• Title/Summary/Keyword: Heating & cooling of bed

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The Study to Suggest a Methods to Evaluate Heating and Cooling Energy Performance based on Daily Life (실생활기반 냉난방에너지 성능평가 방법 제안 연구)

  • Jeon, Gangmin;Lee, Heangwoo;Kim, Yongseong
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.5 no.3
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    • pp.291-299
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    • 2015
  • With recent surge of attention to heating and air conditioning energy consumption, the need for evaluating performance of heating and air conditioning energy is also on the rise. This research aims to propose daily-life based evaluation method as an alternative to existing one, as well as to apply the method in real life to prove its validity. The results are as following. 1) I studied temperatures preferred by persons indoors and appropriate level of temperature, and the results show that properties of such persons such as age is directly linked with pleasantness of the room, but the issue lies with the fact that such properties are not considered in existing performance evaluation of heating and air conditioning. 2) Daily life based evaluation proposed herein reflects such properties of persons indoors. It controls heating / air conditioning devices installed in the test bed with the same size as a real life room to get quantitative and visual performances in our daily life as well as simple temperature information. 3) To verify validity of daily life based evaluation, I conducted different evaluation sessions with and without a blind and also based on ages of persons indoors. Results based on properties of persons showed difference of 77.6%, leading to effective analysis of energy consumption pattern by heating / air conditioning devices. This research takes significance in that it comes with a new performance evaluation method based on real life, and I gather that further studies are required to develop more multilateral performance evaluation in order to verify and improve technology for reduction of energy consumption.

The Influences of Aquifer Thermal Energy Storage (ATES) System on Geochemical Properties of Groundwater (대수층 계간 축열시스템 적용을 위한 지하수의 화학적 특성 변화)

  • Choi, Hanna;Lee, Hong-Jin;Shim, Byoung Ohan
    • Journal of Soil and Groundwater Environment
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    • v.26 no.3
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    • pp.14-24
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    • 2021
  • Aquifer thermal energy storage (ATES) system uses groundwater thermal energy for cooling and heating of buildings, and it is also often utilized to provide warm water to crops and plants for the purpose of enhancing agricultural yields. This study investigated the potential influences of a ATES system on the geochemical properties of groundwater by simulating the variation of hydrochemistry and saturation index of groundwater during ATES operation. The test bed was installed at an agricultural field, which is mainly composed of an groundwater-rich alluvial plain. The simulation results showed no significant precipitation of mineral phases such as manganese-iron oxide, carbonate and sulfate around the ATES test bed, as well as no debasement of other important water quality parameters. The implementation of ATES system in the study area was appropriate and effective for utilizing the thermal energy of groundwater for agricultural use.

Users' Satisfaction on the Dormitory of High School in Jeonju City (고등학교 기숙사 주거시설에 대한 사용자 만족도 - 개인공간 단위실을 중심으로 -)

  • An, Jin-Sook;Choi, Byung-Sook
    • Journal of the Korean housing association
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    • v.18 no.6
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    • pp.93-101
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    • 2007
  • This study was to find out users' satisfaction on the dormitory of high school in Jeonju City and to propose it's physical environmental improvement directions. This was performed by a questionnaire survey method, and the questionnaire was designed by researchers considering relative literatures. Data were collected from 200 students, who had been dwelling 4 high school dormitories in Jeonju City. By analyzing those data, findings were as follows: 1) Users of students were satisfied the whole of their dormitory; facilities, spaces, and living. 2) They were highly concerned about a library and a personal unit space in their dormitory. 3) They needed their personal unit space to be designed bedroom+bathroom type with 2 persons' sharing and be equipped one story bed and desk furniture. Also, they needed improvement on heating & cooling, small space and indoor air quality of unit space. 4) The users' satisfaction on unit space were 2.88, and their satisfaction of the technical factor was 2.71 that was the lowest score in them. And The functional factor was highly effected their satisfaction. 5) The space utility and the space size of functional factor, the soundproof, the heating/ventilation and the indoor quality of technical factor, and the privacy of behavior factor were highly correlative to their satisfaction of unit space.

Users' Satisfaction on the Dormitory of High School in Jeonju City (고등학교 기숙사 주거시설에 대한 사용자 만족도)

  • An, Jin-Sook;Choi, Byung-Sook
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2006.11a
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    • pp.202-207
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    • 2006
  • This study was to find out users' satisfaction on the dormitory high school in Jeonju City and to propose it's physical environmental improvement directions. This was performed by a questionnaire survey method, and the questionnaire was designed by researchers considering relative literatures. Data were collected from 200 students, who had been dwelling 4 high school dormitories in Jeonju City. By analyzing those data, findings were as follows : 1) Users of students were satisfied the whole of their dormitory; facilities, spaces, and living. 2) They were highly concerned about a library and a personal unit space in their dormitory. 3) They needed their personal unit space to be designed bedroom+bathroom type with 2 persons' sharing and be equipped one story bed and desk furniture. Also, they needed improvement on heating & cooling, small space and indoor air quality of unit space. 4) The users' satisfaction on unit space were 3.23, and the space utility and the space size of functional factor and the heating/ventilation of technical factor were highly effected their satisfaction.

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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 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.12
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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.

Data Analysis for Structural Design of Pleurotus Eryngii Cultivation Facilities (큰느타리버섯 재배사의 구조설계용 자료 분석)

  • Suh, Won-Myung;Yoon, Yong-Cheol
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.3
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    • pp.29-37
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    • 2005
  • This study was carried out to file up structural design data for optimizing Pleurotus eryngii growing houses. Design data are including current farm status of Pleurotus eryngii growing houses in the aspect of structural configuration as well as environmental conditions to be controlled and maintained inside. A structural analysis was performed for the on-farm structures as well as some structures modified and suggested through field survey and analysis. The results are summarized as follows. According to the results of status analysis, Pleurotus eryngii growing houses were categorized as arch-roofed simple type and sandwich panel type. Though the size of Pleurotus eryngii cultivation facilities were considerably diverse, the basic dimensions of Pleurotus eryngii cultivation facilities showed relatively similar pattern: more or less of 20m of length, $6.6\~7.0m$ of width, $4.6\~5.0m$ of peak height, $1.2\~1.6m$ of bed width, and 4 layers of bed. In the aspect of spatial use of cultivation facilities, suggested models were shown to be mostly reasonable in the aspect of heating and cooling, micro-meteorological stability, land use efficiency per unit floor area, etc.. Especially, the standard models suggested so far were thought to be not efficient in its surface area and spatial volume per unit floor area as well as its uneffective structural design in the area around ceiling. In the results of structural analysis for the models suggested through this study by using those section frames to be found on farms, the panel type structures of both single span and double span were estimated to be over designed, whereas arch-roofed pipe houses were mostly found to be under-designed.

Pilot Scale Anaerobic Digestion of Korean Food Waste (파일로트 규모 음식쓰레기 2상 혐기소화 처리공정에 관한 연구)

  • Lee, J.P.;Lee, J.S.;Park, S.C.
    • Solar Energy
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    • v.18 no.3
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    • pp.197-203
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    • 1998
  • A 5 ton/day pilot scale two-phase anaerobic digester was constructed and tasted to treat Korean food wastes in Anyang city. The process was developed based on 3 years of lab-scale experimental results on am optimim treatment method for the recovery of biogas and humus. Problems related to food waste are ever Increasing quantity among municipal solid wastes(MSW) and high moisture and salt contents. Thus our food waste produces large amounts of leachate and bed odor in landfill sites which are being exhausted. The easily degradable presorted food waste was efficiently treated in the two-phase anaerobic digestion process. The waste contained in plastic bags was shredded and then screened for the removal of inert material such as fabrics and plastics, and subsequently put into the two-stage reactors. Heavy and light inerts such as bones, shells, spoons and plastic pieces were again removed by gravity differences. The residual organic component was effectively hydrolyzed and acidified in the first reactor with 5 days space time at pH of about 6.5. The second, methanization reactor part of which is filled with anaerobic fillters, converted the acids into methane with pH between 7.4 to 7.8. The space time for the second reactor was 15 days. The effluent from the second reactor was recycled to the first reactor to provide alkalinities. The process showed stable steady state operation with the maximum organic rate of 7.9 $kgVS/m^3day$ and the volatile solid reduction efficiency of about 70%. The total of 3.6 tons presorted MSW containing 2.9 tons of food organic was treated to produce about $230m^3$ of biogas with 70% of methane and 80kg humus. This process is extended to full scale treating 15 tons of food waste a day in Euiwang city and the produced biogas is utilized for the heating/cooling of adjacent buildings.

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Research on Heat and Mass Transfer Coefficient in the Packing Layer With a Solar Desiccant Heating/Cooling System (태양열 데시컨트 냉난방시스템 중 충진층에 있어서의 열 물질전달에 관한 연구)

  • Yohana, Eflita;Choi, Kwang-Hwan;Kim, Bu-Ahn;Kim, Dong-Gyu;Paek, Ki-Dong;Kim, Ji-Won
    • Journal of the Korean Solar Energy Society
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    • v.26 no.3
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    • pp.17-24
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    • 2006
  • 최근에 에너지절약 차원에서 종래의 공조방식을 대신할 새로운 냉난방시스템 개발이 요구되고 있는데, 본 논문에서는 태양열 집열기를 이용하는 데시컨트 시스템 중 제습역할을 실질적으로 담당하는 제습기의 충진층 부분에서의 열 및 물질전달에 관한 일련의 해석 결과를 발표하고 있다. 제습과정에서 액체흡수제는 충진층에서 열 뿐만 아니라 물질전달을 수반하게 되는데, 이 결과 건물에 냉방 및 난방효과를 가져다 준다. 따라서 이 충진층의 최적 설계가시스템의 효율을 극대화하기 위해서는 무엇보다도 중요한데, 이를 위해서는 충진층에서의 열 및 물질전달 양상을 규명하여야 한다. 따라서 금번 실험에서는 공기와 액체흡수제와의 접촉면적을 넓히기 위해서 충진재로써 3cm(직경) ${\times}$ 3cm(높이)인 시판중인 플라스틱 재질을 사용하고, 실질적으로 40cm(너비)${\sim}$40cm(깊이)${\times}$40cm(높이)의 충진층을 직접 제작하여 실험을 행하였다. 그 결과, 공기측 열 및 물질전달 계수는 공기 온도와 밀접한 관계를 갖고 있으며, 또한 물질전달계수는 열전달계수와 같은 경향을 보이고 있음을 알 수 있었다.

Evaluation of Heat Exchange Efficiency and Applicability for Parallel U-type Cast-in-place Energy Pile (병렬 U형 현장타설 에너지파일의 열교환 효율 및 적용성 평가)

  • Park, Sangwoo;Kim, Byeongyeon;Sung, Chihun;Choi, Hangseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.2
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    • pp.361-375
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    • 2015
  • An energy pile is one of the novel ground heat exchangers (GHEX's) that is a economical alternative to the conventional closed-loop vertical GHEX. The combined system of both a structural foundation and a GHEX contains a heat exchange pipe inside the pile foundation and allows a working fluid circulating through the pipe, inducing heat exchange with the ground formation. In this paper, a group of energy piles equipped with parallel U-type (5, 8 and 10 pairs) heat exchange pipes was constructed in a test-bed by fabricating in large-diameter cast-in-place concrete piles. In addition, a closed-loop vertical GHEX with 30m depth was constructed nearby to conduct in-situ thermal response tests (TRTs) and to compare with the thermal performance of the cast-in-place energy piles. A series of thermal performance tests was carried out with application of an artificial cooling and heating load to evaluate the heat exchange rate of energy piles. The applicability of cast-in-place energy piles was evaluated by comparing the relative heat exchange efficiency and heat exchange rate with preceding studies. Finally, it is concluded that the cast-in-place energy piles constructed in the test-bed demonstrate effective and stable thermal performance compared with the other types of GHEX.

Recent Progress in Air Conditioning and Refrigeration Research - A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2002 and 2003 - (공기조화, 냉동 분야의 최근 연구 동향 -2002년 및 2003년 학회지 논문에 대한 종합적 고찰 -)

  • Chung Kwang-Seop;Kim Min Soo;Kim Yongchan;Park Kyoung Kuhn;Park Byung-Yoon;Cho Keumnam
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.12
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    • pp.1234-1268
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    • 2004
  • A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2002 and 2003 has been carried out. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment/design. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation in diverse facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat transfer, humidity was also interesting to promote comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing research topics. Well developed CFD technologies were widely applied for analysis and design of various facilities and their systems. (2) Heat transfer characteristics of enhanced finned tube heat exchangers and heat sinks were extensively investigated. Experimental studies on the boiling heat transfer, vortex generators, fluidized bed heat exchangers, and frosting and defrosting characteristics were also conducted. In addition, the numerical simulations on various heat exchangers were performed and reported to show heat transfer characteristics and performance of the heat exchanger. (3) A review of the recent studies shows that the performance analysis of heat pump have been made by various simulations and experiments. Progresses have been made specifically on the multi-type heat pump systems and other heat pump systems in which exhaust energy is utilized. The performance characteristics of heat pipe have been studied numerically and experimentally, which proves the validity of the developed simulation programs. The effect of various factors on the heat pipe performance has also been examined. Studies of the ice storage system have been focused on the operational characteristics of the system and on the basics of thermal storage materials. Researches into the phase change have been carried out steadily. Several papers deal with the cycle analysis of a few thermodynamic systems which are very useful in the field of air-conditioning and refrigeration. (4) Recent studies on refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement when new alternative refrigerants are applied. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and new alternative refrigerants including natural refrigerants. Efficiency of various compressors and performance of new expansion devices are also dealt with for better design of refrigeration/air conditioning system. In addition to the studies related with thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out. It should be noted that the researches on two-phase flow are constantly carried out. (5) A review of the recent studies on absorption refrigeration system indicates that heat and mass transfer enhancement is the key factor in improving the system performance. Various experiments have been carried out and diverse simulation models have been presented. Study on the small scale absorption refrigeration system draws a new attention. Cooling tower was also the research object in the respect of enhancement its efficiency, and performance analysis and optimization was carried out. (6) Based on a review of recent studies on indoor thermal environment and building service systems, it is noticed that research issues have mainly focused on several innovative systems such as personal environmental modules, air-barrier type perimeterless system with UFAC, radiant floor cooling system, etc. New approaches are highlighted for improving indoor environmental conditions and minimizing energy consumption, various activities of building energy management and cost-benefit analysis for economic evaluation.