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Supercritical Fluids for Thermal Energy Applications

A special issue of Entropy (ISSN 1099-4300). This special issue belongs to the section "Thermodynamics".

Deadline for manuscript submissions: closed (20 April 2022) | Viewed by 7599

Special Issue Editors


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Guest Editor
Department of Chemistry, Energy and Mechanical Engineering, Universidad Rey Juan Carlos, 28932 Mostoles, Spain
Interests: solar thermal energy; integration of renewable energy sources; energy optimization; thermal energy storage; advanced power cycles; combined heat and power; power plant technologies; thermodynamics optimization; turbomachinery characterization; additive manufacturing
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Department of Energy Engineering, Universidad Nacional de Educación a Distancia (UNED), Madrid, Spain
Interests: solar thermal power plants; solar central receivers; supercritical power cycles; heat exchangers; solar heat for industrial processes

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Guest Editor
Department of Energy Technology, KTH Royal Institute of Technology, Brinellvägen 68, 100 44 Stockholm, Sweden
Interests: renewable energy; concentrating solar power; advanced energy systems; energy storage; power-to-X; thermoeconomics
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Worldwide energy demand increase is a clear indicator of human and wealth development as we, as a modern society, require higher levels of energy to maintain our living standards. Nevertheless, a change in electricity and heat generation is required, including more efficient energy conversion systems. In order to achieve that, supercritical fluids have drawn the attention of the scientific community based on their peculiar thermophysical properties leading to highly efficient solutions according to thermodynamics. New materials developments together with stringent emission legislation are contributing to the rapid deployment of supercritical fluid technologies for power conversion systems and waste heat recovery applications. However, there are still many areas of research and challenges to address to exploit the benefits of supercritical fluids to the fullest.

Noting all these exciting developments, it has never been more pertinent to launch a Special Issue that seeks to capture the latest research in supercritical fluids for thermal energy applications whether for renewable applications, nuclear engineering, waste heat recovery, and much more, with a clear interest in entropy analysis and thermodynamics optimization.

Authors are encouraged to submit their research to this Special Issue. Topics include but are not limited to:

  • Supercritical CO2 cycles
  • Supercritical steam cycles
  • Entropy analysis
  • Thermodynamics optimization
  • Energy and exergy optimization
  • New concepts in thermodynamics cycles
  • Supercritical cycles for nuclear applications
  • Waste heat recovery applications
  • Concentrating solar power applications
  • Energy sources and renewable energy integration
  • Heat exchangers
  • Turbomachinery design

Dr. Miguel Ángel Reyes
Dr. María José Montes
Dr. Rafael Guédez
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Entropy is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • entropy
  • supercritical cycles
  • multi-objective optimization
  • energy and exergy optimization
  • exergoeconomic analysis
  • thermodynamics optimization
  • waste heat recovery
  • concentrating solar power
  • thermoeconomic analysis
  • integration into renewable energy sources

Published Papers (3 papers)

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Research

29 pages, 7592 KiB  
Article
Performances of Transcritical Power Cycles with CO2-Based Mixtures for the Waste Heat Recovery of ICE
by Jinghang Liu, Aofang Yu, Xinxing Lin, Wen Su and Shaoduan Ou
Entropy 2021, 23(11), 1551; https://doi.org/10.3390/e23111551 - 21 Nov 2021
Cited by 13 | Viewed by 1675
Abstract
In the waste heat recovery of the internal combustion engine (ICE), the transcritical CO2 power cycle still faces the high operation pressure and difficulty in condensation. To overcome these challenges, CO2 is mixed with organic fluids to form zeotropic mixtures. Thus, [...] Read more.
In the waste heat recovery of the internal combustion engine (ICE), the transcritical CO2 power cycle still faces the high operation pressure and difficulty in condensation. To overcome these challenges, CO2 is mixed with organic fluids to form zeotropic mixtures. Thus, in this work, five organic fluids, namely R290, R600a, R600, R601a, and R601, are mixed with CO2. Mixture performance in the waste heat recovery of ICE is evaluated, based on two transcritical power cycles, namely the recuperative cycle and split cycle. The results show that the split cycle always has better performance than the recuperative cycle. Under design conditions, CO2/R290(0.3/0.7) has the best performance in the split cycle. The corresponding net work and cycle efficiency are respectively 21.05 kW and 20.44%. Furthermore, effects of key parameters such as turbine inlet temperature, turbine inlet pressure, and split ratio on the cycle performance are studied. With the increase of turbine inlet temperature, the net works of the recuperative cycle and split cycle firstly increase and then decrease. There exist peak values of net work in both cycles. Meanwhile, the net work of the split cycle firstly increases and then decreases with the increase of the split ratio. Thereafter, with the target of maximizing net work, these key parameters are optimized at different mass fractions of CO2. The optimization results show that CO2/R600 obtains the highest net work of 27.43 kW at the CO2 mass fraction 0.9 in the split cycle. Full article
(This article belongs to the Special Issue Supercritical Fluids for Thermal Energy Applications)
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33 pages, 85198 KiB  
Article
Bibliometric Analysis on Supercritical CO2 Power Cycles for Concentrating Solar Power Applications
by Miguel Angel Reyes-Belmonte, Rafael Guédez and Maria José Montes
Entropy 2021, 23(10), 1289; https://doi.org/10.3390/e23101289 - 30 Sep 2021
Cited by 7 | Viewed by 2191
Abstract
In recent years, supercritical CO2 power cycles have received a large amount of interest due to their exceptional theoretical conversion efficiency above 50%, which is leading a revolution in power cycle research. Furthermore, this high efficiency can be achieved at a moderate [...] Read more.
In recent years, supercritical CO2 power cycles have received a large amount of interest due to their exceptional theoretical conversion efficiency above 50%, which is leading a revolution in power cycle research. Furthermore, this high efficiency can be achieved at a moderate temperature level, thus suiting concentrating solar power (CSP) applications, which are seen as a core business within supercritical technologies. In this context, numerous studies have been published, creating the need for a thorough analysis to identify research areas of interest and the main researchers in the field. In this work, a bibliometric analysis of supercritical CO2 for CSP applications was undertaken considering all indexed publications within the Web of Science between 1990 and 2020. The main researchers and areas of interest were identified through network mapping and text mining techniques, thus providing the reader with an unbiased overview of sCO2 research activities. The results of the review were compared with the most recent research projects and programs on sCO2 for CSP applications. It was found that popular research areas in this topic are related to optimization and thermodynamics analysis, which reflects the significance of power cycle configuration and working conditions. Growing interest in medium temperature applications and the design of sCO2 heat exchangers was also identified through density visualization maps and confirmed by a review of research projects. Full article
(This article belongs to the Special Issue Supercritical Fluids for Thermal Energy Applications)
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19 pages, 14169 KiB  
Article
Structural and Parametric Optimization of S–CO2 Nuclear Power Plants
by Nikolay Rogalev, Andrey Rogalev, Vladimir Kindra, Ivan Komarov and Olga Zlyvko
Entropy 2021, 23(8), 1079; https://doi.org/10.3390/e23081079 - 19 Aug 2021
Cited by 13 | Viewed by 2556
Abstract
The transition to the use of supercritical carbon dioxide as a working fluid for power generation units will significantly reduce the equipment′s overall dimensions while increasing fuel efficiency and environmental safety. Structural and parametric optimization of S–CO2 nuclear power plants was carried [...] Read more.
The transition to the use of supercritical carbon dioxide as a working fluid for power generation units will significantly reduce the equipment′s overall dimensions while increasing fuel efficiency and environmental safety. Structural and parametric optimization of S–CO2 nuclear power plants was carried out to ensure the maximum efficiency of electricity production. Based on the results of mathematical modeling, it was found that the transition to a carbon dioxide working fluid for the nuclear power plant with the BREST–OD–300 reactor leads to an increase of efficiency from 39.8 to 43.1%. Nuclear power plant transition from the Rankine water cycle to the carbon dioxide Brayton cycle with recompression is reasonable at a working fluid temperature above 455 °C due to the carbon dioxide cycle′s more effective regeneration system. Full article
(This article belongs to the Special Issue Supercritical Fluids for Thermal Energy Applications)
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