Thermal performance analysis of multi-slab phase change thermal energy storage unit with heat transfer enhancement approaches

Dan Zhou, Shaowen Wu, Zhigen Wu and Xingjuan Yu

Renewable Energy, 2021, vol. 172, issue C, 46-56

Abstract: A novel multi-slab thermal energy storage (TES) unit with NaNO3 as PCM is designed for concentrating solar thermal power plants due to its easy manufacture and high energy storage density. A numerical model, based on the k−ε turbulence model, is used in studying the thermal performance of the system. To enhance the efficiency, two heat transfer enhancement methods are compared with the original unit, which is adding plate fins or 10 wt%EG into NaNO3. The numerical model is validated to be reliable for simulating the heat transfer with natural convection by a lab-built rig. The numerical results show that adding fins shortens the phase change time by up to 18% with an HTF flow rate of 4.0 × 10−3 m3/s in each channel and adding 10 wt%EG is the most effective way to enhance the heat transfer. The role of natural convection in heat transfer is analyzed. In practical applications, the sensible heat during the charging/discharging process cannot be neglected, which occupies 45%–55% of the total heat stored/released. This paper is expected to provide a detailed investigation of the thermal performance of the unit with two different thermal enhancement methods to give some rational advice in optimizing the system design and operation.

Keywords: Thermal energy storage (TES); Phase change material (PCM); Expanded graphite (EG); Turbulent flow; Enhanced heat transfer (search for similar items in EconPapers)
Date: 2021
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0960148121003232
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:renene:v:172:y:2021:i:c:p:46-56

DOI: 10.1016/j.renene.2021.02.144

Access Statistics for this article

Renewable Energy is currently edited by Soteris A. Kalogirou and Paul Christodoulides

More articles in Renewable Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().