• Title/Summary/Keyword: laten heat

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Charateristics on the PCM absorbed porous media as thermal storage applicable for construction material (건자재활용을 위한 축열용 다공성 미립자 상변환 물질 흡착 특성)

  • Lee, Hyo-Jin
    • KIEAE Journal
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    • v.17 no.3
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    • pp.107-112
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    • 2017
  • Purpose: Both silica gel and activated carbon black particles were adopted for use as PCM absorbed porous media applicable as construction materials. To investigate usable methods for absorbing PCM into the media, they were soaked into PCM and also tested for enhancement of PCM absorption into them. Method: To test PCM absorption into some porous media such as both ${\varphi}1{\sim}2mm$ and $10{\mu}m$ silica gels, and $50{\mu}m$ activated carbon black, $43^{\circ}C$ PCM was used as a laten heat material. The method, soaking into PCM was applied to this study, and the media were moderately rotated by centrifuge to have the extra PCM flow out. DSC analysis was conducted to investigate the melting and solidifying of the PCM absorbed into the porous media. Result: It was found that PCM was absorbed into the porous media by over 85 wt% of all particles. In addition, it was noted that the ultrasonic vibrator was accelerating the PCM absorption into the particles to three times higher speed than simple soaking. Centrifuge was adopted to remove extra PCM sticking on the particle surfaces and extra PCM was moderately removed from the surfaces of the particles. DSC analysis indicated that the latent heat of the absorbed PCM particles was 160 J/g, and the melting temperature was approximately $40^{\circ}C{\sim}50^{\circ}C$.

Preparation and Thermal Characteristics of Hexadecane/xGnP Shape-stabilized Phase Change Material for Thermal Storage Building Materials (축열건축자재 적용을 위한 Hexadecane/xGnP SSPCM 제조 및 열적특성)

  • Kim, Sug-Hwan;Jeong, Su-Gwang;Lim, Jae-Han;Kim, Su-Min
    • Journal of the Korean Solar Energy Society
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    • v.33 no.1
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    • pp.73-78
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    • 2013
  • Hexadecane and exfoliated graphite nanoplate (xGnP)composite was prepared as a shape-stabilized phase change material (SSPCM) in a vacuum to develope thermal energy storage. The Hexadecane as an organic phase change material (PCM) is very stable against phase separation of PCM and has a melting point at $18^{\circ}C$ that is under the thermally comfortable temperature range in buildings. The xGnP is a porous carbon nanotube material with high thermal conductivity. Scanning electron microscope (SEM) and Fourier transformation infrared spectrophotometer (FT-IR)were used to confirm the chemical and physical stability of Hexadecane/xGnP SSPCM. In addition, thermal properties were determined by Deferential scanning calorimeter(DSC) and Thermogravimetric analysis (TGA). The specific heat of Hexadecane/xGnPSSPCM was $10.0J/g{\cdot}K$ at $21.8^{\circ}C$. The melting temperature range of melting and freezing were found to be $16-25^{\circ}C$ and $17-12^{\circ}C$. At this time, the laten heats of melting and freezing were 96.4J/g and 94.8J/g. The Hexadecane was impregnated into xGnP as much about 48.8% of Hexadecane/xGnP SSPCM's mass fraction.

Analysis of Vertical Structure of Atmosphere on the Middle Part of the Yellow Sea (서해 중부 해상 대기의 연직구조 분석)

  • Yun, Yong Hun;Im, Ju Yeon;Kim, Baek Jo;Kim, Tae Hui;Seo, Jang Won;Jo, Ha Man
    • Journal of the Korean earth science society
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    • v.21 no.1
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    • pp.22-22
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    • 2000
  • To search out the characteristics of the lower and the upper atmospheric vertical structure, we selected the island(Oeyoundori Ochun-myen Poryeng city Chung-Nam) as an observation site, which is thought to represent the characteristics of ocean well, and observed the vertical structure of the atmosphere by Radiosonde. By using the results of the observation, we analyzed the changes of relative humidity(RH), temperature and wind when the cyclone and the anticyclone passed and compared the results in case of each event. To compare the vertical structure of the ocean atmosphere with those of the continent, we analyzed the values observed with using Radiosonde at Osan site.Through this study, we found that relative humidity changed as the cyclone and the anticyclone passed. That is, when the cyclone came, RH increased first in the upper atmosphere than in the lower and when the high came, RH in the upper decreased sharply to 10%. And the variations of relative humidity in ocean are bigger than those in continent. In the future, we plan to find out the relation between the vapor water in ocean and continent seasonally and daily through the observation in ocean and continent at same time.

Analysis of Vertical Structure of Atmosphere on the Middle Part of the Yellow Sea (서해 중부 해상 대기의 연직구조 분척)

  • Youn, Yong-Hoon;Lim, Joo-Yun;Kim, Baek-Jo;Kim, Tae-Hee;Seo, Jang-Won;Cho, Ha-Man
    • Journal of the Korean earth science society
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    • v.21 no.1
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    • pp.23-39
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    • 2000
  • To search out the characteristics of the lower and the upper atmospheric vertical structure, we selected the island(Oeyoundori Ochun-myen Poryeng city Chung-Nam) as an observation site, which is thought to represent the characteristics of ocean well, and observed the vertical structure of the atmosphere by Radiosonde. By using the results of the observation, we analyzed the changes of relative humidity(RH), temperature and wind when the cyclone and the anticyclone passed and compared the results in case of each event. To compare the vertical structure of the ocean atmosphere with those of the continent we analyzed the values observed with using Radiosonde at Osan site. Through this study, we found that relative humidity changed as the cyclone and the anticyclone passed. That is, when the cyclone came, RH increased first in the upper atmosphere than in the lower and when the high came, RH in the upper decreased sharply to 10%. And the variations of relative humidity in ocean are bigger than those in continent. In the future, we plan to f d out the relation between the vapor water in ocean and continent seasonally and daily through the observation in ocean and continent at same time.

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