• 제목/요약/키워드: Heating and Cooling Channel

검색결과 32건 처리시간 0.026초

마이크로 채널 디자인에 따른 온 칩 액체 냉각 연구 (Study of On-chip Liquid Cooling in Relation to Micro-channel Design)

  • 원용현;김성동;김사라은경
    • 마이크로전자및패키징학회지
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    • 제22권4호
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    • pp.31-36
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    • 2015
  • 전자소자의 다기능, 고밀도, 고성능, 그리고 소형화는 전자 패키지 기술에 초미세 피치 플립 칩, 3D 패키지, 유연 패키지, 등 새로운 기술 패러다임 전환을 가져왔으며, 이로 인해 패키지 된 칩의 열 관리는 소자의 성능을 좌우하는 중요한 요소로 대두되고 있다. Heat sink, heat spreader, TIM, 열전 냉각기, 등 많은 소자 냉각 방법들 중 본 연구에서는 냉매를 이용한 on-chip 액체 냉각 모듈을 Si 웨이퍼에 제작하고, 마이크로 채널 디자인에 따른 냉각 효과를 분석하였다. 마이크로 채널은 딥 반응성 이온 에칭을 이용하여 형성하였고, 3 종류 디자인(straight MC, serpentine MC, zigzag MC)으로 제작하여 마이크로 채널 디자인이 냉각 효율에 미치는 영향을 관찰하였다. 가열온도 $200^{\circ}C$, 냉매 유동속도 150 ml/min의 경우에서 straight MC가 약 $44^{\circ}C$의 높은 냉각 전후의 온도 차를 보였다. 냉매의 흐름과 상 변화는 형광현미경으로 관찰하였으며, 냉각 전후의 온도 차는 적외선현미경을 이용하여 분석하였다.

마이크로 캡슐 잠열재 슬러리를 적용한 미소채널 열교환기의 열분배 성능평가 (Experimental Study on the Heat Distribution in the Rectangular Mini Channel Heat Exchangers with MPCM Slurry)

  • 전종욱;백창현;김용찬;김영득;최종민
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.645-650
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    • 2006
  • The heat transfer performance and energy transport ability are relatively high due to higher specific heat. Therefore, it can be used in fields such as heating, ventilating, air-conditioning, refrigeration and heat exchangers. In this study, liquid-cooling heat exchangers were designed and tested by varying geometry and operating conditions. In addition, liquid-cooling heat exchangers were tested to provide performance data for MPCM slurry. The liquid-cooling heat exchangers had twelve rectangular channels with flow paths of 1, 2, 4 and 12. Silicon rubber heaters were used to control the heat load to the heat exchanger. Heat input ranged from 293 to 800 W, and inlet temperatures of working fluid varied from 15S to $27^{\circ}C$. The standard deviation of surface temperature was strongly affected by the coolant of MPCM Slurry, All MPCM-cooling heat exchangers showed higher cooling performance than the water-cooling heat exchanger except one path channel heat exchanger.

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Jet A-1 연료의 열전달 특성에 관한 실험적 연구 (Experimental Study on Heat Transfer Characteristics of Jet A-1 Fuel)

  • 이준서;이봄;안규복
    • 한국추진공학회지
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    • 제24권5호
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    • pp.1-12
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    • 2020
  • 본 논문에서는 재생냉각 연소기에서 냉각제 및 연료로 사용되는 Jet A-1의 열전달 특성에 대해 실험적으로 연구하였다. 냉각채널 가열을 위한 인가 전류, 모사 시편 지름, 시편 후단 압력, Jet A-1 유속을 변화시키며, 시편에서의 벽면 온도 및 시편 전/후단에서의 Jet A-1 온도를 측정하였다. 시편 지름과 유속이 열전달 특성에 중요한 인자임을 알 수 있었으며, 시편의 후단 압력은 열전달 성능에 영향을 주지 않음을 확인할 수 있었다. 열전달 실험결과는 기존 Nu수 경험식들과 비교하였으며, 최종적으로 새로운 Nu수 경험식을 도출하였다.

다공형 유로를 적용한 전열교환기 소자의 성능향상에 관한 연구 (A Study on Improvement of Performance for Perforated Type Total HEX Element)

  • 곽경민;배철호;김지용;주의성
    • 설비공학논문집
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    • 제19권7호
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    • pp.529-536
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    • 2007
  • The perforated type element for a heat recovery ventilation system has been studied to improve the performance. Four holes of diameter of 6mm are punched out for each flow channel to break the boundary layer development and increase the turbulence. KS cooling and heating conditions and test procedures are applied for study. The efficiencies are compared to those of the typical element with smooth surface. For cooling operations, the temperature, latent and enthalpy efficiencies increase 2.5%, 18% and 8%, respectively. For heating operations, the temperature, latent and enthalpy efficiencies increase 3%, 5% and 3.2%, respectively.

환상유로에 있어서 수직고온관의 과도적 냉각과정에 관한 연구 (A study on the transient cooling process of a vertical-high temperature tube in an annular flow channel)

  • 정대인;김경근
    • Journal of Advanced Marine Engineering and Technology
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    • 제10권2호
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    • pp.156-164
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    • 1986
  • In the case of boiling on high temperature wall, vapor film covers fully or parcially the surface. This phenomenon, film boiling or transition boiling, is very important in the surface heat treatment of metal, design of cryogenic heat exchanger and emergency cooling of nuclear reactor. Mainly supposed hydraulic-thermal accidents in nuclear reactor are LCCA (Loss of Coolant Accident) and PCM (Power-Cooling Mismatch). Recently, world-wide studies on reflooding of high temperature rod bundles after the occurrence of the above accidents focus attention on wall temperature history and required time in transient cooling process, wall superheat at rewet point, heat flux-wall superheat relationship beyond the transition boiling region, and two-phase flow state near the surface. It is considered that the further systematical study in this field will be in need in spite of the previous results in ref. (2), (3), (4). The paper is the study about the fast transient cooling process following the wall temperature excursion under the CHF (Critical Heat Flux) condition in a forced convective subcooled boiling system. The test section is a vertically arranged concentric annulus of 800 mm long and 10 mm hydraulic diameter. The inner tube, SUS 304 of 400 mm long, 8 mm I.D, and 7 mm O.D., is heated uniformly by the low voltage AC power. The wall temperature measurements were performed at the axial distance from the inlet of the heating tube, z=390 mm. 6 chromel- alumel thermocouples of 76 .mu.m were press fitted to the inner surface of the heating tube periphery. To investigate the heat transfer characteristics during the fast transient cooling process, the outer surface (fluid side) temperature and the surface heat flux are computed from the measured inner surface temperature history by means of a numerical method for inverse problems of transient heat conduction. Present cooling (boiling) curve is sufficiently compared with the previous results.

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로켓엔진 연소기 재생냉각채널을 모사한 탄화수소계 연료가열시험 (Hydrocarbon Fuel Heating Experiments Simulating Regeneratively Cooled Channels of LRE Combustor)

  • 임병직;이광진;김종규;양승호;김희태;강동혁;김홍집;한영민;최환석
    • 한국추진공학회지
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    • 제11권5호
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    • pp.78-84
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    • 2007
  • 탄화수소계 연료를 사용하는 재생냉각 로켓엔진 연소기에서는 벽면온도가 올라감에 따라 냉각채널 벽면에 화합물이 침전되는 코킹현상이 발생하는 것으로 알려져 있다. 이 현상은 냉각 유체에 의한 냉각 성능을 감소시키고 결과적으로 과열에 의한 연소기 손상을 야기할 수 있다. 본 논문에서는 재생냉각채널을 모사하는 전기가열장치 실험결과를 소개하고 실험결과를 바탕으로 구리합금과 탄화수소계 연료(Jet A-1)와의 적합성에 대해서 검토하였다.

Micro Mold 제작 및 RTP 공정에 의한 미세 패턴의 성형 (Micro Mold Fabrication and the Micro Patterning by RTP Process)

  • 김흥규;고영배;강정진;임성한;오수익
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 추계학술대회논문집
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    • pp.294-297
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    • 2004
  • RTP(Rapid Thermal Pressing) is to fabricate desired pattern on polymer substrate by pressing patterned mold against the substrate heated around glass transition temperature. For a successful RTP process, the whole process including heating, molding, cooling and demolding should be conducted 'rapidly' as possible. As the RTP process is effective in replicating patterns on flat large surface without causing shape distortion after cooling, it is being widely used for fabricating various micro/bio application components, especially with channel-type microstructures on surface. This investigation finally aims to develop a RTP process machine for mass-producing micro/bio application components. As a first step for that purpose, we intended to examine the technological difficulties for realizing mass production by RTP process. Therefore, in the current paper, 4 kinds of RTP machines were examined and then the RTP process was conducted experimentally for PMMA film by using one of the machines, HEX 03. The micro-patterned molds used for RTP experiment was fabricated from silicon wafer by semi-conduct process. The replicated micro patterns on PMMA films were examined using SEM and the causes of defect observed in the replicated patterns were discussed.

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태양열 공기-물 가열기의 공기 가열 성능 평가 및 열적 성능 개선을 위한 실험적 연구 (Experimental Study for Estimation of Air Heating Performance and Improvement of Thermal Performance of Hybrid Solar Air-water Heater)

  • 최휘웅;김영복;윤정인;손창효;최광환
    • 한국태양에너지학회 논문집
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    • 제37권1호
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    • pp.47-57
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    • 2017
  • Solar energy is one of the important renewable energy resources. It can be used for air heating, hot water supply, heat source of desiccant cooling system and so on. And many researches for enhancing efficiency have been conducted because of these various uses of solar thermal energy. This study was performed to investigate the air heating performance of hybrid solar air-water heater that can heat air and liquid respectively or simultaneously and finding method for improving thermal performance of this collector. This collector has both liquid pipe and air channel different with the traditional solar water and air heater. Fins were installed in the air channel for enhancing the air heating performance of collector. Also air inlet & outlet temperature, ambient temperature and solar collector's inner part temperature were confirmed with different air velocity on similar solar irradiance. As a result, temperature of heated air was shown about $43^{\circ}C$ to $60^{\circ}C$ on the $30^{\circ}C$ of ambient temperature and thermal efficiency of solar collector was shown 28% to 73% with respect to air velocity. Also, possibility of improvement of thermal performance of this collector could be ascertained from the heat transfer coefficient calculated from this experiment. Thus, it is considered that the research for finding optimal structure of hybrid solar air-water heater for enhancing thermal performance might be needed to conduct as further study based on the method for improving air heating performance confirmed in this study.

설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제27권7호
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

핀-휜 구조물을 삽입한 채널의 열전달 특성과 압력강하에 관한 수치해석 (Numerical Analysis on the Heat Transfer and Pressure Drop Characteristics of a Channel with Pin-fin Structure)

  • 허주녕;김지훈;손영석;신지영
    • Journal of Advanced Marine Engineering and Technology
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    • 제35권2호
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    • pp.224-231
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    • 2011
  • 핀-휜 구조물이 삽입된 채널은 열전달이 향상되는 것으로 알려져 있다. 복잡한 핀-휜 구조물은 다공성 매체로 모사할 수 있을 만큼 매우 불규칙적인 유동을 보여준다. 본 연구는 수치해석을 통하여 핀-휜 구조물이 삽입된 채널의 열전달과 압력강하의 특성을 분석하였다. 유효유동공간비가 높고 직경이 큰 경우 실험데이터를 잘 예측 하였지만, 유효유동공간비가 낮은 경우 비교적 오차가 큰 편이었다. 유효유동 공간비가 낮을수록 유동교란이 강해져서 열전달이 증가하지만 압력강하도 증가하여 팬의 동력이 증가하기 때문에 최적점을 찾아서 설계하여야 한다. 본 연구에서는 전면유속이 5m/s 일 때, D25 모델에서는 유효유동공간비가 0.5인 지점에서, D05 모델에서는 0.9에서 압력강하가 급격하게 늘어나기 때문에 이보다 더 작은 유효유동공간비에서의 작동은 바람직하지 않다.