• 제목/요약/키워드: ground heat exchanger

검색결과 259건 처리시간 0.03초

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.

냉방설비 성능개선 및 에너지 절약을 위한 응결수 활용성 분석 (An analysis on the utility of congealing water to improve efficiency of the air cooling equipment and save energy)

  • 박근수;박영호;유정범
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.974-981
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    • 2007
  • Seoul Metro has operated the air cooling equipment established in a machine room of a station building to improve our services focused on our customers who use Seoul Metro during the summer season. However, a new set of problems has arisen with the cooling tower to support a heat exchange of cooling water. One of them is loss of efficiency in the air conditioner. The leading cause of this problem is that we use an underground type of the cooling tower. As the machine room of a station building is located in the underground of inner city because of the nature of the subway, it is difficult to establish the cooling tower on the ground. The underground structure of the No. $1{\sim}4$ subway line is unsuitable for the location requirements of the underground type of the one because it has a limited space to set up the air cooling equipment, for example, the cooling tower and a ventilating opening. As a result of such an unfavorable condition, the cooling tower doesn't work efficiently and the warmth of cooling water because of insufficiency of a heat exchange and a refrigerator's technical obstacle such as a high-temperature and a high-pressure has arisen. Accordingly, the efficiency of the air conditioning is getting lower and lower. Another problem is too wasteful with water. Each station uses the water over 30 tons every day with waterworks to replenish the cooling tower such as a evaporation, a scattering and a distribution of water. Nevertheless, the more an air conditioner increase, the more the use of water supply increase. For this reason, we can't help wasting an enormous amount of water and discharging the congelation of a low temperature(about $15^{\circ}C$) occurred in a heat exchanger inside an air conditioner. The purpose of this study is to analyze the utility of congealing water to improve efficiency of the air cooling equipment and save energy as a supplementary water for the cooling tower.

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에너지 파일의 현장 열응답 시험에 관한 연구 (Evaluation of Thermal Response Test of Energy Pile)

  • 윤석;이승래;김민준;고규현
    • 한국지반공학회논문집
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    • 제30권4호
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    • pp.93-99
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    • 2014
  • 최근 들어 경제적인 지열에너지 활용을 위하여 에너지 파일의 적용이 확대되고 있다. 특히 더 높은 열 교환 효율을 확보하고자 에너지 파일의 경우 통상적인 U자형 또는 W자형과 같은 라인형 지중 열교환기가 아닌 코일형 지중 열교환기를 매입하는 경우가 늘어나고 있다. 본 연구에서는 매립지 부지에 PHC 코일형 열교환기 형태의 에너지 파일을 설치하고 240시간 동안 현장 열응답 시험(thermal response test)을 실시하였다. 또한 현장에서 지층별로 시료를 채취하여 실내에서 현장 지층 물성으로 시료를 재조성한 후 비정상 탐침법(non-steady state probe method)을 이용하여 지층별 열전도도와 열확산계수를 측정하였고 등가의 열물성으로 환산하였다. 실험 결과 현장 열응답 시험에 의한 지반의 열전도도와 실내 탐침법으로 측정된 지반의 열전도도는 5%내에서 일치하였으며 아울러 지반의 또 하나의 중요한 설계인자인 등가 열확산계수의 측정방법도 제시하였다.

수직 밀폐형 지중열교환기 뒤채움재로서 시멘트 그라우트의 적용성 검토 (Study on Cement-based Grout for Closed-loop Vertical Grout Heat Exchanger)

  • 박문서;위지혜;이철호;최항석;강신형
    • 한국지반공학회논문집
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    • 제26권7호
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    • pp.107-115
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    • 2010
  • 본 연구에서는 수직 밀폐형 지중열교환기 뒤채움 용도로, 기존 벤토나이트 그라우트의 대안으로서 시멘트 그라우트의 적용성을 검토하였다. 실내 시험을 통하여 물/시멘트 비, 천연규사 첨가비 흑연 첨가비의 변화에 따른 시멘트 그라우트 열전도도 및 유동성에 미치는 영향을 평가하였으며 배합비에 따른 시멘트 그라우트의 일축압축강도를 측정하였다. 실제 지중열교환기용 파이프내 순환유체의 온도변화가 시멘트 그라우트의 재료적 안정성에 미치는 영 향을 검토하기위해 $-5^{\circ}C$$50^{\circ}C$를 한 주기로 하여 일축압축강도를 반복적으로 측정하였다. 또한, 시멘트 그라우트가 지중에서 양생된 후, 냉난방 운전에 따른 순환수의 계절적 변화에 의한 시멘트 그라우트와 순환파이프의 접촉면의 양호한 부착성 유지 여부를 판단하기 위해 시멘트 그라우트에 HDPE 파이프를 삽입한 시료의 등가투수계수를 flexible wall penneameter) 이용하여 장기간 측정하였다.

설비공학 분야의 최근 연구 동향 : 2009년 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 2009)

  • 한화택;이대영;김서영;최종민;백용규;권영철
    • 설비공학논문집
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    • 제22권7호
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    • pp.492-507
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    • 2010
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2009. 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) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery and piping, and new and renewable energy. Various topics were covered in the field of general thermal and fluid flow such as an expander, a capillary tube, the flow of micro-channel water blocks, the friction and anti-wear characteristics of nano oils with mixtures of refrigerant oils, etc. Research issues mainly focused on the design of micro-pumps and fans, the heat resistance reliability of axial smoke exhaust fans, and hood systems in the field of fluid machinery and piping. Studies on ground water sources were executed concerning two well type geothermal heat pumps and multi-heat pumps in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included the heat transfer in thermoelectric cooling systems, refrigerants, evaporators, dryers, desiccant rotors. In the area of industrial heat exchangers, researches on high temperature ceramic heat exchangers, plate heat exchangers, frosting on fins of heat exchangers were performed. (3) In the field of refrigeration, papers were presented on alternative refrigerants, system improvements, and the utilization of various energy sources. Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and $CO_2$ were studied. Efforts to improve the performance of refrigeration systems were made applying various ideas of suction line heat exchangers, subcooling bypass lines and gas injection systems. Studies on heat pump systems using unutilized energy sources such as river water, underground water, and waste heat were also reported. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. In the area of cogeneration systems, papers on energy and economic analysis, LCC analysis and cost estimating were reported. Studies on ventilation and heat recovery systems introduced the effect on fire and smoke control, and energy reduction. Papers on district cooling and heating systems dealt with design capacity evaluation, application plan and field application. Also, the maintenance and management of building service equipments were presented for HVAC systems. (5) In the field of architectural environment, various studies were carried to improve indoor air quality and to analyze the heat load characteristics of buildings by energy simulation. These studies helped to understand the physics related to building load characteristics and to improve the quality of architectural environment where human beings reside in.

구조물 및 기기의 내진성능 평가를 위한 고주파수 지진에 의한 원자력발전소의 지진응답 증폭계수 (Seismic Response Amplification Factors of Nuclear Power Plants for Seismic Performance Evaluation of Structures and Equipment due to High-frequency Earthquakes)

  • 임승현;최인길;전법규;곽신영
    • 한국지진공학회논문집
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    • 제24권3호
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    • pp.123-128
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    • 2020
  • Analysis of the 2016 Gyeongju earthquake and the 2017 Pohang earthquake showed the characteristics of a typical high-frequency earthquake with many high-frequency components, short time strong motion duration, and large peak ground acceleration relative to the magnitude of the earthquake. Domestic nuclear power plants were designed and evaluated based on NRC's Regulatory Guide 1.60 design response spectrum, which had a great deal of energy in the low-frequency range. Therefore, nuclear power plants should carry out seismic verification and seismic performance evaluation of systems, structures, and components by reflecting the domestic characteristics of earthquakes. In this study, high-frequency amplification factors that can be used for seismic verification and seismic performance evaluation of nuclear power plant systems, structures, and equipment were analyzed. In order to analyze the high-frequency amplification factor, five sets of seismic time history were generated, which were matched with the uniform hazard response spectrum to reflect the characteristics of domestic earthquake motion. The nuclear power plant was subjected to seismic analysis for the construction of the Korean standard nuclear power plant, OPR1000, which is a reactor building, an auxiliary building assembly, a component cooling water heat exchanger building, and an essential service water building. Based on the results of the seismic analysis, a high-frequency amplification factor was derived upon the calculation of the floor response spectrum of the important locations of nuclear power plants. The high-frequency amplification factor can be effectively used for the seismic verification and seismic performance evaluation of electric equipment which are sensitive to high-frequency earthquakes.

에너지 슬래브의 열-역학적 수치해석 모델 개발 (Development of Thermomechanical Coupled Numerical Model for Energy Slab)

  • 박상우;최항석;이석재
    • 한국지반공학회논문집
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    • 제40권1호
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    • pp.55-63
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    • 2024
  • 본 연구에서는 에너지 슬래브의 안정성을 검토하기 위해 열-역학적 수치해석 모델을 개발하였다. 먼저, 주거용 건물 지하주차장에 벽체형 에너지 슬래브를 설치한 뒤 현장 열성능 평가시험(Thermal performance test, TPT)을 수행하였다. 이를 기반으로 현장 열성능 평가시험의 열-수리학적 거동을 정교하게 모사할 수 있는 에너지 슬래브의 열-수리학적 수치해석 모델을 개발하였다. 마지막으로, 열-수리학적 모델을 통해 도출된 시간-온도 데이터를 기반으로 에너지 슬래브의 열-역학적 수치해석 모델을 개발하였다. 개발된 모델을 기반으로 에너지 슬래브의 운용에 따른 열응력을 산정한 결과 최대 5,300kPa의 열응력이 발생하였으며, 이는 에너지 슬래브의 안정적인 운용을 위해 충분한 인장강도가 확보된 시멘트 몰탈 활용이 필요하다는 것을 시사한다.

수주지열정(SCW)을 이용한 천부지열 냉난방시스템 설계지침 (Design Guidlines of Geothermal Heat Pump System Using Standing Column Well)

  • 한정상;한혁상;한찬;김형수;전재수
    • 자원환경지질
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    • 제39권5호
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    • pp.607-613
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    • 2006
  • 내 수문지열계 가운데 수주지열정(SCW)시스템을 합리적으로 설치이용할 수 있는 조건들은 심도별 지온증가율이 명확하고($2^{\circ}C/100m$심도), 기존의 지하수 열펌프가 필요로 하는 순환수의 유량에 비해 최소 $10{\sim}30%$의 중온의 심부지하수가 산출될 수 있어야 하며, 순환수를 공내로 재주입시 공내붕괴가 일어나지 않는 견고한 암석들이 존재 하여야 한다. 수주지열정의 1개공당 굴착심도는 평균 $400{\sim}500m$이며, 이로 부터 개발가능한 지열에너지는 공당 약 $30{\sim}40RT$ 규모인데 비해 1개 수직지중열교환기가 공급가능한 지열에너지는 $2{\sim}3RT$ 정도이다. 즉 수주지열정 1개공은 $10{\sim}15$개의 수직지중열교환기 역할을 한다. 따라서 이 방식은 수직루프 설치장소의 공간 문제를 해소할 수 있는 유일한 대안으로 인식되어, 현재 전국 각지에서 많은 수의 SCW들이 무분별 하게 비과학적으로 설치되고 있다. 이와 같이 해당지역 수문지열계의 수리 지질학적인 특성과 열적인 특성을 명확히 파악하지 않은 상태에서 수주지열정을 설계 시공하는 경우에 나타날 문제점들은 추후 합리적인 천부지열 개발 이용에 지대한 장애요인이 될 것이다. 따라서 본고는 국내 수문지열계에 적합한 수주지열정을 설계 하는데 있어 필요한 일종의 지침서를 제시하기 위해 작성되었다.

지열 난방시스템을 이용한 분만돈사의 난방효과 분석 (Evaluation on Heating Effects of Geothermal Heat Pump System in Farrowing House)

  • 최희철;박재홍;송준익;나재천;김민지;방한태;강환구;박성복;채현석;서옥석;유영선;김태원
    • 한국축산시설환경학회지
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    • 제16권3호
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    • pp.205-215
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    • 2010
  • 지열히트펌프를 이용한 축사용 냉난방시스템을 개발하고 농장 적용성을 검토하기 위하여 330 $m^2$ 규모의 농장에 개발 시스템을 설치하여 돈사에서의 난방 이용효과를 분석하였으며, 그 결과는 다음과 같다. 1. 지열 난방시 부하량은 24,104 kcal이었으며 농장시험 지열이용 냉난방시스템의 제원은 히트펌프 용량은 10 USRT 였으며, 상부 덕트형 30,000 kcal 홴코일유니트를 사용하였으며 FCU의 풍량은 90 $m^3$/분 이었다. 2. 지열 난방 1주령시 외부 최고기온 $14.2^{\circ}C$, 최저 영하 $9.3^{\circ}C$일때 시험구는 평균 $21.5^{\circ}C$로서 대조구 $19.8^{\circ}C$에 비하여 높았다. 3. 지열 난방 시험돈사의 먼지 농도는 PM10 185.3, PM2.5 40, PM1.0 $23.4{\mu}g/m^3$으로 대조구 PM10 481.4, PM2.5 47, PM1.0 $28.2{\mu}g/m^3$에 비하여 낮았다.4. 지열 난방 시험돈사의 유해가스농도는 $CO_2$ 1,470, $NH_3$ 10.6, $H_2S$ 0.05 ppm으로서 대조구 $CO_2$ 2,025, $NH_3$ 23.3, $H_2S$ 0.69 ppm에 비하여 유의적으로 (p<0.05) 낮았다. 5. 지열난방시 복당 이유두수는 10.5두로 대조구 10.4두에 비하여 높았으며 이유시체 중도 6.93 kg으로 대조구 6.86 kg에 비하여 컸으며 특히 온도가 낮은 대조구에서 모돈사료 섭취량이 99.6 kg으로 시험구 88.2 kg 보다 유의적으로 (p<0.05) 많았다. 6. 지열 난방시 외부기온과 지하수 순환량에 있어서 외부기온이 낮을 경우 1일간 8.4-12.9톤으로 지하수 순환량이 많았다.