• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.317-322
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• 1996

고온으로 유지되는 원자로에는 열손실을 줄이기 위하여 단열재가 설치되어 있다. 일반직으로 열손실 시험에서 나타난 실제 열손실은 설계상의 열손실보다 크며, 이의 원인은 단열설계의 부적절, 단열재 설치상의 미흡 등에 기인한다. 본 연구에서는 단열재 두께와 간격에 대한 열전달 특성을 분석하여 단열설계변수를 최적화하며, chimney effect에 의한 열손실 증가를 정량적으로 분석하였다. 본 연구의 결과는 원자로용기 뿐아니라 가압기, 증기발생기 등의 큰 규모의 단열재 설계에 적용될 수 있다.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.285-292
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• 1999

The design parameter of the reactor vessel insulation for the Korea Standard Power Plant has been studied numerically. The heat loss from the reactor vessel through the insulation is analysed by using the computational fluid dynamics code, FLUENT. Parametric study has been performed on the air gap width between the reactor vessel wall and the inner surface of the insulation, and on the insulation thickness. Also evaluated is the performance degradation due to the chimney effect caused by gaps between the panels during the installation of the insulation system. From the analysis results, the optimal air gap width and the optimal insulation thickness are obtained.

• Land and Housing Review
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• v.15 no.2
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• pp.29-37
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• 2024

This study investigates the thermal conductivity and density of expanded polystyrene insulation materials collected from buildings under going energy retrofit projects. Due to the absence of initial thermal conductivity data, determining precise long-term patterns was challenging. Analysis based on design documents revealed that expanded polystyrene insulation maintained consistent performance over ten years. Notably, the thermal conductivity measurements of insulation samples of the same grade and age varied significantly. Additionally, the insulation density was found to be substantially below the standard specified in the design documents. The results of the experiment indicate that performance management during both construction and operation phases is lacking. It is crucial to apply building commissioning, which involves performance verification throughout the building's life cycle, to properly evaluate building energy performance improvements, such as building energy retrofit projects.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.843-848
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• 2013

As the LNG demands are growing, the constructions of LNG FPSO (Floating Production Storage and Off-loading) and LNG carriers have been constantly increased, and the various design of storage tank has been tried. This paper propose that the material of inner storage tanks is made of 5~9% Ni steel plate and perlite powder insulation instead of urethane foam block. It needs essentially to obtain the proper design specifications that are the pressure of perlite, the characteristics of resilient blanket as the pressure absorber, optimum thickness of blanket and design pressure of tank wall, etc. to enable the perlite insulation system to LNG carrier, The results show that the design thickness of blanket should be between 1/4 to 1/3 of insulation width and the optimum rate becomes 30%, and the design pressure be applied below 1,500 Pa with blanket thickness.

• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.595-601
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• 2016

The insulation performance of the insulation currently used in building structures is reflected only during design based on initial performance and the reduction in heat insulation performance due to the degradation of long-term durability is not reflected. This study reviewed the degradation of heat insulation performance due to the durability degradation of insulating materials through the accelerated durability test. The study findings showed that the foamed polystyrene insulation bead method did not show performance degradation due to aging in the standard environmental condition and laboratory accelerated test condition but the performance is degraded in the freeze-thaw test condition. On the other hand, in the case of the extrusion method, the degradation of the heat insulation performance was less in the freeze-thaw test condition, but the rapid performance degradation was caused by the release of the internal gas at the beginning of aging. In addition, the hard polyurethane foam insulation showed better initial insulation performance than other insulation materials, but the performance was found to be degraded somewhat under laboratory accelerated test conditions and freeze-thaw test conditions.

• Journal of the Korea Institute of Building Construction
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• v.19 no.6
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• pp.539-547
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• 2019

Recently, the international community signed a climate change agreement to prevent global warming. Yet currently, the fossil fuels have been widely used in to supply building energy for cooling and heating. The Green Building certification (G-SEED), an energy efficiency rating for new or existing buildings requires that buildings meet certain conditions. Insulation is used as a building material to reduce the energy supply to buildings and to improve the thermal insulation, and it accounts for more than 90% of the total heat resistance provided by the building surface components that meet the energy-saving design standards of new buildings. In this investigation, a performance evaluation study was conducted through an experimental study by directly extracting the foam polystyrene insulation on-site during the remodeling of a building that was in the range of 22~38 years old. Through tests, it was found that the thermal conductivity of the extrusion method insulation (XPS) was reduced by 48% and the compressive strength of XPS decreased by 36% compared to KS M 3808, which is the initial quality standard. For bead method insulation (EPS) with a thickness of 50mm, the thermal conductivity, the compressive strength, and flexural failure load were similar to the initial quality standard. Therefore, in the calculation of the primary energy requirement per unit area per year, the performance of bead method insulation can be estimated simply by considering the thickness of the insulation, while a correction factor that considers its performance deterioration should be applied when extrusion method insulation is used.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.207-207
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• 2012

진공단열재는 폴리우레탄 폼 대비 10배 이상의 단열성능을 갖는 고효율 단열재로서 고차단성 필름 봉투 내부에 무기 소재를 진공감압시켜 대류에 의한 열전달을 최소화시킨 차세대 단열재이다. 특히 진공단열재에 있어 열전달의 경로는 전도에 의한 효과가 가장 크므로, 진공단열재 내부의 Glass Fiber 심재의 최적화 설계에 따라 단열 성능을 극대화 시킬 수 있다. 이에, 본 연구에서 GLass Fiber의 배열에 따른 성능 비교 평가를 통해, 전도의 특성을 최소화 시킬 수 있는 Glass Fiber의 배열 및 다층 적층 구조를 통해 성능 개선 효과를 고찰 하였다.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1578-1583
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• 2003

LAVA-ERVC experiments have been performed to investigate the effect of insulation design features on the coolability in case of the external reactor vessel cooling (ERVC). All the 4 tests have been performed using Alumina iron thermite melt as a corium simulant. Due to the limited steam venting through the insulation, steam binding occurred inside the annulus in the KSNP case simulation. On the contrary, in the tests which were performed for simulating the APR1400 insulation design, sufficient water ingression and steam venting through the insulation lead to effective cool down of the vessel characterized by nucleate boiling. It could be found from the experimental results that modification of the insulation design allowing sufficient ventilation could increase the positive effects of the external reactor vessel cooling.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.390.2-390
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• 2002

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.3
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• pp.219-224
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• 2013

In this study, the inorganic insulating material was fabricated with quartzite, ordinary portland cement(OPC), lime and anhydrous gypsum. After characteristic analysis of slurry, the optimum mixing ratio was derived with different $CaO/SiO_2$ mole ratio. Based on derived mixing ratio, the inorganic insulating material was fabricated at different water content and hydrothermal synthesis conditions. Specific gravity was $0.26g/cm^3$, compressive strength was 0.4 MPa, and thermal conductivity was 0.064 W/mK. This properties were enhanced performance of conventional ALC (Autoclaved Lightweight Concrete). And it can replace organic insulation with harmless inorganic insulation through continues research and development.