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Prof. Frédéric Kuznik
INSA-Lyon, CETHIL, F-69621 Villeurbanne, France

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Research Keywords & Expertise

0 CUDA
0 Numerical Modeling
0 zeolite
0 Natural convection
0 Lattice Boltzmann method

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heat storage
Lattice Boltzmann method
phase change material
Natural convection
CUDA
Building Application
physisorption
zeolite
Numerical Modeling
physical adsorption

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Journal article
Published: 04 June 2021 in Energies
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Sorption thermal heat storage is a promising solution to improve the development of renewable energies and to promote a rational use of energy both for industry and households. These systems store thermal energy through physico-chemical sorption/desorption reactions that are also termed hydration/dehydration. Their introduction to the market requires to assess their energy performances, usually analysed by numerical simulation of the overall system. To address this, physical models are commonly developed and used. However, simulation based on such models are time-consuming which does not allow their use for yearly simulations. Artificial neural network (ANN)-based models, which are known for their computational efficiency, may overcome this issue. Therefore, the main objective of this study is to investigate the use of an ANN model to simulate a sorption heat storage system, instead of using a physical model. The neural network is trained using experimental results in order to evaluate this approach on actual systems. By using a recurrent neural network (RNN) and the Deep Learning Toolbox in MATLAB, a good accuracy is reached, and the predicted results are close to the experimental results. The root mean squared error for the prediction of the temperature difference during the thermal energy storage process is less than 3K for both hydration and dehydration, the maximal temperature difference being, respectively, about 90K and 40K.

ACS Style

Carla Delmarre; Marie-Anne Resmond; Frédéric Kuznik; Christian Obrecht; Bao Chen; Kévyn Johannes. Artificial Neural Network Simulation of Energetic Performance for Sorption Thermal Energy Storage Reactors. Energies 2021, 14, 3294 .

AMA Style

Carla Delmarre, Marie-Anne Resmond, Frédéric Kuznik, Christian Obrecht, Bao Chen, Kévyn Johannes. Artificial Neural Network Simulation of Energetic Performance for Sorption Thermal Energy Storage Reactors. Energies. 2021; 14 (11):3294.

Chicago/Turabian Style

Carla Delmarre; Marie-Anne Resmond; Frédéric Kuznik; Christian Obrecht; Bao Chen; Kévyn Johannes. 2021. "Artificial Neural Network Simulation of Energetic Performance for Sorption Thermal Energy Storage Reactors." Energies 14, no. 11: 3294.

Review article
Published: 26 January 2021 in Renewable and Sustainable Energy Reviews
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This paper is an updated, but totally new, version of “A review on phase change materials (PCMs) integrated in building walls”, an article published in 2011 in Renewable and Sustainable Energy Reviews. Both numerical and experimental studies on building walls containing PCMs during the last ten years (2011–2020) are reviewed. The paper also summarizes the main PCMs used in this application and the recent progress in the integration techniques of PCMs in building construction elements. Most of the proposed studies (about 66%) are focused on PCM in walls. In addition, more than half of these studies are numerical where several assumptions are made such as the neglected of both the occupant presence in the building and its behaviour. Based on this review, it is concluded that the used PCMs in building walls showed good potential for reducing both indoor air temperature fluctuations and energy consumption. However, further numerical and experimental studies are needed that take other aspects into consideration, such as the real use of buildings with the occupant behaviour, the economic viability and the environmental impact. This review paper will help scientific researchers and engineers to update the integration techniques of PCM in building walls and to define potential future research works.

ACS Style

B. Lamrani; K. Johannes; F. Kuznik. Phase change materials integrated into building walls: An updated review. Renewable and Sustainable Energy Reviews 2021, 140, 110751 .

AMA Style

B. Lamrani, K. Johannes, F. Kuznik. Phase change materials integrated into building walls: An updated review. Renewable and Sustainable Energy Reviews. 2021; 140 ():110751.

Chicago/Turabian Style

B. Lamrani; K. Johannes; F. Kuznik. 2021. "Phase change materials integrated into building walls: An updated review." Renewable and Sustainable Energy Reviews 140, no. : 110751.

Journal article
Published: 09 December 2020 in Journal of Energy Storage
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The mismatch between renewable energy supply and demand requires energy storage technologies to work out the dilemma. In the thermal energy field, ettringite-based energy storage seems to be a good solution thanks to its high energy density and low material cost. It can store excess solar energy to meet the heating and domestic hot water demand in buildings. Therefore, the current work experimentally examines the energetic performance of an ettringite-based material made of commercial cements. The TG-DSC analysis shows the energy storage capacity of the investigated material is as high as 282 kWh/m3 original hydrated materials. Besides, the laboratory reactor tests prove the charging temperature is as low as 55–65°C for ettringite. Under operating conditions, the average energy-releasing power during the full period is about 33.3 W/kg while the maximum power is about 915 W/kg original hydrated materials, which are significantly higher than most materials from the literature. The best volumetric energy-releasing density and the corresponding prototype storage density of the fixed-bed obtained are 176 kWh/m3 original hydrated materials and 104 kWh/m3, respectively.

ACS Style

B. Chen; K. Johannes; M. Horgnies; V. Morin; F. Kuznik. Characterization of an ettringite-based thermochemical energy storage material in an open-mode reactor. Journal of Energy Storage 2020, 33, 102159 .

AMA Style

B. Chen, K. Johannes, M. Horgnies, V. Morin, F. Kuznik. Characterization of an ettringite-based thermochemical energy storage material in an open-mode reactor. Journal of Energy Storage. 2020; 33 ():102159.

Chicago/Turabian Style

B. Chen; K. Johannes; M. Horgnies; V. Morin; F. Kuznik. 2020. "Characterization of an ettringite-based thermochemical energy storage material in an open-mode reactor." Journal of Energy Storage 33, no. : 102159.

Journal article
Published: 19 November 2020 in Solar Energy Materials and Solar Cells
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Ettringite-based thermochemical energy storage has been recommended to be used in buildings for thermal energy supply because of its low material cost (<1000 €/m3), low working temperature and high energy storage capacity. However, several physicochemical properties of ettringite were still not clear, such as reversible reaction enthalpies, thermodynamic equilibrium, and kinetics of the dehydration/hydration reactions. In this study, the dehydration of ettringite was experimentally confirmed as stepwise in TGA-DSC, Ett30.6 → Ett30 → Met 17.8 → Met11.7 → Met7.5, which is consistent with the inference according to the crystal structure. The thermodynamic equilibrium of the reversible reactions presented the impact of water activity on the stability of ettringite at controlled temperatures and water vapor partial pressures. The thermodynamic modeling based on experiment results is consistent with the extrapolated model from the literature. The rehydration enthalpy of ettringite has been confirmed about 1370 kJ/mol, which equals an energy density of 547 kWh/m3 under the operating conditions of 20 °C and 90% RH.

ACS Style

B. Chen; K. Johannes; L. Ratel; M. Horgnies; V. Morin; F. Kuznik. Investigation on ettringite as a low-cost high-density thermochemical heat storage material: Thermodynamics and kinetics. Solar Energy Materials and Solar Cells 2020, 221, 110877 .

AMA Style

B. Chen, K. Johannes, L. Ratel, M. Horgnies, V. Morin, F. Kuznik. Investigation on ettringite as a low-cost high-density thermochemical heat storage material: Thermodynamics and kinetics. Solar Energy Materials and Solar Cells. 2020; 221 ():110877.

Chicago/Turabian Style

B. Chen; K. Johannes; L. Ratel; M. Horgnies; V. Morin; F. Kuznik. 2020. "Investigation on ettringite as a low-cost high-density thermochemical heat storage material: Thermodynamics and kinetics." Solar Energy Materials and Solar Cells 221, no. : 110877.

Data article
Published: 05 March 2020 in Data in Brief
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HVAC systems are often used to reach thermal comfort in buildings. It is then necessary to understand the resulting indoor airflow and thermal conditions to optimize the systems. Therefore, this paper presents detailed measurements of axisymmetric and anisothermal jets developing near the ceiling of a thermally controlled room called MINIBAT. Air temperature, velocity and turbulent quantities over five vertical plans on the room were measured using adequate materials such as Pt100 probes and a hot-wire anemometer. These data are to be used for the analysis of indoor air mixing processes and CFD validation. The detailed experimental process and measurements as well as CFD results are exposed in [1].

ACS Style

Teddy Gresse; Lucie Merlier; Frédéric Kuznik. Detailed airflow dynamics and temperature data of axisymmetric and anisothermal jets developing in a room. Data in Brief 2020, 29, 105382 .

AMA Style

Teddy Gresse, Lucie Merlier, Frédéric Kuznik. Detailed airflow dynamics and temperature data of axisymmetric and anisothermal jets developing in a room. Data in Brief. 2020; 29 ():105382.

Chicago/Turabian Style

Teddy Gresse; Lucie Merlier; Frédéric Kuznik. 2020. "Detailed airflow dynamics and temperature data of axisymmetric and anisothermal jets developing in a room." Data in Brief 29, no. : 105382.

Journal article
Published: 02 March 2020 in Thermochimica Acta
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Magnesium sulfate–water vapor is an interesting working pair of thermochemical materials for compact inter-seasonal heat storage at low temperature. Total dehydration of magnesium sulfate heptahydrate shows a theoretical storage energy density of 2.8 GJ m−3. However, kinetic data are poorly studied up to now making use of this material difficult for a practical storage application. In the present work, a kinetic study of the dehydration of MgSO4·6H2O powder at low temperature (35–60 °C) and at low water vapor pressure (2–21 hPa) is carried out using thermogravimetric analysis in isobaric-isothermal conditions. A mathematical model is developed for this bivariant system and validated representing the mechanism of dehydration: water molecules diffusion in the solid solution followed by transfer of these molecules from the surface to the atmosphere. The transfer of water molecules at the surface during dehydration is identified as rate-determining step. The fractional conversion and reaction rate of the dehydration reaction are calculated and compared to the experimental data.

ACS Style

Larysa Okhrimenko; Loïc Favergeon; Kévyn Johannes; Frédéric Kuznik. New kinetic model of the dehydration reaction of magnesium sulfate hexahydrate: Application for heat storage. Thermochimica Acta 2020, 687, 178569 .

AMA Style

Larysa Okhrimenko, Loïc Favergeon, Kévyn Johannes, Frédéric Kuznik. New kinetic model of the dehydration reaction of magnesium sulfate hexahydrate: Application for heat storage. Thermochimica Acta. 2020; 687 ():178569.

Chicago/Turabian Style

Larysa Okhrimenko; Loïc Favergeon; Kévyn Johannes; Frédéric Kuznik. 2020. "New kinetic model of the dehydration reaction of magnesium sulfate hexahydrate: Application for heat storage." Thermochimica Acta 687, no. : 178569.

Journal article
Published: 09 January 2020 in Applied Sciences
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The theoretical limits of water sorbate-based chemical sorption heat storage are investigated in this study. First, a classification of thermochemical heat storage is proposed based on bonding typology. Then, thermodynamics of chemical solid/gas sorption is introduced. The analysis of the reaction enthalpy from the literature indicates that this value is only slightly varying for one mole of water. Using this observation, and with the help of thermodynamic considerations, it is possible to derive conclusions on energy efficiency of closed and open heat storage systems. Whatever the salt, the main results are (1) the energy required for evaporation of water is, at least, 65% of the available energy of reaction, and (2) the maximum theoretical energy efficiency of the system, defined as the ratio of the heat released to the building over the heat provided to the storage, is about 1.8. Considering the data from literature, it is also possible to show that perfectly working prototypes have an energy efficiency about 49%. Based on those results, it is possible to imagine that for the best available material, a perfect thermochemical heat storage system would correspond to 12 times water with a temperature difference about 50 °C. Such solution is definitely competitive, provided that some difficult issues are solved—issues that are discussed throughout this paper.

ACS Style

Frédéric Kuznik; Kévyn Johannes. Thermodynamic Efficiency of Water Vapor/Solid Chemical Sorption Heat Storage for Buildings: Theoretical Limits and Integration Considerations. Applied Sciences 2020, 10, 489 .

AMA Style

Frédéric Kuznik, Kévyn Johannes. Thermodynamic Efficiency of Water Vapor/Solid Chemical Sorption Heat Storage for Buildings: Theoretical Limits and Integration Considerations. Applied Sciences. 2020; 10 (2):489.

Chicago/Turabian Style

Frédéric Kuznik; Kévyn Johannes. 2020. "Thermodynamic Efficiency of Water Vapor/Solid Chemical Sorption Heat Storage for Buildings: Theoretical Limits and Integration Considerations." Applied Sciences 10, no. 2: 489.

Journal article
Published: 16 December 2019 in Renewable Energy
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Physisorption heat storage in buildings can be a key technology for a more effective use of heating energy. However, a better understanding of key factors influencing the design and control of such systems is necessary. This paper presents the sensitivity analysis of the modeling parameters in the case of an open zeolite 13X/moist air heat storage system for building applications. The quantities of interest are the heat storage density and the discharge power density of the system. At the beginning, the whole analysis space is composed of 21 physical properties and 7 operating conditions and geometrical properties. After a first threshold selection, analysis of variance is carried on the remaining parameters, with a full factorial design of experiments to perform a complete sensitivity analysis of the model. The results show that only 3 thermophysical properties, i.e. the heat of adsorption, the water vapor molar mass and the adsorption equilibrium, and 3 operating conditions and system geometry parameters, i.e. the inlet relative humidity, the bed length and the inlet fluid flow rate, drive the outlet power density and heat storage density. The way those 6 parameters influence the outputs is also discussed and quantitatively assessed.

ACS Style

Frédéric Kuznik; Damien Gondre; Kévyn Johannes; Christian Obrecht; Damien David. Sensitivity analysis of a zeolite energy storage model: Impact of parameters on heat storage density and discharge power density. Renewable Energy 2019, 149, 468 -478.

AMA Style

Frédéric Kuznik, Damien Gondre, Kévyn Johannes, Christian Obrecht, Damien David. Sensitivity analysis of a zeolite energy storage model: Impact of parameters on heat storage density and discharge power density. Renewable Energy. 2019; 149 ():468-478.

Chicago/Turabian Style

Frédéric Kuznik; Damien Gondre; Kévyn Johannes; Christian Obrecht; Damien David. 2019. "Sensitivity analysis of a zeolite energy storage model: Impact of parameters on heat storage density and discharge power density." Renewable Energy 149, no. : 468-478.

Conference paper
Published: 23 October 2019 in IOP Conference Series: Materials Science and Engineering
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Excessive indoor moisture promotes the growth of mold and condensation on building envelope, which lead to severe IAQ problems. Given the transient, unsteady heat and mass transfer problem, studies dealing with the condensation phenomenon are generally lacking in the literature, especially studies on the condensation rate prediction. Consequently, this paper presents a method to quantify experimentally the condensation rate of droplets formed on a cold glazing surface in a full-scale entirely controlled test room (6.2 x 3.1 x 2.5 m). The condensation qualitative characterization, i.e. the moment of its appearance and its growth mechanism, is achievable using a macro-photography technique. From the time-series of droplet images captured, an image post-processing method is used to detect the droplet contours and to estimate the condensation mass flow rate. Comparisons between experimental and theoretical results show some agreement, which could validate the feasibility of imaging techniques in full-scale condensation studies. Those first results are encouraging and valuable since there were no similar studies in the literature at such the scale. Further investigations are needed in order to clarify all these aspects related to the accuracy of the condensation rate quantification methodology developed in this work.

ACS Style

C K Nguyen; C Teodosiu; Frédéric Kuznik; D David; G Rusaouën. Full-scale experimental study of moisture condensation on the glazing surface: condensation rate characterization. IOP Conference Series: Materials Science and Engineering 2019, 609, 032035 .

AMA Style

C K Nguyen, C Teodosiu, Frédéric Kuznik, D David, G Rusaouën. Full-scale experimental study of moisture condensation on the glazing surface: condensation rate characterization. IOP Conference Series: Materials Science and Engineering. 2019; 609 (3):032035.

Chicago/Turabian Style

C K Nguyen; C Teodosiu; Frédéric Kuznik; D David; G Rusaouën. 2019. "Full-scale experimental study of moisture condensation on the glazing surface: condensation rate characterization." IOP Conference Series: Materials Science and Engineering 609, no. 3: 032035.

Proceedings article
Published: 31 July 2019 in Materials and Contact Characterisation IX
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ACS Style

Bao Chen; Matthieu Horgnies; Vincent Morin; Mouna Boumaaza; Bruno Huet; Edouard Gengembre; Isabelle Baco; Kevyn Johannes; Frédéric Kuznik. STUDY OF CARBONATION DURABILITY OF SEVERAL ETTRINGITE-ENRICHED PASTES. Materials and Contact Characterisation IX 2019, 1 .

AMA Style

Bao Chen, Matthieu Horgnies, Vincent Morin, Mouna Boumaaza, Bruno Huet, Edouard Gengembre, Isabelle Baco, Kevyn Johannes, Frédéric Kuznik. STUDY OF CARBONATION DURABILITY OF SEVERAL ETTRINGITE-ENRICHED PASTES. Materials and Contact Characterisation IX. 2019; ():1.

Chicago/Turabian Style

Bao Chen; Matthieu Horgnies; Vincent Morin; Mouna Boumaaza; Bruno Huet; Edouard Gengembre; Isabelle Baco; Kevyn Johannes; Frédéric Kuznik. 2019. "STUDY OF CARBONATION DURABILITY OF SEVERAL ETTRINGITE-ENRICHED PASTES." Materials and Contact Characterisation IX , no. : 1.

Research article
Published: 13 April 2019 in Building Simulation
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To better predict the effective energy performance of buildings in cities, this study addresses the modelling of local external radiative, thermal and aeraulic conditions. After reviewing existing modelling approaches that are suitable for estimating the building boundary conditions in energy simulation, this paper analyses external conditions derived from a building energy model (BuildSysPro) or a microclimatic model (SOLENE microclimat). Comparisons are made for the different faces of a generic building standing alone or located in an urban environment, with or without a thermally efficient envelope. When the modelling approach is adjusted, the results highlight significant deviations on the estimated radiative temperatures and wind-based quantities around the isolated building. When accounting for surrounding buildings, the results show a substantial reduction in short-wave radiative fluxes, which is explained by an imbalance between solar masks and multireflections, and a reduction in the wind-driven ventilation potential.

ACS Style

Lucie Merlier; Loïc Frayssinet; Kévyn Johannes; Frédéric Kuznik. On the impact of local microclimate on building performance simulation. Part I: Prediction of building external conditions. Building Simulation 2019, 12, 735 -746.

AMA Style

Lucie Merlier, Loïc Frayssinet, Kévyn Johannes, Frédéric Kuznik. On the impact of local microclimate on building performance simulation. Part I: Prediction of building external conditions. Building Simulation. 2019; 12 (5):735-746.

Chicago/Turabian Style

Lucie Merlier; Loïc Frayssinet; Kévyn Johannes; Frédéric Kuznik. 2019. "On the impact of local microclimate on building performance simulation. Part I: Prediction of building external conditions." Building Simulation 12, no. 5: 735-746.

Research article
Published: 13 April 2019 in Building Simulation
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Most of the building energy models are not suited to properly integrate local urban ambient conditions; thus, this study initiates a sensitivity analysis of the heating and cooling needs and operative temperature of buildings to local radiative, thermal and aeraulic external conditions. These conditions were estimated using the possibilities of a building energy model (based on the BuildSysPro Modelica library) or derived from microclimatic simulations (SOLENE microclimat) for generic isolated or urban buildings. The thermal behaviors of both energy-inefficient and energy-efficient buildings in summer and winter are examined. The results show major effects of short- and long-wave radiative heat transfers as well as aeraulics. According to present results, and given current urban growth and climate change challenges as well as the development of energy conservative buildings, this last point may become particularly critical in the future.

ACS Style

Lucie Merlier; Loïc Frayssinet; Kévyn Johannes; Frédéric Kuznik. On the impact of local microclimate on building performance simulation. Part II: Effect of external conditions on the dynamic thermal behavior of buildings. Building Simulation 2019, 12, 747 -757.

AMA Style

Lucie Merlier, Loïc Frayssinet, Kévyn Johannes, Frédéric Kuznik. On the impact of local microclimate on building performance simulation. Part II: Effect of external conditions on the dynamic thermal behavior of buildings. Building Simulation. 2019; 12 (5):747-757.

Chicago/Turabian Style

Lucie Merlier; Loïc Frayssinet; Kévyn Johannes; Frédéric Kuznik. 2019. "On the impact of local microclimate on building performance simulation. Part II: Effect of external conditions on the dynamic thermal behavior of buildings." Building Simulation 12, no. 5: 747-757.

Journal article
Published: 13 April 2019 in Building and Environment
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Superficial condensation phenomena often occur on the glazed elements of buildings. As a result, the aim of this study is to put forward an experimental approach to assess the condensation rate on building glazing surface for full-scale room tests under realistic conditions. The proposed method for condensation quantification is applied in this work for surface condensation on a cold glazing (2.90 m × 2.30 m) within a ventilated test room (6.20 m × 3.10 m x 2.50 m). We first describe the full-scale test cell, focusing then on the experimental apparatus employed for the condensation study. This is followed by the description of the methodology for the condensation rate quantification. The approach is based on image processing techniques, using condensation pictures. This allows also to reveal the mechanisms behind the condensation appearance and growth. On the other hand, the experimental data achieved by this method are compared with theoretical results based on condensation rate and heat transfer coefficient correlations available in the literature. An overall difference of up to 18% between the measured results and the theoretical results was found for the condensation rate. Consequently, the method proposed in this work leads to promising results concerning the condensation rate quantification on cold glazing within full-scale enclosures.

ACS Style

Chi-Kien Nguyen; Cătălin Teodosiu; Frédéric Kuznik; Damien David; Raluca Teodosiu; Gilles Rusaouën. A full-scale experimental study concerning the moisture condensation on building glazing surface. Building and Environment 2019, 156, 215 -224.

AMA Style

Chi-Kien Nguyen, Cătălin Teodosiu, Frédéric Kuznik, Damien David, Raluca Teodosiu, Gilles Rusaouën. A full-scale experimental study concerning the moisture condensation on building glazing surface. Building and Environment. 2019; 156 ():215-224.

Chicago/Turabian Style

Chi-Kien Nguyen; Cătălin Teodosiu; Frédéric Kuznik; Damien David; Raluca Teodosiu; Gilles Rusaouën. 2019. "A full-scale experimental study concerning the moisture condensation on building glazing surface." Building and Environment 156, no. : 215-224.

Preprint
Published: 08 April 2019
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The theoretical limits of water sorbate based chemical sorption heat storage are investigated in this study. First, a classification of \textit{thermochemical heat storage} is proposed based on bonding typology. Then, thermodynamics of chemical solid/gas sorption is introduced. The analysis of the reaction enthalpy from the literature indicates that this value is only slightly varying for one mole of water. Using this observation, and with the help of thermodynamical considerations, it is possible to derive conclusions on energy efficiency of closed and open heat storage systems. Whatever the salt, the main results are 1) the energy required for evaporation of water is, at least, 65% of the available energy of reaction and 2) the maximum theoretical energy efficiency of the system is about 1.8.

ACS Style

Frédéric Kuznik. Thermodynamic Efficiency of Water Vapor / Solid Chemical Sorption Heat Storage for Buildings: Theoretical Limits and Integration Considerations. 2019, 1 .

AMA Style

Frédéric Kuznik. Thermodynamic Efficiency of Water Vapor / Solid Chemical Sorption Heat Storage for Buildings: Theoretical Limits and Integration Considerations. . 2019; ():1.

Chicago/Turabian Style

Frédéric Kuznik. 2019. "Thermodynamic Efficiency of Water Vapor / Solid Chemical Sorption Heat Storage for Buildings: Theoretical Limits and Integration Considerations." , no. : 1.

Journal article
Published: 30 January 2019 in Solar Energy Materials and Solar Cells
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The cost of materials is one of main obstacles for the development of thermochemical energy storage. Compared with traditional inorganic salt hydrates, a mineral named ettringite can easily overcome this limit thanks to its large resource from cementitious materials. Meanwhile, possession of high energy density (about 500 kWh/m3), low corrosiveness, non-toxicity and low working temperature (~ 60 °C) around or below common heat resource (solar energy, industrial waste heat, urbane heat system, and even combination with grid) makes ettringite very competitive to be used in an integrated thermal energy storage system. In this paper, the analysis on the available data for structure, preparation of material, thermal conversion, reaction enthalpies, carbonation durability, and ionic substitution of ettringite has been established. Moreover, potential research directions and solutions to improve thermal performance of ettringite-based materials are proposed.

ACS Style

B. Chen; Frédéric Kuznik; Matthieu Horgnies; K. Johannes; V. Morin; E. Gengembre. Physicochemical properties of ettringite/meta-ettringite for thermal energy storage: Review. Solar Energy Materials and Solar Cells 2019, 193, 320 -334.

AMA Style

B. Chen, Frédéric Kuznik, Matthieu Horgnies, K. Johannes, V. Morin, E. Gengembre. Physicochemical properties of ettringite/meta-ettringite for thermal energy storage: Review. Solar Energy Materials and Solar Cells. 2019; 193 ():320-334.

Chicago/Turabian Style

B. Chen; Frédéric Kuznik; Matthieu Horgnies; K. Johannes; V. Morin; E. Gengembre. 2019. "Physicochemical properties of ettringite/meta-ettringite for thermal energy storage: Review." Solar Energy Materials and Solar Cells 193, no. : 320-334.

Journal article
Published: 25 January 2019 in Applied Energy
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Recent developments in building energy models for urban energy simulation are primarily based on bottom-up modelling (N models used for N buildings). This work aims to develop a single assembled model for multiple buildings for convenient use in detailed urban analysis. The proposed model exhibits state-space model formalism, and a state-size reduction technique is applied to maintain model accuracy, even for a low-order representation. To accelerate the calculation time and ensure numerical stability, a direct solver is proposed to eliminate the iterative calculations required in Dymola for annual load calculations. The results of the proposed reduced model are in good agreement with the reference model. For a test case of ten buildings, a 2nd order reduced model (i.e., 2 differential equations) with the proposed direct solver can predict accurately the dynamic energy behaviour, resulting in an error of about 0.43% for the annual loads.

ACS Style

Eui-Jong Kim; Xi He; Jean-Jacques Roux; Kévyn Johannes; Frédéric Kuznik. Fast and accurate district heating and cooling energy demand and load calculations using reduced-order modelling. Applied Energy 2019, 238, 963 -971.

AMA Style

Eui-Jong Kim, Xi He, Jean-Jacques Roux, Kévyn Johannes, Frédéric Kuznik. Fast and accurate district heating and cooling energy demand and load calculations using reduced-order modelling. Applied Energy. 2019; 238 ():963-971.

Chicago/Turabian Style

Eui-Jong Kim; Xi He; Jean-Jacques Roux; Kévyn Johannes; Frédéric Kuznik. 2019. "Fast and accurate district heating and cooling energy demand and load calculations using reduced-order modelling." Applied Energy 238, no. : 963-971.

Abstract
Published: 01 January 2019 in Proceedings
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More attention on renewable energy has been attracted after the achievement of Paris Agreement against climate change. Solar-based technology is supposed to be one of the most promising green energy technologies for residential buildings since its wide thermal usage for hot water and heating. However, the seasonal mismatch between its energy-production and consumption makes buildings need an energy storage system to improve the efficiency of renewable energy use. Indeed, even if different kinds of energy storage systems using sensible or latent heat already exist, thermochemical energy storage can be then recommended by considering the problems of energy dissipation during storage and low energy density for the first two methods. As potential thermochemical storage materials, ettringite (3CaO∙Al2O3∙3CaSO4∙32H2O) based materials possess high energy densities (~500 kWh/m3), low material cost (70°C) from solar collectors dehydrates ettringite to meta-ettringite, and consequently store heat to chemical energy; ii) discharging mode: humid air is pumped to material container to rehydrate meta-ettringite, and consequently release stored chemical energy as heating. However, the lack of extensive examination leads to poor knowledge on their thermal properties and limits maturity of this technology. Therefore, the aim of this work is to characterize the capacity of an ettringite-based material (named C80P20, containing ~70 wt.% ettringite) in terms of thermal energy storage by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Besides, a modular reactor adapting to thermal characterizations of C80P20 particles has been developed for various weights (up to 300 grams). In our case, the energy density of pure ettringite is around 1012 J/g while 708 J/g for C80P20 powder in TGA-DSC. First preliminary results from modular reactor demonstrate a general energy density of 150 kWh/m3 released by the hydration process of C80P20 grains (pre-dehydrated at 80 °C) at 25 °C and 85% relative humidity. Moreover, the reactor is intended to study the durability of the energy storage material over time, and also as function of the number of charging/discharging cycles.CaO∙Al2O3∙3CaSO4∙32H2O ettringite+heat↔3CaO∙Al2O3∙3CaSO4∙32-XH2Ometa-ettringite+XH2O

ACS Style

Bao Chen; Frédéric Kuznik; Matthieu Horgnies; Kévyn Johannes; Vincent Morin; Edouard Gengembre. A Modular Reactor for Thermochemical Energy Storage Examination of Ettringite-Based Materials. Proceedings 2019, 34, 18 .

AMA Style

Bao Chen, Frédéric Kuznik, Matthieu Horgnies, Kévyn Johannes, Vincent Morin, Edouard Gengembre. A Modular Reactor for Thermochemical Energy Storage Examination of Ettringite-Based Materials. Proceedings. 2019; 34 (1):18.

Chicago/Turabian Style

Bao Chen; Frédéric Kuznik; Matthieu Horgnies; Kévyn Johannes; Vincent Morin; Edouard Gengembre. 2019. "A Modular Reactor for Thermochemical Energy Storage Examination of Ettringite-Based Materials." Proceedings 34, no. 1: 18.

Journal article
Published: 15 August 2018 in Renewable Energy
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Thermal energy storage is a key technology for heat management and efficient use of renewable energy production. High-power and high-density heat storage in buildings can be achieved with physisorption. The present work presents a study of a full-scale zeolite 13X open reactor to be integrated in the ventilation system of a dwelling. An original numerical model of the system is developed and validated using various data obtained from eight sets of experiments. The analysis of the energy chain shows that approximately 70% of absorbed energy is converted into useful heat released on discharge. However, approximately half of the total heat is also directly lost at the outlet of the adsorbent bed. The overall system efficiency is 36%.

ACS Style

Frédéric Kuznik; Damien Gondre; Kévyn Johannes; Christian Obrecht; Damien David. Numerical modelling and investigations on a full-scale zeolite 13X open heat storage for buildings. Renewable Energy 2018, 132, 761 -772.

AMA Style

Frédéric Kuznik, Damien Gondre, Kévyn Johannes, Christian Obrecht, Damien David. Numerical modelling and investigations on a full-scale zeolite 13X open heat storage for buildings. Renewable Energy. 2018; 132 ():761-772.

Chicago/Turabian Style

Frédéric Kuznik; Damien Gondre; Kévyn Johannes; Christian Obrecht; Damien David. 2018. "Numerical modelling and investigations on a full-scale zeolite 13X open heat storage for buildings." Renewable Energy 132, no. : 761-772.

Journal article
Published: 01 August 2018 in Sustainable Cities and Society
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The study aims at analyzing the performance of phase change material (PCM) in two residential rooms within heating periods. This paper presents the results of experiments performed in the Faculty of Science Aïn Chock, Casablanca. The in-situ cells are identical with dimension of 3 m × 3 m × 3 m. The walls are made with double layer of alveolar brick (72 mm) separated by an air layer (126 mm). The internal faces of one of these cavities are embedded with a PCM layer (5.3 mm). The tested PCM is Energain® wallboard manufactured by DuPont™. The cavities are heated by oil radiators which delivered the same energy power. Measures focus on ambient temperatures, wall temperatures and instantaneous heat flux densities through the walls. Also, the effect of phase change material on energy consumption was investigated. The results, related to two periods (January 25th to 27th, 2015 and April 1st to 3rd, 2015), show that the inclusion of the PCM to a standard wall leads to a temperature increase about 6 °C during the night and increases strongly the apparent thermal mass of the room, which allows a reduction in heat fluxes. Finally, the heating energy savings resulting from PCM application can reach up to 20%.

ACS Style

Amina Mourid; Mustapha El Alami; Frédéric Kuznik. Experimental investigation on thermal behavior and reduction of energy consumption in a real scale building by using phase change materials on its envelope. Sustainable Cities and Society 2018, 41, 35 -43.

AMA Style

Amina Mourid, Mustapha El Alami, Frédéric Kuznik. Experimental investigation on thermal behavior and reduction of energy consumption in a real scale building by using phase change materials on its envelope. Sustainable Cities and Society. 2018; 41 ():35-43.

Chicago/Turabian Style

Amina Mourid; Mustapha El Alami; Frédéric Kuznik. 2018. "Experimental investigation on thermal behavior and reduction of energy consumption in a real scale building by using phase change materials on its envelope." Sustainable Cities and Society 41, no. : 35-43.

Review
Published: 29 June 2018 in Renewable and Sustainable Energy Reviews
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On one hand, physical adsorption, also named physisorption, is a process that can be used to storage thermal energy with an energy density higher than sensible or latent storages. On the other hand, in Europe, 26% of the final energy consumption is related to the energy systems of households [1] and 80% of this energy is needed for heating purposes [2]. The consequence is the development of thermal energy storage systems, based on physisoprtion, for building application. The objective of this paper is first to present the basics concerning physisorption heat storage. Then, experimental developments from the literature are reviewed, based on three scales: the material scale, the reactor scale and the system scale. From the review, development of commercial systems faces with scientific and technological issues that must be addressed to reach a higher technology readiness level with an acceptable system cost.

ACS Style

Frédéric Kuznik; Kevyn Johannes; Christian Obrecht; Damien David. A review on recent developments in physisorption thermal energy storage for building applications. Renewable and Sustainable Energy Reviews 2018, 94, 576 -586.

AMA Style

Frédéric Kuznik, Kevyn Johannes, Christian Obrecht, Damien David. A review on recent developments in physisorption thermal energy storage for building applications. Renewable and Sustainable Energy Reviews. 2018; 94 ():576-586.

Chicago/Turabian Style

Frédéric Kuznik; Kevyn Johannes; Christian Obrecht; Damien David. 2018. "A review on recent developments in physisorption thermal energy storage for building applications." Renewable and Sustainable Energy Reviews 94, no. : 576-586.