• Textile Coloration and Finishing
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• v.19 no.1 s.92
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• pp.24-30
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• 2007

Heat storage/release system in textile is a useful tool to increase energy efficiency and enhance comfortable microclimate of clothing. Phase change materials(PCM) are used in regulating storage and release properties of thermal energy. To investigate the temperature regulating ability of fabrics with PCM microcapsule(PCMMc), Nylon fabrics were coated with PCMMc via wet processing and they were characterized by SEM, DSC and infrared thermal analyzer. Also, water moisture transpiration, water penetration resistance, peel strength and washing durability of the fabrics were assessed. The water vapor permeation and water penetration resistance decreased with increasing PCMMc content. In DSC analysis, it can be seen that the microencapsulated fabric showed both exothermic md endothermic phenomena at specific temperature. Peel strength was decreased with increasing PCMMc content.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.202-202
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• 2011

Performance of the raw water-source heat pump system with a thermal storage tank has been analyzed in winter season. The raw water is transferred through the multi-regional water supply system from Han river. Raw water is large temperature difference resource compared with groundwater. Although the raw water temperature drops to $0.6^{\circ}C$ due to the heavy snowfall and the severe cold in late January and early February, 2010, the system has been normally operated without any trouble this winter. The unit COP and system COP considered all pump power consumption were estimated based on the second-by-second data of the all sensors. The monthly averaged unit COP and system COP are 3.37 and 2.76 respectively with $1.4^{\circ}C$ of raw water in January, 3.55 and 2.89 with $1.6^{\circ}C$ raw water in February, 3.82 and 3.15 with $5.4^{\circ}C$ raw water in March. The performance of the system are increased with raw water temperature, and the COPs are higher than the water-to-air heat pump system using relatively high temperature raw water from Daecheong reservoir because the water-to-water system was operated on the full load condition and was stopped when the thermal storage tank was full of the high temperature water.

• Tunnel and Underground Space
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• v.14 no.4
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• pp.287-294
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• 2004

To predict the temperature distribution around a underground rock storage cavern, two- and three- dimensional numerical analysis using FLAC was conducted. The effects of groundwater and latent heat on thermal properties were considered in numerical calculation. The temperature estimated by FLAC are compared with the temperature measured for 5-year operation at Gonjiam storage cavern. Estimated and measured temperatures showed great discrepancy when thermal properties from laboratory tests were used and showed good agreement when the effects from 20% of volumetric water fraction and latent heat were considered. However, the discrepancy still increased with operation time due to the heat flow from ground surface. Three-dimensional numerical models were established to closely approximate the boundary condition of the test site, and numerical results better agreement when groundwater and latent heat effects were considered.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.239-245
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• 2005

The reduction of heat transfer rate to the stored liquid hydrogen from outside condition is extremely important to keep the liquid hydrogen longer. In this paper the highly efficient support system for the liquid hydrogen storage vessel was newly developed and analysed. The support system was composed of a spherical ball in the center of supporter to reduce the heat transfer area, with its above and below supporting blocks which are the SUS and PTFE blocks inserted in the SUS tube. The heat transfer rate and temperature distribution of the support system were evaluated by FLUENT, and the thermal stress and strain were estimated by ANSYS software. The results showed that the heat transfer rate from outer vessel to inner one was extremely decreased compared with the common method which is simply SUS tubes inserted between inner and outer tanks. The thermal stress and strain were obtained well below the limited values. As a result, it was the most efficient support system of storage vessel for liquid hydrogen and most cryogenic fluids.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1261-1266
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• 2008

Experimental study was performed to understand the operations of a showcase working in a discount store. Temperatures of evaporation, condenser were measured and also electric power consumption of compressor were measured. The purpose of this study is to application use of cold-heat storage systems operated the showcase. At the condition using ice storage system, the ice making process was operated during midnight being not needed the cooling of the showcase through the continuous running of the condenser unit. And then, the refrigerant was sub-cooled using stored cold-heat after being discharged from the air cooling condenser during the day time. The cooling performance was increased owing to the sub-cooling of refrigerant during day time, hence the running time of the compressor was effectively decreased. In other words, this study showed that power consumption during daytime can be transferred to the midnight for making use of the refrigerant sub-cooling. So the operating characteristics of the showcase system under various working conditions were analyzed and discussed.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.4
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• pp.363-369
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• 2007

Probably the most significant heat transfer in the cryogenic liquid hydrogen storage tank from the atmosphere may occur through its support system. In this paper the efficient support system for the cryogenic storage vessel was newly developed and analysed. The support system was composed of a spherical ball as a supporter to reduce the contact area. which is located between two supporting SUS tubes inserted SUS and PTFE blocks. Numerical analyses for temperature distribution, and the thermal stress and strain of the support system were performed by the commercial codes FLUENT and ANSYS. The heat transfer rate of the supporter was evaluated by the thermal boundary potential method which can consider the variation of thermal conductivity with temperature. The results showed that the heat transfer rate through the developed supporter compared with the common SUS tube supporter was significantly reduced. The thermal stress and strain were obtained well below the limited values. It was found that the developed supporter can be one of the most efficient support systems for cryogenic liquid storage vessel.

• Journal of Hydrogen and New Energy
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• v.26 no.5
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• pp.431-437
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• 2015

Recently, a miniaturized measurement cell of effective thermal conductivity was developed to evaulate the heat transfer characteristics of hydrogen stroage material in the initial step of its development. In this work, the realiablity issues which can occur from this miniaturization of measurement cell were studied in detail by both experiments and numerical simulation of heat transfer. $LaNi_5$ as a reference was used for the reliability evaluation of the miniaturized measurement cell. Numerical simulations of heat transfer for this measurement system were verified through comparison with the experimental data. Under these reliablity studies, we discuss how to overcome the inherent drawbacks of this miniaturized system in order to achieve the high reliability.

• Journal of Climate Change Research
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• v.2 no.3
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• pp.175-189
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• 2011

In this research, we describe the methodology and the quantification about GHG reduction effects, expected by optimization of operation mode according to establishing additional heat storage system of Bundang Combined Cycle Power Plant. As an intermediate form of General Combined Cycle Power Plant and Heat supply only district heating plant, Bundang Combined Cycle Power Plant(and Ilsan, Anyang, Bucheon) is possible to satisfy demand for the electrical load and thermal load capacity at the same time through changes to the operation mode itself. Therefore, through the operating transition of high-efficiency mode that the condenser cooling water is recovered and supplied to district heat and cooling, establishing additional heat storage system have flexible supply ability at the power and heat market. In this research, We calculated using the operating performance for the last three years(2008~2010) and efficiency of each mode-specific values. As a result, GHG reduction effects were calculated as $97.95kg_{-}CO_2/Gcal$ per heat energy 1 Gcal supplied at the heat storage system and we expected emmision reduction effect about $13,500Ton_{-}CO_2/yr$.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.1
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• pp.25-41
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• 1990

The purpose of this study was to evaluate and compare the dimensional changes of relined dentures with a light-curing resin, a heat-curing resin, and a direct, hard reline resin. And also to measure the transverse strength, impact strength, surface hardness of the three resins used in relining. The surface textures of three resins also of evaluated by using scanning electron microscope. Through analyses on the data from this study, the following conclusions were obtained. 1. Impact strength of heat-curing resin was highest, and direct, hard reline resin higher, light-curing resin lowest. 2. Transverse strength of heat-curing resin was highest, and direct, hard reline resin and light-curing resin was lower and not signiicantly different. 3. Surface hardness of light-curing resin was lighest, heat-curing resin higher, and direct, hard reline resin was lowest. 4. After storage of the relined dentures for 1 day and 1 week in water at room temperature, linear shrinkage of distance between the reference points in the maxillary base relined with direct, hard reline resin was lowest, and those relined with light-curing resin and heat-curing resin were lower and were not significantly different. 5. After storage for 4 weeks in orator at room tempeature, linear shrinkage of distance between ridge crests of dentures relined with heat-curing resin was highest and that of distance between denture borders was not significantly different. 6. The dimensional changes of relined dentures during storage in water was not significant except those of distance between denture borders relined with light-curing resin at 1 day and 1 week storage in water. 7. At low magnification (x40) of SEM examination, the surface textures of three resins were similar except light-curing resin which had some defects. At high magnification (x200), the surface textures of hard, direct reline resin were smooth with little defects, but those of heat-curing resin and light-curing resin w ere irregular.

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.34-38
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• 2014

Purpose: In this study, the performance of cooling system with the water-water heat pump system of 100kW scale made for cooling agricultural facilities, especially for horticultural facilities, was analyzed. It was intended to suggest performance criteria and performance improvement for the effective cooling system. Methods: The measuring instruments consisted of two flow meters, a power meter and thermocouples. An ultrasonic and a magnetic flow meter measured the flow rate of the water, which was equivalent to heat transfer fluid. The power meter measured electric power in kW consumed by the heat pump system. T-type thermocouples measured the temperature of each part of the heat pump system. All of measuring instruments were connected to the recorder to store all the data. Results: When the water temperature supplied into the evaporator of the heat pump system was over $20^{\circ}C$, the cooling Coefficient Of Performance(COP) of the system was higher than 3.0. As the water temperature supplied into the evaporator, gradually, lowered, the cooling COP, also, decreased, linearly. Especially, when the water temperature supplied into the evaporator was lower than $15^{\circ}C$, the cooling COP was lower below 2.5. Conclusions: In order to maintain the cooling COP higher than 3.0, we suggest that the water temperature supplied into evaporator from the thermal storage tank should be maintained above $20^{\circ}C$. Also, stratification in the thermal storage tank should be formed well and the circulating pumps and the pipe lines should be arranged in order for the relative low-temperature water to be stored in the lower part of the thermal storage tank.