• Title/Summary/Keyword: Ice storage tank

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An Experimental Study on Characteristics of Heat Flow in the Cylindrical Storage Tank with Ice Ball (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))

  • Jang, Y.G.;Lee, W.S.;Pak, J.W.
    • Solar Energy
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    • v.18 no.1
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    • pp.99-109
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    • 1998
  • The study on ice thermal storage system is to improve total system performance in actual air-conditioning facilities. To attain the high efficiencies in ice thermal storage system, the improvement of thermal stratification is essential, therfore the process flow must be piston flow in thermal storage tank. Ice packing factor is better on condition that the inflowing temperature is low, the flow direction in the thermal storage is upward and the cylindericalthermal storage type is used. This result shows that the cylinderical ice storage tank has better storage capacity than the rectangular type in case of the same porocity.

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A Study on the DSM Effect of a Refrigerant-Subcooling Refrigeration System with an Ice Storage Tank (축열조를 이용한 냉매과냉각 시스템의 전력수요관리 효과에 대한 연구)

  • Kim, Jeong-bae;Lee, Eun-Ji;Lee, Dong-Won
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.12
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    • pp.845-851
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    • 2010
  • This study was experimentally performed to find the effects of refrigerant subcooling in the refrigeration system and to propose how to get the efficient use of energy. A refrigerant-subcooling refrigeration system consisted of a typical single vapor-compression refrigeration cycle, a subcooler, and an ice storage tank. The degree of subcooling at the exit of the condenser can be increased by the heat transfer between the subcooler and the ice storage tank. The cold heat in the ice storage tank was stored by using the refrigeration cycle during night time and then used to absorb the heat from the subcooler during daytime. The cooling capacity and COP of this system were higher than those of the conventional system due to the increase in the degree of subcooling. Typically, the refrigerant-subcooling system showed superior performance to the conventional refrigeration system and would also contribute to load leveling.

Optimal Scheduling of Ice Storage System with Prediction of Cooling Loads (예측 냉방부하를 이용한 빙축열시스템의 최적 운전계획)

  • 이경호;최병윤;주용진;이상렬;한승호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.11
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    • pp.982-993
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    • 2000
  • This paper describes an optimal control scheduling of an encapsulated ice storage system with a chiller of nominal chiller 34RT(103,200kcal/hr) and an ice storage tank of 170RT-hrs(514,080 kcal). The optimization technique used in the study is dynamic programing. The objective function is summed cost during a day including charge and discharge periods. Control strategies being used commercially are chiller priority and storage priority control. In chiller priority control, the chiller is allowed to run at full capacity during the day, subject to limitations of the building load, and the ice is only melted when and if the load exceeds the chillers full capacity. In contrast to chiller priority control, the aim in storage priority control is to melt as much as ice as possible during the day time period. The system simulation calculates the operation costs for the three control strategies in the condition of the same cooling load and the same ice storage system. The simulation period is a day, assuming that initially the tank is stored fully and the cooling load is perfectly predicted for the scheduling. Also Final state of the tank is to be charged fully.

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Simulation and Energy Cost Calculation of Encapsulated Ice Storage System (캡슐형 빙축열시스템에 대한 운전 시뮬레이션 및 에너지비용 분석)

  • Lee, K.H.;Joo, Y.J.;Choi, B.Y.;Kim, S.J.
    • Solar Energy
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    • v.19 no.3
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    • pp.63-73
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    • 1999
  • Ice storage systems are used to shift the peak load in day time into night time in summer. This paper describes a system simulation of partial ice storage system composed of an encapsulated ice storage tank, a screw compressor chiller, a heat exchanger, and a brine pump. For the system simulation, a one-dimensional model of ice storage tank is developed and validated by comparison with the performance data from measurements of an ice storage tank installed at a building. The control strategies considered in this study are chiller priority and storage priority being used commercially. The system is simulated with design cooling load of 600 RT peak load in design day and with off-design day cooling load, and the electric energy costs of the two control strategies for the same system size are compared. As a result of calculation, the energy consumption in a week for storage priority is higher than that for chiller priority control. However due to lower cost of night electric charge rate, energy cost for storage priority control is lower than chiller priority.

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Optimal Scheduling for Dynamic Ice Storage System with Perfectly Predicted Cooling Loads (동적제빙형 빙축열시스템에 대한 최적운전계획)

  • Lee, Kyoung-Ho;Lee, Sang-Ryoul;Choi, Byoung-Youn;Kwon, Seong-Chul
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.286-291
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    • 2001
  • This paper describes an optimal scheduling for ice slurry systems for energy cost saving. The optimization technique applied in the study is the dynamic programming method, for which the state variable is the storage in the ice storage tank and the control variable is the state of chiller's on-off switching. Though the costs during charge period is included in optimization by taking the average cost of ice per hour for slurry making, the time horizon for the simulation is limited building cooling period because accurate charge rate from the ice maker into the ice storage tank cannot be estimated during the charge period. In the operating simulation after optimizing procedure, energy consumption and operating cost for the optimal control are calculated and compared with them for a conventional control with one case of cooling load profile.

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Performance Simulation of One-Dimensional Ice Storage Tank Model for Refrigeration System Using Night Electricity (심야전력이용 냉방시스템용 캡슐형 빙축열조에 대한 1차원 모델 축방냉 성능 시뮬레이션)

  • 이경호;주용진;최병윤
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1999.05a
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    • pp.193-196
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    • 1999
  • This paper describes one dimensional transient modeling of encapsulated ice storage tank and its experimental validation. This model simulates the performance of tile tank for charge and discharge process with brine mass flow operating conditions.

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An Experimental Study on the Performance Characteristics of a Refrigerant-Subcooling Refrigeration System with an Ice Storage Tank (축냉시스템을 이용한 냉매과냉각형 냉동시스템의 성능특성에 관한 실험적 연구)

  • Lee, Eun-Ji;Lee, Dong-Won;Kim, Yong-Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.6
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    • pp.369-374
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    • 2010
  • A refrigerant-subcooling refrigeration system consisted of a typical single vapor-compression refrigeration cycle, a subcooler, and an ice storage tank. The degree of subcooling at the exit of the condenser can be increased by the heat exchange between the subcooler and the ice storage tank. The cold heat in the ice storage tank was stored by using the refrigeration cycle during night time and then used to absorb the heat from the subcooler during daytime. The performance of the refrigerant-subcooling refrigeration system was measured by varying the degree of subcooling. In addition, the performance characteristics of the present system were compared with those of a conventional refrigeration system. The mass flow rate of the present system was higher than that of the conventional system due to the increase in the degree of subcooling. Generally, the refrigerant-subcooling system showed superior performance to the conventional refrigeration system.

Study on operation characteristics of the cold air distribution systems with an ice storage tank (빙축열을 이용한 저온공조시스템 운전 특성 연구)

  • 염한길;박병규;고득용
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.3
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    • pp.301-312
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    • 1999
  • Experiments were carried out to evaluate performance of the cold air distribution systems with an ice storage tank in test room. Cold air distribution systems provide primary air for comfort conditioning or process cooling at coil discharge temperatures$4^{\circ}C$ to$11^{\circ}C$. The application of a cold air distribution system allows for the downsizing of air distribution equipment and central plant equipment when ice storage tank is used. The benefit of a cold air distribution system include a decrease in the floor-to-floor height, increase floor space, reduced building capital costs, reduced energy use and demand. The use of cold air distribution can result in the most cost effective system and is currently being implemented world wise as the new standard in air conditioning systems. In this study, the cold air distribution system is compared with the general ice storage system. Under the same cooling load conditions, experimental results show that the supply air volume of cold air distribution system decrease 38%, and decrease 45% flow rate of brine for the general ice storage system.

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Modelling of Thermal Discharge Performance for Ice-on-coil Type Ice-Storage Tank (관외착빙형 빙축열조의 방열성능 모델링)

  • Lee, Sang-Ryoul;Lee, Kyoung-Ho;Choi, Byoung-Youn;Han, Seong-Ho
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.280-285
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    • 2001
  • This paper presents a modelling of thermal discharge performance for a static ice-on-coil ice-storage tank. Through the present study, discharging characteristics were examined with the existing results of theoretical and numerical heat transfer analyses. Also, an experiment was conducted to obtain a real set of discharge performance. The thermal effectiveness, the ratio of the actual heat transfer rate to the maximum possible heat transfer rate, decreased when the stored energy decreased during discharging period. And the effectiveness increased as the coolant flow rate through the storage increased, of which increasing rate decreased abruptly near the maximum and the minimum stored energy. An empirical correlation was obtained from the experimental and the numerical analysis data.

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A study on the Operating Characteristics of the Capsule-type Ice Storage System (캡슐형 빙축열 시스템의 운전특성에 관한 연구)

  • Kim, Kyung-Hwan;Cho, Sung-Woo;Choi, Jeong-Min;Ha, Suk-Young
    • Proceedings of the SAREK Conference
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    • 2005.11a
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    • pp.199-204
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    • 2005
  • The decrease of summer peak electric load of our country is very important. The government is arranging a lot of support policies and statutes. etc. to decrease of peak electric load. And ice storage system is known as one of the alternatives. The purpose of this study is to collect basic data for operating characteristics to plan the most suitable operation of capsule-type ice storage system. The storaging tank is designed to take charge 40% of total cooling load in building, In operation condition the storage tank took charge 50%. Coefficient Of Performance of daily screw refrigerator is around 4.

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