A ce jour, les solutions de stockage d'énergie apparaissent comme des solutions pertinentes permettant d'atteindre les cibles énergétiques futures et de répondre aux exigences environnementales actuelles. Le but de cette thèse est d’optimiser un système de stockage d'énergie thermique innovant basé sur un échangeur eau – matériaux à changement de phase. Ce système est couplé à l’architecture énergétique multi-sources d’un îlot composé de trois bâtiments à énergie positive situé à Lyon : l’îlot HIKARI. Afin de disposer d’un outil numérique robuste pour pouvoir optimiser cette technologie, un modèle numérique du système de stockage d’énergie thermique a été développé dans le but de reproduire le comportement du système de stockage de référence. Une fois fini, le modèle a été validé en trois étapes: une numérique et deux expérimentales. Dans un premier temps il a été validé numériquement, en comparant ses résultats avec un modèle conçu en adoptant une approche numérique différente (« Computational Fluid Dynamics »), dans un second temps il a été validé à l’échelle réelle en exploitant les données in-situ du système de HIKARI. Enfin, le modèle numérique a été validé expérimentalement grâce à un prototype expérimental conçu et réalisé à l’ENTPE dans le cadre des travaux de cette thèse reproduisant le comportement du système de stockage étudié. Après avoir été validé, le modèle a été utilisé pour procéder à l’optimisation de sa performance en utilisant la technique des algorithmes génétiques. L’analyse des résultats de ces simulations a notamment abouti sur des recommandations de dimensionnement et d’usage pour l’Ilot HIKARI et des bâtiments futurs intégrant la technologie de stockage étudiée. La thèse a été financée par l’Agence de l’environnement et de la maîtrise de l’énergie (ADEME) dans le cadre du projet « Optimisation des architectures Énergétiques multi-sources couplées aux techniques avancées du stockage d'énergie dans le bâtiment » en partenariat avec Bouygues immobilier et Manaslu – CMDL. / One of the most promising technics used in building applications for energy efficiency purposes is the thermal energy storage (TES). Despite the thorough research on TES techniques of the last years, the release to market of cost effective technologies is quite recent. The aim of this study is to optimize the energetic behavior of an innovative TES technology consisting on a water/PCM exchanger that is part of the multi-energy production and storage systems of HIKARI, a positive energy district located in Lyon and consisting of three buildings. In order to optimize this innovative technic, a numerical model reproducing the functioning of the reference system was created. In order to make a numerical validation a second numerical model was developed using a different software based on a different numerical method and, once the in situ data obtained from the reference system monitoring, a first experimental validation was obtained. Subsequently, an innovative experimental prototype reproducing the behavior of the reference PCM-Water heat exchanger has been realized, in order to validate and calibrate the numerical model and carry out a large amount of operating scenarios. Once the model numerically and experimentally validated, the optimization of the HIKARI’s cold storage system technology has been obtained using Genetic Algorithms (GAs) finding the best values to allocate to four characteristics of the cold storage system, in order to minimize two predefined objective functions linked to its functioning. This work was supported by the French Agency for Environment and Energy Management (ADEME) and it was part of the project “Optimization of innovative energy storage technologies when coupled to multi-sources energy architectures”, in cooperation with Bouygues immobilier and Manaslu – CMDL.

The study compared four different cooling systems and analyzed the competitiveness in those systems regarding electricity consumption, environmental impact and life cycle cost analysis. The assignment was given from the consultant company Ramböll who believed in these systems design as a solution to minimize the energy consumption in cooling systems. The purpose of the study was to facilitate the selection of cooling system by finding a key ratio for profitability in terms of energy consumption. This makes it easier to select one of these systems in project planning. A representative building model was built in the energy simulation program IDA ICE. From these result an energy profile was achieved.   The energy profile was then used in another simulation program called Polysun were detailed system regulations could be made. By programing the controllers to regulate the distribution in an efficient way the energy consumption was minimized and matches the building cooling demand. The simulation was done for one full year and the obtained total energy consumption for each system, it was then used to calculate the operational cost. The life cycle cost analysis is a tool that compare each system costs during its lifetime. A depth analysis was also done regarding the sensitivity of changes in the profitability for the systems, by applying different electrical price and cost of capital.   The study shows that the systems with different borehole storage solutions proves to be effective systems for covering the building cooling demand with a significant lower electricity consumption, compared to the system with a chiller. The different borehole storage systems also contribute to cover some parts of the heat demand, since the stored heat needs to be used in order to make the borehole storage functional. By analyzing the cooling systems in a comparative perspective, the most effective solution is identified from an economic and environmental point of view. The cooling system that only contained a borehole storage was the solution that distinguished the most regarding total electricity consumption and environmental impact. This system resulted in being the most profitable cooling system between the compared systems. The combined system with a borehole storage system and a heat pump solution was also proven to be an effective cooling system, additionally with an advantage of providing parts of the hot water demand in the building.

Ces dernières années, la technologie RFID (identification par radiofréquence) s’est fortement développée dans de nombreuses applications industrielles parmi lesquelles les secteurs de l’aéronautique et l’automobile où il y a une forte demande en systèmes d’auto-identification fonctionnant dans des environnements difficiles. Dans ce contexte, l'objectif de ces travaux de thèse est d'étudier les effets du stockage thermique sur la fiabilité des tags RFID UHF passifs. Pour ce faire nous avons adopté une méthodologie homogène contribuant de façon significative à atteindre nos objectifs. La première étape de cette méthodologie consistait à choisir le tag à tester, deux types de tags Web et Tageos provenant de deux fabricants différents ont été soumis à des tests de vieillissement accélérés sous différentes températures. La deuxième étape était de définir les paramètres des tests de vieillissement et de caractériser les tags vieillis. À l'aide d'un banc de mesure dédié, la puissance réfléchie par l’ensemble des tags vieillis est mesurée après chaque phase de vieillissement en fonction de la distance entre l’antenne du tag et celle du lecteur RFID. La puissance réfléchie diminue considérablement après chaque phase de vieillissement avec différentes dynamiques de dégradation pour tous les tags vieillis. Cette dynamique de dégradation dépend du type de tag testé et de la température de test. La dernière étape de la méthodologie comportait l’analyse statistique et physique de défaillance, des différences claires dans les modes, les mécanismes et les temps de défaillance entre les tags Web et Tageos ont été observées. L’analyse physique de défaillance par microscopie optique et MEB a révélé des fissures dans les conducteurs métalliques de l'antenne pour une partie des tags vieillis, cependant pour l’autre partie des tags, aucune défaillance de l'antenne n'a été observée. Des déformations au niveau de la matrice polymère de l'ACP ont été révélées, ce qui a modifié l'adaptation d'impédance entre le RFIC et l'antenne. Des simulations en utilisant le logiciel de modélisation multi-physique COMSOL a été mise en place dans le but de reproduire les mécanismes de défaillances révélés expérimentalement soit au niveau de l’antenne ou de la RFIC. Ces travaux de thèse ont démontré l'importance d'étudier les effets du stockage en haute température sur la fiabilité des tags RFID passifs. Les défaillances sont apparues plus rapidement et les tests ont coûté considérablement moins onéreux par rapport aux autres types de tests de vieillissement accélérés. / Nowadays, RFID has strongly developed in many industrial applications, including the aeronautics and automotive sectors, where there is a strong demand for auto-identification systems operating in severe environments. In this context, the objective of this thesis is to study the effects of thermal storage on the reliability of passive UHF RFID tags. To achieve this, we adopted a consistent methodology. The first step of this methodology was to choose the tag under test. Two types of tags Web and Tageos from two different manufacturers are aged under high temperatures. The second step was to define the parameters of the aging tests and to characterize the aged tags. Using a dedicated measurement bench, the reflected power is measured after each aging phase for all tested tags to determine the power loss caused by the high temperature storage. Reflected power decrease significantly after each aging phase with different dynamics of degradation for all aged tags. This dynamics of degradation depends on the temperature test and the type of tag. The final step involved statistical and physical failure analysis. Clear differences about modes, mechanisms and failure times between Web and Tageos tags have been observed, it seems that Tageos tags are more reliable than Web tags. Failure analysis of the samples, using an optical microscope and SEM, has revealed, cracks in the antenna metallic conductors on a part of the aged tags. In another part of the tags, no failures in the antenna have been seen, but clear deformations at the polymer matrix of the ACP have been observed, thus changing the impedance matching between the RFIC and the antenna. Simulations using the COMSOL multiphysics software have been implemented in order to reproduce the experimental failure mechanisms. This thesis work has demonstrated the importance of studying the effects of high temperature storage on the reliability of passive RFID tags. Failures appeared faster and tests cost considerably less than other types of accelerated aging tests.

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In recent years we may observe a growth in construction of passive houses and low energy houses using lightweight constructions such as modern wooden houses. It is assumed that wooden houses keep overheating more comparing to brick houses during summer period. Due to the lack of research in this field the paper investigates the influence of internal thermal storage mass in passive houses constructions on their summer thermal stability under the Czech climatic conditions. Only sensible heat accumulation without a usage of phase change materials is examined. Differences between wooden houses comparing to brick-built houses are emphasized. Objects of research are mostly residential passive houses in low energy building standards. However, the results of research might be applied to different types of buildings as well. The first section outlines theoretical fundamentals. For the research itself various scientific research methods were used, such as basic mathematical calculations, experimental temperature measurement of two buildings (detached house in Dubňany and in Moravany) and numerical simulations. Own tribute to the research was first of all discussion on the topic of thermal accumulation and structures heat capacity calculation. Experimental measurements outlined conclusive evidence about the importance of internal thermal storage mass in respect of interior summer overheating. The research confirmed that the highest interior temperature reached is mostly influenced by solar gains through unshaded windows. However, the influence of internal thermal storage mass is not remote. If we compare standard timber-framed wooden house to the hole ceramic bricks-built house, the wooden house will overheat by 0,5°C more during a standard day. Wider spread in the maximum temperature reached was measured for lightweight consturctions wooden houses without any internal thermal storage mass. Therefore, such structures should have an additional layer of thermal storage mass.

Dans le contexte énergétique français actuel, deux principaux enjeux émergent. À court terme, des pointes de consommation électrique croissantes sont observées les dernières années pendant la période hivernale. Ces pointes sont fortement liées au chauffage électrique et ont des conséquences économiques, environnementales et sociales importantes. Dans un long terme, des objectifs environnementaux ambitieux ont été fixés au niveau national et européen, nécessitant la technologie de stockage thermique et une gestion efficace de l'environnement bâti. Les Matériaux à Changement de Phase (MCP) ainsi que les dispositifs de type échangeurs thermiques offrent des résultats promettant grâce au stockage thermique et le déplacement des consommations. Dans ce cadre, l’objectif de cette thèse est de développer des solutions de déplacement des consommations énergétiques qui prennent en compte le confort thermique des occupants et la qualité de l’air intérieur. Pour ce faire, deux outils sont nécessaires: un échangeur thermique expérimental (prototype) et un modèle numérique capable de simuler son comportement. L'échangeur contient du MCP macroencapsulé (paraffine) et est conçu de manière à faciliter son intégration dans un système de ventilation. Il a comme but de décaler la consommation due au chauffage électrique vers la période hors pointe. Le dispositif a été caractérisé expérimentalement lors des cycles thermiques complets (charge et décharge) en utilisant une quantité importante de capteurs. Il a ensuite été couplé à une cellule expérimentale, afin de tester des stratégies de contrôle préliminaires. Le modèle numérique est basé sur la discrétisation spatiale et l’établissement du bilan de chaleur des couches considérées, la méthode de la capacité thermique apparente, ainsi que l’utilisation des différences finies. Après validation à l’aide des données expérimentales, le modèle a été utilisé pour optimiser la performance de l'échangeur. Plusieurs paramètres ont été étudiés, y compris les dimensions de l'échangeur, la quantité et les propriétés du MCP, en cherchant la configuration avec le compromis optimal entre la chaleur emmagasinée et le temps nécessaire pour la charge et la décharge. Le modèle numérique a été couplé à un modèle de simulation du bâtiment et un logement de 80m2 a été conçu pour la mise en oeuvre et l'évaluation des stratégies de contrôle, en investiguant différents scénarios sur une période hivernal d’un mois. Les scénarios varient avec une complexité croissante, d'abord en considérant l’effacement énergétique et le confort thermique, ensuite en ajoutant le prix final de la consommation électrique et enfin en prenant compte la qualité de l'air intérieur avec la présence d'une famille de quatre personnes. 6 Cette étude a été menée dans le cadre d'un projet financé par l'Agence National de la Recherche (Stock-Air: ANR-Stock-E) et a également été soutenu par le ministère de l'Ecologie, du Développement durable et de l'Energie. / Considering the current French energy context, two major challenges are emerging. In the short term, significant peak power consumption has been observed in the past few years during the winter season. These peaks are strongly linked to electrical space heating and have important economic, environmental and social implications. In the long term, ambitious environmental goals have been set at national and European levels, requiring thermal storage technology and efficient management of the built environment. As part of the solution, Phase Change Materials (PCM) and heat exchanger applications offer promising results through thermal storage and load shifting techniques. Within this framework, the objective of this thesis is to develop load shifting solutions which also take into account the thermal comfort of the occupants and the indoor air quality. To achieve this, two tools were necessary: an experimental heat exchanger unit (prototype) and a numerical model that accurately simulates its behavior. The exchanger contains macroencapsumated PCM (paraffin) and is conceived in a way that facilitates its integration in a ventilation system. It is aimed to shift space heating electrical consumption from peak to off-peak period. The unit was experimentally characterized, using an important amount of sensors through full thermal cycles (charging and discharging) and was coupled to an experimental test cell, which led to the testing of preliminary control strategies. The numerical model is based on the heat balance approach and the apparent heat capacity method, using finite differences for differential equation solution under Matlab/Simulink environment. After validation with experimental data, the model was used to optimize the performance of the exchanger. Several parameters were investigated, including heat exchanger dimensions, PCM quantity and properties, seeking the configuration with the optimal compromise between stored heat and the time needed for the charging / discharging process. The numerical model was coupled to a building simulation model and an 80m2 dwelling was conceived for control strategies implementation and evaluation, by investigating different scenarios over a one- month winter period. The scenarios vary with increasing complexity, first considering load shifting and thermal comfort, then adding the final price of electricity consumption and finally taking into account the indoor air quality with the presence of a four-person family. This study has been conducted within the framework of a project funded by the French National Research Agency (Stock-Air: ANR-Stock-E) and was also financially supported by the French Ministry of Sustainable Development.

This thesis presents work on a holistic approach for improving the overall design of solar cooling systems driven by solar thermal collectors. Newly developed methods for thermodynamic optimization of hydraulics and control were used to redesign an existing pilot plant. Measurements taken from the newly developed system show an 81% increase of the Solar Cooling Efficiency (SCEth) factor compared to the original pilot system. In addition to the improvements in system design, new efficiency factors for benchmarking solar cooling systems are presented. The Solar Supply Efficiency (SSEth) factor provides a means of quantifying the quality of solar thermal charging systems relative to the usable heat to drive the sorption process. The product of the SSEth with the already established COPth of the chiller, leads to the SCEth factor which, for the first time, provides a clear and concise benchmarking method for the overall design of solar cooling systems. Furthermore, the definition of a coefficient of performance, including irreversibilities from energy conversion (COPcon), enables a direct comparison of compression and sorption chiller technology. This new performance metric is applicable to all low-temperature heat-supply machines for direct comparison of different types or technologies. The achieved findings of this work led to an optimized generic design for solar cooling systems, which was successfully transferred to the market.

This study centered on a novel thermoelectric generator (TEG) integrated into the built environment. Designed by Watts Thermoelectric LLC, the TEG is essentially a novel assembly of thermoelectric modules whose required temperature differential is supplied by hot and cold streams of water flowing through the TEG. Per its recommended operating conditions, the TEG nominally generates 83 Watts of electrical power. In its default configuration in the built environment, solar-thermal energy serves as the TEG’s hot stream source and geothermal energy serves as its cold stream source. Two systems-level, thermodynamic analyses were performed, which were based on the TEG’s upcoming characterization testing, scheduled to occur later in 2011 in Detroit, Michigan. The first analysis considered the TEG coupled with a solar collector system. A numerical model of the coupled system was constructed in order to estimate the system’s annual energetic performance. It was determined numerically that over the course of a sample year, the solar collector system could deliver 39.73 megawatt-hours (MWh) of thermal energy to the TEG. The TEG converted that thermal energy into a net of 266.5 kilowatt-hours of electricity in that year. The second analysis focused on the TEG itself during operation with the purpose of providing a preliminary thermodynamic characterization of the TEG. Using experimental data, this analysis found the TEG’s operating efficiency to be 1.72%. Next, the annual emissions that would be avoided by implementing the zero-emission TEG were considered. The emission factor of Michigan’s electric grid, RFCM, was calculated to be 0.830 tons of carbon dioxide-equivalent (CO2e) per MWh, and with the TEG’s annual energy output, it was concluded that 0.221 tons CO2e would be avoided each year with the TEG. It is important to note that the TEG can be linearly scaled up by including additional modules. Thus, these benefits can be multiplied through the incorporation of more TEG units. Finally, the levelized cost of electricity (LCOE) of the TEG integrated into the built environment with the solar-thermal hot source and passive ground-based cold source was considered. The LCOE of the system was estimated to be approximately $8,404/MWh, which is substantially greater than current generation technologies. Note that this calculation was based on one particular configuration with a particular and narrow set of assumptions, and is not intended to be a general conclusion about TEG systems overall. It was concluded that while solar-thermal energy systems can sustain the TEG, they are capital-intensive and therefore not economically suitable for the TEG given the assumptions of this analysis. In the end, because of the large costs associated with the solar-thermal system, waste heat recovery is proposed as a potentially more cost-effective provider of the TEG’s hot stream source. / text