• 설비공학논문집
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• 제23권6호
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• pp.449-469
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• 2011

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering during 2010. 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 new and renewable energy. Various topics were presented in the field of general thermal and fluid flow. Research issues mainly focused on the thermal reliability of axial fan and compressor in the field of fluid machinery. Studies on the design of ground source heat pump systems and solar chemical reactors were executed 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 heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (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 heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (3) Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and CO2 were studied. Performance improvement of refrigeration systems are tried applying various ideas of refrigerant subcooling, dual evaporator with hot gas bypass control and feedforward control. The hybrid solar systems combining the solar collection devices with absorption chillers or compression heat pumps are simulated and studied experimentally as well to improve the understanding and the feasibility for actual applications. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. Various studies on heating and cooling systems, HVAC facilities, indoor air environments and energy resources were carried to improve the maintenance and management of building service equipments. In the field of heating and cooling systems, papers on a transformer cooling system, a combined heat and power, a slab thermal storage and a heat pump were reported. In the field of HVAC facilities, papers on a cooling load, an ondol and a drying were presented. Also, studies on HVAC systems using unutilized indoor air environments and energy resources such as air curtains, bioviolence, cleanrooms, ventilation, district heating, landfill gas were studied. (5) In the field of architectural environment and energy, studies of various purposes were conducted such as indoor environment, building energy, renewable energy and green building. In particular, renewable energy and building energy-related researches have mainly been studied reflecting the global interest. In addition, many researches which related the domestic green building certification of school building were performed to improve the indoor environment of school.

• 한국태양에너지학회 논문집
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• 제22권1호
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• pp.1-8
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• 2002

With the possibility of hot water being able to be used as a heating source in a liquid desiccant system, an experimental apparatus for regeneration of the liquid desiccant was set up and series of experiments were conducted in a climate-controlled chamber. This study was performed to ascertain the influences of experimental factors on regenerating performance and to suggest the optimal combination of factors affecting regeneration rate. Furthermore. in order to figure out the contribution ratio of the factors on regenerating performance, a multi-way factorial design among the design of experiments was adopted. According to experimental results, the most influential factor on regenerating performance was temperature of the liquid desiccant and its contribution ratio was about 79.4%. In addition. the optimal operating combination was as follows; $60^{\circ}C$ of solution temperature, $14\ell$/min of solution flow rate, and 190m3/h of air volume.

• 설비공학논문집
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• 제27권7호
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• pp.369-374
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• 2015

This study analyzed analyzes the energy performance of six houses in Daejeon completed which were built in 2011. Observed The observed houses, which were all designed and constructed inof the same size and structure, are were highly insulated with triple Low-E coating windows; the insulation level of the walls is was $0.13W/m^2K$ and that of the roof is was $0.10W/m^2K$. As electric houses, all of the energy supplied to the houses, including for cooking, is was supplied by electricity. A and 3~4 kWp of photovoltaic system and a 3~5 kW of ground source heat pump (GSHP) were installed in each house tofor providing provide space heating/and cooling and hot water are installed. We constructed a Web-based remote monitoring system in order to understand energy consumption and the dynamic behavior of the energy system. T, and the results of our metering data analysis of 2013 are as follows. First, the annual residential energy consumption is was 4,400 kWh (${\sigma}=1,209$) and GSHP energy consumption is was 5,182 kWh (${\sigma}=1,164$). Second, residential energy consumption ranked highest in average energy usage, with at 45% of the total, followed by heating with at 30%, hot water supply with at 17% and cooling with at 6%. Third, the average energy independence rate is was 51.8%, the GFA (Gross gross floor area) criteria average energy consumption unit is was $48.7kWh/m^2yr$ (${\sigma}=10.1$), and the net energy consumption unit (except the energy yield of the PV systems) is was $24.7kWh/m^2yr$ (${\sigma}=8.8$).

• 생물환경조절학회지
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• 제18권1호
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• pp.1-8
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• 2009

장미 생산농가의 대부분은 겨울철 난방비가 생산비의 가장 큰 몫을 차지한다. 요즘과 같은 고유가 시대에 농가의 부담을 줄이기 위하여 난방비 절감율이 높은 난방시스템에 대한 연구를 수행하였다. 복사열을 이용한 적외선 등 난방의 경우 식물체와 같은 물체를 먼저 가열하여 주변의 기온이 올리는 방식으로 빠르게 온도를 높일 수 있고 경유를 이용한 난방방식에 비해 비용이 절감되는 장점이 있다. 농가에 설치된 나노탄소 섬유 적외선 등 난방시스템의 현지조사를 실시하여 난방효과 및 난방비 절감율을 분석하고, 나노탄소섬유 적외선 등 난방시스템과 전기히터 난방시스템에서 생산된 '오렌지 플레쉬' 장미의 생육과 절화수명을 조사하였다. 나노탄소섬유 적외선 등의 경우 온실 내부 공기 설정온도가 $20^{\circ}C$인 경우 식물체 온도는 $1{\sim}2^{\circ}C$정도 더 높게 나타났을 뿐만 아니라 베드와 근권부 온도는 $17{\sim}19^{\circ}C$ 정도로 유지하는 등 우수한 난방의 효과를 알 수 있었고, 전기히터 난방시스템과 온수보일러 난방시스템의 추정 난방비를 비교한 결과 난방비 절감 효과가 아주 높게 나타났다. 장미의 생육을 조사한 결과 전기히터 난방시스템에서 생육한 장미와 차이가 없었으며 화색이나 염색의 발현이 더 좋았다. 절화수명에서는 나노탄소섬유 적외선 등에서 생육한 장미가 생체중과 수분 흡수량이 높아 다소 더 길어진 절화수명을 뒷받침 해 주었다.

• 대한건축학회논문집:구조계
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• 제34권7호
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• pp.43-52
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• 2018

In this study, annual site and primary energy use intensities (EUIs) and CO2 emission intensities (CEIs) per area by end use were estimated based on the measurement data from June 2016 to May 2017 of 50 sample apartment units in Seoul. In addition, estimated site EUIs by end use were compared to the U.S. Residential Energy Consumption Survey (RECS) 2009 data. Site EUIs by end use were found to be in the order of heating > electric appliance > domestic hot water > cooking > lighting > cooling > air movement. In the case of primary EUIs and CEIs by end use, electric appliance was found to be the largest. As results of comparison with the RECS 2009 data, it was found that site EUIs were very similar for heating, domestic hot water and electric appliance, etc., but slightly different for cooling. The number of sample apartment units will continue to increase until 2020 (total number of samples 200) and intensities data by end use will be continuously updated through continuous collection of measurement data.

• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.667-672
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• 2023

This study proposes polymer electrolyte membrane fuel cell (PEMFC) based cogeneration system for greenhouse heating and cooling. The main scope of this study is to examine the proposed cogeneration system's suitability for the 660 m²-class greenhouse. A 25 kW PEMFC system generates electricity for two identical air-cooled heat pumps, each with a nominal heating capacity of 70 kW and a cooling capacity of 65 kW. Heat recovered from the fuel cell supports the heat pump, supplying hot water to the greenhouse. In cooling mode, the adsorption system provides cold water to the greenhouse using recovered heat from the fuel cell. As a result, the cogeneration system satisfies both heating and cooling capability, performing 175 and 145 kW, respectively.

• 자원리싸이클링
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• 제24권6호
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• pp.54-60
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• 2015

본 연구의 목표는 1 ton/day용량의 연속 감압식 간접열 방식의 벨트형 건조장치를 개발하여 건조효율을 70% 이상 향상시키며 기존 건조기 장치에 비하여 약 50% 이상의 건조기 크기를 축소시켜 장치의 소형, 경량화를 이루고 그로 인한 설치비 및 운전비 절감효과를 20%이상 향상시키는 것이다. 현재는 기존의 간접열 건조장치를 분석하여 구조적인 개선점을 도출하였으며 기초실험을 통하여 우수한 건조성능을 확인하였다. 또한 감압조건에서의 실험을 수행하여 열전달 및 건조특성이 향상되는 것을 확인하였다.

• 생물환경조절학회지
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• 제26권4호
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• pp.353-360
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• 2017

본 연구에서는 장미 재배온실을 대상으로 온실 내부의 태양잉여열과 외부의 공기열을 선택적 열원으로 이용하여 온실난방용 온수를 생산할 수 있는 공기 대 물 히트펌프의 설계와 성능시험을 수행하였다. 태양잉여열 이용 축열운전과 외기열 이용 축열운전은 작물의 생육적온을 고려한 온실내부의 설정온도에 따라 자동전환 되도록 설계하였다. 제어반에 12개의 기준온도를 설정함으로써 축열운전 전환, 난방, 환기를 자동제어하며, 태양잉여열-외기열 선택적 축열운전에서 축열조의 온도는 축열능력과 난방부하에 대응하여 $35{\sim}52^{\circ}C$로 3단계 변온제어 하였다. 태양잉여열-외기열 선택적 축열에서 태양잉여열 이용 축열은 전체 시간의 23.1%, 외기열 이용 축열은 30.7%, 히트펌프 휴지시간은 46.2%를 차지하였으며, 난방성능계수는 태양잉여열 이용 축열 시 3.83, 외기열 이용 축열시 2.77, 전체 3.24로 평가되었다. 비교시험을 위해 축열조 온도를 $50{\sim}52^{\circ}C$로 항온제어 하는 조건에서 외기열 단독 이용 축열 시험을 수행하였으며 이때의 난방성능계수는 2.33으로 분석되었다. 결과적으로 공기 대 물 히트 펌프의 열원으로 온실내부 태양잉여열과 외부 공기열을 병용하고, 축열조 온도를 변온제어 한 결과 일반적인 외기열 이용 축열운전과 축열조 항온제어에 비해 난방성능 계수가 39% 향상됨을 확인하였다.

• 한국식품과학회지
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• 제29권1호
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• pp.9-14
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• 1997

자색고구마의 동결, 해동 및 blanching방법에 따른 색소의 변화를 조사하였다. $-5^{\circ}C$보다 $-20^{\circ}C$ 그리고 $-40^{\circ}C$에서 동결한 자색고구마는 $4^{\circ}C$로 해동시에 해동시간이 길어질수록 색소함량이 급격하게 감소하는 경향을 보였다. $20^{\circ}C$에서의 해동은 $4^{\circ}C$해동에 비해 뚜렷이 색소함량이 감소하였고, $60^{\circ}C$에서 해동시에는 색소의 함량에 대한 동결온도의 영향이 작았으며, microwave가열을 이용하여 3분간 급속해동하고 추출한 색소의 함량은 각 동결온도에 따라 큰 차이가 없었다. Microwave blanching으로 해동한 것은 동결온도에 대해 영향이 미미하였다. 동결전에 blanching처리한 경우는 해동시에 공기의 접촉 유무가 색소의 추출량에 큰 차이가 없었으며 자색고구마 색소감소를 억제하기 위해서는 $3{\sim}4$분 동안의 microwave blanching이 $100^{\circ}C$에서는 $10{\sim}15$분 정도의 가열이 적당하였다.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2009년도 추계학술대회
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• pp.269-272
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• 2009

The temperature of PV modules that integrated into building facades or roof increases that could reduce the electrical efficiency of the PV system. In order to incresae PV system's efficiency it is very important to remove the heat from the PV modules. For this purpose, hot air can be extracted from the space between PV modules and building envelope, and used for heating in buildings. The solar collector utilizing this thermal effect is called photovoltaic-thermal(PVT) solar collector. This paper compares the experimental performance of building-integrated PVT collectors that applied on building roof and facade. There are two different case: a roof-integrated PVT type and a facade-integrated PVT type. The experimental results show that the collected thermal energy of the roof-integrated type was 24% higher, compared to that of the facade-integrated.