• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.529-534
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• 2016

Calcium silicate inorganic insulating material is a porous material which is made of 90 wt% of cement. Unlike existing inorganic insulation materials, it is produced without high temperature curing process and also it costs much less than existing inorganic insulation materials. It is an innovative insulation material that supplemented disadvantages of conventional inorganic insulation material. Researches and developments about inorganic insulation materials have been actively researched abroad. Calcium silicate insulation has $0.13g/cm^3$ of specific gravity. Its heat conductivity is under 0.050W/mK, which it similar to conventional inorganic insulation. However, it has weak compressive strength compared to other inorganic insulation. The point of this research is to manifest that calcium silicate inorganic insulating material can have certain compressive strength after curing process with high insulating performance and to find out the proper curing methods and period.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.9
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• pp.430-435
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• 2002

The $SF_{6}$ gas insulated power equipments have the insulation systems which are composed of $SF_{6}$ gas and insulation paper. It is repored that their insulation abilities are influenced by the $SF_{6}$ gas gaps in those insulation systems and gas pressures. This paper describes partial discharge phenomena with $SF_{6}$ gas pressures in insulation system of $SF_{6}$ gas-insulation paper Specimens of $SF_{6}$ gas-insulation paper were prepared and aramid paper was used as insulation paper. Partial discharge inception voltages(PDIV) and breakdown voltages for the existence of $SF_{6}$ gas gaps were measured by short term tests with gas pressures. Also, average PD quantities and pulse counts, life times of each specimens were calculated from the results of long term aging tests with gas pressures. It was found that the $SF_{6}$ gas gaps decrease increasing rates of PDIV and brealdown voltages according to gas pressure increase and the insulation breakdown caused by the smaller PD quantities than 1[pC] at the high gas pressure of 300kPa is due to the increase of energy density with increase of gas pressure.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.419-429
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• 2024

Purpose: To enhance the non-combustibility of fire protection piping insulation and improve the heat resistance of smoke extraction duct insulation, I plan to verify the suitability of AES insulation materials for these applications through performance testing. Method: The non-combustibility, heat resistance, and thermal insulation performance of AES insulation materials will be verified through various tests. Result: According to the 'Standards for Flame Retardancy and Fire Spread Prevention of Building Finishing Materials,' the results of non-combustibility and gas toxicity tests confirmed the non-combustible properties. The standard fire resistance tests verified the fire resistance performance. Additionally, the thermal insulation performance was confirmed through building insulation tests. Conclusion: As the performance tests on AES inorganic insulation materials have proven their noncombustibility, fire resistance, and thermal insulation performance, these materials are considered a viable alternative for improving fire spread prevention in buildings.

• Fashion & Textile Research Journal
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• v.3 no.5
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• pp.479-485
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• 2001

This study was to determine the effect of garment closures and layering systems on insulation, using a thermal movable manikin in cold weather conditions. The insulation values of ensembles with opened and closed features were measured, and those of four different layered clothing ensembles were tested while standing and while walking. Our research indicated that when there was an opening involved in design the system, insulation decreased; even a zip-out lining in the armpit affected little. If a light weight jacket and pants are put on over a fleece shirt and pants instead polyester underwear, the amount of insulation increase was 0.43 clo.

• Journal of the Korean Ceramic Society
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• v.53 no.1
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• pp.63-67
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• 2016

Mineral hydrate is a new insulation material that compensates for the defects of existing materials. Mineral hydrate is made of inorganic ingredients; therefore, it is nonflammable. The porous structure of mineral hydrate makes the material lightweight and insulating. Mineral hydrate insulation and similar products have been studied and manufactured in Korea and abroad. However, these insulation materials need to improve in terms of strength. In this study, basalt fiber was used to enhance the strength. In order to observe the property changes, compressive strength, heat conductivity, and specific gravity were measured and XRD pattern analysis was performed. These tests confirmed that basalt fiber was effective at improving the strength and lowering the heat conductivity of mineral hydrate insulation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.179-180
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• 2015

In this study, the experimental study on Insulation performance of insulated forms utilizing NT frame heat insulation at low Temperature. For this study, placing insulated TEGO film plywood based form between two constant temperature and humidity chamber that maintaining 10℃, decrease temperature of one chamber to -10℃ and -20℃. Each of steps, maintaining period of temperature was 1 hour. After placing the insulated form, measure temperature of outside if insulated form. As a result of experiment, temperature difference of Fumed Silica Vacuum insulation was lowest.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.285-292
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• 1999

The design parameter of the reactor vessel insulation for the Korea Standard Power Plant has been studied numerically. The heat loss from the reactor vessel through the insulation is analysed by using the computational fluid dynamics code, FLUENT. Parametric study has been performed on the air gap width between the reactor vessel wall and the inner surface of the insulation, and on the insulation thickness. Also evaluated is the performance degradation due to the chimney effect caused by gaps between the panels during the installation of the insulation system. From the analysis results, the optimal air gap width and the optimal insulation thickness are obtained.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.10
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• pp.1712-1720
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• 2016

AC and DC insulation breakdown voltage was studied for magnet wire coated with double layers of high flexural PAI layer and high anti-corona PAI/nanosilica (15 wt%) layer. The specimens were prepared at various drying temperatures (T/D): $22^{\circ}C$, $240^{\circ}C$, and $260^{\circ}C$, respectively. The increase effects of nanosilica on AC and DC insulation breakdown voltage were not so significant compared to that of magnet wire coil coated with original PAI. And the AC and DC insulation breakdown voltage was improved by decreasing diameter of winding coil. As T/D temperature increased, AC and DC insulation breakdown voltage decreased.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1463-1470
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• 2018

In this study, 20 types of samples were prepared by mixing different kinds of inorganic materials to develop insulation materials for epoxy - based GIS substation equipment used under high voltage environmentally friendly insulation gas. One of the electrical characteristics, AC insulation breakdown experiment was performed. As mixing ratio of mixed heterogeneous inorganic materials, the dielectric breakdown strength was increased with increasing filler ratio of micro silica, micro silica : micro Alumina, 1:9, 3:7, 5:5, 7:3, 9:1, and decreased as the filling amount of micro alumina increased. The AC insulation breakdown characteristics were the best when the composition ratio was 9:1. The higher the content of silica, the better the interfacial properties, and the larger the alumina content ratio, the worse the interfacial properties.

• Proceedings of the KIEE Conference
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• 2006.05a
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• pp.71-73
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• 2006

Our company(KOWACO) has periodically performed off-line diagnostic test for 14 hydro generators (rated 11 kV over) for 15 years. In this paper, we summarized results of dissipation factor tip-up test and partial discharge test about these generators. Among these, we chose two generators and performed insulation reinforcement (cleaning and varnish Painting). We compared change of insulation condition for the stator winding based upon off-line diagnostic test result before and after repair. Test result shows that insulation condition was improved after insulation reinforcement. This insulation reinforcement has a function to reduce cause of deterioration, so we can know that it extends lifetime of generator and it is a very important factor for stable operation of facilities.