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Journal of Thermal Science

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2024 , Vol. 33 >Issue 3: 1026 - 1036

DOI: https://doi.org/10.1007/s11630-024-1946-8

Numerical Analysis on Charging Performance of the Macro-Encapsulating Combined Sensible-Latent Heat Storage System with Structural Parameters

  • WANG Wei ,
  • PAN Zhenfei ,
  • WANG Jingfu ,
  • WU Yuting ,
  • MA Chongfang
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  • 1. Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, College of Energy and Power Engineering, Beijing University of Technology, Beijing 100124, China
    2. Key Laboratory of Heat Transfer and Energy Conversion, Beijing Municipality, College of Energy and Power Engineering, Beijing University of Technology, Beijing 100124, China

网络出版日期: 2024-04-30

基金资助

This work was supported by National Key R&D Program of China (Grant numbers 2022YFB2405202).

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This work was supported by National Key R&D Program of China (Grant numbers 2022YFB2405202).
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Numerical Analysis on Charging Performance of the Macro-Encapsulating Combined Sensible-Latent Heat Storage System with Structural Parameters

  • WANG Wei ,
  • PAN Zhenfei ,
  • WANG Jingfu ,
  • WU Yuting ,
  • MA Chongfang
Expand
  • 1. Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, College of Energy and Power Engineering, Beijing University of Technology, Beijing 100124, China
    2. Key Laboratory of Heat Transfer and Energy Conversion, Beijing Municipality, College of Energy and Power Engineering, Beijing University of Technology, Beijing 100124, China

Online published: 2024-04-30

Supported by

This work was supported by National Key R&D Program of China (Grant numbers 2022YFB2405202).

Copyright

This work was supported by National Key R&D Program of China (Grant numbers 2022YFB2405202).
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摘要

采用宏观封装方法的显热-潜热复合蓄热结构（CSLHS）能够有效地解决其内部相变材料（PCMs）的泄漏问题。然而，由于PCMs的导热性能较差，与固体结构相比，复合蓄热结构蓄热性能的提高十分有限。但其PCMs区域内的自然对流能够改善其蓄热性能。因此，如何提高宏观封装的复合蓄热结构内的自然对流强度成为关键问题。在本文中，我们提出了一种宏观封装的复合蓄热结构，并通过计算流体动力学（CFD）模拟分析了结构参数对其蓄热性能的影响。在该蓄热结构中，显热蓄热材料为高温混凝土，PCM为低熔点的混合熔盐。我们分别分析了翅片数量、翅片长度和翅片厚度对复合蓄热结构蓄热性能的影响。结果表明，蓄热性能随着翅片数量的增加而提高，但增长速率逐渐减缓。当翅片数量为6时，蓄热性能相较于无翅片的复合蓄热结构提升了20.18%。蓄热性能随着翅片长度的增加逐渐提高。与无翅片的复合蓄热结构相比，翅片长度每增加10毫米，其蓄热性能分别提升了4.09%、5.26%、7.02%、8.77%、11.70%和15.79%。与翅片数量和翅片长度不同，翅片厚度对蓄热性能的影响非常小。当翅片厚度从1毫米增加到4毫米时，蓄热性能仅提升了2.3%。这表明，改善蓄热性能的主要原因是翅片划分了PCM区域，从而提高了相变区域内的自然对流强度。这些结果表明，宏观封装的显热-潜热复合蓄热结构的蓄热性能可以通过优化结构参数得到改善。

关键词： macro-encapsulation; hybrid configuration; natural convection; structural parameter; charging performance

本文引用格式

WANG Wei , PAN Zhenfei , WANG Jingfu , WU Yuting , MA Chongfang . Numerical Analysis on Charging Performance of the Macro-Encapsulating Combined Sensible-Latent Heat Storage System with Structural Parameters[J]. 热科学学报, 2024 , 33(3) : 1026 -1036 . DOI: 10.1007/s11630-024-1946-8

Abstract

For combined sensible-latent heat storage system (CSLHS) (termed as the hybrid configuration), macro encapsulation can effectively solve the leakage problem of PCMs. However, due to the poor thermal conductivity of PCMs, the charging performance of the hybrid configuration slightly increases compared to the solid structure (with only sensible materials). Meanwhile, the natural convection in the PCMs zone could improve the charging performance. So, how to improve natural convection intensity is a key issue for the CSLHS by macro encapsulating. It is found that adding fins can significantly enhance natural convection and accelerate the melting of PCM. In this paper, we proposed the hybrid configuration with fins built-in by macro encapsulation, and analyzed its charging performance with different fin structural parameters in the PCM zone by CFD simulation. In the case, the sensible heat storage material is high-temperature concrete and the PCM is a low-melting-point mixed molten salt. We analyzed the effects of fin number, fin length and fin thickness on the charging performance of the hybrid configuration respectively. From the result, the charging performance increases with the fin number, but the increase rate gradually decreases. When the fin number is 6, the charging performance increases by 20.18% compared to the situation without fin. The charging performance increases gradually with the fin length. Compared with the hybrid configuration without fin, for each 10 mm increase in fin length, its charging performances increase by 4.09%, 5.26%, 7.02%, 8.77%, 11.70%, and 15.79%, respectively. Different from number and length of fins, the effect of thickness on the charging performance is very small. When the fin thickness increased from 1 mm to 4 mm, the charging performance only increased by 2.3%. It indicates that the main reason for the improving the charging performance is to increase the natural convection intensity by dividing the PCM zone through fins. These results show that the charging performance of the CSLHS with macro encapsulation can be improved by optimizing fin structural parameters.

Key words： macro-encapsulation; hybrid configuration; natural convection; structural parameter; charging performance

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