Publication detail

Numerical analysis on the improved thermo-chemical behaviour of hierarchical energy materials as a cascaded thermal accumulator

Li, W., Klemeš, J.J., Wang, Q., Zeng, M.

Original Title

Numerical analysis on the improved thermo-chemical behaviour of hierarchical energy materials as a cascaded thermal accumulator

Type

journal article in Web of Science

Language

English

Original Abstract

The present study aims to improve the thermo-chemical conversion behaviours, including reactive transport processes and output performances of an open thermochemical energy storage (TCES) unit. The local thermal non-equilibrium (LTNE) model and the effect of non-uniform porosity are adopted and considered to better elucidate the conversion processes. Cascading the reaction sub-units filled with different thermochemical materials (TCMs), i.e., zeolite, salt hydrate-based composite sorbent, and pure salt of SrBr2·6H2O, to form an integrated storage bed ameliorates the output performance. The numerical results indicate that the maximum temperature difference ranging from 3.5 to 4.9 °C between heat transfer fluid and solid reactants exists during desorption, and the realistic non-uniform porosity facilitates the reactant conversion near the wall compared to the uniform porosity assumption. The cascaded scheme promotes the charging and discharging processes compared to the cases filled with sole TCM, the time required for charging this 10.8 kWh storage model is 16 h. Increasing the charging temperature from 100 °C to 145 °C, the charging time reduced to 6.5 h, saving 59.4%. Boosting the inlet velocity of airflow also accelerates the charging rate. The cascaded storage unit significantly stabilises the output temperature during discharging, warming up the airflow from 20 °C to 35 °C for 24 h with a tiny temperature fluctuation. Airflow with higher relative humidity facilitates hydration but shortens the stable period. Overall power and thermal efficiency of the “thermal accumulator” in charging are 598 W and 92.8%, 164 W and 92.4% in discharging, with a total COP of 0.71. The satisfying performances suggest that the cascaded TCES unit may provide a strategy and reference in the design and promotion of the low-grade energy storage system. © 2021 Elsevier Ltd

Keywords

Cascaded thermochemical materials; Local thermal non-equilibrium; Output temperature; Thermal performance; Thermochemical energy storage

Authors

Li, W., Klemeš, J.J., Wang, Q., Zeng, M.

Released

1. 10. 2021

Publisher

Elsevier Ltd.

Location

PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND

ISBN

0360-5442

Periodical

Energy

Number

232

State

United Kingdom of Great Britain and Northern Ireland

Pages from

120937

Pages to

120937

Pages count

13

URL

https://www.sciencedirect.com/science/article/abs/pii/S0360544221011853?via%3Dihub

BibTex

@article{BUT171764,
  author="Jiří {Klemeš}",
  title="Numerical analysis on the improved thermo-chemical behaviour of hierarchical energy materials as a cascaded thermal accumulator",
  journal="Energy",
  year="2021",
  number="232",
  pages="120937--120937",
  doi="10.1016/j.energy.2021.120937",
  issn="0360-5442",
  url="https://www.sciencedirect.com/science/article/abs/pii/S0360544221011853?via%3Dihub"
}