Experimental investigation of thermal performance of vertical multitube cylindrical latent heat thermal energy storage systems

Gang Shen; Xiaolin Wang; Jie Yu; Yuejing Bin; Shan Zhong; Shengqi Yang; Jianguo Wang

doi:10.1007/s11356-024-31864-7

Experimental investigation of thermal performance of vertical multitube cylindrical latent heat thermal energy storage systems

Environ Sci Pollut Res Int. 2024 Jan 8. doi: 10.1007/s11356-024-31864-7. Online ahead of print.

Authors

Gang Shen^{1

2}, Xiaolin Wang³, Jie Yu¹, Yuejing Bin¹, Shan Zhong¹, Shengqi Yang⁴, Jianguo Wang⁴

Affiliations

¹ School of Mechanical and Resource Engineering, Wuzhou University, Wuzhou, 543002, China.
² School of Engineering, University of Tasmania, Hobart, TAS, 7001, Australia.
³ School of Engineering, University of Tasmania, Hobart, TAS, 7001, Australia. Xiaolin.wang@utas.edu.au.
⁴ School of Mechanics and Civil Engineering, China University of Mining Technology, Xuzhou, China.

PMID: 38190065
DOI: 10.1007/s11356-024-31864-7

Abstract

The multitube design in the shell-and-tube type latent heat thermal energy storage (LHTES) system has received intensive attention due to its promising benefits in enhancing heat storage efficiency. In this paper, single and multi-tube shell LHTES systems were experimentally investigated. First, this study experimentally compared the thermal characteristics between a multiple-tube heat exchanger (MTHX) and a single-tube heat exchanger (STHX). The STHX's geometrical parameters coincided with a virtual cylindrical domain in the MTHX, being similar to the single-tube model formulated by simplifying the numerical solution to investigate the MTHX. The experimental data was then used to validate the simplified numerical model commonly used in the literature that converted the multi-tube problem to a single-tube model by formulating a virtual cylindrical domain for each tube in the MTHX system. The results showed that there was a noticeable difference in the thermal characteristics between the actual STHX and the virtual cylindrical STHX domain in the MTHX system. The comparison indicated that the simplified numerical model could not accurately reflect the thermal performance of the MTHX system. An experimental study or three-dimensional numerical modelling was required for the thermal analysis of the multi-tube problems. Second, the effect of tube number in the MTHX was experimentally investigated. It was found that an increase in tube number boosted both charging and discharging rates without inhibiting the natural convection. The five-tube configuration decreased the total charging and discharging duration by 50% compared to the two-tube one. Finally, the effect of heat transfer fluid (HTF) operating parameters on the system performance was evaluated on the five-tube MTHX system. The results revealed that the adoption of higher HTF temperature considerably improved the charging performance. The charging time decreased by up to 41% with the HTF temperature increasing from 70 to 80 °C. Meanwhile, a variation in the HTF flow rate from 5 to 20 L/min showed a more pronounced influence on charging than on discharging due to the different dominant heat transfer mechanisms.

Keywords: Latent heat storage; Multiple tube; Natural convection; Phase change material; Shell-and-tube heat exchanger; Thermal performance.

Grants and funding

WZUQDJJ30113/Wuzhou University