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Entropy: Thermodynamics – Energy – Environment – Economy

Entropie : thermodynamique – énergie – environnement – économie

Entropie - ISSN 2634-1476 - © ISTE Ltd

Aims and scope

Objectifs de la revue

In 1965, the first edition of the journal Entropie announced that thermodynamics was the basis for many industrial applications, but also for advanced techniques (aerospace, particle and universe physics, metrology). It is a science of energy and entropy, a branch that studies the properties of materials and fluids, conversion processes.


But since then, it has also become clear that thermodynamics and energy have a major role in the living world and its evolution. This aspect is therefore an integral part of the themes of this journal, as well as the relationship with the environment and the economy: are we not talking about thermo-economics, climate change with the temperature drift, a thermodynamic notion if ever there was one?


In summary, the "new edition" of Entropie confirms the previous major fundamental and applied themes, but also opens up to various everyday applications in our societies, and offers new sections on the living world, on the economy (thermo-economics) and the environment through a systemic approach.


Publication Ethics and Malpractice Statement

Le premier éditorial de la revue Entropie annonçait, en 1965, que la thermodynamique est à la base de nombreuses applications industrielles, mais aussi de techniques de pointe (aérospatial, physique des particules et de l’univers, métrologie). Elle est une science de l’énergie et de l’entropie, branche qui étudie les propriétés des matériaux et des fluides, les processus de conversion.


Mais depuis lors, il est aussi apparu que la thermodynamique et l’énergie avait un rôle majeur dans le monde du vivant et de son évolution. Cet aspect fait donc partie intégrante des thèmes de la revue, de même que la relation à l’environnement et l’économie : ne parle-t-on pas de thermo économie, de changement climatique avec la dérive en température, notion thermodynamique s’il en est.


En résumé, la « nouvelle édition » d’Entropie confirme les thèmes majeurs antérieurs fondamentaux et appliqués, mais y ajoute une ouverture sur des applications diffuses de tous les jours dans nos sociétés, et de nouvelles rubriques du côté du monde du vivant, puis de l’économie (thermo-économie) et de l’environnement par une approche systémique.


Publication Ethics and Malpractice Statement

Journal issues

Recent articles

A state-of-the-art review of Geographic Information System applications, the main criteria of selection, and available data that may be used in the process of site selection for floating offshore wind farms
Krzysztof Szczepaniec, Fergal O’Rourke, Peter Ryan

The energy crisis, global warming, and rising energy consumption have positioned renewable energy as a priority from national and international planning perspectives. Not only to reach the goals of the renewable energy mix, but also as part of overall energy security strategy. Rising energy prices and supply concerns have made the need for energy changes tangible for society and have increased public awareness of renewable energy. To achieve its renewable energy targets, Ireland has placed a focus on the development of offshore wind energy projects, due to its massive potential in the region. Other regions have already commenced the deployment of large-scale offshore wind farms and the technology is now competitive with fossil fuels. This work presents a comparison of Geographic Information System (GIS) applications and Multi-Criteria Decision-Making (MCDM) methods applied in the process of multicriteria site selection for Floating Offshore Wind Farms (FOWF) and highlights current trends in FOWF site selection and characterisation. This work is an objective review of the methodologies applied by researchers and a discussion of their adequacy to find the answer to the research questions posed by industry. Furthermore, it outlines the limitations of the methods and comments on the chosen criteria in the context of reaching the researches objectives. It also highlights the suitability of the industry standards methods and best practices. Finally, the work attempts to map the next steps that shall be taken to improve the methodology for criteria selection.

Application of Machine Learning in Energy Systems – a Comparative Analysis of Three Review Case Studies
Michael Rath, Naga Lokesh Gunturu Venkata, Kiran George, Jayares Prince

The exponential growth in the number of papers published annually in the field of machine learning applications in energy systems presents a challenge to researchers seeking to conduct comprehensive and effective literature reviews. To address this issue, we took a systematic literature review approach with three distinct smaller case studies focusing on the application of machine learning in energy systems, namely 1. Machine learning in drilling, 2. Machine learning for rooftop solar energy potential quantification, and 3. Machine learning in district heating and cooling in the context of seasonal thermal energy storages. In each case, we employed a systematic literature review methodology. For topic one, we utilized an existing comprehensive review to generate further insights and information. For topics two and three, we used predefined search criteria to conduct relevant publications in a systematic and reproducible manner. We investigate the state of the art of the use of machine learning in these distinct areas of inquiry, thereby facilitating the identification of research gaps. Ultimately, we compare approaches and models utilized in each field, identified common best practices, and propose methods to address potential challenges. The instructions put together below fall into four categories.

Low-temperature compressed air energy storage with reversibly operable turbo- and piston machines
Markus Hadam, Marcus Budt

Adiabatic compressed air energy storage (A-CAES) is a promising storage technology to face the challenges of high shares of renewable energies in an energy system by storing electric energy for periods of several hours up to weeks. In order to reduce the investment costs and increase the flexibility of the storage system, the so called KompEx LTA-CAES® was developed by Fraunhofer UMSICHT. This new A-CAES concept is using a combination of reversibly operable turbo- and piston machines (KompEx machines). Doing so, these modules can achieve wide CAS pressure ranges (corresponding to high exergy densities) and thus can be combined with any compressed air storage volume. To realize efficient and stable operation despite a wide pressure range, a suitable control strategy of both KompEx machines is required. This paper investigates the introduced A-CAES system by a dynamic simulation, focusing on the interaction and synergy between the reversibly operable turbo- and piston machines. Results indicate that the roundtrip efficiency of this system is expected to be at the low end (55,5%) of literature values for A-CAES (52–66% for low-temperature A-CAES), which is relatively high compared to published A-CAES systems considering similar pressure ranges.

Thermodynamic analysis of a high-temperature heat pump using low GWP natural working fluids for upgrading district heating to process heating
Mohsen Sadeghi, Tage Petersen, Zhenyu Yang, Benjamin Zühlsdorf, Kim Stenholdt Madsen, Ahmad Arabkoohsar

High-temperature heat pump (HTHP) is a promising technology for decarbonization of process heating through electrification and energy efficiency. Exploiting the potentials requires a simultaneous optimization of the cycle layout and the working fluid. This paper proposes an efficient cascade HTHP and optimizes its thermodynamic performance. Using steam for high-temperature loop and use of alternative hydrocarbons for low-temperature loop are examined. On the application level, district heating is considered as a heat source and evaluated for different supply temperatures, including 80 °C, 70 °C and 40 °C. The results reveal that pentane with highest critical temperature among the suggested hydrocarbons, shows the best energy performance to be paired with steam in the proposed cascade HTHP system. However, concerning the hydrocarbon compressor volumetric heating capacity (VHC) and safety issues, butane is an excellent candidate. In addition, when the heat available in the main transmission lines of district heating unit is considered as the source cooled from 80 °C down 70 °C, the highest value of coefficient of performance (COP) is achieved as 2.74 for the sink condensation temperature of 160 °C.

Editorial Special issue IREEC 2

Le laboratoire d’énergétique et environnement de l’école nationale d’ingénieurs de Tunis et le centre d’énergétique et thermique de Lyon se sont associés en mars dernier pour organiser le second colloque international froid énergie et environnement (IREEC2). Ce colloque qui a réuni une centaine de participants, a été organisé avec l’appui de la société tunisienne de dessalement et de l’association tunisienne de réfrigération et climatisation sous l’égide de l’institut international du froid et de l’Association française du froid. Plus de cinquante communications ont été présentées en trois ateliers parallèles ainsi que six plénières. Un franc succès a été remporté par ces présentations dont nous avons retenus quelques exemples marquants qui font l’objet de ce numéro spécial d’Entropie.

Numerical Study of the Influence of Operating Conditions on the Overall Efficiency of a Photovoltaic Thermal System

Photovoltaic (PV) panels are an integral part of solar energy systems, converting sunlight directly into electricity. With the increasing demand for renewable energy sources, PV panels have gained significant attention due to their ability to generate clean and sustainable power. However, the performance of PV panels is influenced by various factors, including their design, materials, operating conditions, and environmental factors. Cooling is a crucial aspect in the operation of PV panels, as high temperatures can significantly affect their efficiency and overall performance. Water and nanofluid cooling have emerged as promising strategies to mitigate temperature-related issues and enhance the energy output of PV panels. This abstract focuses on the application of water and nanofluid cooling techniques in PV panels and their impact on performance. This work explores the influence of parameters such as mass flow rate, nanofluid concentration, and nanofluid type on cell temperature reduction and resulting thermal and electrical efficiencies of a PV panel situated in the Gabes region. The study considers three cases: a standalone PV panel, a PV/T system with water cooling, and a PV/T system with nanofluid cooling. To maximize the interaction between the cooling fluid and the back surface of the solar panel, the tested fluids are circulated through a rectangular heat exchanger.

Prediction analysis of using phase change materials to increase the stability of a salt gradient solar pond
Karim Choubani, Sirine Dhaoui, Ons Ghriss, Abdallah Bouabidi

Solar Ponds are large areas consisting essentially of three density-stratified zones: an energy storage zone (Layer Convective Zone ’LCZ’), a thermal insulation zone (Non-Convective Zone ’NCZ’), and a protection zone against natural hazards such as wind and dust (Upper Convective Zone ’UCZ’). The performance and efficiency of solar ponds depend on the stability of the gradient layer. The latter is subject to double molecular diffusion of heat and mass and hydrodynamic movements (double convective diffusion) tend to be homogenized. The coexistence of different diffusions in the stratified system constitutes complex instability phenomena whose physics is poorly known until today. In this study, preliminary experiments showed that the stability of a solar pond could be increased by using phase change materials (PCM) placed at the bottom of the pond.

Simulation of a "box" type solar oven by the Runge-Kutta method and optimization of the quantity to be heated by an exergy study
Tahar Kateb

Among the thermal applications of solar energy, solar cooking is considered one of the simplest, most viable and most attractive options in terms of using solar energy. In isolated mountainous regions, or in the desert where wood energy resources are constantly decreasing while heat needs are constantly growing, solar cooking of food products then appears to be the ideal way to remedy this problem. issue. This study focuses on the numerical simulation of a prototype solar cooker. This device is designed to ensure food cooking thanks to solar radiation which will be captured and trapped to reach temperature levels favorable to healthy food cooking. The modeling of the prototype of the solar cooker studied is carried out by introducing the different heat exchanges involved between the different elements of the solar cooker. We present an analysis of the results of the numerical simulation of the system processed using MATLAB software with a calculation algorithm based on the Runge-Kutta method. An analysis of the exergy of the studied solar oven is carried out to analyze and optimize the operation of the oven.

Optimization of a highly-efficient hydro-CO2 piston for commercial refrigeration
François FARALDO, Philippe LOISEAU, Paul BYRNE

This paper presents a novel thermodynamic system developed to generate heat and cold for industrial processes. The efficiency is improved compared to commercialized ones and current state-of-the-art systems. The proposed hydro-CO2 piston combines three counter-intuitive innovations with the operation of discontinuous and slowed thermodynamic cycles where mechanical work is transferred to the refrigeration through a hydraulic circuit based on modified transcritical Carnot and Rankine cycles. This allows to operate unusual thermodynamic transformations such as isothermal compression and two-phase isentropic expansion. The cycles are tailored to the demand and irreversibilities are minimized to make cold/heat generation valorisation highly efficient and cost-effective. This study focuses on the technology energetic efficiency for commercial refrigeration producing negative (-20°C) and positive (0°C) cold. Based on numerical analysis and validated models using numerical tools (EES, Python) and thermodynamic data bases (REFPRP), simulations results compare standard CO2 transcritical cycles (STC) to the hydro-CO2 piston in two different case studies. The results show an increase in COP between 38 and 112% showing the energy efficiency and environmental impact decrease potential of the technology.

Editorial Board

Editor in Chief

Michel FEIDT
Université de Lorraine

Vice Editor in Chief

Philippe GUIBERT
Sorbonne Université


Université de Gabès

Université de Franche-Comté

George DARIE
Université Politehnica de Bucarest
Lazlo KISS
Université du Québec à Chicoutimi
Université Rovira i Virgili
Gianpaolo MANFRIDA
Université de Florence
Phillipe MATHIEU
Université de Liège
Université de Toulouse


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