华电技术 ›› 2020, Vol. 42 ›› Issue (4): 12-16.

• 储能材料 • 上一篇    下一篇

超声-微波法制备熔盐纳米复合材料试验研究

  

  1. 北京工业大学 传热强化与过程节能教育部重点实验室,传热与能源利用北京市重点实验室,北京 100124
  • 出版日期:2020-04-25 发布日期:2020-05-15

Experimental study on preparation of a molten salt nanocomposite by ultrasonic dispersion and microwave method

  1. MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation,Beijing Key Laboratory of Heat Transfer and Energy Conversion,Beijing University of Technology,Beijing 100124,China
  • Online:2020-04-25 Published:2020-05-15

摘要: 为提高熔盐的比热容,将平均粒径为20 nm的SiO2纳米粒子以1%质量分数添加到自主研发的四元混合硝 酸盐中,采用超声−微波法,得到低熔点熔盐纳米复合材料。采用同步热分析仪测量熔盐纳米复合材料的比热容。 试验结果表明,微波干燥法可使熔盐纳米复合材料的比热容提高约 38.8%,而常规干燥方法仅能使其比热容提高 19.4%。采用扫描电子显微镜(SEM)观察熔盐纳米复合材料的微观结构,发现固体熔盐表面形成了类似链状的特 殊纳米结构。这种具有高比表面积和高表面能的特殊结构是比热容提升的关键。此外,采用微波干燥法还可以提 高熔盐纳米复合材料的制备效率。

关键词: 蓄热材料, 熔融盐, 纳米粒子, 微波干燥, 纳米结构, 比热容

Abstract: In order to increase the specific heat capacity of molten salt,a low-melting-point molten salt nanocomposite was obtained through ultrasonic dispersion and microwave method,by doping SiO2 nanoparticles with an average size of 20 nm into the independently developed quaternary mixed nitrates . The mass concentration of SiO2 was 1%. The specific heat capacity of molten salt nanocomposite was measured with a differential scanning calorimeter(DSC). The experimental results showed that the specific heat capacity of nanocomposite could be enhanced by about 38.8%,which was much higher than that of nanocomposite prepared by traditional drying method which can be increased by only 19.4%. The microstructure characterization of the molten salt nanocomposite was analyzed by a scanning electron microscope(SEM), which showed that the special nanostructure(resembling chain-like nanostructure)formed on the surface of the solid salt who was dried by microwave. The special nanostructure with large specific surface area and high surface energy can enhance the specific heat capacity. Furthermore,the microwave drying can improve the preparation efficiency of the molten salt nanocomposite.

Key words:  , heat storage material;molten salt;nanoparticles;microwave drying;nanostructure;specific heat capacity