• 한국태양에너지학회 논문집
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• 제37권6호
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• pp.51-58
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• 2017

This study proposes an appropriate level of insulation standards by region through annual heating energy requirements according to regional climate. The reference buildings out of non-residential buildings approved by the energy saving design standard for buildings were derived in the previous study, in which the annual heating energy requirements for each building were as follows when the insulation standard for building members in four regions (Pyeongchang, Seoul, Gwang-ju, and Jeju) suggested by the energy saving design standard for buildings: $29.8kWh/m^2$ in Pyeongchang, $17.5kWh/m^2$ in Seoul, $14.4kWh/m^2$ in Gwangju, and $16.7kWh/m^2$ in Jeju. To satisfy the passive level of insulation standards for these buildings, in case that roof/floor of buildings in Pyeongchang and Seoul was $0.2W/m^2K$, the minimum window thermal transmittance should satisfy $0.9W/m^2K$ and the minimum wall thermal transmittance should satisfy $0.1W/m^2K$ in the case of Pyeongchang. On the other hand, the minimum window thermal transmittance should satisfy $1.5W/m^2K$ and the minimum wall thermal transmittance should satisfy $0.14W/m^2K$ in the case of Seoul. For Jeju regions, the minimum wall thermal transmittance should satisfy $0.34W/m^2K$ to meet the passive level of buildings. Based on the above results, the thermal transmittance of each member by region should take the outdoor climate condition of the region into consideration to satisfy the passive level of buildings.

• 유기물자원화
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• 제26권1호
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• pp.39-45
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• 2018

FA(Fly ash)에 대해서는 연구가 활발히 진행되는 반면 BA(Bottom ash)의 연구실적은 많지 않으며, 특히 BA 재활용 분야의 연구가 절실히 요구된다. 따라서 본 연구에서 다공성인 건식(공랭식) BA를 연구대상으로 선택해 이를 재료로 활용하여 만든 BA 모르터와 일반 모르터를 비교 분석하여 BA 모르터의 경량 및 단열 특성을 알아보고자 하였다. BA의 경량성을 알아보기 위해 밀도 시험, 단위용적질량 시험, SEM 시험을 하였으며, 단열 시험을 위해 BA 모르터와 일반 모르터 몰드를 KS A 0006에서 정한 상온 상습의 환경조건에서 제작 후 항량이 될 때까지 온도 $105{\pm}2^{\circ}C$에서 건조하였다. 경량성 시험 결과 BA 모르터의 경량성은 일반 모르터의 0.72배로 일반 모르터에 비해 약 30%정도 가볍게 측정되어 BA를 건축물 재료로 활용할 경우 건축물 하중을 줄이는데 크게 기여할 것이다. 또한 단열 시험 결과 BA 모르터의 열전도율은 일반 모르터의 0.70배로 약 30%정도 단열성이 우수하다.

• 한국태양에너지학회 논문집
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• 제37권4호
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• pp.35-47
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• 2017

Energy efficiency solutions are being pursued as a sustainable approach to reducing energy consumption and related gas emissions across various sectors of the economy. Vacuum Insulation Panel (VIP) is an energy efficient advanced insulation system that facilitates slim but high-performance insulation, based on a porous core material evacuated and encapsulated in a barrier envelope. Although VIP has been applied in buildings for over a decade, it wasn't until recently that efforts have been initiated to propose and adopt a global standard on characterization and testing of VIP. One of the issues regarding VIP is its durability and aging due to pressure and moisture dependent increase of the initial low thermal conductivity with time; more so in building applications. In this paper, the aging of commercially available VIP was investigated experimentally; thermal conductivity was tested in accordance with ISO 8302 standard (guarded hot box method) and long-term durability was estimated based on a non-linear pressure-humidity dependent equation based on study of IEA/ECBCS Annex 39, with the aim of assessing durability of VIP for use in buildings. The center-of-panel thermal conductivity after 25 years based on initial 90% fractile with a confidence level of 90 % for the thermal conductivity (${\lambda}90/90$) ranged from 0.00726-0.00814 (W/m K) for silica core VIP. Significant differences between manufacturer-provided data and measurements of thermal conductivity and internal pressure were observed.

• 한국분말재료학회지
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• 제29권6호
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• pp.477-484
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• 2022

Thermal protection systems (TPS) are a group of materials that are indispensable for protecting spacecraft from the aerodynamic heating occurring during entry into an atmosphere. Among candidate materials for TPS, ceramic insulation materials are usually considered for reusable TPS. In this study, ceramic insulation materials, such as alumina enhanced thermal barrier (AETB), are fabricated via typical ceramic processing from ceramic fiber and additives. Mixtures of silica and alumina fibers are used as raw materials, with the addition of B4C to bind fibers together. Reaction-cured glass is also added on top of AETB to induce water-proof functionality or high emissivity. Some issues, such as the elimination of clumps in the AETB, and processing difficulties in the production of reusable surface insulation are reported as well.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.105-106
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• 2016

The study of the sandwich wall with the increasing interest in building energy consumption have been actively conducted. This study designed exposed sandwich wall in the light of energy saving design standard and thermal bridge of share connection. The heat insulating performance was analyzed U-fator using calculation program provided in passive houses association and KS F 2277 (method of measuring thermal insulation of construction component materials).

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.96-97
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• 2013

Research and analysis on thermal insulation status of existing buildings are needed to make data for repair and rehabilitation caused by deterioration in insulating material performance. To do this, we have researched and analyzed the insulation status of existing buildings according to the balcony with measuring instruments in pre-set investigation conditions.

• 한국세라믹학회지
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• 제55권6호
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• pp.527-555
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• 2018

High-temperature thermal insulation materials challenge extensive oxide candidates such as porus $SiO_2$, $Al_2O_3$, yttria-stabilized zirconia, and mullite, due to the needs of good mechanical, thermal, and chemical reliabilities at high temperatures simultaneously. Recently, porous rare earth (RE) silicates have been revealed to be excellent thermal insulators in harsh environments. These materials display attractive properties, including high porosity, moderately high compressive strength, low processing shrinkage (near-net-shaping), and very low thermal conductivity. The current critical challenge is to balance the excellent thermal insulation property (extremely high porosity) with their good mechanical properties, especially at high temperatures. Herein, we review the recent developments in processing techniques to achieve extremely high porosity and multiscale strengthening strategy, including solid solution strengthening and fiber reinforcement methods, for enhancing the mechanical properties of porous RE silicate ceramics. Highly porous RE silicates are highlighted as emerging high-temperature thermal insulators for extreme environments.

• 에너지공학
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• 제23권3호
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• pp.82-87
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• 2014

적층 단열재(multi-layer insulation, MLI)는 초전도 마그넷과 초전도 전력 케이블과 같은 초전도 응용기기의 냉각에 사용되는 저온유지장치(cryostat)에 외부 열침입을 차단하여 단열성능을 향상시키기 위해 사용된다. 적층 단열재는 인공위성에 사용되는 단열재로 적층단열재를 구성하는 자재의 종류와 적층층수 등에 따라 단열 성능이 변화한다. 본 연구에서는 적층 단열재의 원리를 이용한 축열조용 복합 다층 단열재(composite multilayer insulation, CMI)의 구성 재질 종류를 변경하고 적층 방식을 바꿈으로서 단열 성능이 바뀌는 것을 확인하였다. 실험은 KS C 9805의 방법을 이용하였으며, 복합 다층 단열재의 단열 성능 확인을 위해 동일한 조건의 축열조에 스티로폼을 적용하여 비교하였다. 또한, 실험 결과를 분석하기 위한 방법으로 기존 단열재에 대한 등가 두께를 비교하고 type별 CMI의 열전도율을 구해 비교하였다. 그 결과 복합 다층 단열재의 등가 두께는 스티로폼 보다 작아 동일 두께인 경우 스티로폼 보다 단열성능이 더 우수함을 확인할 수 있었다. 또한, 복합 다층 단열재의 구성 소재 및 적층 방식에 따라 전도, 대류 및 복사와 관련된 값들의 변화가 총괄 열전달계수에 영향을 미치는 것을 확인할 수 있었다.

• Structural Engineering and Mechanics
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• 제64권3호
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• pp.339-346
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• 2017

Slabs prevent harmful effects of fire that may occur in any floor. However, it is necessary to protect the slabs from fire. Insulation materials may be appropriate to protect reinforced concrete (RC) slab from elevated temperature. In the present study, a model has been developed in artificial neural network (ANN) to predict the moment capacity ($M_r$) of RC slabs exposed to fire with insulation material. 672 data were obtained for ANN model through author's prepared program. Input layer in model consisted of seven input parameters; such as effective depth (d), ratio of d'/d, thermal conductivity coefficient ($k_{insulation}$), insulation materials thickness ($L_{insulation}$), reinforcement area ($A_{st}$), fire exposure time ($t_{\exp}$), and concrete compressive strength ($f_c$). The predicted $M_r$ by ANN was consistent with the obtained $M_r$ by author. It is proposed to ease computational complexity in determining $M_r$ using ANN. The effects of using insulation material on the moment capacity in RC slabs were also investigated. Insulating material with low thermal conductivity has been found to be more effective for durability to high temperature.

• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.585-591
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• 2021

Liquefied hydrogen have advantage which reduces the volume by about 800 times or more compared to hydrogen gas, so it is possible to increase the storage density. However, liquefied hydrogen produced by cryogenic cooling of 20 K or less at normal pressure has a problem of maximizing the insulation effect that blocks heat introduced from the outside. Representative insulation technologies include vacuum insulation and multi-layer insulation materials and in general, heat blocking is attempted by combining insulation technologies. Therefore, in this study, the pressure of the internal vacuum layer was changed to 10^-1, 10^-2, 10^-3 and 10^-4 Torr to confirm the thermal insulation performance of the vacuum jacket valve for transporting liquefied hydrogen. As a result, it was confirmed that the insulation performance improved as the degree of vacuum increased.