• Title/Summary/Keyword: Thermal Insulation

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A Study on the Thermal Insulation Property of Concrete Composites using Light-weight Aggregate (경량골재를 사용한 콘크리트 복합체의 단열성능에 관한 연구)

  • So, Seung-Yeong
    • Journal of the Korea Institute of Building Construction
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    • v.4 no.3
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    • pp.93-100
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    • 2004
  • In recent years, it has widely been studied on the light-weight composites for the purpose of the large space and thermal insulation of building structures. The purpose of this study is to evaluate the properties of light-weight composites made by binders as cement, resin and polymer cement slurry. The concrete composites are prepared with various conditions such as polymer-cement ratio, void-filling ratio, type of resin, filler content and light-weight aggregate content, tested for thermal conductivity. From the test results, the thermal conductivity of concrete composites with the binder of cement tends to decrease with increasing polymer-cement ratio, and to increase with increasing void-filling ratio. The thermal conductivity of concrete composites with the binder of resin are markedly affected by the light-weight aggregate content, type of resin and filler content. The composites made by polymer-modified concrete and polymer cement slurry have a good thermal insulation property. From the this study, we can recommend the proper mix proportions for thermal insulation Panel or concrete. Expecially. the thermal conductivity of concrete composites made by polyurethane resin is almost the same as that of the conventional expanded polystyrene resin.

Analysis of Thermal Characteristics and Insulation Resistance Based on the Installation Year and Accelerated Test by Electrical Socket Outlets

  • Kim, Kyung Chun;Kim, Doo Hyun;Kim, Sung Chul;Kim, Jae Ho
    • Safety and Health at Work
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    • v.11 no.4
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    • pp.405-417
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    • 2020
  • Background: Electrical socket outlets are used continuously until a failure occurs because they have no indication of manufacturing date or exchange specifications. For this reason, 659 electrical fires related to electrical socket outlets broke out in the Republic of Korea at 2018 only, an increase year on year. To reduce electrical fires from electrical socket outlets, it is necessary to perform an accelerated test and analyze the thermal, insulation resistance, and material properties of electrical socket outlets by installation years. Methods: Thermal characteristics were investigated by measured the temperature increase of electrical socket outlets classified according to year with variation of the current level. Insulation resistance characteristics was measured according to temperature for an electrical socket outlets by their years of use. Finally, to investigate the thermal and insulation resistance characteristics in relation to outlet aging, this study analyzed electrical socket outlets' conductor surface and content, insulator weight, and thermal deformation temperature. Results: Analysis showed, regarding the thermal characteristics, that electrical socket outlet temperature rose when the current value increased. Moreover, the longer the time that had elapsed since an accelerated test and installation, the higher the electrical socket outlet temperature was. With respect to the insulation resistance properties, the accelerated test (30 years) showed that insulation resistance decreased from 110 ℃. In relation to the installation year (30 years), insulation resistance decreased from 70 ℃, which is as much as 40 ℃ lower than the result found by the accelerated test. Regarding the material properties, the longer the elapsed time since installation, the rougher the surface of conductor contact point was, and cracks increased. Conclusion: The 30-year-old electrical socket outlet exceeded the allowable temperature which is 65 ℃ of the electrical contacts at 10 A, and the insulation resistance began to decrease at 70 ℃. It is necessary to manage electrical socket outlets that have been installed for a long time.

Problem Analysis of Sandwich Insulation Wall System (중단열 시스템의 문제점 분석)

  • Park, Jun-Ho;Yu, Jung-Ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.11a
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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.

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Thermal Insulation and Flame Retardant Properties of Cement Based Super Light-weight Inorganic Thermal Insulation using 100㎛ Grade Glass Bubble (100㎛급 글라스 버블 혼입 시멘트계 초경량 무기 단열재의 단열 및 난연특성)

  • Son, Bae-Geun;Song, Hun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.9 no.4
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    • pp.642-649
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    • 2021
  • Energy saving standard for buildings are strengthened, the application of exterior insulation finishing system and thickness of insulation materials are increasing. Most buildings with exterior insulation finishing system is applied organic insulating material. Organic insulating material have workability, economic feasibility, reduction in construction cost, and excellent thermal insulation performance. However, Organic insulating material is very vulnerable to heat, so when a fire occurs, rapid fire spread and toxic gas are generated, causing many casualties. Inorganic insulating material can be non-combustible performance, but it is heavy and has low thermal insulation performance. Mineral wool has higher thermal insulation performance than other types of inorganic insulating material, but mineral wool is disadvantageous to workability and vulnerable to moisture. Glass bubble are highly resistant to water and chemically stable substances. In addition, the density of the glass bubble is very low and the particles are spherical, fluidity is improved by the ball bearing effect. Glass bubbles can be used with cement-based ino rganic insulating material to impro ve the weight and thermal insulatio n perfo rmance o f cement-based inorganic insulation. This study produced a inorganic insulating materials were manufactured using cement-based materials and glass bubble. In order to evaluate the insulation performance and flame retardant performance of cement-based super light-weight inorganic insulating materials using with glass bubble, insulation performance or flame retardant and non-combustible performance were evaluated after manufacturing insulating materials using micro cement and two types of glass bubbles. From the test result, Increasing the mixing ratio of glass bubbles improved the insulation performance of cement-based super light-weight inorganic insulating materials, and when the mixing ratio of glass bubbles was 10%, it sho wed sufficient flame retardant and no n-co mbustible perfo rmance.

A Study on the Insulation of Thermal Clothing Under Dynamic Air Condition (풍속 존재 시 쾌적보온성 의복의 온열특성에 관한 연구)

  • Song, Min-Kyu;Kwon, Myoung-Sook
    • Journal of the Korean Society of Costume
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    • v.58 no.9
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    • pp.29-37
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    • 2008
  • The purpose of this study was to investigate insulation of thermal clothing under still and dynamic air conditions(with 2.1m/sec air velocity) and decrease of insulation in both conditions, to analyze correlations among them, and to estimate insulation and decrease of insulation using factors, such as fabric insulation, fabric weight, clothing weight, air permeability, and water vapor resistance. A total of 25 kinds of clothing were tested(9 types for suits, 6 types of jacket, 5 types for shirts, and 5 types for trousers). The results of this study were as follows; Thermal resistance of clothing under the dynamic air condition decreased comparing to that of clothing under still air condition in all types of clothing. Decrease in shirts was the biggest(47.5%), followed by suits(39.51%), trousers(37.48%), and jackets(34.49%) in sequence. Thermal resistance of clothing under dynamic air condition showed very high correlation(0.98, p<0.01) with that of clothing under still air condition, followed by thermal resistance of fabric(0.86, p<0.01). Decrease in thermal resistance of clothing showed the highest correlation with air permeability. It didn't show correlation with other factors. Regression analysis showed that fabric thickness would be useful factor for estimating thermal resistance of clothing and air permeability also would be useful factor for estimating decrease in thermal resistance of clothing.

The Evaluation of Thermal Aging Characteristics in Insulating Materials of the Pole Transformers (가속열화 방법에 의한 주상변압기 절연물의 열 열화 특성 평가)

  • 이병성;송일근;이재봉;한상옥
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.12
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    • pp.1136-1141
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    • 2003
  • The primary insulation materials used in an oil filled transformer are kraft paper, wood, porcelain and oil. Modern transformers use chemically treated paper to improve its tensile strength and resistance to aging caused by immersion in oil. But these insulation papers are mainly aged by thermal stress. Over the life time of the insulation paper and oil, it is exposed to high temperatures, oxygen and water. Its interaction with the steel of the tank and core plus the copper and aluminium of the windings will eventually cause the chemical properties of the oil to decay. High temperature have an effect on mechanical strength of cellulous paper used in the layer insulation. We made two aging cells in which insulation papers and mineral oil are conducted to test thermal properties. It is measured dielectric strength, number of acid, moisture, etc. of insulation paper and oil aged in the aging cells.

Comparative Performance Evaluation by Winter Apartment Temperature on the Outer Surface of the Insulation (동계 아파트 외표면 온도에 의한 단열성능 비교평가)

  • Park, Jung-Hun;Kim, Bong-Joo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.4
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    • pp.91-100
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    • 2013
  • This research is to measure and analyze the thermal performance of the apartment structure and to evaluate and establish standards of thermal insulation defect in order to make the basic data necessary for determining the degree of the thermal performance degradation and for repairing and reinforcing the exterior wall of the existing apartment. Furthermore, it is to predict the part of occurrence of the thermal bridge and condensation at the apartment building structure. On the other one hand, it is also to analyze the degree of thermal insulation performance according to the standards of thermal insulation and elapsed time, through the analysis by the workability of concrete.

Thermal Performance of TI-wall System (투과형단열재 부착 건물외피구조체의 열성능)

  • Yoon, Yong-Jin;Kim, Hea-Jeong;Kim, Byoung-Soo
    • KIEAE Journal
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    • v.4 no.3
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    • pp.121-128
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    • 2004
  • One of the most weak parts for energy loss through the whole building components are building envelopes. Lots of technbologies to increase the thermal performance of building envelopes have been introduced in recent years. Transparent insulation is a new technology for building insulation and has function both solar transmittance and thermal insulation. This study has been carried out to develope the transparent insulation panels and TI-wall system and to analyze the thermal performance of TI-wall system by experiments using test-cell and dynamic energy simulation program ESP-r 9.0. This system is regarded as a efficient building envelope system suitable for to reduce the heating and cooling load of the buildings in our country.

Improvement of the Thermal Behavior of Linear Motors through Insulation Layer (단열재에 의한 리니어모터의 열특성의 향상)

  • Eun, L.D.;Lee, C.M.;Chung, W.J.;Choi, Y.H.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.785-790
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    • 2001
  • Linear motors can drive a linear motion without intermediate gears, screws or crank shafts. Linear motors can successfully replace ball lead screw in machine tools, because they have a high velocity, acceleration and good positioning accuracy. On the other hand, linear motors emit large amounts of heat and have low efficiency. In this paper, heat sources of a synchronous linear motor with high velocity and force are measured and analyzed. To improve the thermal stiffness of the linear motor, an insulation layer with low thermal conductivity is inserted between cooler and machine table. Some effects of the insulation layer are presented.

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Thermal Conductivity Properties of Building Insulation Materials with Freezing and thawing Cycles (동결융해 반복에 따른 건축용 단열재의 열전도 특성)

  • Lee, Gun-Cheol;Choi, Jung-Gu;Lee, Gun-Young;Lim, Sun-Hyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.190-191
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    • 2014
  • The building insulation materials shall keep their thermal conductivity constant even when the freezing and thawing repeats for over a long time. But, in this condition of repeated freezing and thawing, the organic building insulation material may suffer the degradation in the thermal performance as the gas put into the insulation materials gets out slowly over a long time. Accordingly, in this study, the change in the thermal performance has been tested and evaluated when the repeated freezing and thawing cycles happen.

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