진공단열재 복합보드 설계 최적화에 관한 연구

김영탁(Young Tag Kim),배민정(Min Jung Bae),최경석(Gyeong Seok Choi),이용준(Young Jun Lee) 대한설비공학회 2021 대한설비공학회 학술발표대회논문집 Vol.2021 No.6

This study aims to establish guidelines for insulation design of new and remodeling buildings in the application of Vacuum Insulation Panel(VIP), which are high insulation thin film insulation. To this end, effective thermal conductivity that reflects thermal bridge phenomena occurring at the edge of VIP can be applied in the insulation design of VIP and vacuum insulation panel composite board. In this case, reasonable effective thermal conductivity is 1.5 times of the core thermal conductivity. In addition, the actual construction site was not applied as a single vacuum insulation panel, but was accompanied by protective materials. In this case, the insulation design specification of the vacuum insulation panel composite board was proposed, and the insulation thickness of a VIP composite board satisfying U-Value 0.15 [W/㎡K] or less is not more than 60[mm].

Shielding Public Agencies from Political Influence:Does Structural Insulation Really Matter?

이정욱(Jung Wook Lee) 한국국정관리학회 2016 현대사회와 행정 Vol.26 No.3

This study tests the moderating effect of ‘structural insulation,’ an agency design strategy for shielding a public agency from external political influences. Since ‘politics-administration dichotomy’ was put forward as a core theory for administrative reform, various schemes have been proposed for safeguarding administrative agencies from political influence, thereby enhancing their neutral competence. Structural insulation-structuring agencies with insulating features such as fixed-term for agency head(s), governance by multi-member board, etc.-is one of such ideas. A review of the literature, however, reveals a paucity of systematic evidence of whether and how structural insulation matters. Few studies tested the efficacy of each insulating feature, using data from a representative sample. Yet another problem is that studies on structural insulation are based largely on discussions of how politics affects the policies of public agencies, to the virtual exclusion of discussions of how politics affects their organizational characteristics. Using data collected from 115 U.S. federal agencies, this study attempted to address these voids in the current literature. It examined whether the impact of ‘political salience’ of a federal agency-salience to the president and Congress-on its ‘priority goal ambiguity’ is moderated by insulating features, extending Lee et al.’s (2009) study, which reported a positive relationship between the two. Regression results provide partial support for the moderating effect of structural insulation: three out of the four insulating features were found to mitigate the impact of congressional salience on priority ambiguity, while no such effect was detected when it comes to presidential salience. This study discusses the implications of these results and puts forward suggestions for future research.

공동주택 발코니창에 설치된 가동단열 시스템의 열성능 평가

윤종호(Yoon Jong-Ho),김병수(Kim Byoung-Soo) 한국태양에너지학회 2008 한국태양에너지학회 논문집 Vol.28 No.5

The aim of this study was to analysis the Heating/cooling performance of movable insulation system built in apartments. The process of this study is as follows: 1) Test-cells of movable insulation are designed through the investigation of previous paper and work. The type of the movable insulation used in test-cell is low emissivity(5%) insulation, measured for heating season and the thermal effects are analyzed. 2) The simulation program(Design Builder) was used in energy performance analysis. the reference model of simulation was made up to analysis energy performance on movable insulation system. 3) Selected reference model(Floors:15, Area of Unit:115.5㎡) for heating/cooling energy analysis, Energy performance simulation with various variants, such as slate angle of movable insulation(5°, 30°, 50°) and position of movable insulation. Consequently, When movable insulation system is equipped with balcony window of Apartment, Annual heating energy of reference model was cut down at the average of 5.4kWh/㎡ or 4.6% of heating/cooling energy.

원전용 금속단열재의 내부 형상결정을 위한 설계인자 별 열전달 특성 분석

송기오(Ki O Song),유정호(Jeong Ho Yu),이태호(Tae Ho Lee),전현익(Hyun Ik Jeon),하승우(Seung Woo Ha),조선영(Sun Young Cho) 대한기계학회 2015 大韓機械學會論文集A Vol.39 No.11

일반적으로 산업현장에서 많이 사용되고 있는 단열재는 유리섬유와 같은 열전도도가 낮은 재료를 사용함으로써 단열성능을 확보하고 있다. 이와 달리 원전용 금속단열재의 경우 높은 열전도도를 가진 TP 304 스테인리스 박판을 재료로 한정하고 있어 단열성능을 확보하기 위해서는 구조적 측면에서의 접근이 필요하다. 본 연구에서는 금속단열재 내부구조에 대한 설계인자를 전도, 대류, 복사로 구성된 3가지 열전달 모드를 고려해 추출하고 각 인자들이 열전달에 미치는 영향과 각각의 열전달이 전체 열전달에 차지하는 비율을 열 유동해석을 이용하여 파악하고자 하였다. 본 연구를 통해 단열재 내부에서 발생되는 대류현상을 최소화하기 위해 다수의 박판을 삽입함과 동시에 증가하는 전도 비율을 비교하여 내부형상결정을 위한 세 가지 열전달 모드 하에서의 단열성능을 분석하였다. A heat insulating material used in the industrial site normally derives its heat insulating performance by using a low thermal conductivity material such as glass fiber. In case of the metal insulation for nuclear power plant, in contrast, only TP 304 stainless steel foil having high thermal conductivity is the only acceptable material. So, it is required to approach in structural aspect to ensure the insulation performance. In this study, the design factors related to the metal insulation internal structure were determined considering the three modes of heat transfer, i.e., conduction, convection, and radiation. The analysis of heat flow was used to understand the ratio of the heat transfer from each factor to the overall heat transfer from all the factors. Based on this study, in order to minimize the convection phenomenon caused by the internal insulation, a multiple foil was inserted in the insulation. The increase in the conduction heat transfer rate was compared, and the insulation performance under the three modes of heat transfer was analyzed in order to determine the internal geometry.

건물의 배관 단열 두께 기준 개정에 관한 연구

최승혁(Seung-Hyuck Choi),류형규(Hyung-Kyou Ryu),윤희원(Hi-Won Yun) 대한설비공학회 2016 대한설비공학회 학술발표대회논문집 Vol.2016 No.6

To reduce energy loss in cold water pipes of building mechanical systems is crucial for building energy consumption, and the relevant pipe insulation standards are intimated by the government. However, the latest standards were established in 2002, although the important of building energy conservation has been sharply magnified ever since. In this study, we propose a performance design method for the cold water pipe insulation. Based on the method, an approach to determine optimum insulation thickness for energy conservation and condensation prevention has been proposed.

표면 조도에 따른 고체 절연물의 연면방전 특성에 관한 연구

박준영(Junyoung Park),신우철(Woocheol Shin),강형구(Hyoungku Kang) 한국조명·전기설비학회 2024 조명·전기설비학회논문지 Vol.38 No.1

This study investigates the impact of surface roughness on the surface discharge characteristics of solid insulators under high vacuum conditions, essential for the insulation design of superconducting magnets operated in such environments. Experiments were conducted to analyze the surface discharge properties in relation to the surface roughness of Polyether ether ketone (PEEK), a material commonly used as a solid insulator in superconducting applications, both in atmospheric and high vacuum conditions. Furthermore, additional experiments were carried out on other widely used solid insulators in superconducting applications, namely Monomer Casting (MC) Nylon, Glass Fiber Reinforced Polymer (GFRP), and Teflon, to assess their surface discharge characteristics under high vacuum. The results indicated that the surface discharge behavior of these solid insulators is significantly influenced by their surface roughness under high vacuum conditions. It was observed that an increase in surface roughness led to a decrease in surface discharge values, whereas a decrease in roughness resulted in higher discharge values. This trend is attributed to the variation in the amount of residual charge on the insulator’s surface, which is affected by the surface texture. Consequently, for enhanced electrical stability of superconducting magnets in high vacuum, it is crucial to optimize the surface roughness of solid insulators to minimize residual charges and prevent insulation breakdown due to collision ionization.

PVC를 이용한 소형 고체 로켓 모터 개념 설계

전명식(Myoungsik Jeon),고영우(Yeongwoo Ko),한형석(Hyungseok Han),이나원(Nawon Lee),한철희(Cheolheui Han) 한국추진공학회 2012 한국추진공학회 학술대회논문집 Vol.2012 No.11

본 논문에서는 PVC를 이용한 소형 고체 로켓 모터와 노즐 설계에 중점을 두었다. 기존 steel을 이용한 로켓 모터 설계에서 높은 가공비용 문제를 해결하고자 수행하였으며, steel을 이용한 로켓모터와 동등대비 같은 성능을 낼 수 있도록 중점을 두었다. 모터 설계에 있어서 중요한 노즐 설계와 케이스 설계, 내부 단열 설계를 중점으로 다루었으며, 차후 본 과정을 수십 회의 실험을 통해 안정성을 검토 하겠다. In this study, it focuses on a small solid rocket motor using PVC and a nozzle design. This study is carried out in order to lessen the high processing cost of the rocket motor design using the existing steel motor. It focuses on obtaining the same performance compared to the rocket motor using steel. This paper covers nozzle design, case design and internal insulation design which are important in designing motor. Through several numbers of the experiment, the safety of the small solid rocket motor using PVC will be examined.

습열 거동 분석을 통한 국내 에너지절약설계기준의 방습층에 관한 문제점 분석

권혜주,최정만 한국생활환경학회 2019 한국생활환경학회지 Vol.26 No.1

This study analyzed the vapor barrier regulations of the Korean Energy-Saving Design Standards to determine whether the allowable permeance of the vapor barrier is enough and to determine if the exemption condition based on the installation of a vapor barrier is based on the reality of a construction site. Using a hygrothermal simulation, we conclude that the Korean vapor barrier regulations must be effectively strengthened and that the exemption condition based on the installation of a vapor barrier ignores construction errors that typically occur at construction site; for example, the gap between insulations. Thus, to revise this vapor barrier regulation, we propose the minimum allowable vapor permeance and the specifications of the vapor barrier installation.

저에너지건축물 설계를 위한 건축물 단열성능의 효과적 조정과 야간외기 도입에 따른 에너지 시뮬레이션 연구

윤현수(Hyun-Su Yun),이태규(Tae-Kyu Lee),김정욱(Jeong-Uk Kim) 한국산학기술학회 2018 한국산학기술학회논문지 Vol.19 No.10

본 연구는 최근 자원고갈 문제에 따른 에너지 절감을 바탕으로 총 에너지 수요에서 높은 비중을 차지하고 있는 건축물 에너지의 수요 감축에 목적을 두었고 국내에서 에너지절약형 건축물 설계를 위해 고시한 단열기준을 보다 효과적으로 조정하기 위한 보완점을 제시하고 에너지절약형 고단열, 고기밀 건축물의 쾌적성 유지의 한계점을 추가 보완하고자 야간외기 환기시스템을 도입하며 종합하여 최종 저에너지건축물 설계모델을 제시하였다. 먼저, 단열성능의 효과적 조정 모델은 건축물의 각 경사면별로 다르게 조정하여 각각의 수요 민감도를 충분히 고려할 수 있는 방법을 제시하고, 야간외기 도입 모델의 경우 건축물의 에너지 성능을 최대로 할 수 있는 모델을 선정하였다. 두 가지 모델을 결합한 최종 저에너지건축물 모델은 결과적으로 대상 건축물의 남, 북의 경사면 단열을 강화한 모델과 야간외기를 통한 환기 시스템을 단시간 운전한 모델이었으며 국내 단열기준에 의거한 Base 모델과 비교할 때 약 6~7%의 절감효과를 보였다. 따라서, 본 연구에서 제시하는 효과적 단열조정법과 야간외기 도입은 저에너지건축물 모델 설계에 있어 수요 민감도 분석 선행의 필요성을 환기시키는 점에서 시사점이 높고 대상 건축물의 건물에너지 수요를 저감할 수 있는 설계모델로 활용도가 높을 것이다. This study was done to reduce total energy demand based on resource shortage problems and to provide improvement points for more efficient adjustment of the high insulation standards for saving energy in Korea. The demand sensitivity was fully considered by varying the slope of each building. The energy performance of the building was maximized by the introduction of outdoor air at night. A final low-energy building model was developed with the two measures combined, and the short-term operation of the night-fuzzy ventilation system was simulated. The result showed a reduction of about 6 to 7 percent compared to the base model. The results could have many implications in terms of the need to conduct demand sensitivity analyses in architectural design.

고온초전도 자석 개발을 위한 진공에서의 절연파괴 특성 분석

신우철,Bimaridi Afif,박준영,구본혁,이호빈,강형구 한국조명.전기설비학회 2023 조명·전기설비학회논문지 Vol.37 No.2

The high-temperature superconducting (HTS) magnet used in particle accelerators for cancer treatment exhibits a large current change for a short period of time due to its fast ramp-up characteristics, which results in high voltage and instant vulnerability to electrical insulation. This research introduces the saddle-coil, which, due to its complex shape and small bending radius, allows for the local concentration of electric field intensity. Reports from the European particle physics laboratory, CERN have revealed dielectric breakdown due to 1000V between layers during low-temperature superconducting (LTS) magnet experiments for accelerators, yet no research has been conducted to solve this problem. HTS magnets operating in vacuum may be susceptible to electrical breakdown due to high induced voltage and local quench due to rapid-ramp characteristics. Therefore, this paper deals with the dielectric characteristics of vacuum to develop an electrically stable HTS magnet. Specifically, dielectric experiments on penetration and creepage discharge were conducted under various vacuum conditions, and empirical formulae for calculating the electric field intensity at sparkover for the insulation design of HTS magnets was derived.