• Journal of Biosystems Engineering
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• v.16 no.3
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• pp.290-297
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• 1991

For the efficient utilization of the solar thermal energy to overcome the time gap between to supply and demand, an efficient heat storage technique, especially high density-latent-heat storage system, is necessary. In this study, the performance of a panel type latent heat storage equipment during heat discharging process was analyzed theoretically and experimentally. In order to find out the performance of the system, computer simulation programs were developed by finite difference method. The governing equations were constructed by two dimensional heat conduction model with moving boundary. The results of the experimental and the theoretical analysis were reasonably well agreed. The efficiencies of the double pipe type and the panel type latent heat storage equipment were compared.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.296-301
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• 2009

The ice storage system uses water for low temperature latent heat storage. However, a refrigerator capacity is increased and COP is decreased due to supercooling of water in the course of phase change from solid to liquid. This study investigates the cooling characteristics of the TMA-water clathrate compound including TMA (Tri-methyl-amine, $(CH_3)_3N)$ of $20{\sim}25wt%$ as a low temperature latent heat storage material. The results showed that the phase change temperature and the specific heat is increased and the supercooling degree is decreased as the weight concentration of TMA increased. Especially, the clathrate compound containing TMA 25wt% has the average phase change temperature of $5.8^{\circ}C$, the supercooling degree of $8.0^{\circ}C$ and the specific heat of 3.499 kJ/kgK in the cooling process. This can lead to reduction of operation time of refrigerator in low temperature latent heat storage system and efficiency improvement of refrigerator COP and overall system. Therefore, energy saving and improvement of utilization efficiency are expected.

• Proceedings of the KWS Conference
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• v.43
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• pp.283-285
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• 2004

In this paper an important class of problems in welding which come under the category of phase change is considered, Solidification and melting are important process in welding field. Phase change problems are accompanied by either absorption or release of thermal energy i,e, heat transfer process. This is complicated by the release or absorption of the latent heat of fusion at the solid-liquid interface. In this study the liberation of latent heat is taken in to account using fixed grid method. The numerical simulation and the finite element codes for the heat transfer analysis including the latent heat term has been developed based on this fixed grid method.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1385-1390
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• 2009

In this study the purpose is development of passive cooling system for telecommunication cabinet used by latent heat material. This cooling system is not required for electronic power. It was tested for the performance of the telecommunication combined latent heat material with $48^{\circ}C$ of phase changed temperature and heat pipe. At $45^{\circ}C$ of outside temperature, when heater power was 1,000 W and 1,500 W, the inside temperature of the cabinet was $55^{\circ}C$ and $62^{\circ}C$. This system was showed better performance than the other systems.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.8
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• pp.807-812
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• 2015

A microcapsule water slurry is a latent heat-storage material having a low melting point. In this study, the thermal properties of a microcapsule water slurry are measured. The physical properties of the test microcapsule water slurry, i.e., thermal conductivity, specific heat, latent heat, and density, are measured, and the results are discussed for the temperature region of solid and liquid phases of the dispersion material (paraffin). It is clarified that Eucken's equation can be applied to the estimation of the thermal conductivity of the microcapsule water slurry. Useful correlation equations of the thermal properties of the microcapsule water slurry are proposed in terms of the temperature and concentration ratio of the microcapsule water slurry constituents.

• Smart Structures and Systems
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• v.33 no.3
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• pp.243-251
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• 2024

Modeling of vibrations of a rotating pendulum with working shape memory alloy rod has been performed in the frames of a microstructural model taking into account the latent heat release, absorption and the heat exchange during direct and reverse martensitic transformation. It has been shown that the influence of the latent heat, the rate of preliminary deviation of the pendulum from the equilibrium, the rate of heating and cooling can have a significant impact on the vibrations and damping characteristics of the system.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.197-206
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• 1995

Surface heat balance of the northern sea of Cheju Island for summer in 1993 and 1994 is analyzed using the observation data obtained by Marine Research Institute, Cheju National University. Each flux elements at the sea surface is derived from the marine meteorological reports with application of an aerodynamical bulk method for the turbulent heat fluxes, and empirical formulae for the long-wave radiation heat fluxes. The flux divergence of oceanic heat transport and the rate of heat storage in the ocean are estimated as residual. The features of the surface heat balance are mainly decided by the solar radiation flux and the latent heat flux for 199B. But the Bowen Ratios were large for 1993. This means that the sensible heat fluxes were nearly equal to the latent heat fluxes for 1993. In this period, mean flux divergence of oceanic heat transport is about 130 W/$m^2$.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.3
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• pp.79-84
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• 1998

It is very difficult to analyze the transient temperature distribution during quenching of the steel because of coupled effects among temperature, structures and stresses. In this paper, using Inoue's equation of evolution and mixture rule, transient temperature distribution is calculated by the finite element method considering latent heat of transformation structure and temperature dependence of physical and mechanical prperties for the 0.45% carbon cylindrical steel bar with 40mm diameter and 20mm height during end-quenching.

• Ocean and Polar Research
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• v.27 no.3
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• pp.237-250
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• 2005

To investigate the air mass modification related with Yeongdong Heavy snowfall events, we examined sensible and latent heat fluxes on the East Sea, the energy exchange between atmosphere and ocean in this study. Sensible and latent heats were calculated by a bulk aerodynamic method, in which NCEP/NCAR reanalysis data and NOAA/AVHRR weekly SST data with high resolution were used. Among winter precipitation events in the Yeongdong region, 19 heavy precipitation events $(1995{\sim}2001)$ were selected and classified into three types (mountain, cold-coastal, and warm types). Mountain-type precipitation shows highly positive anomalies of sensible and latent heats over the southwestern part of the East Set When separating them into the two components due to variability of wind and temperature/ specific Humidity, it is shown that the wind components are dominant. Cold-coastal-type precipitation also shows strong positive anomalies of sensible and latent heats over the northern part and over the central-northern part of the East Sea, respectively. It is shown that the sensible heat anomalies are caused mostly by the decrease of surface air temperature. So it can be explained that cold-coastal-type precipitation is closely related with the air mass modification due to cold air advection over warm ocean surface. But in warm-type precipitation, negative anomalies are found in the sensible and latent heat distributions. From this result, it may be postulated that warm-type precipitation is affected by the internal process of the atmosphere rather than the atmosphere-ocean interaction.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.5
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• pp.218-226
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• 2011

Low heat concrete using strontium hydroxide based latent heat material was manufactured in ready-mixed concrete batcher plant and its fundamental properties were tested. As a result of B/P test, its applicability to the construction site was verified. After B/P test, low heat concrete using strontium hydroxide based latent heat material was applied to the real construction site of bridge footing. Through the analysis and the actual measurement of the hydration heat of the concrete footing, the reduction effect of hydration heat and thermal crack was confirmed.