储能科学与技术 ›› 2020, Vol. 9 ›› Issue (6): 1755-1759.doi: 10.19799/j.cnki.2095-4239.2020.0204

• 储能材料与器件 • 上一篇    下一篇

新型低熔点混合熔盐储热材料的开发

罗海华1(), 沈强2, 林俊光1, 张艳梅3(), 徐云柯2   

  1. 1.浙江浙能技术研究院有限公司,浙江 杭州 311100
    2.浙江浙能嘉兴发电有限公司,浙江 嘉兴 314000
    3.上海电气集团股份有限公司中央研究院,上海 200070
  • 收稿日期:2020-06-05 修回日期:2020-07-21 出版日期:2020-11-05 发布日期:2020-10-28
  • 通讯作者: 张艳梅 E-mail:chdluo@126.com;zhangym8@shanghai-electric.com
  • 作者简介:罗海华(1983—),男,高级工程师,主要从事综合能源技术研究;E-mail:chdluo@126.com

Development of new low melting point mixed molten salt heat storage material

Haihua LUO1(), Qiang SHEN2, Junguang LIN1, Yanmei ZHANG3(), Yunke XU2   

  1. 1.Zhejiang Zheneng Technology Research Institute Co. , Ltd. , Hangzhou 311100, Zhejiang, China
    2.Zhejiang Zheneng Jiaxing Power Generation Co. , Ltd. , Jiaxing 314000, Zhejiang, China
    3.Central Research Institute of Shanghai Electric Group Co. , Ltd. , Shanghai 200070, China
  • Received:2020-06-05 Revised:2020-07-21 Online:2020-11-05 Published:2020-10-28
  • Contact: Yanmei ZHANG E-mail:chdluo@126.com;zhangym8@shanghai-electric.com

摘要:

硝酸盐作为储热介质具有使用温度高、传热性能好、比热容大等优势,开发新型多元低熔点熔盐储热材料可以解决传统二元盐存在的储能效率低和管道冻堵等问题。本文基于相图热力学计算CALPHAD方法,利用PANDAT软件开展NaNO3-NaNO2-KNO2三元体系相图热力学计算并获得该三元体系的共晶点成分配比,经测试实验结果和理论结果基本一致。在三元共晶点成分配比基础上添加LiNO3制备了NaNO3-KNO2-NaNO2-LiNO3四元熔盐,通过实验优化筛选获得四元低熔点熔盐成分配比,其组成为w(NaNO3)=21.57%,w(KNO2)=41.27%,w(NaNO2)=17.16%,w(LiNO3)=20%,经DSC和TG测试该低熔点熔盐熔点为84.2 ℃,上限使用温度为583.3 ℃,步冷曲线实验测试其固-液相变温度为78.9 ℃。研究结果表明该低熔点熔盐作为储热传热介质可广泛应用于光热发电、工业储热等领域。

关键词: 熔盐, 储热材料, 热物性

Abstract:

As a heat storage medium, nitrate molten salt has the advantage of high use temperature, good heat transfer performance, and large specific heat capacity. The development of a new low-melting point mixed molten salt heat storage material can solve the problems of low energy storage efficiency and pipeline freezing and blocking in binary solar salt. This study accurately predicts that the composition of the ternary eutectic point and the experimental results are basically consistent with the theoretical results based on the CALPHAD method and the results from PANDAT for the phase diagram of the NaNO3-NaNO2-KNO2 ternary system. We add LiNO3 on the basis of the ternary eutectic point composition ratio and prepare NaNO3-KNO2-NaNO2-LiNO3 quaternary molten salt. The quaternary low-melting point molten salt composition ratio is obtained through experimental optimization screening, resulting to 21.57% NaNO3, 41.27% KNO2, 17.16% NaNO2, and 20% LiNO3. The melting point of the low-melting molten salt is 84.2 °C, as obtained from the DSC test. The upper limit of temperature usage is 583.3 °C by the TG test. The step cooling curve test shows a solid-liquid phase transition temperature of 78.9 °C. The results show that the low-melting point molten salt can be widely used as a heat storage and heat transfer medium in CSP and industrial heat storage, among others.

Key words: molten salt, heat storage material, thermal properties

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