• 전기학회논문지
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• 제56권9호
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• pp.1561-1565
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• 2007

According to thermal degradation on power transformers, it is known that electrical, mechanical and chemical characteristics for power transformer's oil-paper are changed. In the chemical property, especially, when the kraft paper is aged, the cellulose polymer chains break down into shorter lengths. It causes decrease in both tensile strength and degree of polymerization of paper insulation. Also the paper breakdown is accompanied by an increase in the content of various furanic compounds within the dielectric liquid. It is known that furanic components in transformer oil come only from the decomposition of insulating paper rather than from the oil itself. Therefore the analysis of furanic degradation products provides a complementary technique to dissolved gas analysis for monitoring transformers when we evaluate the aging of insulating paper by the total concentration of carbon monoxide and carbon dioxide dissolved in oil only. Recently, the analysis of furanic compounds by high performance liquid chromatography(HPLC) using IEC 61198 method for estimating degradation of paper insulation in power transformers has been used more conveniently for assessment of oil-paper. It is know that the main products which is produced by aging are 2-furfuryl alcohol, 2-furaldehyde(furfural), 2-furoic acid, 2-acetylfuran, 5-methyl-2-furaldehyde, and 5-hydroxymethyl-2-furaldehyde. For investigating the accelerated aging process of oil-paper samples we manufactured accelerating aging equipment and we estimated variation of insulations at $140^{\circ}C$ temp. during 500 hours. Typical transformer proportions of copper, silicon steel and iron have been added to oil-paper insulation during the aging process. The oil-paper insulation samples have been measured at intervals of 100 hours. Finally we have analyzed that 2-furoic acid and 2-acetylfuran products of furanic compounds were detected by HPLC, and their concentrations were increased with accelerated aging time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.1909-1911
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• 2005

The electrical and chemical characteristics in transformer insulations are changed due to thermal stress. In the chemical property, as the Kraft paper ages, the cellulose polymer chains breakdown into shorter lengths with a corresponding decrease in both tensile strength and degree of polymerization(DP). Furthermore, cellulous chains breakdown is accompanied by an increase in the content of various furanic compounds within the dielectric liquid. It is known that furanic components in transformer oil come only from the decomposition of insulating paper rather than from the oil itself. Therefore the analysis of furan products provides a complementary technique to dissolved gas analysis for monitoring transformers when we evaluate the aging of insulating paper by the total concentration of carbon monoxide and carbon dioxide dissolved in oil only. In this paper the accelerated aging process of oil--paper samples have been investigated at a temperature up to $140^{\circ}C$ for 500 hours. The oil-paper insulation samples have been measured at intervals of 100 hours. For analysis we used high performance liquid chromatography(HPLC) in accordance with IEC 61198 method.

• 전기학회논문지P
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• 제58권4호
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• pp.499-504
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• 2009

The analysis for furan compound has provided a complementary technique to dissolved gas analysis(DGA) for monitoring transformers when total concentration of CO and $CO_2$ dissolved in oil only has been evaluated the aging of insulating paper. But, the analysis of furanic compounds by high performance liquid chromatography(HPLC) has been important more than DGA recently. Because it has been known that furanic components in transformer oil have come only from the decomposition of insulating paper. Therefore we have manufactured accelerating aging cell which was aged during 60 hours at 100, 150, 180 and $200^{\circ}C$, respectively, for investigating the characteristics of cellulose paper by thermal using analysis for CO, $CO_2$ and furan compound.

• 한국식품과학회지
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• 제31권4호
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• pp.894-898
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• 1999

둥굴레속 중에서도 흔하지 않는 용둥굴레(약초로 다룰 때는 옥죽이라고도 함)를 이용하여 제조되는 옥죽차를 사용하여 향기성분의 연구를 행하였다. 옥죽차의 제조법은 천성산 일대에서 인공재배하여 $4{\sim}5$년 자란 용둥굴레의 뿌리를 9번 찌고 9번 건조하는 방법인 9증 9포(九蒸九曝)법을 적용하는데, 그 제조 과정중의 향기성분을 단계별로 Likens and Nickerson의 연속증류추출법으로 추출하고, GC 및 GC-MS법으로 분석, 동정하였다. 그 결과 원재료에는 향기성분이 거의 없었으나, 찌고 덖는 과정을 거치는 동안 furfural, furfuryl alcohol, 2-acetylfuran, 5-methylfurfural, 5-hydroxymethylfurfural 및 2-methyl-dihydro-2(3Η)-furanone등과 methylpyrazine과 2,3-dimethylpyrazine 등의 pyrazine류, acetic acid 및 propionic acid등의 acid류가 생성되었다.

• 접착 및 계면
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• 제11권2호
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• pp.41-49
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• 2010

탄소 중립형 친환경 접착소재로서, 퓨란기를 함유하는 에폭시 단량체(8, 9)를 설계하고 합성하였다. 바이오매스로부터 바이오-리파이너리 공정을 통해 쉽게 얻을 수 있는 퓨란과 메틸 아크릴레이트를 출발물질로 하여 Diels-Alder 반응을 통하여 이중고리 뼈대를 합성하였다. 이후 에스테르 작용기를 알코올로 환원한 후 에피클로로하이드린과 반응하여 에폭시기를 함유하는 새로운 퓨란계 단량체(8, 9)를 합성하였다. 구조는 $^1H$ and $^{13}C$ NMR으로 확인하였으며, UV 경화형 단량체로서의 기본적인 성질인 광경화 속도 및 광경화율은 Photo-DSC를 사용하여 확인하였다. 또한 선형가변 미분변환기(Linear Variable Differential Transformer transducer LVDT)와 UV Spot curing 장비를 통해 화합물의 경화 수축율을 측정하여 화합물의 분자구조가 경화수축율에 미치는 영향을 살펴보았으며, 각 합성 화합물을 폴리카보네이트 피착재 사이에 도포하고 광경화 후 lab shear test를 수행한 결과 3 MPa 이상의 전단강도를 보임으로써 재생자원 유래 신규 화합물이 접착소재로서 적용이 가능하다는 것을 확인하였다.

• 전기학회논문지
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• 제59권4호
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• pp.693-699
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• 2010

General transformer's life is known as paper insulation' life. If a transformer is degraded by these aging factors, it is known that electrical, mechanical and chemical characteristics for transformer's oil-paper are changed. When the kraft paper is aged, the cellulose polymer chains break down into shorter lengths. It causes decrease in both tensile strength and degree of polymerization of paper insulation. The paper breakdown is accompanied by an increase in the content of furanic compounds within the dielectric liquid. In this paper it is aimed at analysis on correlation between aging characteristics for insulating diagnosis of thermally aged paper. For investigating the accelerated aging process of oil-paper samples accelerating aging cell was manufactured for estimating variation of paper insulation during 500 hours at $140^{\circ}C$ temperature. To derive the results, it was performed analysis such as tensile strength(TS), depolymerization(DP), dielectric strength(DS), relative permittivity, water content(WC) and furan compound(FC) for aged paper. Also for analyzing correlation between insulating degradation characteristics, we used linear regression method. As as results of linear regression analysis, there was a close correlation between TS and DP. WC, FC. But dielectric strength was a weak correlation with aging time.