储能科学与技术 ›› 2019, Vol. 8 ›› Issue (2): 371-378.doi: 10.12028/j.issn.2095-4239.2018.0209

• 研究开发 • 上一篇    下一篇

膨胀石墨/石蜡复合相变材料的电阻率分析

徐众1,2,3, 黄平1, 吴恩辉1, 侯静1, 李军1, 刘黔蜀2,3   

  1. 1 攀枝花学院钒钛学院, 四川 攀枝花 617000;
    2 四川省太阳能利用技术集成工程实验室, 四川 攀枝花 617000;
    3 太阳能技术集成及应用推广四川省高校重点实验室, 四川 攀枝花 617000
  • 收稿日期:2018-10-10 修回日期:2018-11-27 出版日期:2019-03-01 发布日期:2018-11-28
  • 作者简介:徐众(1985-),男,硕士研究生,主要研究方向为太阳能热利用,E-mail:418968604@qq.com
  • 基金资助:
    国家级大学生创新项目(0191100349);四川省教育厅太阳能高校重点实验室项目(2018TYNSYS-Y-04)

Analysis of electrical resistivity of expanded graphite/paraffin composite phase change material

XU Zhong1,2,3, HUANG Ping1, WU En'hui1, HOU Jing1, LI Jun1, LIU Qianshu2,3   

  1. 1 College of Vanadium and Titanium, Panzhihua University;
    2 Sichuan Provincial Engineering Laboratory of Solar Technology Integration;
    3 Application and Solar Technology Integration Sichuan Provincial Key Laboratory of University, Panzhihua 617000, Sichuan, China
  • Received:2018-10-10 Revised:2018-11-27 Online:2019-03-01 Published:2018-11-28

摘要: 采用熔融共混法制备石蜡/膨胀石墨复合相变材料,使用半导体粉末电阻率测试仪对天然鳞片石墨、提纯石墨、可膨胀石墨、石蜡/膨胀石墨复合相变材料在不同压强下的电阻率进行测试。发现所有材料的电阻率都随压强的增加而减小,对导热性能最好的相变材料进行7次重复测试,材料电阻率在0.210~0.535 Ω·cm之间变化,依然小于1 Ω·cm,属于低电阻率材料。根据测试数据计算不同压强情况下相变材料单位体积蓄热量、密度、体积和电阻值。材料的单位体积蓄热量和密度随压强增大而增大,体积和电阻则相反,压强在4~10 MPa之间时物理性能比较稳定,在10 MPa左右时,相变材料电阻值比天然鳞片石墨最大增大884倍、体积1.9倍、密度0.6倍,单位体积蓄热量同比4 MPa时最大增加22.8%,压缩之后单位体积蓄热量提高。说明膨胀石墨/石蜡复合材料属于低电阻率相变材料,应用于沥青路面,能够实现升温和降温的双重效果。

关键词: 天然鳞片石墨, 可膨胀石墨, 复合相变材料, 电阻率

Abstract: Expandable graphite-paraffin composite phase change materials were prepared by a melt-blending process. The resistivity of natural flake graphite, purified graphite, expandable graphite, paraffin-expanded graphite composite phase change materials formed at different pressures was measured using a semiconductor powder resistivity tester. The results showed that the resistivity of all materials decreased with increasing pressure, seven repeated tests were performed on the material with the best thermal conductivity, and the resistivity of the material varied between 0.210-0.535 Ω·cm, which was lower than 11 Ω·cm and hence can be classified as a low-resistivity material. According to the measurement data, the amount of heat storage per unit volume, density, volume and resistance of the composite phase change materials were calculated. The amount of heat storage per unit volume and density of the material increased with increasing pressure, however, the resistivity and volume showed the opposite as expected. The physical properties of materials were found to be stable when the formation pressure was between 4 and 10 MPa; at about 10 MPa, the resistivity of the phase change material was 884 times larger than that of natural scale graphite, 1.9 times the volume and 0.6 times the density. The amount of heat storage per unit volume was 22.8% higher than that at 4 MPa. It was shown that the expanded graphite/paraffin composite was a low resistivity phase transition material, which can be applied on asphalt pavement, achieving both heating up and cooling down effects.

Key words: natural flake graphite, expandable graphite, composite phase change material, resistivity

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