膨胀石墨/石蜡复合相变材料的导电及发热特性  

Characters of electric resistance and heating of expanded graphite/paraffin composite phase change materials

作　　者：周涛涛 熊志波[1] 吴志根[2,3] 李尚 ZHOU Taotao;XIONG Zhibo;WU Zhigen;LI Shang(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;College of Environmental Science and Engineering,Tongji University,Shanghai 200092,China;Shanghai Institute of Pollution Control and Ecological Security,Shanghai 200092,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]同济大学环境与科学工程学院,上海200092 [3]上海污染控制与生态安全研究院,上海200092

出　　处：《化工进展》2022年第2期892-900,共9页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51106112);上海杨帆计划(18YF1418000);国家重点研发计划(2019YFC1805204);上海理工大学科技发展项目(2019KJFZ196)。

摘　　要：采用混合搅拌方法制备膨胀石墨(EG)/石蜡复合相变材料,测试分析了EG含量、施加电压与EG/石蜡复合相变材料体积电阻率的关系,研究了直接自发热和正温度系数(PTC)电阻发热时复合相变蓄热单元的发热特性。结果表明,随着EG含量或施加电压的增大,复合相变材料体积电阻率逐渐减小;施加电压对样品体积电阻率的影响与复合相变材料中EG含量有关,EG含量越高,施加电压对复合相变材料体积电阻率的影响越明显。当施加电压为4.0V时,EG质量分数分别为4%、5%、8%的复合相变材料体积电阻率分别只有0.5V时的0.481倍、0.185倍、0.068倍。基于复合相变材料导电特性,直接负载电压可实现复合相变材料电热转化和相变蓄热;结合PTC电阻发热可灵活控制复合相变蓄热单元加热功率,实现其快速充热。Expanded graphite/paraffin composite phase change materials were prepared by blending method using expanded graphite and paraffin.The effects of EG content and voltage on the volume resistivity of EG/paraffin composites were investigated.The electrothermal properties of EG/paraffin composites unit were also studied under direct heating and positive temperature coefficient(PTC)resistance heating.The results showed that volume resistivity of composite decreased with the increase of EG content and voltage.The effect of voltage on the volume resistivity of composite was related to EG content and the higher EG content was,the more obvious the effect was.The volume resistivity of 4%,5%and 8%EG/paraffin composites at 4.0V voltage was 0.481 times,0.185 times and 0.068 times of that at 0.5V voltage,respectively.Both direct load voltage and PTC resistance heating can realize electrothermal conversion and heat storage.The heating power of the composite unit can be controlled flexibly by combining PTC resistance heating,which can realize rapid heat charging.

关 键 词：复合相变材料 相变蓄热 膨胀石墨 电阻率 自发热 

分 类 号：TK02[动力工程及工程热物理]