• 제목/요약/키워드: Thermal storage system

검색결과 650건 처리시간 0.027초

축열시스템의 온수이용 예측에 관한 연구 (The Study on Prediction of Hot Water Extraction in a Thermal Energy Storage System)

  • 조운;박이동
    • 태양에너지
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    • 제18권3호
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    • pp.71-80
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    • 1998
  • In thermal energy storage system, energy collected from many types of heat source is stored in a storage tank and then supply to load for demand. Lately, practical use of thermal energy storage system and attention to essential use of energy have been increased. From this point of view, especially, a study about the energy extraction process from a storage tank is necessary. So in this study, useful rate of hot water and hot water extraction efficiency was analysed respect to dynamic and geometric parameters dominating the hot water extraction process.

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축열식 열원시스템 적용에 의한 전력부하 평준화의 경제성 검토 (Feasibility Study on Leveling Method of Electric Power Load by Applying Thermal Storage Air Conditioning System)

  • 이철구
    • 한국지열·수열에너지학회논문집
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    • 제15권1호
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    • pp.9-17
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    • 2019
  • Reducing global warming potential has become important, and as one of those methods for reducing it, economic evaluation by applying ice thermal storage air conditioning system was performed. The floor area and height of the subject building was assumed $5,000m^2$ and 20 m. Absorption chillerheater system and air source heat pump system was used for comparing to the subject system, and payback period method was used to perform economic evaluation. Although the running cost of ice thermal storage system is reduced compared to two systems, the ratio is not significant compared to the increase of initial construction expenses, and payback period was calculated to be about 7.7 and 79.3 years. However, the heat storage system should be approached from the viewpoint of long term rather than the economic standard in the present standard.

지하대수층을 이용한 축열시스템의 설계(II) : 열해석 (Design of an Aquifer Thermal Energy Storage System(II) : Thermal Analysis)

  • 이관수;이태희;송영길
    • 설비공학논문집
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    • 제6권3호
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    • pp.315-324
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    • 1994
  • The energy recovery efficiency(ERE) of an aquifer thermal energy storage system was calculated using curvilinear coordinate. The results of the calculation were compared with the experimental results, and agreed within 11% of the discrepancy. The variation of ERE was investigated as a function of the underground water natural velocity, the amount of the stored energy, and period of the energy recovery. The slower the natural velocity and shorter the recovery period, the higher ERE was yielded. Also it was found that increase in the amount of energy storage yields higher ERE, and carries out less influential ERE to the natural velocity. Reiterative usage of the aquifer as a thermal storage tends to gradually increase ERE. The result of this study implements that the aquifer thermal energy storage system is suitable for large cooling/heating loads, such as district cooling/heating.

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지하대수층을 이용한 축열시스템의 설계 (I) : 등온해석 (Design of an Aquifer Thermal Energy Storage System (I) : Isothermal Analysis)

  • 송영길;이관수;이태희;김양현
    • 설비공학논문집
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    • 제5권2호
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    • pp.102-110
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    • 1993
  • An isothermal analysis was conducted to develop the design tool of an aquifer thermal energy storage system. Taejeon aquifer was chosen for the analysis, and the variation of FRE(Fluid Recovery Efficiency) with respect to the aquifer natural velocity and thermal load were investigated. The analysis results were compared with those of ATESSS(Aquifer Thermal Energy Storage System Simulator) and agreed within 2% of discrepancy. It is recommended, based on the result of this study, that the system may be suitable for a large volume of hot or chill thermal energy storage system, such as for district heating or cooling.

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구배법 알고리즘에 의한 슬래브축열의 최적제어 해석 (An Analysis of the Optimal Control of Air-Conditioning System with Slab Thermal Storage by the Gradient Method Algorithm)

  • 정재훈
    • 설비공학논문집
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    • 제20권8호
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    • pp.534-540
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    • 2008
  • In this paper, the optimal bang-bang control problem of an air-conditioning system with slab thermal storage was formulated by gradient method. Furthermore, the numeric solution obtained by gradient method algorithm was compared with the analytic solution obtained on the basis of maximum principle. The control variable is changed uncontinuously at the start time of thermal storage operation in an analytic solution. On the other hand, it is showed as a continuous solution in a numeric solution. The numeric solution reproduces the analytic solution when a tolerance for convergence is applied severely. It is conceivable that gradient method is effective in the analysis of the optimal bang-bang control of the large-scale system like an air-conditioning system with slab thermal storage.

빙축열시스템의 실질적인 최대 축열 가능량 예측 (Prediction of practically chargeable cold energy in an ice storage system)

  • 이대영;강병하;김민수
    • 설비공학논문집
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    • 제11권1호
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    • pp.133-146
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    • 1999
  • The charge operation of an ice storage system has been analyzed in this paper. The thermal characteristics of major components of the ice storage system. i.e., the refrigerator and the ice storage tank are evaluated from performance tests on an existing ice storage system. Based on the measured data for thermal characteristics, a simulation is carried out for the charge operation and the effect of the refrigerator size on the system performance is investigated. The results indicate that the larger the refrigerator size for a given storage capacity, the lower the inlet temperature of the ice storage tank so that the lower the efficiency of charge operation. It is also found that there exists an optimal size of the refrigerator with which the ice storage at the end of the charge operation is maximized, but the complete charge is not possible even with the optimally sized refrigerator. This leads to the result that the design capacity of the storage tank should be larger than the required amount of cold energy for the daytime cooling considering the practically chargeable amount of cold energy during the nighttime. Where the cooling load sharing of the storage is 40%, the nominal capacity of an ice storage tank needs to be larger than the required storage amount by 30%.

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냉방에너지 저감을 위한 PCM적용 축열벽 시스템 연구 (Study on PCM Applied Thermal Storage Wall System to Reduce Cooling Energy)

  • 이규영;류리;서장후;김용성
    • 설비공학논문집
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    • 제26권6호
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    • pp.247-256
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    • 2014
  • The regulations to reduce energy consumption and carbon dioxide emission in building sectors are being developed and promoted all over the world. However, in Korea, as balcony extension of the apartments has been legally allowed, it became prevalent and resulted in excessive energy consumption. This study derived the possibility of PCM application to the thermal storage wall system through theoretical consideration and investigated the problems occurring when the balcony space has been extended to the diverted space. In addition, this study aims at the possibility of verifying the installation and confirming the cooling energy reduction effect, by conducting measuring tests with the actual installation of PCM applied thermal storage wall system. As a result of theoretical consideration, it is determined that the disadvantages with the existing thermal storage wall system can be complemented by applying PCM, and this study suggests the PCM applied Thermal Storage Wall System. The study was conducted on 1/6 of a miniature inner room of a domestic apartment with 84 $m^2$ of exclusive area. From the results of actual measurements, it is confirmed that the balcony extension structure can gain 11.3% of more calories than the existing balcony structure, resulting in the increase in cooling energy usage. It is determined that the installation of the PCM applied Thermal Storage Wall System may gain 25.2% of less calories to reduce cooling energy usage.

태양열원 난방기의 수축열조 효율개선에 관한 연구 (The Study on Efficiency Improvement of a Thermal Storage Tank for Solar Combined Heating System)

  • 류남진;한유리;박윤철
    • 한국태양에너지학회 논문집
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    • 제27권4호
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    • pp.43-49
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    • 2007
  • This study is conducted to improve the efficiency of a thermal storage tank. The thermal storage tank was designed to store heat energy that obtained from the solar or the others heat sources. However, it has difficulties in storing heat with nonuniform temperature through the entire tank with respect to the vertical direction, This study is focused on the thermal stratification to improve thermal comfort for the resident in house. To enhance temperature stratification of the tank, a distributor was designed and installed in the middle of the storage tank vertically. The vertically designed distributor could supply the return water with stratified temperature in the storage tank with respect to the height. The water velocity from the distributor hole is the same with the other outlet in the distributor. However, gravity effect on the flow in the storage tank is much higher than that of the velocity effect due to that Froude Number is less than 1. During the heat charging process in the storage tank, temperature maintained with little difference with respect to the height. However the charging process takes long time to get a effective temperature for the heating or hot water supply because of all of water in the storage tank needs to be heated.

열펌프-잠열축열 시스템의 온실 난방 특성 연구 (Greenhouse Heating Characteristics of Heat Pump-Latent Heat Storage System)

  • 강연구;송현갑
    • Journal of Biosystems Engineering
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    • 제25권5호
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    • pp.379-384
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    • 2000
  • In order to use the natural thermal energy as much as possible for greenhouse heating, the air-air heat pump system involved PCM(phase change material) latent heat storage system was composed, and three types of greenhouse heating system(greenhouse system, greenhouse-PCM latent heat storage system, greenhouse-PCM latent heat storage-heat pump system) were recomposed from the greenhouse heating units to analyze the heating characteristics. The results could be concluded as follows; 1) In the greenhouse heated by the heat pump under the solar radiation of 406.39W/$m^2$, the maximum PCM temperature in the latent heat storage system was 24$^{\circ}C$ and the accumulated thermal energy stored in PCM mass of 816kg during the daytime was 100,320kJ. In the greenhouse without heat pump under the maximum solar radiation of 452.83W/$m^2$, the maximum PCM temperature in the latent heat storage system was 22$^{\circ}C$ and the accumulated thermal energy stored during the daytime was 52.250kJ. 2) In the greenhouse-PCM system without heat pump the heat stored in soil layers from the surface to 30cm of the soil depth was 450㎉/$m^2$. 3) In all of the greenhouse heating systems, the difference between the air temperature in greenhouse and the ambient temperature was about 20~23$^{\circ}C$ in the daytime. In the greenhouse without heat pump and PCM latent heat storage system the difference between the ambient temperature and the air temperature in the greenhouse was about 6~7$^{\circ}C$ in the nighttime, in the greenhouse with only PCM latent heat storage system the temperature difference about 7~13$^{\circ}C$ in the nighttime and in the greenhouse with the heat pump and PCM latent heat storage system about 9~14$^{\circ}C$ in the nighttime.

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Ice Ball을 내장(內裝)한 빙축열조내(氷蓄熱槽內)의 열유동(熱流動) 특성(特性)에 관한 실험적(實驗的) 연구(硏究) (An Experimental Study on Characteristics of Heat Flow in the Cylindrical Storage Tank with Ice Ball)

  • 장영근;이원섭;박정원
    • 태양에너지
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    • 제18권1호
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    • pp.99-109
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    • 1998
  • 공기조화 설비에 있어서 시스템의 성능을 향상시키고 에너지의 유효이용 및 경제성을 높일 수 있는 빙축열 시스템에 대한 연구이다. Ice Ball을 내장한 빙축열조를 횡형 사각형과 입형 원통형 축열조에 대하여 조내로 유입하는 브라인의 유량(2, 4, 6LPM)과 온도(-3, -5, $-7^{\circ}C$)를 변화시키고, 또한 유입 브라인의 유동을 상 하향유동으로 하면서 빙축열조내의 온도분포를 파악하여 열유동 특성 및 빙충전율에 대하여 고찰하였다. 연구결과 빙축열조내 열성층을 향상시키기 위해서는 조내 유입 브라인의 유동이 상향 압출흐름이어야 한다는 것을 알았다.

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