• Title/Summary/Keyword: per-cooling

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강변여과수와 천부 지하수를 이용하는 지하수 열펌프시스템의 적정유량 (Optimum Pumping Rates of Ground-Water Heat Pump System Using Groundwater or Bank Infilterated Water)

  • 한정상;한혁상;한찬;전재수;김형수
    • 자원환경지질
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    • 제40권6호
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    • pp.833-841
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    • 2007
  • 지하수열펌프시스템(GWHP)은 지원열펌프시스템(GSHP)가운데 성능이 가장 우수하며 저온의 천부지하수열을 이용하는 시스템이다. GWHP시스템은 지중연결 열펌프시스템(GCHP)에 비해 최대 블록부하와 전 시스템 성능에 부합되는 지하수유량을 기준으로 하여 설계를 하며 최적 지하수유량은 해당지역의 지하수온도, 판형열교환기의 규격과 전체펌프와 배관류의 전 양정고에 따라 결정한다. 대체적으로 전형적인 빌딩루프순환수의 필요유량은 1RT당 $9.5{\sim}11.4lpm$ 정도인데 비해 GWHP시스템이 필요로 하는 최적 지하수유량은 이보다 꿜씬 적은 $3.8{\sim}9.5lpm$정도이다.

자동차용 연료전지 시스템의 가습모델과 열/물균형 유지방법 (Humidification model and heat/water balancing method of PEMFC system for automotive applications)

  • 정승훈;윤석호;김민수
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.339-344
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    • 2005
  • A PEMFC system model for FCEV was constructed and simulated numerically to examine the heat/water flow of the system and air/fuel humidification process for various operation conditions (ambient pressure /temperature/humidity, operating temperature, power load). We modeled PEMFC stack which can generate maximum electricity of about 80 kW. This stack consists of 400 unit cells and each unit cell has $250cm^2$ reacting area. Uniform current density and uniform operating voltage per each cell was assumed. The results show the flow characteristics of heat and water at each component of PEMFC system in macro-scale. The capacity shortage of the radiator occurred when the ambient was hot $(over\;40^{\circ}C)$ and power level was high (over 50 kW). In spite of some heat release by evaporation of water in stack, heat unbalance reached to 20kW approximately in such a severe operating condition. This heat unbalance could be recovered by auxiliary radiators or high speed cooling fan with additional cost. In cold environment, the capacity of radiator exceeded the net heat generation to be released, which may cause a problem to drop the operating temperature of stack. We dealt with this problem by regulating mass flow rate of coolant and radiator fan speed. Finally, water balance was not easily broken when we retrieved condensed and/or unused water.

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25BAR급 바이오가스 고압 압축공급시스템 상세설계 (Detailed Design for 25bar-class Biogas Compression Supplying System)

  • 허광범;박정극;윤은영;이정빈
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.173.1-173.1
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    • 2011
  • The high fuel flexibility of gas turbine power system has boosted their use in a wide variety of applications. Recently, the demand for biogas generated from the digestion of organic wastes and sewage waste water as a fuel for gas turbines has increased. We investigated the performance of high pressure biogas compression system and operating conditions for supplying biogas. The total flow per minute of biogas from food waste water digestion tank is $54Nm^3$. The main type of biogas compression system is the reciprocating system and screw type system. The target of biogas mechanical data is the as belows; inlet pressure 0.045bar, supplying biogas temperature is $30{\sim}60^{\circ}C$, and final pressure is above the 25 bar. Also, inlet conditions of biogas consist of CH4 48.5%~83%, $H_2S$ Max. 500ppm, $NH_3$ Max. 1,500ppm and Siloxane 2.7~4.6ppm. The boosting Blower system raises a pressure from 0.045bar to 1bar before main compressor. The main system lay out of reciprocating consisits of compressor driver, filter, cooling system, blowdown vessel, control system and ESD(Emergency Shut Down) system. And an enclosure package needs to be installed for reducing noise up to 75dB. The system driver is the electronic motor of explosion proof type. Forthe compressor system reliable operation, the cleaning system something like particulate filter needs to be set up in the inlet of compressor and Coalescing Filter in the outlet of compressor. Particulate Filter has to be removed above $10{\mu}m$ size of the particles in biogas. The coalescing filter(Micofine Borosilicate Glass Fibers Filter treated phenol acid) also removes moisture and oil of above $0.3{\mu}m$ to be involved in high pressure biogas up to 90%~98%.

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비냉각형 고효율 태양광 채광시스템 및 응용에 관한 연구 (Un-Cooled High Efficient Solar Lighting System and its Application)

  • 이호열;김명진;신서용
    • 한국통신학회논문지
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    • 제36권11B호
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    • pp.1394-1402
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    • 2011
  • 본 논문은 포물 반사경 방식 및 프레넬 렌즈 방식을 이용한 태양광 집광장치 및 이의 응용에 관한 것이다. 본 시스템은 대구경 반사경과 더불어 2차 광학계를 도입하여 광섬유로 입사되는 빛의 입사각을 광섬유의 개구수보다 작게 함으로써 집광효율을 극대화하였다. 또한 광섬유 단면에 입사하는 빛의 에너지 밀도를 낮게 하기 위해 광섬유 다발 직경 크기와 동일한 평행광이 광섬유로 입사되게 함으로써 반사경을 사용한 집광 시 문제가 되는 열발생 문제를 별도의 냉각장치 없이 근원적으로 차단하였다. 최근 각광받고 있는 식물공장에 주로 쓰이는 LED와 같은 인공광원 대신 본 연구에서 개발한 태양광 집광장치를 식물공장에 적용하여 인공조명과 태양광의 혼합조명장치를 통해 식물을 재배하였다. 그 결과 낮 시간대에 인공조명에 소요되는 전기에너지를 대폭 절감할 수 있었다. 혼합조명장치에서는 조도센서를 활용하여 항상 일정량의 빛이 식물에 제공되도록 LED등의 밝기를 조절하였다. 하루 10시간 기준으로 100형 규모의 식물공장에 태양광 채광시스템을 적용할 경우 한 달에 약 28,080KWh의 에너지 절감효과가 있다.

루푸스 동물 모델에서 인삼부자탕(人蔘附子湯)이 미치는 영향 (Study of Insam-Buja-Tang (IBT) on MRL/MpJ-Faslpr lupus-prone mice)

  • 김경신;문성식;김병수;강정수
    • 혜화의학회지
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    • 제20권1호
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    • pp.11-23
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    • 2011
  • Systemic Lupus Erythematosus(SLE) is an autoimmune disease invading the skin, joint, kidney, intestinal membrane, neurosystem and other organs. SLE is an autoimmune disease characterized by immune dysregulation resulting in the production of antinuclear antibodies(ANA), generation of circulating immune complexes, and activation of the complement system. In Korean medicine, lupus can be classified as acute arthritis, reddish butterfly erythema, asthenic disease, edema and so on. The cause and procedure of the diseases are flourishing noxious heat, excessive fire due to deficiency of yin, blood stasis due to stagnation of qi, internal movement of the liver-wind, congenital deficiency, exhausted vital-qi, which are treated by clearing away heat and cooling the blood, nourshing yin and extinguishing fire, treating flatulence and activating blood circulation, nourishing the blood to expel wind, invigorating the liver and kidney, invigorating qi and replenishing the blood. To experimentally examine the influence of Insam-Buja-Tang (Ginseng & Aconiti Extract, IBT) on the outbreak and development of lupus, lupus induce MRL/MpJ-Faslpr lupus-prone mice model was used. As IBT was orally administrated to a lupus model mouse, various tests such as the weight, urine protein, renal function, Lymph cell test of the spleen, Cytokine expression, histopathological analysis of kideny were performed to see the influence on the kidney and whether it work effectively on the immune function. The main purpose of this study is to evaluate the effect of IBT on MRL/MpJ-Faslpr lupus-prone mice model. The effect of IBT on MRL/MpJ-Faslpr lupus-prone mice that can have autoimmune disease similar to SLE in human was evaluated after IBT per oral in the present study.

동부와 녹두전분의 이화학적 특성비교 (Comparison of Physicochemical Prolperties of Cowpea and Mung Bean Starches)

  • 윤계순
    • 대한가정학회지
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    • 제27권1호
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    • pp.39-46
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    • 1989
  • Mung bean starch gel (Mook) and gel made from starch of cowpea are similar properties in texture. In order to elucidate the similarity between these two starch gels, some physicochemical properties of cowpea starch were compared with those of mung bean starch. Water bildings capacity of cowpea starch (183.6%) was a little low than that of mung bean starch (184.2%). The solobility, swelling power and optical transmitance of the cowpea starch showed a smiliar pattern to mung bean starch, but cowpea starch had a little lower solubility than mung bean starch. Amylogram of mung bean strach (4, 5, 6, 7%) shoved no peak viscosity but cowpea starch (4, 5, 6%) showed peak viscosity and both starches showed high viscosities when cooling. Cowpea and mung bean starches had the blue value of 0.41 and 0.47, the alkali number of 8.4 and 8.0, the amylose content of 30.5 and 32.1%, the molecular weight of amylose of 30,000 adn 29,258 and glucose unit per segment of amylopectin of 27.6 and 26.8 respectively. The shape of cowpea and mung bean strach granules were round and elliptical, and the mean vlalue of major axis, minor axis and the ratio of these were 20.7 and 21.8 ${\mu}{\textrm}{m}$, 14.6 and 14.4 ${\mu}{\textrm}{m}$ and 1.42 and 1.51, respectively. The extent of retrogradation determined by the glucoamylase digestion method and syneresis showed that cowpea starch gel was larger than that syneresis showed than cowpea starch gel was larger than that of mung bean starch gel. The redults of X-ray diffraction studies showed A pattern for two starches, Diffraction peak of gels disappeared with gelatinization of starches but that of two starch gels storaged for 2 days at 5$^{\circ}C$ showed a similar patterm.

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The CO2 Reduction Potential Calculation through the Urban Park Construction

  • Lee, Eun Yeob;Kang, Myung Soo;Kim, Jong Kon
    • KIEAE Journal
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    • 제14권2호
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    • pp.87-98
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    • 2014
  • This study is to identify quantitatively the function of carbon dioxide emissions reduction due to temperature and energy reduction according to direct carbon dioxide storage, shade provision, and evaportanspiration of urban park. According to the result of study, landscape tree indicated high carbon dioxide storage effect compare to bush, in which broadleaf tree indicated higher storage function than coniferous tree. It is believed to be the storage of carbon dioxide can be increased by increasing the composition rate of forest plants in the urban park. According to the direct estimation result of carbon dioxide storage in terms of example area, storage of carbon dioxide is estimated to be "seoul a zone" $476,818.8kg{\cdot}CO_2/m^2yr$, "anyang b zone" $186,435.7{\cdot}CO_2/m^2yr$, "daejeon c zone" $262,826{\cdot}CO_2/m^2yr$, "kwangju d zone" $231,657.8{\cdot}CO_2/m^2yr$. The carbon dioxide storage per unit area estimated to be "seoul a zone" $3.4{\cdot}CO_2/m^2yr$, "anyang b zone" $5.0{\cdot}CO_2/m^2yr$, "daejeon c zone" $2.6{\cdot}CO_2/m^2yr$, "kwangju d zone" $5.6{\cdot}CO_2/m^2yr$. The result of indirect carbon dioxide reduction effect estimated to be "seoul a zone" $291,603.4{\cdot}CO_2/m^2yr$, "anyang b zone" $165,462.4{\cdot}CO_2/m^2yr$, "daejeon c zone" $141,719.2{\cdot}CO_2/m^2yr$, "kwangju d zone" $154,803.4{\cdot}CO_2/m^2yr$. Carbon dioxide reduction potential amount through the urban park was increased to 1.6 times to 1.8 times when calculated to the indirect effect.

대구시 중구의 옥상녹화를 통한 환경 및 경제적 편익 분석 (An Analysis of Environmental and Economic Benefits of Green Roof in Jung-Gu, Daegu)

  • 김수봉;장중근
    • 한국환경과학회지
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    • 제16권5호
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    • pp.603-610
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    • 2007
  • Recent urban sprawl has destroyed various kinds of green space in tile city. It has affected duality of people's life in the city, as well as urban ecosystem. Recent study shows the possibilities of roofs as green spaces in urban central site where the land costs are generally high. This research focuses on Jung-Gu district in Daegu Metropolitan city as a study area and calculates possible area of green roof using 2002 Autocad program based on aerial photographs and land registration maps. And the purpose of this research is to analyze environmental and economic effects of green roof. The environmental effects are as follows. It is expected that $91,106m^2$ green spaces, 12.13 % of study site, will be added if green roof is performed in the study site. It is assumed that the expanded areas could reduce the highest temperature to $0.5-1.0^{\circ}C$ during the summer in terms of environmental effect. And the following shows the economic effects. If green roof and greening urban central site are created as a same size of $91,106m^2$, it will be expected that the costs of green roof will be much more in-expensive than about 98 billions won. It will be also found that the expense of cooling energy can be saved out about 8 millions won per day in summer, if grass planting is accomplished on the possible areas of green roof in the study site. Therefore, it is desirable to take legal supports such as enacting regulations to activate green roof for more environmental and economic effects. For instance, green roof for public institutions, school and model area selection are desirable method to publicize the effect of greening program for citizen's participation.

한반도 겨울철 한파와 관련된 대기 순환과 열원의 특성 (Characteristics of Atmospheric Circulation and Heat Source related to Winter Cold Surge in Korea)

  • 김맹기;신성철;이우섭
    • 한국지구과학회지
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    • 제26권6호
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    • pp.560-572
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    • 2005
  • 이 연구에서는 1979년부터 1999년까지 21년 동안에 한반도 겨울철 한파와 관련된 대기 순환 및 열원$(Q_1)$의 분포 특성을 조사하였다. 한파 발생 빈도는 1년간 약 1개로 나타났으며, 1989년을 중심으로 전반기에 전체의 $60\%$가 발생하였다. 한파 발생 동안 하층의 대기 순환 패턴은 평년에 비해 서고동저형의 기압 패턴이 더 뚜렷하며, 상층에서도 한반도에 기압골의 영향이 더 강하게 나타난다. 한파가 발생하는 동안에 한반도 부근의 기온 하강 패턴은 바이칼호 부근의 기온 패턴과 반대로 나타나며, 기온의 연직 구조에서도 400 hPa을 기준으로 하층과 상층의 기온 편차는 반대로 나타난다. 열원에 대한 분석은 한파 발생 시 한랭 이류에 의한 냉각은 하강 운동에 의한 단열 승온에 의해 균형을 이룬다는 것을 보여주는데, 이것은 한랭 핵의 이동이 열흡수원의 이동 경로와 연관되어 있음을 나타낸다. 따라서 한파의 유지 기작을 이해하고 한파를 예측하기 위해서는 열원 그리고 열흡수원의 이동 기작이 밝혀져야 할 것이다.

온도 인지 마이크로프로세서를 위한 듀얼 레지스터 파일 구조 (A Dual Integer Register File Structure for Temperature - Aware Microprocessors)

  • 최진항;공준호;정의영;정성우
    • 한국정보과학회논문지:시스템및이론
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    • 제35권12호
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    • pp.540-551
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    • 2008
  • 오늘날 마이크로프로세서의 설계는 전력 소모 문제만이 아닌 온도 문제에서도 자유롭지 않다. 제조 공정의 미세화와 고밀도 회로 집적화가 칩의 전력 밀도를 높이게 되어 열성 현상을 발생시키기 때문이다. 이를 해결하기 위해 제안된 동적 온도 제어 기술은 냉각 비용을 줄이는 동시에 칩의 온도 신뢰성을 높인다는 장점을 가지지만, 냉각을 위해 프로세서의 성능을 희생해야 하는 문제점을 가지고 있다. 본 논문에서는 프로세서의 성능 저하를 최소화하면서 온도를 제어하기 위해 듀얼 레지스터 파일 구조를 제시한다. 온도 제어를 고려하였을 때 가장 관심을 끄는 것은 레지스터 파일 유닛이다. 특히 정수형 레지스터 파일 유닛은 그 빈번한 사용으로 인하여 프로세서 내부에서 가장 높은 온도를 가진다. 듀얼 레지스터 파일 구조는 정수형 레지스터 파일에 대한 읽기 접근을 두 개의 레지스터 파일에 대한 접근으로 분할하는데, 이는 기존 레지스터 파일이 소모하는 동적 전력을 감소시켜 열성 현상을 제거하는 효과를 가져온다. 그 결과 동적 온도 제어 기법에 의한 프로세서 성능 감소를 완화시키는데, 평균 13.35% (최대 18%)의 성능 향상을 확인할 수 있었다.