Enhanced melting behavior of carbon based phase change nanocomposites in horizontally oriented latent heat thermal energy storage system
Enhanced melting behavior of carbon based phase change nanocomposites in horizontally oriented latent heat thermal energy storage system
复制标题
DOI：
10.1016/j.applthermaleng.2017.07.084
复制
发表时间：
2017-10
影响因子：
6.4
通讯作者：
N. Das;M. Kohno;Y. Takata;D. Patil;S. Harish
中科院分区：
文献类型：
--
作者：
N. Das;M. Kohno;Y. Takata;D. Patil;S. Harish
本文对水平取向管壳式潜热蓄能系统中相变纳米复合材料的熔融过程进行了数值分析。有机烷烃二十烷被认为是最原始的相变材料。本工作考虑了不同的碳基同素异形体对正二十烷导热系数的影响。为了提高有机烷烃的导热系数，人们考虑了球形(纳米金刚石)、一维(单壁碳纳米管)和二维(石墨烯纳米片)结构等不同维度的高导电性碳纳米夹杂。基于有效介质公式，考虑了纳米结构与周围基质之间界面热阻的影响，从理论上模拟了这种纳米复合材料的有效导热系数。数值结果表明，界面热阻和纳米夹杂物的尺寸对纳米复合材料导热系数的提高有显著影响。在固定的纳米材料载量为1%的情况下，球形纳米颗粒夹杂物仅使熔化速度提高∼2%。单壁碳纳米管和石墨烯纳米片的体积分数为1%时，由于纳米复合材料的导热系数较纯有机烷烃有显著提高，熔融速率分别提高了27%和40%。
Present study describes the numerical analysis of the melting process of phase change nanocomposites in a horizontally oriented shell-tube latent heat thermal energy storage system. Organic alkanen-eicosane is considered as the pristine phase change material. The influence of different carbon based allotropes in enhancing the thermal conductivity ofn-eicosane is considered in this work. To enhance the thermal conductivity of organic alkane, highly conductive carbon nano inclusions of various dimensionalities such as spherical (nanodiamond), one dimensional (single-walled carbon nanotube) and two-dimensional (graphene nanoplatelets) structures were considered. Effective thermal conductivity of such nanocomposites are theoretically modeled based on effective medium formulation considering the influence of interfacial thermal boundary resistance between the nanostructure and the surrounding host matrix into account. Numerical results show that the interfacial thermal boundary resistance and dimensionality of the nano inclusion significantly affects the thermal conductivity enhancement of such nanocomposites. For a fixed nanomaterial loading of 1 vol%, spherical nanoparticle inclusions enhance the melting rate only by ∼2%. The inclusion of 1 vol% loading of single-walled carbon nanotube and graphene nanoplatelets increases the melting rate by 27% and 40% respectively due to significant thermal conductivity enhancement of the nanocomposite compared to that of pure organic alkane.