• Journal of the Korean Institute of Gas
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• v.12 no.1
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• pp.31-35
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• 2008

Natural gas vehicles are being applied to city buses for improving air quality in metropolitan and have proved the effective way to reduce the pollutant emissions. Liquified Natural Gas(LNG) has also attempted a vehicle fuel in order to raise the fuel storage density that is a disadvantage of Compressed Natural Gas(CNG). This paper described insulation characteristic of a LNG storage tank. From the results, adiabatic coefficient of a tested tank was around $40J/h{\cdot}^{\circ}C{\cdot}m^2$ and it was the lower level than gas safety regulation limit. Two experimental methods were adopted to justify the evaluation results and they were revealed that the results were very similar to each other. Also, through testing relief valve operation characteristic it was investigated venting amount of boiled off gas.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2274-2276
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• 1999

In this work, temperature rise and eddy current distribution on the enclosure and conductor of 3 pole gas insulated switchgear were investigated using analytical and experimental measures. The design of the diameters of the conductors and the enclosures of a meal clad gas insulated switchgear is primarily based on the insulation requirements. It is very difficult problem to predict the temperature rise of enclosed switchgear due to the complexity of the phenomena of heat transfer and existence of eddy current loss. To overcome this situations, we focused on the eddy current distribution on the enclosure of switchgear caused by high current 3 pole conductor as a fundamental basis. The experimental results about temperature distribution of 3 pole gas insulated switchgear were reported and measurements are compared with predictions of three-dimensional thermal model for eddy current analysis. As a result, three dimensional numerical analysis found to be in close relationship with experimental results and thermal model is efficient to predict the abnormal temperature rise in switchgear.

• Journal of the Korean Institute of Gas
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• v.2 no.1
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• pp.83-89
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• 1998

Experiments had been conducted Qualitatively regarding flow measurement errors of orifice flowmeter due to temperature difference between the inside and outside the natural gas meter-run in case of no pipe insulations. The primary factors considered in this study are fluid velocity and surrounding temperature. In addition, a portion of thermal radiation due to the sun was involved as a factor. The results showed that the considerable errors were not detected even in conditions of low flow rates and large temperature difference between the inside and outside the meter-run.

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.111-118
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• 2022

SF₆ is used as an insulating gas because of its excellent electrical insulation properties, non-toxicity, and non-inflammability. On the other hand, the global warming potential of SF₆ is 23,900 times higher than that of CO₂. The Korea electric power cooperation (KEPCO) is responsible for 80% of the domestic SF₆ usage, and approximately 6,000 tons are currently charged in electrical and power facilities. KEPCO will gradually replace the insulating gas with SF₆-free gas from 2023. SF₆ decomposition facilities are required because more than 60 tons of SF₆ will need to be disposed of annually from existing equipment. This study developed a novel decomposition and pollution control system that can process 60 tons of SF₆ per year. This facility can decompose more than 97.7% of SF₆, with the emissions of hazardous and toxic materials below the legal limit.

• 전기의세계
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• v.28 no.8
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• pp.3-7
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• 1979

일반적으로 고전압의 절연물로 사용되어 지고 있는 gas를 고기압으로 압축하여 사용하므로써 그 압력에 비례하여 절연내력을 증가시킬 수 있다는 사실을 알고 있다. 따라서 전력계통에서 그 사용전압이 점차 초고전압화 됨에 따라 그에 따른 절연물로써 압축가스의 이용이 증가일로에 있으며 어떤 압축가스를 사용하므로서 높은 절연내력을 얻을 수 있음은 물론이거니와 열적으로 안정하며 전도성이 좋고 또한 교류송전선로에 이용될때는 Corona가 발생하는 가능성도 적으며 유전손실도 줄일 수 있는 장점을 가지고 있다. 특히 이러한 압축가스는 고전압발생장치, 고전압변환장치 및 고전압용 개폐기등의 절연에 상당히 많이 사용되고 있으며 5기압 정도의 부성기체는 고전압변압기나 Compact Substation의 절연물로써 점차 이용이 증가되고 있다.

• 한국가스학회:학술대회논문집
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• 1997.09a
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• pp.274-283
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• 1997

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.189-189
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• 2010

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1807-1809
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• 1996

The axial discharge at switching operations of EHV $SF_6$ disconnector can lead to the breakdown to the enclosure. Precursor in periphery zone leads to formation of leader over some time delay. Injected charge value depends on electric field and gap geometry. The calculation method for parameters of $SF_6$ insulation for DS in EHV-GIS is suggested by using the new criterion of leader inception in connection with periphery field nearby the boundary of streamer zone.

• Journal of the Korean Institute of Gas
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• v.15 no.1
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• pp.9-14
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• 2011

Heavy duty diesel engine has relatively small portion of whole vehicles due to long drive distance and large engine displacement, but largely influences atmosphere environment. City buses changed to CNG (Compressed Natural Gas) bus with Korea-Japan Worldcup. Heavy duty truck and intercity bus, however, were impossible to use CNG because those kinds of vehicles had long drive distance and CNG station was installed mainly at the around of the bus garage of city. Insulation container storing the natural gas as a liquid makes heavy duty truck and intercity bus possible to use the natural gas. Drive using diesel is possible where is hard to recharge the gas. With LNG (Liquefied Natural Gas), the dependence on oil is largely decreased, PM (Particulate Matter) and NOx which is chronic disadvantage of diesel is remarkably reduced and finally $CO_2$, the representative green house gas, is reduced over 10%.

• Transactions on Electrical and Electronic Materials
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• v.16 no.6
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• pp.338-341
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• 2015

Epoxy/micro-sized alumina composite was prepared, and the effects of alumina content on the dielectric properties were investigated in order to develop an insulation material for gas-insulated switchgears (GIS). Nano-sized alumina (average particle size: 30 nm) was also incorporated into the epoxy/micro-sized alumina composite. Dielectric tests were carried out in ASTM D 150, and capacitance (Cp) and dielectric loss (tanδ) were measured. The dielectric constant increased with increasing alumina content in the epoxy/micro-alumina system and the epoxy/micro-alumina/nano-alumina system. As 1,3-diglycidyl glyceryl ether (DGE) content increased, the dielectric constant decreased and dielectric loss increased. This ocurred as a result of the weak electric field enhancement due to homogeneous dispersion of micro- and nano-sized alumina particles in an epoxy composite.