The investigation of thermal conductivity and energy storage properties of graphite/paraffin composites
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Phase change materials (PCM) have been extensively scrutinized for their widely application in thermal energy storage (TES). Paraffin was considered to be one of the most prospective PCMs with perfect properties. However, lower thermal conductivity hinders the further application. In this letter, we experimentally investigate the thermal conductivity and energy storage of composites consisting of paraffin and micron-size graphite flakes (MSGFs). The results strongly suggested that the thermal conductivity enhances enormously with increasing the mass fraction of the MSGFs. The formation of heat flow network is the key factor for high thermal conductivity in this case. Meanwhile, compared to that of the thermal conductivity, the latent heat capacity, the melting temperature, and the freezing temperature of the composites present negligible change with increasing the concentration of the MSGFs. The paraffin-based composites have great potential for energy storage application with optimal fraction of the MSGFs.
KeywordsThermal conductivity Paraffin MSGFs Heat network Latent heat capacity
This study is supported by the National Natural Science Foundation of China (Grant No. 20346001), Science and technology of Guangzhou (Grant No. 2008Z1-1061), and Program for New Century Excellent Talents in University (Grant No. NCET-04-0826).
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