• 한국재료학회지
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• 제30권4호
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• pp.155-159
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• 2020

Nanoporous silica aerogel insulation material is both lightweight and efficient; it has important value in the fields of aerospace, petrochemicals, electric metallurgy, shipbuilding, precision instruments, and so on. A theoretical calculation model and experimental measurement of equivalent thermal conductivity for nanoporous silica aerogel insulation material are introduced in this paper. The heat transfer characteristics and thermal insulation principle of aerogel nano are analyzed. The methods of SiO₂ aerogel production are compared. The pressure range of SiO₂ aerogel is 1Pa-atmospheric pressure; the temperature range is room temperature-900K. The pore diameter range of particle SiO₂ aerogel is about 5 to 100 nm, and the average pore diameter range of about 20 ~ 40 nm. These results show that experimental measurements are in good agreement with theoretical calculation values. For nanoporous silica aerogel insulation material, the heat transfer calculation method suitable for nanotechnology can precisely calculate the equivalent thermal conductivity of aerogel nano insulation materials. The network structure is the reason why the thermal conductivity of the aerogel is very low. Heat transfer of materials is mainly realized by convection, radiation, and heat transfer. Therefore, the thermal conductivity of the heat transfer path in aerogel can be reduced by nanotechnology.

• 한국재난정보학회 논문집
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• 제12권3호
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• pp.292-299
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• 2016

건축물에서 단열재는 매우 중요하다. 건축물에 사용하는 단열재는 재료에 따라 유기단열재와 무기단열재로 크게 나누는데 스티로폼이나 우레탄으로 만들어진 유기단열재는 화재에 매우 취약하다. 반면 펄라이트 무기단열재는 불연재이나 습기에 매우 취약하여 사용범위가 제한적이다. 본 연구에서는 단열성능이 보드의 두께가 50mm 이내의 샘플에서 열전도율과 흡수율은 각각 0.05W/mk, 3.0% 이하, 휨강도와 발수율은 각각 $25N/cm^2$, 98% 이상인 무기단열재를 개발하고 열전도 특성을 평가하였다.

• Transactions on Electrical and Electronic Materials
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• 제2권4호
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• pp.19-23
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• 2001

In this paper, design considerations and manufacturing procedure of 200 class insulation system with polyimide(Kapton) main insulation and silicone resin VPI process on the traction motor thor EMU will be reviewed. The performance test and the long life evaluation test that prove stability and reliability of Insulation system for traction motor will also be introduced.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.433-436
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• 2004

In this paper, we studied on the electrical safety evaluations of transformer insulation cover. In order to take preventive measures against an electric shock disaster in 22.9kV transformer installation, we put the insulation cover on a transformer charging parts. It needs to be designed so that the insulation covers have superior properties such as, arc-resistance, weather-resistance and heat-resistance, because they are used until the damage and destruction occur. To establish the protection cover to reduce the electrical shock, we analyzed damage mechanism and risk factors which happened by structural fault of an insulation cover in this paper. Also, based on the experimental results, we are planing to suggest new improved insulation cover models.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.468-469
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• 2007

$SF_6$ gas used widely as insulating component in electric power industry has excellent in insulation and arc extinguishing performance in gas-insulated switchgear. However, the concern about eco-friendly alternative gas is currently rising, because $SF_6$ gas is one of the main greenhouse gases. As one of the study for $SF_6$ free technology, composite-insulation technology is focused in this paper. To analyze the influence by epoxy thickness change, the composite-insulation composed of dry-air and epoxy was used in this paper. To analyze AC breakdown by the epoxy thickness, needle-plane electrode was used and needle was molded by epoxy. Under the gas pressure ranged from 0.1 to 0.6MPa, the breakdown voltage of dry-air were measured in AC electric field. The data of composite-insulation were acquired by changing the thickness of epoxy used in each composite-insulation under the same condition.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.115-118
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• 2000

In case of developing new motor, many examinations was tested to decide a motor efficiency and reliability. To give reliability judgment, traction motor winding insulation was tested by electrical method after appling electrical, heat, mechanical, environmental stress. In this study, stator form-wound winding of traction motor in urban transit E.M.U was tested by accelerative thermal degradation test. Stator form-wound winding was tested on the accelerative degradation composed of heat, vibration, moisture, overvoltage and researched insulation resistance, dielectric loss, partial discharge for insulation degradation properties, evaluated withstand voltage. Degradation temperature was $230[^\circ{C}]$, $250[^\circ{C}]$, $270[^\circ{C}]$, for stator form-wound winding respectively. On the test results of accelerative thermal degradation, insulation properties were relied all temperature until 10 times and expected life was evaluated by the rule of reducing $10[^\circ{C}]$ life into halves. Expected life was 31.8 years. It is guaranteed insulation reliability because of exceeding 25 years life times as considering.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.195-196
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• 2022

Insulation material absorption rate is closely related to thermal conductivity. In Korea, there is no study on the change of insulation material in a long-term continuous exposure environment. In this study, basic data on the long-term durability of insulation materials were obtained by measuring the absorption rate of insulation materials over time. For the purpose of providing, as a result of the measurement, PIR class2 No.2 and PIR noncombustible show similar absorption rate trends, which is thought to be due to the fact that both are made of rigid urethane foam, and flame retardant EPS has the highest absorption rate except for PF. This is thought to be because there is a space for absorption between the beads and the beads. In the case of XPS, it is thought that the reason for showing the lowest absorption rate is that because it is produced by extrusion, it has a high density and thus has less space for moisture to penetrate.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.37-40
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• 2001

This paper describes a study for the development of light weight transformer with hybrid insulation system consists of A class insulation material and H class insulation material.

• 한국농촌건축학회논문집
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• 제19권4호
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• pp.57-65
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• 2017

Life quality in farming areas is declining these days on account of decrease in population with the outflow of young generations, advent of aging society, and also lack of social and physical infrastructure. To reverse this, the central and local governments have been devising policies in many ways; however, the vulnerable class in farming area suffering from financial difficulty is not supported with that properly. The results of applying insulation materials applicable to rural houses, EPS, e-board, and glass wool, actually to rural houses are summed as follows. EPS is the most inexpensive among the three installations in terms of material cost and expenses. The indoor and outdoor temperature difference increased from $0.9^{\circ}C$ to $2.5^{\circ}C$, and the temperature change reduced as $0.04^{\circ}C$. With e-board, the indoor and outdoor temperature difference increased from $3.3^{\circ}C$ to $7.5^{\circ}C$; however, the temperature change increased as $0.09^{\circ}C$. Unlike the other two methods, glass wool requires the additional installation of wooden frames. The material cost is highest, and the indoor and outdoor temperature difference increased from $1.1^{\circ}C$ to $8.0^{\circ}C$, and the temperature change reduced as $0.01^{\circ}C$. According to the results of measuring temperature, glass wool's temperature difference is measured to be the highest, but temperature change is found to be the most effective in EPS. Among the three insulation methods, EPS is the most economically advantageous as the material supply is easy and the cost is low. The material is easily processible, so ordinary town residents can install it easily, and it is effective at improving insulation performance, too. But this method cannot be applied when the house has walls that are not even. Also, as the insulator is thick, after the installation, the living space may be narrower as a result.

• 한국해양공학회지
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• 제30권5호
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• pp.349-355
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• 2016

Divinycell, which functions as both insulation and a supporting structure, is generally applied in the NO96-type liquefied natural gas (LNG) insulation system. Polymer-material-based Divinycell, which has a high strength and low weight, has been widely used in the offshore, transportation, wind power generation, and civil engineering fields. In particular, this type of material receives attention as an insulation material because its thermal conductivity can be lowered depending on the ambient temperature. However, it is difficult to obtain research results for Divinycell, even though the component materials of the NO96-type LNG cargo containment system, such as 36% nickel steel (invar steel), plywood, perlite, and glass wool, have been extensively studied and reported. In the present study, temperature and strain-rate dependent compressive tests on Divinycell were performed. Both the quantitative experimental data and elastic recovery are discussed. Finally, the mechanical characteristics of Divinycell were compared to the results of polyurethane foam insulation material.