• 대한기계학회논문집B
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• 제28권4호
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• pp.415-424
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• 2004

Cooling the electronic equipment is one of the major focal points of the design process and the key to successful product launch. The two-phase loop thermosyphone which is a good candidate among many available options was investigated fur cooling of the high power amplifiers. The system is composed of evaporator which contains 6 parallel cold plates, fan cooled condenser, gas-liquid separator, and interconnecting tubes. Experiments were performed for several refrigerant charging values, hs and as a experiment result, the optimum charging value fur this system was proposed. In order to optimize the system design, the operating cycle pressure and inlet/outlet temperatures of evaporator and condenser are measured and analyzed. The effect of the three parameters such as flow rate and temperature of condenser cooling air, and thermal load on the evaporator are investigated. The lower the operating pressure and the cycle temperatures are also better to prevent the leakage of the system. The system invesigated in this paper can be directly used for cooling of a real unmanned wireless communication station.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.290-291
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• 2017

This study deals with an evaluation method for testing the robustness of the 4 kW commercial power electronic cooling system to the thermal environment. The power electronic cooling system consists of a cascaded push-pull DC / DC converter, a three-phase DC / AC inverter, and an electric compressor. The system manufactured by the thermal environment evaluation test (heat distribution test, thermal impact test, high temperature operation test, temperature cycle test, low temperature operation test) for the commercial electric power cooling system for commercial vehicle proves that it is robust against thermal environment.

• Journal of Advanced Marine Engineering and Technology
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• 제32권6호
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• pp.854-861
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• 2008

Heat transfer characteristics of protruding electronic components in a horizontal channel are studied numerically. The system consists of two horizontal channels formed by two covers and one printed circuit board which has three uniform protruding heat source blocks. A two-dimensional numerical model has been developed to predict the conjugate heat transfer. and the finite volume method is used to solve the problem. Five different cooling methods are considered to examine the heat transfer characteristics of electronic components according to the different cooling methods. The velocity and temperature of cooling medium and the temperature of the heat source blocks are obtained. The results of the five different cooling methods are compared to find out the most efficient cooling method in a given geometry and heat sources.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3294-3299
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• 2007

These days the exhaustion of petroleum resources and environmental problems are getting serious. Many researchers are focused on low emission and high performance vehicles. Therefore, we should concern about emission regulation when we design a new car. In this study, we investigated the characteristics of the traditional mechanical engine cooling systems which control the engine temperature using engine speed and wax type thermostat. This experiment used three components which are Radiator fan, water pump and water valve controlled by an electronic system based on the engine status (load, speed). We elucidated how different between traditional mechanical cooling system and electronic cooling system which control coolant temperature and coolant flow rate in a DI diesel engine in this paper. The results revealed a fuel saving and an emission (CO, HC) reduction on NEDC cycle.

• 수산해양교육연구
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• 제16권2호
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• pp.210-217
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• 2004

Cooling technology has been a vital prerequisite for the rapid, if not explosive, growth of the electronic equipment industry. This has been especially true during the last 20 years with the advent of intergrated circuit chips and their applications in computers and related electronic products. The purpose of this study is to develop a telecommunication equipment cooling system using a thermoelectric module combined with cooling fan. Thermoelectric module is a device that can perform cooling only by input of electric power. In the present study, the cooling package using the thermoeletric module has been developed to improve the thermal performance. The cooling characteristics of the electronic chip was placed into the subrack and it can be rapidly assembled or disassembled in the equipment rack. As a preliminary experiment, the cooling performances between a conventional way using a cooling fin and a proposed method applying the thermoelectric module was comosed and analyzyed. The cooling performance at a simulated electronic component packaging a thermomodule operated well.

• 한국군사과학기술학회지
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• 제16권1호
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• pp.74-80
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• 2013

In this paper, we have proposed a vapor cycle refrigeration system as a cooling system to provide cooling air to the aircraft external reconnaissance stores. In the proposed vapor cycle system, receiver which prevents refrigerant from subcooling was eliminated and thermal expansion valve was replaced with electronic expansion valve. The vapor cycle refrigeration system is aimed to provide cooling air to the reconnaissance stores which is added to the aircraft in the form of external store. The wide temperature range of ambient air from the flight conditions can decrease the cooling performance and can make the refrigeration system unstable in low ambient temperature. Performance characteristics of the vapor cycle refrigeration system has been experimented under air conditions which is derived from the flight envelope. From the experiments, the vapor cycle refrigeration system has been proved to provide enough cooling air to the reconnaissance equipment and to be stable under all the flight conditions.

• Journal of Advanced Marine Engineering and Technology
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• 제28권1호
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• pp.46-55
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• 2004

Thermal characteristics of the various cooling methods in electronic equipment are studied numerically. A common chip cooling system is modeled as a parallel channel with protruding heat sources. A two-dimensional model has been developed for the numerical analysis of compressible. viscous. laminar flow. and conjugate heat transfer between parallel plates with uniform block heat sources. The finite volume method is used to solve this problem. The assembly consists of two channels formed by two covers and one printed circuit board that is assumed to have three uniform heat source blocks. Various cooling methods are considered to find out the efficient cooling method in a given geometry and heat sources. The velocity and the temperature fields. the local temperature distribution along the surface of blocks. and the maximum temperature in each block are obtained. The results are compared to examine the thermal characteristics of the different cooling methods both quantitatively and qualitatively.

• 한국산학기술학회논문지
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• 제11권1호
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• pp.13-20
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• 2010

본 연구의 목적은 Display 산업의 중요성에 주목하여 옥외 광고를 위한 LCD 패널용 콘솔(이하 'LCD 콘솔'이라 한다.)을 개발하는데 있다. 본 연구의 핵심 과제는 LCD 콘솔의 내부온도를 제어할 수 있도록 해주는 냉각시스템(Cooling System)을 개발하는 것이다. 냉각시스템은 상용화되어 있는 냉각휀(Cooling Fan), 히트싱크(Heat sinks), 열전소자(Thermo Electronic Module) 등의 제품들을 시스템적으로 통합시키는 응용기술로서 통계적 검정기법을 적용하여 개발되었다. 본 연구는 먼저 냉각시스템을 설계/제작한 후 실험을 통하여 냉각시스템 제어에 필요한 인자들의 설정 값들을 구하는 과정을 보였다. 이어서 개발된 냉각시스템을 이용하여 46인치 LCD Panel이 탑재된 LCD 콘솔을 설계/제작하고 실험을 통하여 완성품 LCD 콘솔의 성능을 확인하는 과정을 보였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.31-36
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• 2003

Recently, the power consumption and heat generation in an electronic equipment increase as the components are miniaturized and the computing speed becomes faster. Effective cooling method is required to ensure the guaranteed performance and reliable operation of the electronic devices. The aim of the present study is to investigate the cooling characteristics of a pin-fin heat exchanger as a candidate for cooling system of the electronic devices. Various configuration of the pin-fin array is selected in order to find out the effect of spacing and diameter of the pin-fin on the heat transfer characteristics. The results are compared with the experimental data or correlations of several researchers for the channel flow with pin-fin arrays.

• 동력기계공학회지
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• 제21권6호
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• pp.79-85
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• 2017

A heat pump system is a highly efficient, eco-friendly device which consumes a small amount of energy and supply a lot of energy for heat formation. In addition, it is a single device system that has low generation effect about carbon dioxide. There are many researches related to the electronic expansion valve and the heat pump, but the detailed data analysis of each influence is insufficient. In this study, the cooling capacity and COP of the heat pump system were investigated by varying frequency of the inverter connected to compressor, inlet temperature of chilled water into evaporator and inlet temperature of cooling water into condenser. The results are as follows : (1) The cooling capacity increased as the inverter frequency, inlet temperature of chilled water into evaporator increased, and inlet temperature of cooling water into condenser decreased. (2) The COP increased as the frequency of inverter, inlet temperature of cooling water into condenser decreased and the inlet temperature of chilled water into evaporator increased.