• Title/Summary/Keyword: 자연에너지

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Characteristics of Coal Devolatilization and Spontaneous Combustion at Low Temperatures (저온영역에서 석탄의 탈휘발 및 자연발화 특성 연구)

  • Sung Min Yoon;Seok Hyeong Lee;Tae Hwi An;Myung Won Seo;Sang Won Lee;Dae Sung Kim;Tae-Young Mun;Sung Jin Park;Sang Jun Yoon;Ji Hong Moon;Jae Goo Lee;Jong Hoon Joo;Ho Won Ra
    • Clean Technology
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    • v.29 no.4
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    • pp.288-296
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    • 2023
  • Coal is abundantly available compared to other energy sources and is used as a versatile energy resource worldwide. To address the environmental issues stemming from conventional coal utilization, efforts are underway to develop clean coal utilization technologies, with IGCC technology being a notable example. In IGCC plants, coal is subjected to a CMD process where both drying and pulverization are achieved by supplying hot air. However, if the temperature of the supplied hot air is excessively high, it can lead to devolatilization and spontaneous combustion, thereby compromising the stable operation of the CMD process. This study aimed to measure the devolatilization and spontaneous combustion temperatures of different types of bituminous coal, and to explore their correlations with the characteristics of the coals. Six coal types exhibited devolatilization between 350 and 400 ℃, while three coal types showed devolatilization at temperatures exceeding 400 ℃. Spontaneous combustion ℃curred in one coal type below 100 ℃, six coal types between 100 and 150 ℃, and two coal types above 150 ℃. The measured initiation temperatures were compared with the coal characteristics including the oxygen, moisture, Fe2O3, and CaO content, the H/C ratio, and the O/C ratio to establish correlations. Regression analysis was used to calculate the regression coefficients and determination coefficients for each ignition temperature. It was found that 52.44% of the FC/VM data significantly influenced the volatile matter ignition temperature, and 59.10% of the Fe2O3 data significantly affected the spontaneous combustionignition temperature.

Trend of the Unconventional Energy Resources (비재래 에너지자원 동향)

  • Cho, Jin Dong;Kim, Jong Hyun;Park, Kwan Soon
    • Economic and Environmental Geology
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    • v.47 no.3
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    • pp.265-273
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    • 2014
  • Unconventional resources are natural resources which require greater than industry-standard levels of technology or investment to exploit the commercial development. The key point is that unconventional resources are lower quality fuel sources and are not as economically viable as crude oil and conventional gas. Over the past 100 years, Conventional oil and gas has been satisfied with the energy demands. But developing countries such as China and India, the introduction of the developed countries and the surge of energy due to the depletion of unconventional energy resources will be the limelight. According to be analyzed in the academic literature to unconventional gas and oil(2000~2012) by the program of 'web of science', the research activities 402 papers in unconventional gas and 1,581 papers in unconventional oil.

A Study on Lighting Energy Prediction by Using Daylight during Daytime (자연채광 이용에 따른 조명에너지 예측방법에 관한 연구)

  • Chung, Yu-Gun;Kim, Jeong-Tai
    • Solar Energy
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    • v.11 no.2
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    • pp.9-19
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    • 1991
  • Lighting is one of the largest energy consumption in commercial building. For saving such lighting energy, integrated lighting system with daylight and artificial lighting has been suggested. In such system, perimeter zone can be illuminated by daylighting and the deep area of room by artificial lighting. So, the study aimed to develope of lighting energy prediction nomograph by turnning-off depth and lighting control systems during daytime. For the purpose, energy nomo-graph has been developed to apply to side-lit office building and the use and limitation of the nomograph has been discussed.

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Application of Sun Control Devices and Energy Conservation (Theory and Practice) (주광제어 장치를 이용한 건물의 에너지 절약(이론 및 실제))

  • Han, Hyun-Joo;Cho, Yil-Sik;Song, In-Choon
    • Solar Energy
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    • v.10 no.2
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    • pp.77-85
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    • 1990
  • In the present analysis, a number of sun control devices are examined for their performance in promoting the interior visual environment. Two exemplary cases are introduced for their excellence in harnessing the concept of daylighting and passive concepts. Of these, the Johnson Controls branch office building in Salt Lake City manifests the effectiveness of light shelves and clerestory windows in implementing these concepts. Distinct optical characteristics are found for overhangs, light shelves, louvers, and blinds as they interfere with the path of sunlight. Substantial amount of energy could be saved if the fundamentals of these devices are truly understood in their application to residential and commercial buildings. Sustained efforts should be made in this regard by the builders, architects, energy consultants, and educators who make contributions in energy management.

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