纳米粒子对熔盐复合蓄热材料热物性的影响  

Effect of nanoparticles on thermal properties of molten salt composite heat storage materials

作　　者：于强 鹿院卫[1] 张晓盼 吴玉庭[1] YU Qiang;LU Yuanwei;ZHANG Xiaopan;WU Yuting(College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China)

机构地区：[1]北京工业大学环境与能源工程学院

出　　处：《化工学报》2019年第A01期217-225,共9页CIESC Journal

基　　金：国家自然科学基金项目(51576006);国家重点研发计划项目(2016YFE0124900);北京市自然科学基金重点项目(3151001);青海省科技计划项目(2017-GX-A3)

摘　　要：为了得到SiO2纳米粒子含量对SiO2/NaNO3-KNO3/EG复合蓄热材料比热容和热导率的影响,通过机械分散法,采用NaNO3-KNO3和不同质量分数(0.1%,0.5%,1%,2%,3%)的SiO2纳米粒子所形成的熔盐纳米材料作为蓄热材料,膨胀石墨(EG)作为基体材料,制备出纳米SiO2/NaNO3-KNO3/EG复合材料。对复合材料的比热容和热导率进行了测量,同时用扫描电镜对其微观结构特征进行了分析。结果表明,SiO2纳米粒子的质量分数为1%时,复合材料的平均比热容和热导率分别为3.92J/(g·K)和8.47W/(m·K),与其他纳米SiO2添加比例相比,其比热容和热导率分别提高了1.37~2.17倍和1.7~3.2倍。这是由于复合材料表面会形成高密度的网状结构,这种具有较大比表面积和高表面能的特殊纳米结构可以提高复合材料的比热容和热导率。In order to study the effects of SiO 2 nanoparticles content on the specific heat capacity and thermal conductivity of nano-SiO 2 /NaNO 3-KNO 3 /EG composite heat storage materials, a series of nano-SiO 2 /NaNO 3-KNO 3 / EG composites were prepared by mechanical dispersion method. NaNO 3-KNO 3 and SiO 2 nanoparticles with different mass fractions (0.1%, 0.5%, 1%, 2%, 3%) were used as heat storage materials and expanded graphite (EG) was used as matrix material. Then the specific heat and the thermal diffusivity of composite heat storage materials were measured, and the microstructural characteristics were analyzed by scanning electron microscopy (SEM). The results show that adding 1% of SiO 2 nanoparticles to the composite can significantly affect its average specific heat capacity and thermal conductivity, with a measured value of 3.92 J/(g·K) and 8.47 W/(m·K), respectively, which are 1.37-2.17 times and 1.7-3.2 times higher than that of the other similar composites. This is owed to its high density network nanostructure with the large specific surface area and high surface energy which can improve the specific heat capacity and thermal conductivity.

关 键 词：二元硝酸盐 二氧化硅 纳米粒子 复合材料 比热容 热导率 

分 类 号：TK512[动力工程及工程热物理—热能工程]