Thermodynamic analysis of a cascaded latent heat store in a pumped thermal electricity storage system
File(s)
Published version
Author(s)
Zhao, Yao
Markides, Christos N
Zhao, Changying
Type
Conference Paper
Abstract
In this paper, the feasibility of replacing sensible-heat, packed-bed stores with cascaded latent-heat stores in pumped thermal electricity storage systems is explored through thermodynamic optimization based on exergy and entropy generation. The effects of the total stage number and of the NTU on the temperature distributions, energy, exergy and entropy generation in each stage, and over the cascaded store during the heat charging and discharging processes are discussed. The optimal outlet and melting temperatures of each stage during the heat charging process are both found to follow a geometric progression along the length of the store. It is found that the first few storage stages play a more important role in terms of overall heat transfer, exergy storage and release in both the heat charging and discharging processes. During the heat charging process, the total exergy storage rate increases and approaches its maximum, while the total entropy generation rate decreases and stabilizes as the total stage number and NTU increase. During the heat discharging process, the total heat transfer and total exergy release rates both increase as the total stage number and NTU increase, while the total entropy generation rate decreases. The highest roundtrip energy and exergy efficiencies are 94%-98% and 88%-95% for the investigated NTUs, respectively. The highest roundtrip energy and exergy efficiencies are 73%-98% and 60%-95% for the investigated total stage numbers.
Editor(s)
Charalambides, A
Streicher, W
Mugnier, D
Date Issued
2020-09-01
Date Acceptance
2020-09-01
Citation
EuroSun 2020 Proceedings, 2020, pp.706-716
Publisher
International Solar Energy Society
Start Page
706
End Page
716
Journal / Book Title
EuroSun 2020 Proceedings
Copyright Statement
© 2020. The Authors. Published by International Solar Energy Society.
Identifier
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000836179100072&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=a2bf6146997ec60c407a63945d4e92bb
Source
13th International Conference on Solar Energy for Buildings and Industry (ISES EuroSun)
Subjects
cascaded store
CONCEPTUAL DESIGN
CYCLES
Energy & Fuels
ENERGY-STORAGE
Engineering
Engineering, Civil
entropy generation
exergy
INTEGRATION
latent heat storage
OPTIMIZATION
PART
pumped thermal electricity storage
Science & Technology
Technology
Publication Status
Published
Start Date
2020-09-01
Finish Date
2020-09-03
Coverage Spatial
Online