• 제목/요약/키워드: warm storage

검색결과 55건 처리시간 0.024초

실내유입온기의 열유동특성과 고효율 축열에 관한 연구 (A Study on the Heat Flow Characteristics and High Efficiency Thermal Storage of Inflowing Warm Air in the Room)

  • 박이동;정운철;이도영
    • 태양에너지
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    • 제17권2호
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    • pp.13-22
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    • 1997
  • 본 연구에서는 실내로 유입되는 온기와 실내공기사이의 온도차 및 유입속도에 따라 발생되는 부력의 영향 및 실내로 유입된 온기의 혼합특성에 관한 열유동특성을 파악하였다. 혼합도의 정의로부터 임계속도($1.2{\sim}1.6m/s$)전 후로 기하학적영향에 대하여서 혼합과의 관계를 파악할 수 있었다. 그리고 축열표율과의 관계는 속도가 크고 기준온도차가 작을수록 부력의 영향을 적게 받아서 아네모스형, 베인형 모두 높은 축열효율을 나타냈다. 그리고 속도가 클 때는 베인형이 전반적으로 우수한 축열효율을 나타냈다. 따라서 유입속도에 의한 영향이 기준온도차에 의한 영향보다 지배적임을 알 수 있었다.

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지하수류가 대수층 열저장 시스템의 성능에 미치는 영향(3) (The Influence of Groundwater Flow on the Performance of an Aquifer Thermal Energy Storage (ATES) System)

  • 한정상;이주현;김영식;이광진;홍경식
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제22권4호
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    • pp.9-26
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    • 2017
  • When a warm well located downgradient is captured by cold thermal plume originated from an upgradient cold well, the warm thermal plume is pushed further downgradient in the direction of groundwater flow. If groundwater flow direction is parallel to an aquifer thermal energy storage (ATES), the warm well can no longer be utilized as a heat source during the winter season because of the reduced heat capacity of the warm groundwater. It has been found that when the specific discharge is increased by $1{\times}10^{-7}m/s$ in this situation, the performance of ATES is decreased by approximately 2.9% in the warm thermal plume, and approximately 6.5% in the cold thermal plume. An increase of the specific discharge in a permeable hydrogeothermal system with a relatively large hydraulic gradient creates serious thermal interferences between warm and cold thermal plumes. Therefore, an area comprising a permeable aquifer system with large hydraulic gradient should not be used for ATES site. In case of ATES located perpendicular to groundwater flow, when the specific discharge is increased by $1{\times}10^{-7}m/s$ in the warm thermal plume, the performance of ATES is decreased by about 2.5%. This is 13.8% less reduced performance than the parallel case, indicating that an increase of groundwater flow tends to decrease the thermal interference between cold and warm wells. The system performance of ATES that is perpendicular to groundwater flow is much better than that of parallel ATES.

충적대수층 계간축열 냉난방 시스템의 온실 난방 효과 (Effects of the Cooling and Heating System with Seasonal Thermal Storage in Alluvial Aquifer on Greenhouse Heating)

  • 문종필;강금춘;김형권;이태석;오성식;진병옥
    • 한국농공학회논문집
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    • 제59권6호
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    • pp.127-135
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    • 2017
  • In this study, a cold well and a warm one with the distance of 100 m were installed in the alluvial aquifer. Groundwater used as the heat and the cold source of heat pump was designed to flow into the warm and the cold well with a diameter of 200 mm. In order to increase the heat and cold storage in aquifer, six auxiliary wells with the diameter of 50 mm and the depth of 30 m were installed at an interval of 5 m from the main well. Also, heat pump 50 RT, the thermal tank $40m^3$, and a remote control and monitoring system were installed in three single-span greenhouses ($2,100m^2$) for growing tomato in Buyeo, Chungcheongnam-do. According to the aquifer heat storage test which had been conducted from Aug. 31 to Sep. 22, 2016, warm water of $850m^3$ was found to flow into warm well. The temperature of the injected water was $30^{\circ}C$ (intake temperature : $15^{\circ}C$), and the heat of 12.8 Gcal was stored. The greenhouse heating test in winter had been conducted from Nov. 21, 2016 to Apr. 30, 2017. On Nov. 21, 2016 when heating greenhouse started, the aquifer temperature of the warm well was $18.5^{\circ}C$. The COP for heating with water source at $18.5^{\circ}C$ was 3.8. The intake water temperature of warm well was gradually lowered to the temperature of $15^{\circ}C$ on Jan. 2, 2017 and the heat pump COP was measured to be 3.2 at that time. As a result, the heat pump COP was improved by 18 %. and retrieval heat was 8 Gcal, the retrieval rate of heat stored in aquifer was estimated at 63 %.

북서태평양에서 난수성(Pleuromamma sp.)과 냉수성(Neocalanus plumchrus) 요각류의 지방 함량 및 구성 분석을 통한 생리/생태 비교 (The Physiological and Ecological Comparisons between Warm (Pleuromamma sp.) and Cold Water Copepod Species (Neocalanus plumchrus) in the Northwestern Pacific Ocean Using Lipid Contents and Compositions)

  • 고아라;주세종;이창래
    • Ocean and Polar Research
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    • 제31권1호
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    • pp.121-131
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    • 2009
  • In an effort to better understand the physiological and ecological differences between warm and cold water copepod species in Korean waters using lipid contents and compositions, two species of copepods (Pleuromamma sp. as a warm water species and Neocalanus plumchrus as a cold water species) were collected from the Northwest Pacific and East Sea/Sea of Japan, respectively. The cold water species showed two fold higher lipid contents than the warm water species (11% vs. 5% of dry weight). Wax esters, known as one of the major storage lipid classes, were found to be the dominant lipid class (accounting for 64% of total lipids) in the cold water species, whereas, in the warm water species, phospholipids, which are known as membrane components, were the dominant lipid class (accounting for 43% of total lipids),with a trace amount of the storage lipids as a form of triacylglycerols (${\leq}1%$ of total lipids). With regard to the fatty acid compositions, saturated fatty acids (SAFA), especially 16:0 (about 30% of total fatty acids), were most abundant in the warm water species, whereas the polyunsaturated fatty acids (PUFA), particularly eicosapentaenoic acid (EPA : 20:5(n-3)) (${\geq}16%$ of total fatty acids), were most abundant in the cold water species. Among the neutral fraction of lipids, phytol, originating from the side chain of chlorophyll and indicative of active feeding on phytoplankton, was detected only in the warm water species. Significant quantities of fatty alcohols were detected in cold water species, particularly long-chain monounsaturated fatty alcohols (i.e. 20:1(n-9) and 22:1(n-11)), which are well known to abound in cold water herbivorous copepods. However, only trace amounts of short-chain fatty alcohols were detected in the warm water species. Twelve different kinds of sterols were detected in these copepod species, with cholest-5-en-$3{\beta}$-ol (cholesterol) and cholesta-5, 24-dien-$3{\beta}$-ol (desmosterol) dominating in cold and warm water species, respectively. In addition, for the warm water species (Pleuromamma sp.), we assessed the latitudinal gradients of lipid contents and compositions using samples from three different latitudinal regions (Philippine EEZ, Japan EEZ, and the East China Sea). Although no latitudinal gradients of lipid contents were detected, the lipid compositions, particularly dietary fatty acid markers, varied significantly with the latitude. The findings of this study confirm that the distribution of lipid contents and compositions in copepods may not only indicate their nutritional condition and diet history, but may also provide insights into their living strategies under different environmental conditions (i.e., water temperature, food availability).

제주한우에 있어서 동결정액 수정방법이 수태에 미치는 영향 제1보 동결정액의 융해방법이 정액상태와 수태에 미치는 영향 (Effect on Conception for Insemination Method of Frozen Semen in Cheju Native Cattle. 1. Effect of motility and fertility after thawing in frozen semen.)

  • 김중규;장덕지
    • 한국가축번식학회지
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    • 제8권2호
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    • pp.79-86
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    • 1984
  • This cepseiment was carried out to cerify the effect of thawing methods and preservative temperature on the sperm motility and fertility after thawing semen with plastic straws in fresh and warm water. Sperm motility in vitro stored at room temperature after thawing were conducted by the various storage hours. A field trial after thawing semen with warmed water in straws from Cheju native cows involving 4 technicians and 800 cows first (or second) services gave the following results. The thawing methods of warmed water for one minute in semen motility were considerably higher than that in iced water during 12 hours after thawing semen, however, the sperm survival index of ice-water shwed a better results according as the time passed away, but not significant differences. Preservative temperaure at 5$^{\circ}C$ (iced water) after thawing gave significantly better results than that of thawed at 3$0^{\circ}C$ (warmed water). The N R rate to 175 inseminations with semen thawed at 15-2$0^{\circ}C$ (fresh water) was 82.8%, 80.9% for 610 inseminations thawed in warm water. Conception rate ofthe semen thawed in warm water for 10-60 secs gave no significant difference among storage hours, because the semen used to be inseminated within one hour almost, but in decreased when semen thawed at the period of one minute over.

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전북 진안 풍혈의 여름철 냉풍 및 겨울철 온풍 발생 연구 (Study of occurrence of cool air in summer and warm air in winter of Chonbuk Jinan Poonghyeol)

  • 김영일;신영기;서정아;최영돈;송태호;강채동;김성실;노정선;정시영;김용찬
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.879-884
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    • 2006
  • Jinan Poonghyeol in Chonbuk province Is famous for emitting cool air in summer and warm air in winter. Cause for these phenomena is studied by measuring temperature, humidity and air velocity of several locations around Jinan Poonghyeol Temperature variations under the ground are also measured. Analyzing data compiled from July 21, 2005 through May 26, 2006, it is presumed that storage effect of rocks and soil in this area and buoyance effect are the main causes for this mysterious natural air-conditioning phenomena.

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성층 축열 시스템에서의 열 저장 특성에 관한 실험적 연구 (An experimental study on thermal storage characteristics in the thermally stratified water storage system)

  • 고재윤;김영기;이채문;임장순
    • 한국태양에너지학회 논문집
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    • 제21권4호
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    • pp.37-46
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    • 2001
  • This study describes the experimental study that focuses on the effects that distributor shapes and flow rate variations have an influence on the stratification in a rectangular thermal storage tank. Experiments were carried out under the conditions that the flow rates of working fluid are 20, 10 and $5\ell$/min. The storage tank is initially filled with chilled water of $1^{\circ}C$, and is extracted through the bottom at the same rate as the return warm water from load is entered through the distributor at the top of the tank. The thermo-cline forms at the top of the storage tank as the warm water enters the tank from the load through the distributor and the thermo-cline thickness increases with time. Emphasis is given to the effects of mixing at the inlet that increases the thermo-cline decay Flow rate variation and inlet distributor shapes are the important parameters in deciding the performance of a storage system. Stratification degree increases with decreasing in inlet flow rate under $10\ell$/min. Experiments shows that better thermal stratification can be obtain using the distributor to limit momentum mixing at the inlets and outlets. Also, 12% of improvement in the thermal energy usage has been achieved using the modified distributor discharging same flow rate in each lateral ports.

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Nutrient Concentration and Stoichiometry in Plant Organs of Four Warm-temperate Forests in Southern Korea

  • Choonsig Kim
    • 한국산림과학회지
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    • 제113권1호
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    • pp.66-72
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    • 2024
  • Determining the nutrient stoichiometry in plant organs is critical for understanding nutrient uptake and cycling in forest ecosystems. This study evaluated nutrient concentrations and stoichiometry in various plant organs (stem, bark, branches, and foliage) of species found in four warm-temperate forests in southern Korea. Cryptomeria japonica D. Don (CJ), Quercus serrata Thunb. (QS), evergreen broadleaved tree species (EB), and bamboo spp. (BB) were destructively sampled to measure nutrient (C, N, and P) concentrations in the plant organs. The mean C concentration in the stem was significantly higher in CJ than in QS, BB, or EB, whereas the C concentration in the foliage was the lowest in BB. The mean foliar N and P concentrations were higher in BB than in EB or CJ. The mean stem C:N and C:P ratios were highest in CJ but were lowest in the foliage of BB. Overall, stems of all species showed a strong positive correlation between C concentration and dry weight, but a negative correlation between N and dry weight. The N and P concentrations of foliage and bark were strongly correlated, whereas those of the stem and branches were poorly correlated. Positive correlations were detected between the C:N and C:P ratios in bark and foliage. These results indicate the existence of intraspecific differences in nutrient requirements in warm-temperate forest species and add to the understanding of nutrient uptake and storage patterns in the organs of species growing in warm-temperate forests.

전기 압력 밥솥 밑 전기 밥솥 취반미의 저장 조건에 따른 품질 특성 (The Quality of Cooked Rice Prepared by Both an Electric Cooker and Electric Pressure Cooker, with Different Storage Conditions)

  • 한귀정;박희정;이혜연;박영희;조용식
    • 한국식품조리과학회지
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    • 제23권5호
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    • pp.635-643
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    • 2007
  • 쌀밥의 저장 특성을 조사하기 위하여 국내산 쌀 탑 라이스 4품종(일품, 새추청, 신동진 및 수라)을 전기 압력 밥솥 및 전기 밥솥을 이용하여 취반한 다음 상온, 보온 및 냉장 저장하면서 수분함량, pH, 색도 및 관능적인 특성을 조사하였다. 취반 직후 쌀밥은 전기압력 밥솥으로 취반했을 때 수분함량이 낮고 pH는 높았으며, 색도에서 b값은 높고 L값은 낮은 경향을 보였다. 관능적으로도 구수한 풍미, 조직감 등이 강하고 기호도가 우수한 것으로 나타났다. 저장 기간에 따라서는 수분함량 및 pH는 취반 용기에 관계없이 모든 저장 온도에서 감소하였고, 색도는 상온 및 냉장 보관시에는 취반 용기에 관계없이 L, a 및 b값 모두 저장기간 동안 유사하였으나 보온 조건에서 전기 밥솥 취반미를 저장했을 때는 초기(6시간)에 녹색도 (a값)이 감소하기 시작하여 24시간 후에는 황색도(b값)가 크게 증가하면서 L값이 감소하였다. 관능적으로도 상온에서는 저장 48시간까지 유의적 차이를 보이지 않은 반면 보온 및 냉장 저장 시에는 각각 24시간 및 3일 경과 후에 대부분의 관능적 특성에서 유의적인 차이를 보이면서 기호도가 감소하였다. 이상으로부터 저장 중 쌀밥의 품질은 상온에서는 48시간까지 색도 및 관능적인 변화가 적어 가장 효과적이었던 반면 보온 및 냉장에서는 각각 황변 및 수분증발과 함께 이취가 증가하면서 관능적으로 품질이 낮아졌으며, 전기 압력 밥솥 보다 전기 밥솥을 사용하여 보온했을 때 품질저하가 더 큰 것을 알 수 있었다.

Greenhouse 보온(保溫)을 위한 태양(太陽)에너지 잠열축열(潛熱蓄熱) 연구(硏究) (Study on the Latent Heat Storage of Solar Energy for Greenhouse Heating)

  • 송현갑;류영선
    • Journal of Biosystems Engineering
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    • 제16권4호
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    • pp.399-407
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    • 1991
  • In Korea, the cultivation area under the plastic greenhouse was 1,746 ha in 1975, and 36,656 ha in 1989, it shows that the greenhouse cultivation area was increased by 21 times during last 14 years. The greenhouse cultivation area of 90~93% has been kept warm with double layers of plastic film and thermal curtain knitted with rice straw, and the rest area of 7~10% has been heated by fossil fuel energy. The use of rice straw thermal curtain is inconvenient to put it on and off, on the other hand the use of fossil fuel heating system results in the increase of production cost. To solve these problems, at first the heating load and the storable solar energy in greenhouse during the winter season were predicted to design solar utilization system, secondly a solar thermal storage system filled with latent heat storage materials was developed in this study. And then finally the thermal performance of greenhouse-solar energy storage system was analyzed theoretically and experimentally.

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