• 제목/요약/키워드: cooling source

검색결과 639건 처리시간 0.033초

육상 수조식 양식장의 해수 열원 히트펌프 시스템 적용을 위한 열부하 분석 (Thermal load analysis of tank culture system for applying seawater source heat pump)

  • 윤민기;김태훈;정석권
    • 수산해양기술연구
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    • 제59권2호
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    • pp.155-163
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    • 2023
  • This study deals with the maximum thermal load analysis and optimal capacity determination method of tank culture system for applying seawater source heat pump to save energy and realize zero energy. The location of the fish farm was divided into four sea areas, and the heat load in summer and winter was analyzed, respectively. In addition, two representative methods, the flow-through aquaculture system and the recirculation aquaculture system were reviewed as water treatment methods for fish farms. In addition, the concept of the exchange rate was introduced to obtain the maximum heat load of the fish farms. Finally, power consumption for heat pumps was analyzed in the view point of sea areas, tank capacity, and exchange rate based on the calculated maximum thermal load.

Cantera를 이용한 케로신 다단연소사이클 엔진용 산화제 과잉 예연소기 설계코드 개발 (Development of Design Code for Oxidizer-Rich Preburner of Staged Combustion Cycle Engine Using Cantera)

  • 강시윤;김성구;유철성;문인상
    • 한국추진공학회지
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    • 제26권6호
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    • pp.10-20
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    • 2022
  • 본 연구에서는 케로신 다단연소사이클 엔진용 예연소기를 설계하기 위해, 고압의 산화제 과잉 조건에서 예연소가스를 계산하고 냉각유로에서 극저온 유체의 복합열전달 및 수력 특성을 해석할 수 있는 설계코드를 개발하였다. 사용자 편의성과 범용성을 가진 오픈 소스 라이브러리 Cantera를 활용하였으며, 실제유체의 열역학/전달 상태량을 정확히 계산하기 위해 관련 소스 코드들을 새로 작성하여 Cantera에 추가하였다. 현재 예비설계 중인 100톤급 부스터 엔진용 예연소기에 적용하였으며, CFD 해석결과와 비교를 통해 설계코드로서의 예측 정확도와 활용성을 확인하였다.

설비공학 분야의 최근 연구 동향 : 2013년 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 2013)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제26권12호
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    • pp.605-619
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    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. 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 fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are 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 general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, 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 is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

Development of liquid target for beam-target neutron source & two-channel prototype ITER vacuum ultraviolet spectrometer

  • Ahn, B.N.;Lee, Y.M.;Dang, J.J.;Hwang, Y.S.;Seon, C.R.;Lee, H.G.;Biel, W.;Barnsley, R.;Kim, D.E.;Kim, J.G.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.421-422
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    • 2011
  • The first part is about development of a liquid target for a neutron source, which is designed to overcome many of the limitations of traditional beam-target neutron generators by utilizing a liquid target neutron source. One of the most critical aspects of the beam-target neutron generator is the target integrity under the beam exposure. A liquid target can be a good solution to overcome damage to the target such as target erosion and depletion of hydrogen isotopes in the active layer, especially for the one operating at high neutron fluxes with no need for water cooling. There is no inherent target lifetime for the liquid target neutron generator when used with continuous refreshment of the target surface exposed to the energetic beam. In this work, liquid target containing hydrogen has been developed and tested in vacuum environment. Potentially, liquid targets could allow a point neutron source whose spatial extension is on the order of 1 to $10{\mu}m$. And the second is about the vacuum ultraviolet (VUV) spectrometer which is designed as a five-channel spectral system for ITER main plasma measurement. To develop and verify the design, a two-channel prototype system was fabricated with No. 3 (14.4 nm~31.8 nm) and No. 4 (29.0 nm~60.0 nm) among the five channels. For test of the prototype system, a hollow cathode lamp is used as a light source. The system is composed of a collimating mirror to collect the light from source to slit, and two holographic diffraction gratings with toroidal geometry to diffract and also to collimate the light from the common slit to detectors. The two gratings are positioned at different optical distances and heights as designed. To study the appropriate detector for ITER VUV system, two different electronic detectors of the back-illuminated charge coupled device and the micro-channel plate electron multiplier were installed and the performance has been investigated and compared in the same experimental conditions. The overall system performance was verified by measuring the spectrums.

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선박배출 배기냉각과 흡수식이 결합된 하이브리드 시스템을 통한 물 회수 및 미세먼지 저감을 위한 기초실험연구 (Preliminary Experimental Study for Water Recovery and Particulate Matter Reduction through a Hybrid System that Combines Exhaust Cooling and Absorption from Ships)

  • 김영민;신동길;류영현
    • 해양환경안전학회지
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    • 제28권7호
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    • pp.1252-1258
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    • 2022
  • 선박용 엔진에서 배출되는 배기가스에는 다량의 수분과 미세먼지를 포함하고 있다. 미세먼지에는 여과성 미세먼지와 배기 배출 후 액상으로 변화하는 응축성 미세먼지가 포함되어 있으며 배출 전에 걸러지는 고체상 미세먼지보다 응축성 미세먼지가 더 많은 것으로 보고되고 있다. 본 연구에서는 배기가스의 배기열과 수분을 회수하고 응축성 미세먼지를 제거하기 위한 실험장치를 실험실 내의 가스보일러 배기가스를 이용하여 테스트 하였다. 배기가스는 1차적으로 냉각방식으로 수분과 응축성 미세먼지가 제거되고 2차적으로 흡수제 방식에 의해 추가적으로 수분이 제거되었다. 상대습도 측정에 의한 배기가스 수분 제거율을 계산하면 1단계 배기냉각 방식으로 73%, 2단계 흡수제 방식으로 90% 제거되는 것으로 측정되었다. 이 과정에서 응축성 미세먼지는 80~90% 제거되는 것으로 측정되었다. 개발 시스템에 의해 회수된 열은 공정열로 활용할 수 있으며, 회수된 물은 수처리 과정을 통해 공정수로 활용할 수 있다. 또한 현재 관리 규제가 되고 있지 않지만 미세먼지의 주요 원인인 응축성 미세먼지를 효과적으로 제거할 수 있을 것으로 기대된다.

FDS를 이용한 교번식 미분무방식의 소화 성능 분석 (Analysis of Fire Suppression Efficiency for Intermittent Water Spray Pattern by Fire Dynamics Simulator)

  • 지문학;이병곤
    • 한국화재소방학회논문지
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    • 제22권3호
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    • pp.216-220
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    • 2008
  • 물분무소화설비는 화원의 냉각, 주변공기의 희석, 미세한 물방울의 증발에 의한 열차단과 같은 소화특성을 이용한다. 미분무수의 운동량은 입자가 큰 물방울에 비해 상대적으로 낮으며 화원의 침투능력도 효과적이지 못하다. 증발된 수증기에 의한 기여는 무게가 가볍고 밀도가 희박하여 화원에 일부분으로 제한되는 경향이 있다. 반면, 사이클식 미분무 패턴은 성층화된 분무 특성에 의해 공기 추출능력과 침투력이 개선될 것으로 예상된다. 이 논문에서는 유체공학적 화재모델인 FDS를 사용하여 교번식 미분무 패턴에 대해 분석된 소화능력을 다룬다. 저자는 이 분석이 미분무 노즐의 표본을 개발하기 위한 기본 개념을 제공할 수 있기를 기대한다.

수평형 지열원 히트펌프 시스템에 관한 연구 (A Study on Horizontal Ground Source Heat Pump Systems)

  • 박용정;김경훈
    • 에너지공학
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    • 제15권3호
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    • pp.160-165
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    • 2006
  • 지열원 히트펌프 시스템은 난방과 냉방부분에서 두드러진 관심을 보이고 있다. 국내에 설치된 지열원 히트펌프 시스템의 대부분은 수직형 방식으로 연구대상 또한 수직형이 주류이다. 본 연구에서는 수평형 지열원 시스템을 시설하우스에 설치하여 성능을 조사하였다. 연구결과, 히트펌프만 고려한 난방성능계수는 3.64이고 지열순환펌프를 포함한 성능계수는 3.31로 나타났다. 응축기 제거열에 대한 순환펌프의 동력은 28.0 W/kW이고, 열교환기길이는 53.3m/kW였다. 지중으로부터의 평균채열량은 14.58 W/m이고, 응축열에 대한 열교환기가 매립된 트렌치길이는 27.7m/kW였다.

블럭이 부착된 수평 유로에서의 강제대류 열전달 해석 (Forced Convection Cooling Across Rectangular Blocks in a Parallel Channel)

  • 조한승;유재석
    • 에너지공학
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    • 제2권3호
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    • pp.251-257
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    • 1993
  • 유한체적법(Finite Volume Method)을 이용하여 블럭이 부착된 수평 유로의 강제 대류 열전달 현상을 해석하였다. 블럭의 갯수, Reynolds 수 그리고 블럭 간의 간격을 변화시키면서 해석하였고 블럭이 부착된 수평판은 전도벽면 (conducting plate)으로 해석하였다. 블럭내에서는 1/2 체적과 전체적에서 열원이 있다고 가정하였으며, 유동은 2차원 정상상태 비압축성 유동이라고 하였다. 전체적에서 열원이 있는 경우보다 1/2 체적에서 열원이 있는 경우가 전체 온도값이 높게 나타났으며, Reynolds 수와 블럭 사이의 간격이 커질수록 온도값이 낮아진다. 수평판이 단열되어 있는 경우보다 전도벽면으로 해석한 경우가 온도값이 낮게 나타나며 수평판이 단옅되어 있다고 가정한 경우에는 최고온도 값의 위치가 단열면 근처이나 전도벽면의 경우에는 블럭내의 중심에서 우측으로 치우쳐 있다. 그리고, 블럭의 1/2 체적에서 열원이 있는 경우의 최고 온도 위치는 블럭의 전체적에서 열원이 있는 경우의 위치보다 더 상단에 치우침을 알 수 있다. Nusselt 수는 블럭 윗면의 좌측 부분에서 다른 부분보다 높은 수치를 나타내고 있으며 Reynolds 수가 커질수록 Nusselt 수의 값이 증가한다. 그리고, 블럭내의 최고 온도값은 이러한 무차원 변수들과의 상관 함수를 이용하여 예측하였다.

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Facade 일체형 태양열 집열기를 갖는 태양열/지열 하이브리드 시스템의 태양열 집열시스템 작동특성 연구 (A Study on the Operating Characteristics of Solar Collecting System in Solar Thermal/Geothermal Hybrid System with Facade Integrated Solar Collector)

  • 백남춘;이진국;유창균;윤응상;윤종호
    • 한국태양에너지학회 논문집
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    • 제30권5호
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    • pp.69-76
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    • 2010
  • In this study, the solar thermal and geo-source heat pump(GSHP) hybrid system for heating and cooling of Zero Energy Solar House(ZESH) was analyzed by experiment. The GSHP in this hybrid system works like as aback-up device for solar thermal system. This hybrid system was designed and installed for Zero Energy Solar House (KIER ZeSH) in Korea Institute of Energy Research. The purpose of this study is to find out that this system is optimized and operated normally for the heating load of ZeSH. The analysis was conducted as followings ; - the thermal performance of facade integrated solar collector - the on/off characteristics of solar system and GSHP - the contribution of solar thermal system. - the performance of solar thermal and ground source heat pump system respectively. - the meet of thermal load (space and water heating load). This experimental study could be useful for the optimization of this system as well as its application in house. This hybrid system could be commercialized for the green home if it is developed to a package type.

국제 호환형 지열히트펌프 시스템 경제성 평가 연구 (International Harmonized Economic Assessment Study of a Ground Source Heat Pump System)

  • 나선익;강은철;이의준
    • 한국지열·수열에너지학회논문집
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    • 제10권1호
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    • pp.7-13
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    • 2014
  • This study intends to analyse the economical aspect of a GSHP(Ground Source Heat Pump) system compared to the conventional system which is consisted with a boiler and a chiller. This study has simulated four systems in Incheon. It developed and analyzed for applications in a residential and an office building which was based on the hourly EPI(Energy Performance Index, $kWh/m^2yr$). Case 1 is utilizing a boiler and a chiller to meet heating and cooling demand of a house. Case 2 is utilizing the same conventional set up as Case 1 of a office. Case 3 is summation of Case 1(house) and 2(office) systems and loads. And Case 4 is utilizing a GSHP to meet the combined loads of the house and office. The method of the economic assessment has been based on IEA ECBCS Annex 54 Subtask-C SPB(Simple Payback) method. The SPB calculated the economic balanced year of the alternative system over the reference system. The SPB of the alternative systems (GSHP) with 10%, 30% and 50% initial incentive has been calculated as 9.38, 6.72 and 4.06 year respectively while the SPB without initial incentive of systems was 10.71 year.