• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.8 no.2
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• pp.9-15
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• 2012

The objective of this study is to investigate the influence on the heating performance for a water-to-water 10RT ground source heat pump by using the water switching and refrigerant switching method. The test of water-to-water ground source heat pump was measured by varying the compressor speed, load side inlet temperature, and ground heat source side temperature. The heating capacity and COP of the heat pump increased with increasing ground heat source temperature. As a result, compared to a refrigerant switching method, the water switching method with counter flow improves the heating capacity and COP by approximately 5% in average, respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.227-228
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• 2017

In this study, the inductor heating which is confined to the metal processing is used by demolition technology in reinforced concrete. And, the purpose is the verification of realization for this technology. Using the inductor heating device, the temperature rising is measured depending on the difference of the generating capacity. And, the demolition of reinforced concrete is evaluated by the vulnerability of concrete due to the inductor heating of rebar in reinforced concrete.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.4
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• pp.20-28
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• 2008

Missile operating at supersonic conditions experiences considerable high temperature environments that is caused by aerodynamic heating as a result of the temperature gradient through boundary layer that surrounds it. This is one of important problems to the designer due to temperature limitation of structural materials. Because prediction of aerodynamic heating on missile needs unsteady calculation according to a flight trajectory, approximate method approach is efficient at design stage. In this paper, improved aerodynamic heating analysis scheme is introduced, which calculates heat flow and temperature by simple pressure field prediction on a missile body and fin. The prediction results are compared with measured data and MINIVER codes results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.6
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• pp.283-292
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• 2015

A model of apartment heating load in a district heating system could be useful in the management and utilization of energy resources, since it could predict energy usage and so could assist in the efficient use of energy resources. The heating load in a district heating system varies in a highly nonlinear manner and is subject to many different factors, such as heating area, number of people living in that complex, and ambient temperature. Thus there are few published papers with accurate models of heating load, especially in domestic literature. This work is concerned with the modeling of apartment heating load in a district heating system in winter, using the reduced least square support vector machine (LS-SVM), and with the purpose of using the model to predict heating energy usage in domestic city area. We collected 23,856 pieces of data on heating energy usage over a 12-week period in winter, from 12 heat exchangers in five apartments. Half of the collected data were used to construct the heating load model, and the other half were used to test the model's accuracy. The model was able to predict the heating energy usage pattern rather accurately. It could also estimate the usage of heating energy within of mean absolute percentage error. This implies that the model prediction accuracy needs to be improved further, but it still could be considered as an acceptable model if we consider the nonlinearity and uncertainty of apartment heating energy usage in a district heating system.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.6
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• pp.604-608
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• 2016

In recent years, research and development has been carried out in order to increase the economical efficiency and stability in terms of efficient use of energy for the heating apparatus. Especially, technology development for high performance and new functional materials is actively being carried out. This paper focuses on the development of exothermic products with excellent energy transfer characteristics. The heating element used for bedding or mattress uses a heating wire. Since the heating wire is thin, the distribution of heat is concentrated only around the heating wire,. In addition, electromagnetic induction is harmful to the human body and energy consumption is high. Therefore, it is aimed to develop a planar heating panel using SiC ceramics which can radiate far-infrared rays and anions to be harmless to the human body, but also has excellent heat conduction to enhance energy efficiency.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.6
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• pp.258-263
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• 2020

Silicon carbide (SiC) fibers mainly fabricated from polycarbosilane, a ceramic precursor, are applied as reinforcing materials for ceramic matrix composites (CMCs) because of their high temperature oxidation resistance, tensile strength, and light weight. In this study, continuous SiC fibers used to fabricate rope-type flexible heating elements capable of generating high-temperature heat (> 650℃). For high-efficiency heating elements, the resistance of SiC fiber rope was measured by 2-point probe method according to the cross-sectional area and length. In addition, the fabrication conditions of rope-type SiC fiber heating elements were optimized by controlling the oxygen impurities and the size of crystal grains present in the amorphous SiC fiber. As a result, the SiC fiber heating element having a resistance range of about 100~200 Ω exhibited an excellent power consumption efficiency of 1.5 times compared to that of the carbon fiber heating element.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.1071-1083
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• 2023

The on-the-fly energy release per fission (OTFK) model is implemented in STREAM to continuously update the Kappa values during the depletion calculation. The explicit neutron and photon energy distribution, which has not been considered in previous STREAM versions, is incorporated into the existing on-the-fly model. The impacts of the modified OTFK model with explicit neutron and photon heating in STREAM on the power distribution, fuel temperature, and other core parameters during depletion with feedback calculations are studied using several problems from the VERA benchmark suit. Overall, the explicit heating calculation provides a better power map for the feedback calculations particularly when strong gamma emitters are present. Generally, the fuel temperature decreases when neutron and photon heating is employed because fission neutrons and gamma rays are transported away from their points of generation. This energy release model in STREAM indicates that gamma energy accounts for approximately 9.5%-10% of the total energy released, and approximately 2.4%-2.6% of the total energy released will be deposited in the coolant for the VERA 5, NuScale, and Yonggwang Unit 3 2D cores.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.621-626
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• 2008

• 한국초전도학회:학술대회논문집
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• v.15
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• pp.36-36
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• 2005

• Journal of the Korean Wood Science and Technology
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• v.35 no.3
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• pp.22-28
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• 2007

Using woodceramics made from sawdust board of pine thinning logs, changes in surface temperature were investigated, by the heating rate and keeping time at maximum temperature. The heating rate of $2^{\circ}C/min$ and keeping time at maximum temperature 1 hour, were the highest in surface temperature. Also, it was found that woodcermics maintained heat for a long time because the descending velocity of their surface temperature was slower than that of the heater.