• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1499-1505
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• 2003

Rapid development of electronic technology requires small size, high density packaging and high power of electronic devices. So, in this paper, characteristics on oscillating heat pipe according to operating conditions(environment temperature, charging ratio of working fluid, inclination) based on experimental study was investigated. From the experimental results, $25^{\circ}C$environment temperature), R-141b(working fluid)40%(charging ratio) was best performace at others of inclination angle and The top heating mode of OCHP performed 80% efficiency of the bottom heating mode.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1330-1335
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• 2007

The HVAC and the air duct is to make optimal indoor environment. By the HVAC position, method and the air duct construction, the important elements can affect on cooling performance, passengers' convenience, and energy efficiency. According to this, there are features, such as the indoor temperature distribution, cooling performance, velocity distribution from diffuser, tend to be come out variously. Also, comparing and analysing temperature distribution, cooling performance, air velocity, noise based on the real practical vehicle tests, it shows features in detail. Besides, it can lead to make design the system of HVAC & air duct effectively.

• 설비공학논문집
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• 제14권5호
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• pp.377-384
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• 2002

For economic evaluation of cooling plant equipments, it is necessary to simplify energy Prediction method, which should includes efficiency corrected by part-load ratio. This study proposed simplified method with regression equations of time-average partial loads and refrigerator capacity. DOE-2 Program was used to carry out a parametric study of twelve design variables. Five input variables were considered to be significant and were used in the regression equations. To test accuracy of simplified method, calculated results were compared with DOE-2 simulated results. Test result showes a good agreement with the simulation result with an error of 5.9∼7.6%. It is expected that this method can be used as an easy prediction tool for comparing energy use of different cooling plants during the early design stage.

• Design & Manufacturing
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• 제10권3호
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• pp.39-45
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• 2016

The purpose of this study is to build effective cooling circuit design in injection mold to improve glass fiber reinforced laptop computer cover plastics' transcription and gloss. Moldflow Insight and Ansys CFD CAE program used to verify efficiency and the experiment mold is precision machined and brazing soldered to make three-dimension cooling channel. The temperature of mold in injection test are fixed to $80^{\circ}C$ and $160^{\circ}C$. The result of this experiment is the improved surface quality of plastics with 85% improvement of transcription in high temperature mold.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.1091-1095
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• 2005

This study is performed to develop a tripple-tube exchanger which can improve the system efficiency. Three different tube diameters are compacted by one body(tripple-tube) to recover waste heat from heat exchanging among the fluids. With this, the tripple-tube shows higher cooling capacity than the double-tube after comparing between those two systems. The results of this study are basic data to design the optimum tripple-tube heat exchanger.

• 한국해양공학회지
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• 제21권3호
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• pp.1-7
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• 2007

In this study, the heat balance test of an engine was conducted, and the heat released to coolant is measured and corrected using a power adjustment factor for high fuel temperature to simulate heat rejection of the engine. An engine-converter matching simulation program which can compute the engine speed, transmission output speed, transmission input and output power is developed from the vehicle, transmission and engine performance curve. With this information and the engine heat rejection characteristics, the engine and transmission heat rejection rates can be determined at given condition. In analyzing the air mass flow, a sub program computing the air mass flow rate from the equation of the pressure balance between cooling fan static pressure rise and pressure losses of cooling components is developed.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.174-178
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• 2011

This paper deals with the free cooling system of express bus using natural energy source in order to improve the room air quality and save cooling energy. In an express bus, there are may passengers in unit area, requiring the improvement of air quality and giving higher energy saving efficiency. Particularly, the express buses running fast make it easy to take in outdoor air at a flow rate controllable with a damper mechanism. This paper proposes the analysis on the air flow achieved by a damper controlled vertically and horizontally in order not to deteriorate the ride comfort of the passengers.

• 설비공학논문집
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• 제9권4호
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• pp.446-453
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• 1997

The superconducting winding in rotor of a superconducting generator should be kept at extremely low temperature of 4-5 K to maintain the superconducting state. For this purpose the liquefied helium is used for the coolant and it is very important to analyze and design a cooling system making effective use of the coolant. In this paper, the typical heat exchanger of a superconducting generator with the flow passage is analyzed with regard to the thermal equilibrium. An experimental constant relevant to the flow condition in the flow passage is determined with heat exchange experiments in cryostat. Also a new heat exchanger with porous material is proposed and designed. Results of the numerical analysis for the temperature distributions for the torque tube and the coolant are reported and the efficiency of the heat exchanger is discussed from the viewpoint of amounts of coolant needed.

• Journal of Advanced Marine Engineering and Technology
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• 제32권4호
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• pp.596-602
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• 2008

The cooling system is one of the most concerning factor for the reliability of the electric propulsion ship. Generally, a drive system operation in higher temperature decreases the device's reliability and power efficiency. The management of power loss and temperature of switching devices is indispensable for the reliability of the power electric system. In this paper, the switching devices are molded by IGBT, and the propulsion system is consisted of MIIR(Motor with Inverter Internal to Rotor). The system composition interacts with each other to calculate the loss and temperature of device. The calculation result is used for modeling and designing of the control and monitoring system for the electric propulsion system.

• 대한기계학회논문집B
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• 제31권2호
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• pp.116-124
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• 2007

An adsorption chiller is expected to have high energy-efficiency in utilizing the waste heat exhausted from a process. The objective of this paper is to investigate the performance of silica gel-water adsorption chiller from the cycle simulation and to provide a guideline for design of the adsorption chiller. The effect of cycle time, inlet temperature and water flow rate on the cooling capacity and COP is quantified during the cycle operation. It is found that the performance of adsorption chiller is more sensitive to the change of inlet water temperature rather than the water flow rate. It is concluded that the COP is 0.57 in the standard conditions(hot water $80^{\circ}C$, cooling water $30^{\circ}C$, chilled water inlet temperatures $14^{\circ}C$ and cycle time 420sec).