• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1585-1591
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• 2010

DMFC uses oxygen by reactants. Therefore, cathode electrode must contact with outside air. However, when used in mobile devices, the user's body by blocking the air intake on the oxygen supply DMFC con not. DMFC to supply air to the cooling fan is used. However, by using cooling fan, air inlet to the pressure loss and changes will occurs, the output will be worse. In this paper, we designed air supplying system using piezo actuators. We DMFC evaluation system was implemented, verified the performance of air supplying system. And the operation was connected to an MP3 player.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.527-530
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• 2010

A performance test of an air cycle machine with an air to air heat exchanger was performed. The air cycle machine designed for avionics cooling in a fighter's external pod is a small turbo machine operated on the reverse Brayton air cycle driven by captured ram air which is the source of driving energy and it can be used as cooling fluid going through electronics in the pod during the flight. The air to air heat exchanger was also used to avoid moisture for avionics. The performance test have verified that the developed ACM and heat exchanger meet the design requirements.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.11
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• pp.873-879
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• 2014

In the present study, water vapor is injected at various positions in a Clean Dry Air (CDA) system such as a system inlet duct, compressor inlet, and compressor outlet by humidified air turbines. The application of evaporative cooling reduces the compression work and enhances the Energy Consumption Index (ECI) per unit volume. The main purpose of this study is to investigate the compressor power performance with different inlet air temperatures and humidity conditions. It is found that the actual power consumption and discharge flow are significantly influenced by the inlet air temperature as well as relative humidity. The results obtained during this study are compared both numerically and experimentally and are found to be in very good agreement.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.05a
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• pp.19-24
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• 1998

vortex tube의 에너지 분리현상이 Ranque에 의해 처음으로 발견된 이래 vortex tube는 산업현장에서의 그 이용률이 점차 증대되고 있다. 특히, 최근에는 작업자의 쾌적한 작업환경을 조성하여 작업능률을 향상시킬 목적으로 제철소 등의 고온, 고습 작업장이나 분진, 석면, 유해먼지나 가스, 증기 등이 많이 발생하는 작업장에서 냉각복(air cool jacket) 또는 공기공급식 호흡보호구의 공기공급시스템에 많이 활용되고 있다. 이러한 vortex tube를 이용한 냉각복 및 호흡보호구는 작업자의 능률향상뿐만 아니라 직업병의 예방 및 안전측면에서 매우 효율성이 높아 그 적용범위가 점차 확대될 전망이다. (중략)

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.10
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• pp.693-698
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• 2017

The 18650 battery cell is known to be reliable and cost effective, but it has a design limitation and low electric capacity compared to pouch-type cells. Because its economy is superior, an 18650-cell-type battery pack is chosen. A reliable temperature is very important in automobile battery packs. Therefore, in this study, the temperature stability of the battery pack is predicted using CFD simulation. Following 3C discharge tests, the results for the heat generation of the battery cell are compared to the simulation results. Based on these results, a natural convection condition, forced convection condition, direct cell-cooling condition, cooling condition on the upper and lower surfaces of the battery pack, and cooling condition using air channels are all simulated. The results indicate that the efficiency and the performance of the air-channel-type cooling system is good.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.802-807
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• 2010

The high efficient and cooling system is very important to the control panels of electrical distributors, and Industrial automated system including computer. Also, it can be used widely in various industrial systems such as industrial robots, numerically controlled machining center, and so on. The cooling method which flowing gasses were forced to circulate by compulsion was adapted in this study. then development of counter flow type of cooling system for effective panel cooling. In the present study, fin assembly was developed for this cooling system. As results, the developed system has the improvements of cooling performances and radiant heat ratio. Its increasing of airflow mass is about 20%, and radiation rate of heating is twice or more as high as the conventional system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.8
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• pp.767-774
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• 2010

In a passive-type PEMFC stack, axial fans operate to supply both oxidant and coolant to cathode side of the stack. It is possible to make a simple system because the passive-type PEMFC stack does not require additional cooling equipment. However, the performance of a cooling system in which water is used as a coolant is better than that of the air-cooling system. To ensure system reliability, it is essential to make cooling system effective by adopting an optimal stack design. In this study, a numerical investigation has been carried out to identify an optimum cooling strategy. Various channel configurations were applied to the test section. The passive-type PEMFC was tested by varying airflow rate distribution at the cathode side and external heat transfer coefficient of the stack. The best cooling performance was achieved when a channel with thick ribs was used, and the overheating at the center of the stack was reduced when a case in which airflow was concentrated at the middle of the stack was used.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.3
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• pp.397-404
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• 2004

냉각탑이란 석유화학플랜트, 철강플랜트 등과 같은 생산 공정이나 냉동기를 비롯한 각종 기계장치에서 발생된 열을 수냉식 열 교환장치에서 물로 직접 냉각시킬 때 공정유체의 열을 전달받아 데워진 물을 대기의 공기와 직접 접촉시켜 물의 증발 잠열을 이용하여 원하는 온도로 냉각시켜 주는 기계장치이다.(중략)

• Resources Recycling
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• v.11 no.3
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• pp.25-30
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• 2002

Heat transfer occurring in the rotary cooler was analyzed by applying a one-dimensional steady state. The temperature of inlet gas and the measured temperature of outlet gas were used as boundary conditions. Axial temperature distribution of solid, gas and wall were calculated by solving two differential equations and two algebraic equations under the constraint of two point boundary conditions and operating conditions. The temperatures of outer wall calculated in this study were in good agreement with those measured from running rotary cooler.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.8
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• pp.69-76
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• 2003

For stable combustion and safety of a structure of the propulsion system, a cooling system to the liquid rocket engine should be incorporated. In this study, Eulerian-Lagrangian scheme for two phase combustion, nongray radiation and soot formation effect, and film-wall interaction have been introduced to study the effect of film cooling. After briefly introducing the governing equation, combustion characteristics with change of wall temperature has been investigated by varying such parameters as fuel mass fraction for film cooling, diameter of the fuel droplet, overall mixture fraction of oxygen to fuel. Also, radiative heat flux is compared with the conductive one at the combustor wall.