Numerical study on dynamic performance of low temperature recuperator in a S-CO2 Brayton cycle
(2023) In Numerical Heat Transfer; Part A: Applications 84(12). p.1436-1458- Abstract
Transient response of the pinch point is crucial to the evaluations of the recuperator efficiency. A reheat and recompression cycle dynamic simulation system for supercritical CO2 is built, and a transient segmented model is developed to explore the dynamic characteristics of the recuperators. The operating conditions including inlet mass flowrate, temperature and pressure of the low temperature recuperator (LTR) change dramatically with the withdraw-mass variation, which causes different response characteristics of the pinch point. The pinch point gradually transfers from the cold end to the hot end of the LTR as the mass flowrate decreases. The higher pinch-point temperature difference leads to lower heat exchanger... (More)
Transient response of the pinch point is crucial to the evaluations of the recuperator efficiency. A reheat and recompression cycle dynamic simulation system for supercritical CO2 is built, and a transient segmented model is developed to explore the dynamic characteristics of the recuperators. The operating conditions including inlet mass flowrate, temperature and pressure of the low temperature recuperator (LTR) change dramatically with the withdraw-mass variation, which causes different response characteristics of the pinch point. The pinch point gradually transfers from the cold end to the hot end of the LTR as the mass flowrate decreases. The higher pinch-point temperature difference leads to lower heat exchanger effectiveness, and the internal pinch point greatly weakens the recuperator performance. A new prediction model is proposed to quickly determine the pinch point location and analyze the operating conditions prone to cause internal pinch point. The range of split ratio in which the internal pinch point exists in the LTR is obtained. The lower-limit of split ratio variation is sensitive to the high- and low-pressures, the isentropic efficiency of the compressor, and the outlet temperature of the precooler, while the upper-limit of split ratio is only related to the pressures of the recuperator.
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- author
- Wang, Limin ; Guo, Yalong ; Liu, Kairui ; Wang, Chao ; Che, Defu ; Yang, Xiaohu and Sundén, Bengt LU
- organization
- publishing date
- 2023
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Pinch point, recuperator, S-CO2 Brayton cycle, transient analysis, variable working conditions
- in
- Numerical Heat Transfer; Part A: Applications
- volume
- 84
- issue
- 12
- pages
- 23 pages
- publisher
- Taylor & Francis
- external identifiers
-
- scopus:85149317116
- ISSN
- 1040-7782
- DOI
- 10.1080/10407782.2023.2176382
- language
- English
- LU publication?
- yes
- id
- 0deec98d-6fb1-4071-be69-8d228051cdcf
- date added to LUP
- 2024-01-12 14:23:49
- date last changed
- 2024-01-12 14:25:10
@article{0deec98d-6fb1-4071-be69-8d228051cdcf,
abstract = {{<p>Transient response of the pinch point is crucial to the evaluations of the recuperator efficiency. A reheat and recompression cycle dynamic simulation system for supercritical CO<sub>2</sub> is built, and a transient segmented model is developed to explore the dynamic characteristics of the recuperators. The operating conditions including inlet mass flowrate, temperature and pressure of the low temperature recuperator (LTR) change dramatically with the withdraw-mass variation, which causes different response characteristics of the pinch point. The pinch point gradually transfers from the cold end to the hot end of the LTR as the mass flowrate decreases. The higher pinch-point temperature difference leads to lower heat exchanger effectiveness, and the internal pinch point greatly weakens the recuperator performance. A new prediction model is proposed to quickly determine the pinch point location and analyze the operating conditions prone to cause internal pinch point. The range of split ratio in which the internal pinch point exists in the LTR is obtained. The lower-limit of split ratio variation is sensitive to the high- and low-pressures, the isentropic efficiency of the compressor, and the outlet temperature of the precooler, while the upper-limit of split ratio is only related to the pressures of the recuperator.</p>}},
author = {{Wang, Limin and Guo, Yalong and Liu, Kairui and Wang, Chao and Che, Defu and Yang, Xiaohu and Sundén, Bengt}},
issn = {{1040-7782}},
keywords = {{Pinch point; recuperator; S-CO2 Brayton cycle; transient analysis; variable working conditions}},
language = {{eng}},
number = {{12}},
pages = {{1436--1458}},
publisher = {{Taylor & Francis}},
series = {{Numerical Heat Transfer; Part A: Applications}},
title = {{Numerical study on dynamic performance of low temperature recuperator in a S-CO<sub>2</sub> Brayton cycle}},
url = {{http://dx.doi.org/10.1080/10407782.2023.2176382}},
doi = {{10.1080/10407782.2023.2176382}},
volume = {{84}},
year = {{2023}},
}