华南理工大学学报(自然科学版) ›› 2025, Vol. 53 ›› Issue (3): 116-126.doi: 10.12141/j.issn.1000-565X.240256

• 材料科学与技术 • 上一篇    下一篇

硝酸盐基中低温储热相变材料的制备及热物性调控

安周建(), 李璐, 毛帅, 刘立功, 杜小泽, 张东   

  1. 兰州理工大学 能源与动力工程学院,甘肃 兰州 730050
  • 收稿日期:2024-05-27 出版日期:2025-03-10 发布日期:2024-08-23
  • 作者简介:安周建(1990—),男,博士,副教授,主要从事储能材料及储能技术研究。E-mail: anzhoujian@lut.edu.cn
  • 基金资助:
    国家自然科学基金项目(52206087);甘肃省重点研发计划项目(23YFGA0066);甘肃省教育厅产业支撑计划项目(2022CYZC-21);兰州理工大学博士科研启动经费项目(061907);兰州理工大学红柳优秀青年人才资助项目

Preparation and Thermal Property Regulation of Nitrates Based Phase Change Material for Low and Medium Temperature Thermal Energy Storage

AN Zhoujian(), LI Lu, MAO Shuai, LIU Ligong, DU Xiaoze, ZHANG Dong   

  1. School of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,Gansu,China
  • Received:2024-05-27 Online:2025-03-10 Published:2024-08-23
  • Supported by:
    the National Natural Science Foundation of China(52206087);the Key R & D Program of Gansu Province(23YFGA0066);the Industrial Support Plan Project of Gansu Provincial Education;Department(2022CYZC-21)

摘要:

利用相变材料储热的方法对工业领域中低温余热进行回收、储存以及再利用,是实现能源梯次利用,提高能源利用效率的重要方法。相变材料的物性是决定储热系统性能的关键因素。因此,开发具有适宜相变温度、高低温循环稳定性较好的相变材料,对于实现高效余热回收具有重要的意义。基于此,该文采用静态熔融法,合成了一种新的相变材料NaNO3-KNO3-NaNO2-LiNO3,通过差热分析、热重分析、X射线衍射分析、傅里叶变换红外光谱分析等方法,对该材料的熔点、潜热、比热容和循环稳定性等热物理性能进行了一系列表征,筛选出配比m(NaNO3)∶m(KNO3)∶m(NaNO2)∶m(LiNO3) = 6.32∶47.83∶36.10∶9.75的熔盐作为最终的优选盐。实验结果表明:优选盐具有显著的性能优势,其熔点低至79.02 ℃,潜热为176.71 J/g,固相和液相的平均比热容分别为1.96和2.09 J/(g·℃),分解温度达到600 ℃以上,展现出宽温度范围的适用性;经过100次高低温循环测试后,优选盐仍表现出良好的热循环稳定性。该研究为中低温余热回收及储热系统提供了一种新型的相变储能材料,对相关领域的能源优化和节能减排具有重要的意义。

关键词: 储热, 混合硝酸盐, 热物理性能, 热稳定性, 相变

Abstract:

The recovery, storage and reuse of low-temperature waste heat in industry by using phase change materials for heat storage is an important method to achieve the gradual utilisation of energy and improve the efficiency of energy utilisation. The physical properties of phase change materials are the key factors determining the performance of heat storage systems.Therefore, the development of phase change materials with an appropriate phase transition temperature and good thermal cycling stability is of great significance for achieving efficient waste heat recovery. Based on this, a new phase change material, NaNO3-KNO3-NaNO2-LiNO3, was synthesized using the static melting method. A series of characterizations were conducted to evaluate its thermal properties, including melting point, latent heat, specific heat capacity, and cyclic stability, using differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy. The optimal composition was identified as m(NaNO3)∶m(KNO3)∶m(NaNO2)∶m(LiNO3)=6.32∶47.83∶36.10∶9.75 which was selected as the final preferred salt. The experimental results demonstrate that the preferred salt has significant performance advantages, with a low melting point of 79.02 ℃ and a latent heat of phase transition of 176.71 J/g; the average specific heat capacities of the solid and liquid phases are 1.96 and 2.09 J/(g·℃), respectively; the decomposition temperature reaches more than 600 ℃, which demonstrates its wide applicability in terms of temperature; after 100 high and low temperature cycling tests, the preferred salt still exhibited good thermal cycling stability. This study provides a new type of phase change energy storage material for low and medium temperature waste heat recovery and heat storage system, which is of great significance for energy optimisation and energy saving and emission reduction in related fields.

Key words: heat storage, mixed nitrate, thermophysical properties, thermal stability, phase change

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