• Title/Summary/Keyword: Solar Heat storage

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Solar Energy Storage Effectiveness on Double Layered Single Span Plastic Greenhouse (2중 단동비닐하우스의 태양열 축열이용 효과)

  • Lee, Sung-Hyoun;Ryou, Young-Sun;Moon, Jong-Pil;Yun, Nam-Kyu;Kwon, Jin-Kyung;Lee, Su-Jang;Kim, Kyeong-Won
    • Journal of Biosystems Engineering
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    • v.36 no.3
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    • pp.217-222
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    • 2011
  • This study was carried out in order to reduce the amount of underground water which is used in the double layered single span plastic greenhouse for retaining heat. For this research, two plastic green houses of the double layered single span plastic greenhouse were installed. There was equipped of internal small tunnel for keeping warm air in the interior of the house. Then the internal small tunnel for keeping warm air was fitted with PVC duct of 50 cm in diameter filled with subsurface water. The surplus solar energy in the greenhouse was stored in the water in the PVC duct. Four FCUs (Fan Coil Unit), which has the capacity of 8,000 kcal per hour, were installed in the middle of the house, and a circulation motor in heat storage water tank was operated from 10:30 a.m. to 16:00 p.m. in order to circulate water between the water tank and the FCUs. Consequently about 5 degrees celsius could be maintained in the interior of the internal small tunnel for keeping warm air with the external temperature of lower than minus 5 degrees celsius. It appeared that the alteration of an internal temperature of the house was flexible depending on the sunlight during daytime. To prevent the water freezing, mixing antifreezing liquid in the water or operating FCU continuously was needed. Also, in order to use the surplus solar thermal energy on plastic green house of water curtain system efficiently, storing the surplus heat during daytime simultaneously finding a method of using water curtain systematic underground water happened to be important. As a result of this research, when the house's interior temperature is below zero the operation of FCU appeared to be impossible. Considering the amount of water used in the house with water-curtain-heating system is 150~200 ton per day, using the system mentioned in this research showed that reducing the underground water more than 80% in order to maintain the internal temperature as the level of 5 degree celsius at the extreme temperature of minus 5 degrees celsius.

Thermally Stratified Hot Water Storage (태양열의 성층축열과 주택이용에 관한 연구(성층축열))

  • Pak, Ee-Tong
    • Solar Energy
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    • v.10 no.3
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    • pp.3-12
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    • 1990
  • This paper deals with experimental research to increase thermal storage efficiency of hot water stored in an actual storage tank for solar application. The effect of increased energy input rate due to stratification has been discussed and illustrated through experimental data, which was taken by changing dynamic and geometric parameters. Ranges of the parameters were defined for flow rate, the ratio of diameter to height of the tank and inlet-exit water temperature difference. During the heat storage, when the flow was lower, the temperature difference was larger and the ratio of diameter to height of the tank was higher, the momentum exchange decreased. As for this experiment, when the flow rate was 8 liter/min, the temperature difference was $30^{\circ}C$ and the ratio of diameter to height of the tank was 3, the momentum exchange was minimized resulting in a good thermocline and a stable stratification. In the case of using inlet ports, if the modified Richardson number was less than 0.004, full mixing occured and so unstable stratification occured, which mean that this could not be recommended as storage through thermal stratification. Using a distributor was better than using inlet ports to form a sharp thermocline and to enhance the stratification. It was possible to get storage efficiency of 95% by using the distributor, which was higher than a storage efficiency of 85% obtained by using inlet ports in same operation condition. Furthermore, if the distributor was manufactured so that the mainpipe decreases in diameter toward the dead end to maintain constant static pressure, it might be predicted that further stable stratification and higher storage efficiency are obtainable(ie:more than 95%).

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Analysis of Long-term Thermal Performance of Solar Thermal System Connected to District Heating System (지역난방 적용 태양열시스템의 장기 열성능 분석)

  • Baek, Nam-Choon;Shin, U-Cheul
    • Journal of the Korean Solar Energy Society
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    • v.27 no.4
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    • pp.167-173
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    • 2007
  • This study analyzed by simulation using TRNSYS as well as by experiment on the solar district heating system installed for the first time for the district heating system in Bundang. Simulation analysis using TRNSYS focused on the thermal behavior and long-term thermal efficiency of solar system. Experiment carried out for the reliability of simulation system. This solar system where the circuits of two different collectors, flat plate and vacuum tube collector, are connected in series by a collector heat exchanger, and the collection characteristics of each circuit varies. Therefore, these differences must be considered for the system's control. This system uses variable flow rate control in order to obtain always setting temperature of hot water by solar system. Specifically, this is a system that heats returning district heating water (DHW) at approximately $60^{\circ}C$ using a solar collector without a storage tank, up to the setting temperature of approximately $85{\sim}95^{\circ}C$ To realize this, a flat plate collector and a vacuum tube collector are used as separate collector loops. The first heating is performed by a flat plate collector loop and the second by a vacuum tube collector loop. In a gross collector area basis, the mean system efficiency, for 4 years, of a flat plate collector is 33.4% and a vacuum tube collector is 41.2%. The yearly total collection energy is 2,342GJ and really collection energy per unit area ($m^2$) is 1.92GJ and 2.37GJ respectively for the flat plate vacuum tube collector. This result is very important on the share of each collector area in this type of solar district heating system.

THE CHINESE TRADITIONAL METHODS FOR ENERGY SAVING AND THEIR APPLICATIONS IN MODER STRUCTURES

  • Chen, Jiancheng
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.617-626
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    • 1993
  • Energy saving is a very important subject for research workers nowadays. While most people are concerning with the modern methods, the authors investigated this problem from another angle- the chinese traditional methods of energy saving. The tunnel with technique and its combination with computer simulation and fuzzy compressive judgement methods are discussed. Earth heat green house, marsh gas, solar energy underground storage system, storing of nature cold sources, have been introduced in this paper.

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A Design of Temperature Management System for Preventing High Temperature Failures on Mobility Dedicated Storage (모빌리티 전용 저장장치의 고온 고장 방지를 위한 온도 관리 시스템 설계)

  • Hyun-Seob Lee
    • Journal of Internet of Things and Convergence
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    • v.10 no.2
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    • pp.125-130
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    • 2024
  • With the rapid growth of mobility technology, the industrial sector is demanding storage devices that can reliably process data from various equipment and sensors in vehicles. NAND flash memory is being utilized as a storage device in mobility environments because it has the advantages of low power and fast data processing speed as well as strong external shock resistance. However, flash memory is characterized by data corruption due to long-term exposure to high temperatures. Therefore, a dedicated system for temperature management is required in mobility environments where high temperature exposure due to weather or external heat sources such as solar radiation is frequent. This paper designs a dedicated temperature management system for managing storage device temperature in a mobility environment. The designed temperature management system is a hybrid of traditional air cooling and water cooling technologies. The cooling method is designed to operate adaptively according to the temperature of the storage device, and it is designed not to operate when the temperature step is low to improve energy efficiency. Finally, experiments were conducted to analyze the temperature difference between each cooling method and different heat dissipation materials, proving that the temperature management policy is effective in maintaining performance.

A Study on the Change of Surface Temperature of Back Panel by Variation of the Air-Space Distances on the Inside of Curtain Wall (커튼월 내부 공기층의 BACK PANEL 표면온도에 관한 연구)

  • Lee, Duck-Hyung;Son, Won-Tug;Choi, Hyun-Sang;Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.14 no.3
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    • pp.87-93
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    • 2011
  • When applying back panel(this material is aluminum complex panel coated with fire resistance substances) for curtain wall, solar radiation and heat storage of indoor air occurs to result in thermal warpage for back panel. The purpose of this analysis is to find out the cause of thermal warpage and come up with a solution to prevent changes of back panel and reduce elements that bring negative visual elements. Also to solve this problem analyse that case to reduce heat transfer by inserting additional material and cases to increase air space distance.

Development of a System-Independent Mobile Smart Shelter using Solar Energy (태양광 에너지를 이용한 계통 독립형 이동식 스마트 쉼터 개발)

  • Joo, Jong-Yul;Lee, Young-Jae;Park, Kyoung-Wook;Oh, Jae-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.6
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    • pp.1061-1068
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    • 2020
  • This paper presents a system-independent mobile smart shelter using solar energy technology that can be freely installed in various places, such as parks, countryside, event area, construction area and walking tour places where the system power are difficult to use. The proposed smart shelter is equipped with solar power generation and energy storage devices that is combined with IoT technology to collect indoor and outdoor humidity, fine dust and tourist awareness in real time. It is possible to efficiently manage energy by performing the optimal energy operation during the heat- wave, cold-wave situation and the presence of travelers and it is possible to serve as a shelter for as long as possible without system power.

Analysis of the Phase Change Temperatures and the Latent Heat Characteristics of $H_2O$-NaCl Mixtures for the Cold thermal Energy Storage (냉축열을 위한 $H_2O$-NaCl 혼합물의 상변화 온도와 잠열 특성분석)

  • Song, H.K.;Ro, J.G.
    • Solar Energy
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    • v.19 no.2
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    • pp.57-65
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    • 1999
  • In this study $H_2O$-NaCl mixture was selected as a cold thermal storage material and its phase change temperature($liquid{\Leftrightarrow}solid$) was controlled with the molar concentration of NaCl. Ion dipole interaction mechanism and the fusion and crystallization structure of $H_2O$-NaCl were visualized with the low and high concentration of NaCl in the heating and cooling processes. In this study, the original cause of the appearance of two steps phase change period in heating and cooing processes were found by the visualization of the ion dipole interaction mechanism of $H_2O$-NaCl, and the theoretical equation of the phase change temperature variation in the NaCl high molar concentration was rearranged.

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Comparison of Annual Heating and Cooling Loads of Internally and Externally Insulated Apartment Buildings According to the Location of Thermal Mass (내, 외단열 공동주택의 축열체 위치 차이에 따른 동단위 연간 냉난방부하 비교평가)

  • Koo, Bo-Kyoung;Lee, Beung-In;Choi, Doo-Sung;Song, Seung-Yeong
    • Journal of the Korean Solar Energy Society
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    • v.30 no.1
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    • pp.42-49
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    • 2010
  • The IIS(Internal Insulation System) is applied in most Korean apartment buildings which are the most common type of residential buildings. Consequently, there are many cases in which the layer of insulation is disconnected by the structural components at the wall-slab and wall-wall joints in the envelope. These joints become thermal bridges where the risk of heat loss increases. It is expected that the EIFS(External Insulation and Finish System) is the solution to this problem. In this study, annual heating and cooling loads of apartment buildings with IIS and EIFS were compared using Design Builder program in order to evaluate the thermal storage effect of EIFS where the concrete thermal mass is located inside of the insulation material. As results, the apartment building with EIFS could reduce annual heating and cooling loads by 2.4% and 4.1%, respectively.

Estimation of Surplus Solar Energy in Greenhouse (II) (온실내 잉여 태양에너지 산정(II))

  • Suh, Won-Myung;Bae, Yong-Han;Ryou, Young-Sun;Lee, Sung-Hyoun;Kim, Hyeon-Tae;Km, Yong-Ju;Yoon, Yong-Cheol
    • Journal of Bio-Environment Control
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    • v.20 no.2
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    • pp.83-92
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    • 2011
  • This study is about an analysis of surplus solar energy by important greenhouse type using Typical Meteorological Year (TMY) data which was secured in order to provide basic data for designing an optimum thermal storage system to accumulate surplus solar energy generated in greenhouses during the daytime. The 07-auto-1 and 08-auto-1 types showed similar heat budget tendencies regardless of greenhouse types. In other words, the ratios of surplus solar energy were about 20.0~29.0% regardless of greenhouse type. About 54.0~225.0% and 53.0~218.0% of required heating energy will be able to be supplemented respectively according to the greenhouse types. The 07-mono-1 and 07-mono-3 types also showed similar heat budget tendencies regardless of greenhouse types. In other words, the ratios of surplus solar energy were about 20.0~26.0% and 21.0~27.0% respectively by greenhouse type. About 57.0~211.0% and 62.0~228.0% of required heating energy will be able to be supplemented by greenhouse type. Except for Daegwallyeong and Suwon area, other regions can cover heating energy only by surplus solar energy, according to the study.