化工学报 ›› 2023, Vol. 74 ›› Issue (8): 3513-3521.DOI: 10.11949/0438-1157.20230595

• 能源和环境工程 • 上一篇    下一篇

逆电渗析热机新型工质开发及电化学特性研究

胡亚丽(), 胡军勇(), 马素霞, 孙禹坤, 谭学诣, 黄佳欣, 杨奉源   

  1. 太原理工大学电气与动力工程学院,太原 山西 030024
  • 收稿日期:2023-06-19 修回日期:2023-08-21 出版日期:2023-08-25 发布日期:2023-10-18
  • 通讯作者: 胡军勇
  • 作者简介:胡亚丽(1998—),女,硕士研究生,m15735267587@163.com
  • 基金资助:
    山西省基础研究项目(202103021223095);中国博士后科学基金项目(2021M702418)

Development of novel working fluid and study on electrochemical characteristics of reverse electrodialysis heat engine

Yali HU(), Junyong HU(), Suxia MA, Yukun SUN, Xueyi TAN, Jiaxin HUANG, Fengyuan YANG   

  1. College of Electrical and Power Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China
  • Received:2023-06-19 Revised:2023-08-21 Online:2023-08-25 Published:2023-10-18
  • Contact: Junyong HU

摘要:

逆电渗析(reverse electrodialysis,RED)热机能够将低品位热能有效地转换为电能。作为热机的核心部件,RED电堆的性能直接影响热机的整体能量转换性能。为提升RED热机能量转换效率,通过开发一种由氯化锂、氯化铵与水混合形成的三元工质用于RED电堆,并与常规氯化钠水溶液对比探讨了进、出口溶液电导率和电化学性能。首先,测试了不同比例氯化锂与氯化铵混合水溶液作为RED电堆工质的电导率,并根据相关性能指标筛选出两种盐的最佳质量摩尔浓度比例为2∶8。然后,将此最佳比例下的溶液应用于RED。通过实验与NaCl水溶液对比研究了改变浓、稀溶液浓度对电堆进、出口溶液电导率和电堆内阻的影响。结果表明,适当增加进料浓、稀溶液浓度有利于降低RED电堆内阻,从而改善电堆性能。

关键词: 逆电渗析, 电化学, 盐差能, 膜, 离子交换, 电导率

Abstract:

Reverse electrodialysis (RED) heat engine can convert low grade heat into electricity. As the core component of the heat engine, the performance of the RED stack directly affects the overall performance. In order to enhance the energy conversion efficiency of the heat engine, this paper develops a ternary working fluid composed of lithium chloride, ammonium chloride, and water suitable for RED heat engine, and compares the electrical conductivity and electrochemical properties of the inlet and outlet solutions of the RED stack with conventional sodium chloride aqueous solution. Firstly, the electrical conductivity of lithium chloride and ammonium chloride with different ratios as the working fluid of the RED stack was tested, and the optimal ratio of the two salts was screened out by comprehensive evaluation based on the electrochemical performance indicators of the stack, such as internal resistance and maximum power density. The optimal molality ratio was found to be 2∶8. The lithium chloride and ammonium chloride salt solution with this optimal ratio were then applied to the RED stack. The influence of different concentrations of concentrated and dilute solutions on the electrical conductivity of the inlet and outlet solutions of the RED stack and the internal resistance of the stack were studied by experimental comparison with conventional NaCl aqueous solution. The results show that appropriately increasing the concentration of concentrated and dilute feed solutions is beneficial to reducing the internal resistance of the RED stack, thereby improving the stack performance.

Key words: reverse electrodialysis, electrochemistry, salinity gradient energy, membranes, ion exchange, electrical conductivity

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