• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.166-167
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• 2015

Because of energy crisis at all around the world, there is many method and system which for improving energy efficiency has appeared in construction industry. And then, 20% of entire building energy loss is emissed to exterior of buildings, that is important to building's entire energy efficiency. So, many research has been conducted for imporve exterior energy efficiency and generally it called insulation of wall. Method for wall insulation can be classified interior system and exterior system which defined installation place of insulation board whether interior or exterior of structural wall. However, interior system has thermal problem such as thermal-bridge which can be necessarily occur condensation. and exterior system has constructional problem such as difficult to construction because exterior and finish work so expensive construction cost than other insulation method. Thus, sandwich insulation wall system has been appeared for solving these problems. Sandwich insulation system must using wall connecting things because both side walls is divided by center insulation. At this, Through the heat at wall connecter, it can be occured thermal-bridge and broken insulation board when under construction will be bring negative effect by reducing wall thickness and insulation deficit. At this study, we were compared previous sandwich insulation system and analysis these system's problem for develop the improving constructability and performance of sandwich insulation system.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.175-176
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• 2015

Insulation in buildings are one of the crucial factors for energy reduction, and depending on the application areas and properties of the insulation requirements, various different types of insulation materials are being developed, produced, and used. Amongst these is the aircaps often used as packing materials. Because of their porous nature, they are highly efficient in preventing heat and are consequently used overseas often as insulation materials and as part of cold water concrete insulation curing method. This paper studies the recently developed usage of aircaps in waterproofing materials and evaluated their performance as supplementary insulation materials.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 1부
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• pp.107-110
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• 2011

커튼월의 단열성이 가장 취약한 패스닝 유닛 부분의 단열성을 향상시키기 위한 연구이다. 멀리온과 연결부위가 최소화 되도록 고안하여 제작하였고, 중간에 방진고무 및 실리콘으로 단열층을 형성하여 그 성능을 평가하였다. 무단열에 비해 방진고무 단열은 2.6℃~4.0℃의 온도차를 보였으며, 실리콘 단열은 2.4℃의 온도차를 보였다. 따라서 패스닝 유닛에는 단열층이 필요하다고 판단된다.

• 청정기술
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• 제28권1호
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• pp.18-23
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• 2022

에너지 절약을 위한 연구 중 단열 기술 분야에서는 공기의 낮은 열전도도를 활용한 연구가 이뤄지고 있으며 널리 상용화 되고 있다. 본 연구에서는 입자 내부에 공기층을 갖는 중공형(hollow) 형태의 실리카 나노 입자를 제조하여 공기층 크기가 단열 성능에 미치는 영향에 대해 고찰하였다. Polystyrene 주형법을 이용하여 졸-겔공정을 통해 속이 빈 중공형 실리카 나노 입자(Hollow silica nanoparticles)를 제조하였고, 입자를 5 wt %로 도료에 첨가한 후 열전달 실험을 통해 단열 성능을 확인하였다. 기존 페인트에 입자를 혼합하여 약 15 %이상의 단열효율을 나타냈으며, 내부 공기층의 크기가 큰 입자가 작은 입자에 비해 5% 높은 단열 성능을 나타냈다. 이번 연구를 통해 내부 크기에 따른 단열효과의 차이를 보여줌으로써, 중공형 형태의 입자를 첨가제나 도료 제조에 사용하는 경우 단열효과를 높이기 위해 매질 내에서 입자가 공기층을 최대로 이룰 수 있도록 입자의 크기를 고려해야함을 제시한다.

• 항공우주시스템공학회지
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• 제18권3호
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• pp.70-75
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• 2024

본 연구에서는 단열재 두께에 따른 소형발사체 공통격벽 추진제 탱크의 단열 성능을 분석하였다. 단일 파트로 이루어진 공통격벽 추진제 탱크는 탱크 연결부가 불필요하여 추진제 탱크의 경량화 설계가 가능하다. 그러나 산화제와 연료의 온도차로 인한 열전달에 의하여 추진제의 손실과 점화 지연 등의 문제가 발생할 수 있다. 따라서 산화제 탱크와 연료 탱크를 구분하는 공통격벽 구조의 단열 성능 확인이 필수적이다. 본 연구에서는 기화 질량(boil- off mass)을 이용한 단열 성능 분석을 위하여 단열재 두께가 50, 55, 60, 65, 70 mm인 추진제 탱크에 대해 과도 열전달 해석을 수행하였다. 이어서 추진제 탱크의 1단 비행시간 동안 발생하는 산화제의 기화 질량을 도출하였다. 그 결과, 단열재 두께가 증가할수록 기화 질량이 감소하여 단열 성능이 향상되었다.

• 한국해양공학회지
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• 제28권6호
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• pp.517-526
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• 2014

The leakage of cryogenic LNG through cracks in the insulation membrane of an LNG carrier causes the hull structure to experience a cold spot as a result of the heat transfer from the LNG. The hull structure will become brittle at this cold spot and the evaporated natural gas may potentially lead to a hazard because of its flammability. This paper presents a computational model for the LNG flow and heat diffusion in an LNG insulation panel subject to leakage. The temperature distribution in the insulation panel and the speed of gas diffusion through it are simulated to assess the safety level of an LNG carrier subject that experiences a leak. The behavior of the leaked LNG is modeled using a multiphase flow that considers the mixture of liquid and gas. The simulation model considers the phase change of the LNG, gas-liquid multiphase interactions in the porous media, and accompanying rates of heat transfer. It is assumed that the NO96-GW membrane storage is composed of glass wool and plywood for the numerical simulation. In the numerical simulation, the seepage, heat diffusion, and evaporation of the LNG are investigated. It is found that the diffusion speed of the leakage is very high to accelerate the evaporation of the LNG.

• 한국포장학회지
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• 제12권1호
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• pp.45-53
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• 2006

Thermal insulation is used in a variety of applications to protect temperature sensitive products from thermal damage. Several factors affect the performance of insulation packages. Among these factors, the thermal resistance of the insulating wall is the most important factor to determine the performance of the insulating package. In many cases, insulating wall consists of multi-layered structure and the heat transfer through this structure is a very complex process. In this study, an one-dimensional mathematical model, which includes all of the heat transfer principles covering conduction, convection and radiation in multi-layered structure, were developed. Based on this model, several heat transfer phenomena occurred in the air space between the layer of the insulating wall were investigated. From the simulation results, it was observed that the heat transfer through the air space between the layer were dominated by conduction and radiation and the low emissivity of the surface of each solid layer of the wall can dramatically increase the thermal resistance of the wall. For practical use, an equation was derived for the calculation of the thermal resistance of a multi-layered wall.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.176-182
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• 2013

In this study, we examine the tracking happen in a polyvinyl-chloride-sheathed flat cord (PVCSFC), which is widely used as a distribution cord. The study classifies the bridge current via the formed conductive paths during tracking in the PVCSFC. Further, it attempts to distinguish the characteristics of heat generation and heat transfer by kind of bridge current. When the PVCSFC is in the static state, the bridge currents flow only through the electrolyte bridge. In the case of the carbonized PVCSFC, the bridge currents flow through one or more conductive paths. One is the electrolyte bridge, the other is the bridge that is consisted electrolyte and carbonized insulation. Currents flowing through different conductive paths have different heat generation and transfer characteristics. As the bridge current flowing in the conductive path consisting of electrolyte and carbonized insulation increases, the temperature difference between the surface of the PVCSFC and ambient air also increases correspondingly.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.178-179
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• 2021

Comparing the absorption volume of test pieces immersed over time in room temperature moisture with weight, WF absorbed about 40% more than PLAIN, and PLAIN stopped absorbing after 10 minutes, but WF continued to absorb. It is thought that the woven fabric layer of the core material continued to absorb moisture. In the heat transfer test, the test piece to which only WF was applied had a temperature difference of about 2℃ compared to PLAIN, and when the insulating liquid was sprayed, there was a difference in heat transfer properties of up to 5℃. This is judged to have low heat transfer properties of the basic woven fabric, but the heat insulating liquid also further reduces heat transfer properties.

• 한국전산유체공학회지
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• 제13권3호
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• pp.21-27
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• 2008

The reactor head of a sodium-cooled fast reactor KALIMER-600 should be cooled during the reactor operation in order to maintain the integrity of sealing material and to prevent a creep fatigue. Analyzing turbulent natural convection flow in the cover gas region of reactor vessel with the commercial CFD code CFX10.0, the cooling requirement for the reactor head and the performance of the insulation plate were assessed. The results showed that the high temperature region around reactor vessel was caused by the convective heat transfer of Helium gas flow ascending the gap between the insulation plate and the reactor vessel inner wall. The insulation plate was shown to sufficiently block the radiative heat transfer from pool surface to reactor head to a satisfactory degree. More than $32.5m^3$/sec of cooling air flow rate was predicted to maintain the required temperature of reactor head.