80^{\circ}C$ to temperature of cooling plate.

• 한국정밀공학회지
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• 제19권5호
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• pp.7-12
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• 2002

• 설비공학논문집
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• 제20권3호
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• pp.189-196
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• 2008

The increase of system weight due to installation of cooling devices adds electrical and mechanical loads of humanoid robot, and in return, results in much heat. Therefore, the weight of cooling system is a critical issue for robot cooling. In this study, we propose non-metallic cold plates to deal with such problems. We compare thermal performances between one metallic cold plate and five different types of non-metallic cold plates. A metallic cold plate is totally made of copper. Five non-metallic PC(polycarbonate) cold plates, which are designed to reduce the overall weight of robot cooling system, are composed of a polycarbonate cover with different types of base plate. The overall heat transfer coefficients per unit mass and thermal resistances are obtained for the cold plates. The metallic cold plate shows the best thermal performance. It is interesting to note that the PC cold plate with an aluminum base plate with 18 channels shows the best overall heat transfer coefficient per unit mass. Most polycarbonate cold plates display fairly comparable thermal performance with more reduced system weight compared to the metallic cold plate.

• 한국태양에너지학회 논문집
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• 제31권5호
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• pp.77-84
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• 2011

Korea and some other countries located in the northern hemisphere employ the air conditioner for the space cooling in the hot summer season and also some kinds of heaters for the space heating in the cold winter season. Especially in Korea, a great number of air conditioners of about 12,700,000 sets have been used these days. However, they are used for a short operation period of only 58 days a year, which results in the material and economic losses. To solve this problem and employ this system for the emergency shelter, a new conversion unit which could convert the existing air conditioner to a heat pump system for simultaneous heating and cooling was developed in this study, and the thermal performance was tested. The results indicated that the indoor air could be heated from $27^{\circ}C$ to $39^{\circ}C$ by the air conditioner converted to a heat pump system with the ambient temperature variation of $-10^{\circ}C{\sim}10^{\circ}C$, and cooled from $20^{\circ}C$ to $15^{\circ}C$ by the converted system with the ambient temperature variation of $20^{\circ}C{\sim}35^{\circ}C$. And also the heating COP increased from 3.3 to 5.3 in case of the heat exchange of the super cooling(HESC) circuit and from 3.0 to 4.0 in case of the By-pass with the ambient temperature variation of $-10^{\circ}C{\sim}10^{\circ}C$, respectively, whereas the cooling COP decreased from 3.1 to 2.1with the increase of the ambient temperature from $20^{\circ}C$ to $35^{\circ}C$.

• 설비공학논문집
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• 제20권4호
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• pp.221-229
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• 2008

This study analyze indoor thermal comfort properties such as PMV, PPD and fluid variables when the cooling loads are light, occupant and ventilation. There are 6 cases to study for the indoor unit installation conditions and ventilation rates. Numerical method is used to study the indoor environmental properties and experimental study is adapted to analyze reaching time by variable cooling load conditions.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.507-513
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• 2009

The cooling technology of power conversion semiconductors in the propulsion system for the HEMU(High Electrical Multi Unit) are applied in water cooling method and phase change method such as the immersed type and the heat pipe type. Both of cooling systems need a condenser and a fan through forced wind to emit that is radiated heat from electric power conversion semiconductor(IGBT) stack effectively, now in the case of Japanese Fastec 360S, is using ram-air that is flowed in establishing cooling passage to propulsion system for cooling of condenser. In this research, it is that achieved the computing numerical analysis using ADINA of commertial program to examine flow characteristics and pressure distribution of ram-air for a condenser in cooling passage.