• 신재생에너지
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• 제10권4호
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• pp.29-35
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• 2014

Non-used waste heat has recently been paid special attention due to several global warming regulation and energy cost rising. In this study, therefore, thermal energy storage system which uses a solid type heat media has been investigated about the possibility of heat accumulation and heat release for thermal energy storage system. 35kWh of bench-scale thermal storage system was used to investigate the characteristics of the solid type heat media. From the result, it is shown that a solid type heat media should be divided to supply constant heat to the customers' side. It is also shown the flow direction should be considered to reduce temperature difference between top and bottom sides in the thermal storage system.

• 한국전산유체공학회지
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• 제21권4호
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• pp.33-39
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• 2016

Generally, thermal analysis of spent fuel storage cask has been conducted using the porous media and effective thermal conductivity model to simplify the structural complexity of spent fuel assemblies. As the fuel assembly is composed of two regions; active fuel region corresponding to UO2 pellets and unactive fuel region corresponding to the top and bottom nozzle, the heat transfer performance can be influenced depending on porous media application at these regions. In this study, numerical analysis on concrete storage cask of spent fuel was performed to investigate heat transfer effects for two cases; one was porous media application only to active fuel region(case 1) and the other one was porous media to whole length of fuel assembly(case 2). Using computational fluid dynamics code, the three dimensional, 1/4 symmetry model was constructed. For two cases, maximum temperatures for each component were evaluated below the allowable limits. For the case 1, maximum temperatures for fuel cladding, neutron absorber and baskets inside the canister were slightly higher than those for the case 2. In particular, even though the helium flows with low velocity due to buoyant forces occurred at the top and bottom of unactive fuel region, treating only active fuel region as the porous media was ineffective in respect of the heat removal performance of concrete storage cask, implying a conservative result.

• Journal of Biosystems Engineering
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• 제9권2호
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• pp.74-80
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• 1984

시설규모(施設規模)가 작은 축소형(縮少型) 열저장장치(熱貯藏裝置)를 개발(開發)하기 위한 기초적(基礎的)인 연구(硏究)로 비교적(比較的) 열흡수능력(熱吸收能力)이 큰 염화칼슘, 황산(黃酸) 나트륨, 산성인산(酸性燐酸)나트륨 등(等)의 수화염류를 축열매체로 한 수직관형축열조(垂直管形蓄熱槽)를 제작(製作)하고 이들 축열장치(蓄熱裝置)를 이용(利用)한 축열매체의 열저장특성(熱貯藏特性)을 실험(實驗)을 통(通)하여 구명(究明)하기 위하여 수행(遂行)되었으며 그 결과(結果)를 요약(要約)하면 다음과 같다. 가. 수직관형축열조(垂直管形蓄熱槽)에서 반경방향 온도분포를 검토한 결과(結果), 본(本) 실험(實驗)에 사용(使用)된 모든 열매체는 가열과정(加熱過程)에서는 결정수(結晶水)의 감소(減少)로 인(因)한 발열현상(發熱現象)때문에 잠열현상(潛熱現象)이 나타나지 않았으나 냉각시(冷却時)에는 이들 축열매체중 염화칼슘이 가장 뚜렷한 잠열현상(潛熱現象)을 보였으므로 상변화를 이용(利用)한 축열매체로서 가장 적합(適合)하다고 사료(思料)되었다. 나. 가열(加熱) 및 냉각시(冷却時) 축열매체에 전달된 열량(熱量)은 같은 조건하(條件下)에서 염화칼슘의 경우(境遇)가 가장 많았다.

• 설비공학논문집
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• 제19권2호
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• pp.175-182
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• 2007

The objective of the present study is to investigate the heat storage characteristics of a packed bed according to periodically oscillating flows. Experiments have been performed to measure transient temperature distributions in solid and fluid Phases of the porous media. A simplified analytical model has been developed with intra-particle and dispersion effects neglected, and non-dimensional parameters have been derived. The transient temperature distributions according to the simplified numerical model agree well with the experimental results. Heat storage efficiencies defined in two different ways are obtained for various time periods and face velocities.

• 터널과지하공간
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• 제22권4호
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• pp.243-256
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• 2012

에너지의 효과적인 저장과 관리는 에너지 공급과 수요의 시간적 양적 불균형을 해소하고, 에너지 이용효율을 향상시킬 수 있다는 점에서 새로운 에너지원을 개발하는 일만큼 중요하다. 열에너지 저장 시스템은 산업폐열이나 태양열과 같은 열원 기반의 에너지를 저장하는 시스템으로서, 대용량 저장 시설에 암반 지하공동을 활용하는 경우 주변 암반의 낮은 열전달 특성과 높은 화학적 안정성을 통해 보다 효율적인 저장 시스템을 구축할 수 있다는 장점이 있다. 본 연구에서는 열에너지 저장 방식과 저장 매질의 일반적인 특성과 열에너지 저장사례에 대하여 살펴보고, 지하공동을 활용한 열에너지 저장 시스템에 대한 각 저장 매질의 적용성에 대해 개괄적으로 검토하였다.

• 유기물자원화
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• 제31권4호
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• pp.5-11
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• 2023

본 연구는 하수 탈수찌꺼기가 건조기에 직 투입되는 경우 함수율 40~60% 구간에서 발생하는 Glue Zone에서 뭉침 및 Fouling 현상 등의 문제점 및 에너지효율 개선을 하기 위해 수행하였다. 열풍 온도는 270~300℃로 낮게, 패들타입의 부상방식과 순환되어진 축열 메디아에 탈수찌꺼기가 도포되어 열풍과의 접촉면적을 증대시켜 에너지 회수 및 가스 배출량을 감소시켰으며, 건조 찌꺼기의 함수율은 2.7~7.5%, 수분 증발열량은 608.0~690.6kcal/kg·H₂O로 축열 메디아 미투입 시 수분 증발열량 714.5 kcal/kg·H₂O과 비교하여 약 8.8%의 에너지 절감 효과를 확인하였다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.304.2-304.2
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• 2007

• 공업화학
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• 제7권4호
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• pp.726-734
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• 1996

본 연구는 $Ba(OH)_2{\cdot}8H_2O$, 나프탈렌, 아세트아미드를 대상으로 이들 물질이 자동차용 축열시스템의 축열매체로서의 사용 가능성여부를 조사하고자 하였다. 이들 물질을 대상으로 고-액상전이 순환과정 동안 상전이에 따른 여러 현상들을 조사하고 축열매체로서 사용되기 위해 위험성없이 재순환시켜 반복할 수 있는 가능성이 조사되었다. 그리고 이들 물질을 안전하게 저장할 수 있는 적절한 저장용기를 찾고자 하였다. 본 연구에서는 이들 물질 중 $Ba(OH)_2{\cdot}8H_2O$가 가장 상안정성이 좋아 자동차용 축열시스템의 축열매체로서의 사용가능성이 높았으며 저장용기는 구리캡슐이 적절하였다.

• KIEAE Journal
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• 제17권3호
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• pp.107-112
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• 2017

Purpose: Both silica gel and activated carbon black particles were adopted for use as PCM absorbed porous media applicable as construction materials. To investigate usable methods for absorbing PCM into the media, they were soaked into PCM and also tested for enhancement of PCM absorption into them. Method: To test PCM absorption into some porous media such as both ${\varphi}1{\sim}2mm$ and $10{\mu}m$ silica gels, and $50{\mu}m$ activated carbon black, $43^{\circ}C$ PCM was used as a laten heat material. The method, soaking into PCM was applied to this study, and the media were moderately rotated by centrifuge to have the extra PCM flow out. DSC analysis was conducted to investigate the melting and solidifying of the PCM absorbed into the porous media. Result: It was found that PCM was absorbed into the porous media by over 85 wt% of all particles. In addition, it was noted that the ultrasonic vibrator was accelerating the PCM absorption into the particles to three times higher speed than simple soaking. Centrifuge was adopted to remove extra PCM sticking on the particle surfaces and extra PCM was moderately removed from the surfaces of the particles. DSC analysis indicated that the latent heat of the absorbed PCM particles was 160 J/g, and the melting temperature was approximately $40^{\circ}C{\sim}50^{\circ}C$.

• 대한설비공학회지:설비저널
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• 제8권2호
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• pp.81-88
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• 1979

The performance of air type solar heating system has been investigated for a system which has been operating continuously for two years. Design factors of a collector, such as the effective transmittance-absorptance and heat transfer factor were also determined experimentally. The flat plate collector is fabricated from steel sheet metal with two sealed glass covers. Solar heat is stored in a pebble bed of primarily granitic rock approximately 20-40 mm in diameter. The system is controled by automatically driven motors and dampers. The ratio of useful collected solar heat divided by the total solar radiation on the collector dropped was the range of 35 to 42 percent in monthly average. As it result, the air system was found fairly competitive with the water system, however, the heat supply from storage was limited because of using the pebble as the heat storage media.