http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Wi, Seunghwan,Jeong, Su-Gwang,Chang, Seong Jin,Lee, Jongki,Kim, Sumin ELSEVIER 2017 APPLIED ENERGY -BARKING THEN OXFORD- Vol.205 No.-
<P>Latent heat storage is considered to be the most effective way to use phase change material (PCM) to charge or discharge thermal energy as latent heat during the phase change period. In this study, hybrid hollow PCM/plaster composite panels were developed to prevent leakage during the solid-liquid phase change, and improve thermal performance using exfoliated graphite nanoplatelets (xGnP) and n-octadecane, which has high thermal conductivity and latent heat. The thermo-physical properties of xGnP and n-octadecane composites were analyzed by TCi thermal conductivity analyzer and differential scanning calorimetry (DSC). The thermographic analysis was performed for the thermal behavior of each prepared specimen during the heating and cooling process. In steady-state simulation analysis using HEAT2 software, the heat flow of the each specimen were analyzed as same boundary conditions for relative comparison. The thermal performance of the PCM/plaster composite panel using dynamic heat transfer analyzer showed reduced peak temperature and a time-lag effect. Furthermore, 138.8 J/m(2) latent heat was stored in the composite PCM, corresponding to approximately 51% of the available latent heat of the plaster panel.</P>
Wi, Seunghwan,Yang, Sungwoong,Lee, Jongki,Chang, Seong Jin,Kim, Sumin Elsevier 2019 Journal of hazardous materials Vol.374 No.-
<P><B>Abstract</B></P> <P>The thermal performance of hybrid hollow plaster panels (HHPPs) was analyzed using the amount of phase change material (PCM) injection as a variable according to the size of the hollow area. This study focuses on <I>n</I>-octadecane, an organic PCM that is used for storing latent heat during the phase change range and to improve thermal transmittance using exfoliated graphite nanoplatelets (xGnPs), which have a high thermal conductivity. When xGnP is applied to <I>n</I>-octadecane, the thermal conductivity improves by 225%, and it is confirmed that the thermal storage or release of the phase change material is an active reaction. The thermo-physical properties of the xGnP and <I>n</I>-octadecane composites were analyzed using a thermal conductivity analyzer (TCi) and differential scanning calorimetry (DSC). The thermal stability of PCM was analyzed over a long duration of 10,000 thermal cycles. The thermal performance of the PCM/plaster composite panel using the dynamic heat transfer device was determined. The peak temperature through the HHPP significantly reduced by 3.8 ℃ in an internal room, and the time-lag effect was confirmed to be 1.56 h. The results indicate that up to 36.6 J/m<SUP>2</SUP> of thermal energy was stored in the 26-Px/O, corresponding to approximately 247% of the available thermal energy of the reference panel.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel HHPPs with excellent thermal energy storage capacity were developed. </LI> <LI> The thermal stability of PCM over a long period of analyzed through after 10,000 times thermal cycling. </LI> <LI> The peak temperature through the HHPPs was significantly reduced of 3.8 ℃ at internal room. </LI> <LI> Time-lag effect in the phase change transition of HHPPs occurred for up to 1.56 h. </LI> <LI> Up to 36.6 J/m<SUP>2</SUP> of thermal energy was stored in the 26-Px/O-HHPP. </LI> </UL> </P>
Wi, Seunghwan,Yang, Sungwoong,Park, Ji Hun,Chang, Seong Jin,Kim, Sumin Elsevier 2020 Building and Environment Vol.167 No.-
<P><B>Abstract</B></P> <P>One of the ways to reduce building energy is to actively release or store the thermal energy through phase change materials (PCMs) to use heat energy efficiently. PCMs have the major drawback of leaking during the solid-liquid phase transition. Therefore, PCMs must be applied to buildings through phase stabilization. Expanded vermiculite (EV) and expanded perlite (EP) are porous nanoclay materials possessing excellent properties as containers for PCMs. The applied PCM is <I>n</I>-octadecane, which belongs to the organic paraffin series, is thermally stable, and has high latent heat capacity. Shape-stabilized PCM (SSPCM) is stabilized by the vacuum impregnation method by physical bonding only, without chemical reaction. The thermal properties of the prepared SSPCM are analyzed by DSC, TGA, TCi, and enthalpy calculation. The RC-SSPCMs panel is developed using red clay (RC), an eco-friendly building material. The thermal performance of the manufactured panels is analyzed by the climate cycling test, which considers the daily temperature behavior. In the analysis of the thermal performance, the peak temperature reduced by up to 1.6 °C during the phase transition of RC/EP-SSPCMs (P10), the time-lag effect in the phase change transition of RC/EP-SSPCMs (P10) occurred for up to 1.33 h.</P> <P><B>Highlights</B></P> <P> <UL> <LI> SSPCMs were developed using expanded vermiculite and expanded perlite. </LI> <LI> The RC-SSPCM panels have excellent thermal energy storage capacity. </LI> <LI> Peak temperature reduced by up to 1.6 °C during the phase transition of PCM. </LI> <LI> Time-lag effect in the phase change transition of PCM occurred for up to 1.33 h. </LI> </UL> </P>