Advanced exergy analysis of a Joule-Brayton pumped thermal electricity storage system with liquid-phase storage
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Pumped thermal electricity storage is a thermo-mechanical energy storage technology that has emerged as a promising option for large-scale (grid) storage because of its lack of geographical restrictions and relatively low capital costs. This paper focuses on a 10 MW Joule-Brayton pumped thermal electricity storage system with liquid thermal stores and performs detailed conventional and advanced exergy analyses of this system. Results of the conventional exergy analysis on the recuperated system indicate that the expander during discharge is associated with the maximum exergy destruction rate (13%). The advanced exergy analysis further reveals that, amongst the system components studied, the cold heat exchanger during discharge is associated with the highest share (95%) of the avoidable exergy destruction rate, while during charge the same component is associated with the highest share (64%) of the endogenous exergy destruction rate. Thus, the cold heat exchanger offers the largest potential for improvement in the overall system exergetic efficiency. A quantitative analysis of the overall system performance improvement potential of the recuperated system demonstrates that increasing the isentropic efficiency of the compressor and turbine from 85% to 95% significantly increases the modified overall exergetic efficiency from 37% to 57%. Similarly, by increasing the effectiveness and decreasing the pressure loss factor of all heat exchangers, from 0.90 to 0.98 and from 2.5% to 0.5% respectively, the modified overall exergetic efficiency increases from 34% to 54%. The results of exergy analyses provide novel insight into the innovation, research and development of pumped thermal electricity storage technology.
Date Issued
2021-03-01
Date Acceptance
2021-01-15
Citation
Energy Conversion and Management, 2021, 231, pp.1-19
ISSN
0196-8904
Publisher
Elsevier BV
Start Page
1
End Page
19
Journal / Book Title
Energy Conversion and Management
Volume
231
Copyright Statement
© 2021 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Identifier
https://www.sciencedirect.com/science/article/pii/S0196890421000443?via%3Dihub
Grant Number
EP/R045518/1
UOB107926
Subjects
0906 Electrical and Electronic Engineering
0913 Mechanical Engineering
Energy
Publication Status
Published
Article Number
113867
Date Publish Online
2021-02-01