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Investigation and optimization on melting performance of a triplex-tube heat storage tank by rotational mechanism

Huang, Xinyu ; Li, Fangfei ; Li, Yuanji ; Gao, Xinyu ; Yang, Xiaohu and Sundén, Bengt LU (2023) In International Journal of Heat and Mass Transfer 205.
Abstract

Phase change heat storage is the backbone of energy storage technology, but its storage time is affected by the low thermal conductivity of phase change materials. Therefore, the melting performance of a triplex-tube latent heat thermal energy storage unit (T-LHTESU) in a phase change heat storage system is studied in this paper, and the rotation mechanism is applied to the unit. Firstly, a numerical model of the T-LHTESU considering the rotation mechanism is constructed, and the validity of the rotation unit is verified by comparison with experimental data. In this unit, N-eicosane is used as a phase change material for heat exchange. The effects of different rotational speeds on the liquid phase distribution, temperature distribution,... (More)

Phase change heat storage is the backbone of energy storage technology, but its storage time is affected by the low thermal conductivity of phase change materials. Therefore, the melting performance of a triplex-tube latent heat thermal energy storage unit (T-LHTESU) in a phase change heat storage system is studied in this paper, and the rotation mechanism is applied to the unit. Firstly, a numerical model of the T-LHTESU considering the rotation mechanism is constructed, and the validity of the rotation unit is verified by comparison with experimental data. In this unit, N-eicosane is used as a phase change material for heat exchange. The effects of different rotational speeds on the liquid phase distribution, temperature distribution, flow velocity distribution, total energy storage, and energy storage efficiency of the T-LHTESU are studied. The results show that the melting time of this unit at 0.1 and 1 rpm is 46.98 and 69.35% lower than that of the stationary model, respectively. The total amount of stored heat is decreased by 0.67 and 2.17%, and the heat storage efficiency is increased by 87.34% and 219.19%, respectively. This indicates that the addition of the rotation mechanism greatly increases the heat storage efficiency of the T-LHTESU and reduces its total melting time, while the reduction of the total energy stored in the melting cycle is small. Then it is proved that rotation improves the single heat transfer mechanism of the stationary model and eliminates the thermal deposition caused by natural convection by studying the internal temperature/velocity response of the stationary model and the speed of 0.1 rpm. The related geometric structure of the model is optimized by response surface optimization design based on 0.1 rpm rotation speed. The influence of each variable on the target response is obtained, and compared with the original model, the melting time of the optimized model is reduced by 12.24%. Finally, based on the geometric optimization design, the influence of element physical factors (temperature and material of fin/tube wall) on the related melting properties is studied. This study is helpful to promote the effective use of rotation mechanism in phase change heat storage systems and has a certain guiding role in the structural design.

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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Heat absorption rate, Phase change material, Response surface method, Rotational mechanism, Thermal energy storage
in
International Journal of Heat and Mass Transfer
volume
205
article number
123892
publisher
Pergamon Press Ltd.
external identifiers
  • scopus:85146701527
ISSN
0017-9310
DOI
10.1016/j.ijheatmasstransfer.2023.123892
language
English
LU publication?
yes
id
a7abec45-4f75-4158-b39e-29fa12ae1634
date added to LUP
2023-02-10 14:04:37
date last changed
2023-11-20 20:30:47
@article{a7abec45-4f75-4158-b39e-29fa12ae1634,
  abstract     = {{<p>Phase change heat storage is the backbone of energy storage technology, but its storage time is affected by the low thermal conductivity of phase change materials. Therefore, the melting performance of a triplex-tube latent heat thermal energy storage unit (T-LHTESU) in a phase change heat storage system is studied in this paper, and the rotation mechanism is applied to the unit. Firstly, a numerical model of the T-LHTESU considering the rotation mechanism is constructed, and the validity of the rotation unit is verified by comparison with experimental data. In this unit, N-eicosane is used as a phase change material for heat exchange. The effects of different rotational speeds on the liquid phase distribution, temperature distribution, flow velocity distribution, total energy storage, and energy storage efficiency of the T-LHTESU are studied. The results show that the melting time of this unit at 0.1 and 1 rpm is 46.98 and 69.35% lower than that of the stationary model, respectively. The total amount of stored heat is decreased by 0.67 and 2.17%, and the heat storage efficiency is increased by 87.34% and 219.19%, respectively. This indicates that the addition of the rotation mechanism greatly increases the heat storage efficiency of the T-LHTESU and reduces its total melting time, while the reduction of the total energy stored in the melting cycle is small. Then it is proved that rotation improves the single heat transfer mechanism of the stationary model and eliminates the thermal deposition caused by natural convection by studying the internal temperature/velocity response of the stationary model and the speed of 0.1 rpm. The related geometric structure of the model is optimized by response surface optimization design based on 0.1 rpm rotation speed. The influence of each variable on the target response is obtained, and compared with the original model, the melting time of the optimized model is reduced by 12.24%. Finally, based on the geometric optimization design, the influence of element physical factors (temperature and material of fin/tube wall) on the related melting properties is studied. This study is helpful to promote the effective use of rotation mechanism in phase change heat storage systems and has a certain guiding role in the structural design.</p>}},
  author       = {{Huang, Xinyu and Li, Fangfei and Li, Yuanji and Gao, Xinyu and Yang, Xiaohu and Sundén, Bengt}},
  issn         = {{0017-9310}},
  keywords     = {{Heat absorption rate; Phase change material; Response surface method; Rotational mechanism; Thermal energy storage}},
  language     = {{eng}},
  publisher    = {{Pergamon Press Ltd.}},
  series       = {{International Journal of Heat and Mass Transfer}},
  title        = {{Investigation and optimization on melting performance of a triplex-tube heat storage tank by rotational mechanism}},
  url          = {{http://dx.doi.org/10.1016/j.ijheatmasstransfer.2023.123892}},
  doi          = {{10.1016/j.ijheatmasstransfer.2023.123892}},
  volume       = {{205}},
  year         = {{2023}},
}