Дисертації з теми "Récupération de la chaleur perdue"
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El, Habchi Abdellilah. "Récupération d'énergies thermiques perdues sur moteur automobiles : mise en jeu d'une approche exergétique." Ecole centrale de Nantes, 2011. http://www.theses.fr/2011ECDN0053.
Nowadays,, because of oil price and the global warming issues, many researchers try to answer to CO2 emission regumations by improving Internal Combustion (IC) engine efficiency, today limited at best around 40%. It is commonly admitted that a large part of the energy losses in IC engine is due to heat transfert: heating coolant, oil, exhaust gases and air around the engine (under the hood). In order to improve engine efficiency, it is interesting to recover a part of the thermal energy available in exhaust gases or coolant, to produce additional work. When heat recovery is considered, a conversion of the recovered (thermal) energy into useful work, has to be done. However, only a part of therma energy is avaible to produce work, that it is the concept of energy (or available energy or availability) was introduce as a supplement to the traditional energy balance. By using the two first laws of thermodynamics, the energy balance finally allows to evaluate the maximum useful work that can be exctracted from the chemical energy content of the fuel. This Ph. D presents exergy balances for Spark-Ignition engine operating under steadystate and transient conditions. To achieve this goal several numerical models have been developed based on the simulation software LMS Imagine. Lab AMESim. First, exergy balances have been realized for a single cylinder engine. These balances have been done in unsteady-state conditions on a given operating point. The use of a simplified system has removed several questions about energy. Secondly, the approach used for the single cylinder engine has been exte"nded to a complete four-cylinder engine working in steady-state conditions. Finally, energy balances have been computed for a vehicle operating user transient conditions
Fofana, Siaka. "Contribution à la conception d'un système informatique d'aide à la valorisation des rejets thermiques des procédés discontinus : application à l'ennoblissement textile." Mulhouse, 1989. http://www.theses.fr/1989MULH0123.
Huang, Feng. "Contribution à l'évaluation et à la configuration optimale des systèmes à énergie distribuée basés sur la récupération de rejets de chaleur industrielle." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30297/document.
Nowadays, industry accounts for about one third of energy consumption and CO2 emissions. Substantial opportunities exist to address environmental and economic challenges, including energy efficiency in general and the use of energy, especially in industrial parks. Distributed Energy Systems (DES) correspond in this sense to a common and promising solution. We have therefore undertaken a global site approach, including the aggregation of all influential energy, economic, environmental and managerial variables in an installation of this type. Implementation on a pilot plant and its validation have made it possible to identify the scientific and technical locks and to measure the relevance and efficiency of the elements and stationary operating modes of the systems. This study offers a method of cooperative use of the indicators of impacted domains and also opens perspectives on developments in dynamic mode for the purposes of optimum driving assistance
Konduru, Raj Narayan. "Coupled Conduction-Convection-Radiation heat transfer using Mesh-less methods : Application to porous heat exchanger." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0190.
This research concentrates on heat recovery in industries operating at high temperatures, such as metallurgy, iron and steel, cement, and glass production, with the goal of mitigating greenhouse gas emissions. An effective approach involves incorporating a porous structure within the heat exchanger to enhance heat transfer rates while minimizing pressure drops. Initially, experiments were conducted using porous heat exchangers with Kelvin cell foam structures. The experimental setup involved placing the foam inside a tube and subjecting it to high temperatures of up to SI{800}{degreeCelsius} radially, while air was flown axially. This arrangement encompassed the physical phenomena of coupled conduction, convection, and radiation. The results of these experiments were subsequently employed to validate a numerical model utilizing a deterministic approach, forming the foundational step of the project. However, these methods encountered challenges in conducting comprehensive analyses, considering various foam types, distinct geometric properties, and thermophysical material attributes that influence heat exchanger performance due to the intricate structure. Moreover, the interplay of conduction, convection, and radiation along with complex foam structures demanded substantial computational resources. Consequently, an alternative to the deterministic method (DM) was sought, leading to the exploration of mesh-free methods. The validated DM numerical model serves as a reference for the alternative models, with two models being adopted/developed. The first model, known as Semi Meshless Method (SMM) or DM-MCM, merges the deterministic approach with the statistical Monte Carlo Method. In this model, the deterministic approach efficiently calculates velocity fields, while the Monte Carlo method determines local temperature distributions. This combination proves effective and robust for complex geometries. Nevertheless, the first model retains a limitation in calculating flow fields using the deterministic approach, prompting the design of a second innovative model. The second model, referred to as SPH-MCM, utilizes smoothed particle hydrodynamics (SPH) to overcome the limitations of grid-based approximations when computing flow fields. SPH eliminates the need for a complicated mesh, facilitating more efficient velocity field calculations. These fields are then employed to compute temperature distributions using the Monte Carlo method. The primary advantage of this model lies in its reliance on a surface mesh and points, instead of solid geometries and a volume mesh. However, the SPH method requires a longer computation time compared to the deterministic approach. Both alternative models exhibit a high level of agreement with the deterministic model, highlighting their potential to advance heat exchanger design. The first model is employed for a comprehensive parametric analysis aimed at studying the power extracted and pressure drop for different porous structure's in the heat exchanger configuration
Bert, Juliette. "Contribution à l'étude de la valorisation des rejets thermiques : étude et optimisation de moteurs Stirling." Phd thesis, Université de Bourgogne, 2012. http://tel.archives-ouvertes.fr/tel-00862454.
Piton, Maxime. "Récupération de la chaleur fatale : application aux fours rotatifs." Thesis, Nantes, Ecole des Mines, 2015. http://www.theses.fr/2015EMNA0235/document.
This work results on a finding: the heat loss from rotary kiln represents a significant energy amount during materials processing in civil engineering domain. Motivated by traditional energy recovery methods from heat exchanger, this thesis is aimed at providing their rigorous thermodynamic diagnostics. Firstly, a thermal-granular model is developed, and then validated in asphalt plant whose the rotary kiln is composed of flights to ensure the materials mixing. Their cross-section distribution is calculated from a granular discharge law. The numerical experiments showed an increase of heat transfer phenomena between gases and solids, and those between the solids and the wall, this latter phenomenon limiting the process performances. Heat recovery exchanger applied to the rotary kiln is studied from a semi-industrial pilot based on a rotor stator configuration including a tangential inlet. Developing a Taylor-Couette-Poiseuille flow, the heat transfer results are undoubted in the range of the studied Reynolds numbers: the axial motion contribution is larger than the rotational turbulent motion. A dimension less criterion is proposed in order to be applied to the aforementioned integrated model including the heat exchanger applied to the rotary kiln, its effect being assessed upon the internal thermalprofiles. Finally, the vortices flow structure within the annular gap exchanger is studied from Large Eddy simulation. The amplitude and frequency passage of the contrarotatives cells located in the turbulent boundary layer are connected to the process parameters (the axial flowrate and the kiln shell rotation)
Chiche, Samuel. "Intégration de sources urbaines de chaleur fatale au sein d'un réseau de chaleur." Thesis, Paris Est, 2020. http://www.theses.fr/2020PESC2007.
District heating systems are considered as key tools to contribute to the energy transition in urban areas through their ability to promote waste and renewable energies. Waste heat sources (also named excess heat) are still under-exploited in district heating systems although there is significant potential, especially in urban areas. Waste heat sources located near or in dense urban areas (wastewater, datacenters, laundries, etc.) are the research topic of this thesis. Methods have been developed to precisely evaluate their energy potential, knowing that all these sources have different technical characteristics (temperature and variability in particular). These methods have been integrated into a simulation tool, named Recov’Heat. It calculates technical, economic and environmental indicators to assess the relevance of an urban heat source. The Recov'Heat model has been tested on various case studies and obtains results close to reality despite a tendency to overestimate the energy recovered. Technical simplifications in the model and the calculation of the maximum energy potential justify these differences. The viability of integrating a waste heat source in a district heating system depends not only on technical and economic parameters, but also on several conditions linked to the local context, which may affect the implementation of such projects. Several case studies show the influence of local authorities’ support on the success of these projects. They have a decisive role to play in stimulating consultation between a multitude of actors involved in these projects and to understand the contractual complexities between them
Razafinjohany, Eddie. "Etude comparative dans les serres agricoles de deux systèmes de stockage de la chaleur, influence de l'humidité de l'air." Perpignan, 1989. http://www.theses.fr/1989PERP0056.
Lagarenne, Denis. "Récupération d’énergie par les régénérateurs de chaleur des fours de verrerie : expérimentation, modélisation, optimisation." Lyon, INSA, 1990. http://www.theses.fr/1990ISAL0052.
[This study deals with energy recovery in high temperature regenerators of glass industry. Experiments are performed in real conditions, on an full industrial scale regenerator , specially designed and built for this stud. The measurements allow on investigation of the whole s stem and an original local description of the heat exchanger. Different methods are used to calculate the thermal performance of the regenerator The heat transfer mechanisms are analysed with some mix convection phenomenon. A new transient thermal simulation has been developed. The model is justified by the experiments. A new geometry of heat transfer surface is proposed to optimize the energy recovered. ]
Malta, de Almeida Elizabeth. "Étude d'un préchauffeur d'air en continu utilisant un stockage latent : application : la valorisation des rejets thermiques intermittents." Compiègne, 1987. http://www.theses.fr/1987COMPD087.
Papadopoulos, Alexandros. "Contribution à l'étude des échangeurs à contact direct sel-gaz utilisant la chaleur latente." Châtenay-Malabry, Ecole centrale de Paris, 1987. http://www.theses.fr/1987ECAP0039.
Gastauer, Paul. "Potentialité des pompes à chaleur chimiques en vue de la revalorisation d'énergie thermique : application du système isopropanol/acétone/hydrogène." Toulouse, INPT, 1993. http://www.theses.fr/1993INPT033G.
Filliard, Bruno. "Étude des possibilités de récupération de chaleur par voie thermodynamique pour la réhabilitation des maisons individuelles." Paris, ENMP, 2009. http://www.theses.fr/2009ENMP1676.
An air-to-air heat pump performs poorly at low ambient temperatures, and its performance decreases in the coldest part of winter when the heating load is greater. Both the COP and the heating capacity of the system decrease as the outdoor temperature decreases. Auxiliary resistance heaters must then be used as back up, reducing the overall performance of the system. Moreover, defrost cycles are necessary in a specific range of outdoor conditions, lowering the heat pump performance. This is of particular interest for electricity utilities, because peak loads generally coincide with the coldest ambient temperatures. Attempts to improve the heat pump efficiency and to reduce the peak-loading problem have led to the coupling of heat pumps with milder temperature air. Different components of a building envelope can contribute to increase the heat pump's heat-source temperature, as for instance sunspaces or attics, and to some extent crawlspaces and earth-to-air heat exchangers. Other sources such as the exhaust air of a ventilation system can be used to preheat the heat pump air-source. This allows the heat pump to operate in more favourable conditions, with a higher efficiency and a higher sink-source temperature adapted to the heat production needed in dwellings retrofit. A global approach is needed to explore the energy potential of such combination and evaluate the relevance of coupling an air-source heat pump with milder air sources from the building environment. Ambient conditions and solar energy both influence the heating load and the air-source temperature that interact directly with the heat pump running conditions and performance. Besides, the heat pump running conditions, and particularly the air flow rate conditions needed at the outdoor unit, interacts directly with the air flow rate of the milder source, influencing the building heating load. The different models of air sources and heat pumps are presented. Then, different coupling configurations are studied in the case of a typical French dwelling, and typical climates
Hoang, Thanh Tung. "Récupération et valorisation d'énergie thermique sur gaz chauds- Approche expérimentale et numérique." Thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2018. http://www.theses.fr/2018ESMA0016/document.
The aim of the thesis is to analyze the heat recovery on hot gases at intermediate temperature range (250°C - 450°C). For this purpose, the thermosyphon heat exchanger recuperation technology has been chosen. The choice of a working fluid adapted to these temperature levels is one of the crucial points. A literature review identified naphthalene as a potentialfluid for this temperature range. However, because of the lack of information about naphthalene heat pipes, the development of a fundamental test-rig was necessary to fully characterize the thermal behavior and transport capacities of this fluid.A thermosyphon heat-pipe charged with naphthalene in the shape of a smooth stainless steel tube with a diameter of 23.9mm, a length of 1 m (evaporator zone: 20 cm, condenser zone: 20 cm) has been manufactured and tested. The experimental results obtained demonstrate the feasibility of such system in this temperature range and for the thermal powers required.They reveal an unusual behavior of the thermosyphon during the start-up process. In steady state, the analysis deals with the influence of the saturation temperatures, the transferred heat power and the thermosyphon inclination. In terms of performances, the thermal conductance (evaporator, condenser, system) increases with the vapor temperature and decreases with the heat power supplied to the evaporator. The heat flow rate can be applied from 0.2 to 1.5 kW, or 1 to 8W/cm² at the evaporator. During the tests, the system is found to be less sensitive to inclination (0° to 78°), but more important for 84°. In the horizontal position, the thermosyphon operates, but its heat transfer remains high even far away from the thermosyphon mode. A theoretical model has been developed in which the local heat transfer coefficients(evaporator and condenser) are evaluated by different correlations from literature. The comparison with the experimental results allowed to validate the models retained with good agreement, and to make it possible to predict the heat pipe operation for other solicitations.Thus, and finally, a first thermosyphon charged naphthalene recuperator prototype was designed, manufactured and coupled to the "hot gas" line designed and performed in the laboratory. The first results obtained from the complete system allowed us to develop a strategy for heat recovery system on the exhaust line of an automotive application
Beaubert, François. "Simulation des grandes échelles turbulentes d'un jet plan en impact." Nantes, 2002. http://www.theses.fr/2002NANT2022.
This work deals with the study of a plane turbulent impinging jet using large eddy simulation. Plane impinging jets are widely used in the industrial domain ; they find many applications in the processing and manufacturing of materials and in the heating and cooling of surfaces.
Ranger, Pascal-Marie. "La rectification inverse appliquée aux pompes à chaleur à absorption pour valorisation d'effluents thermiques industriels." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL081N.
Viel, Maurice. "Controle et valorisation de la thermogénèse microbienne au cours de la biodégradation aérobie de déchets agro-industriels et urbains à teneurs variables en graisses." Toulouse, INPT, 1989. http://www.theses.fr/1989INPT030A.
Belkebir, Mekki Kouider. "Conception de réseaux d'échangeurs de chaleur." Toulouse, INPT, 1989. http://www.theses.fr/1989INPT005G.
Piché, Olivier. "Récupération de chaleur pour le système de ventilation d'un aréna analyse thermique, environnementale et financière." Mémoire, Université de Sherbrooke, 2012. http://savoirs.usherbrooke.ca/handle/11143/1608.
Allyson-Cyr, Mathieu. "Optimisation sous contrainte d'un générateur thermoélectrique pour la récupération de chaleur par différents algorithmes heuristiques." Master's thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/33956.
This study presents a model of a thermoelectric generator placed directly on the surface of a heat source. One unique feature of this model is that the heat source is subject to fixed heat flux and surface temperature that the system must respect. The main objective is to develop this model in this particular context with the possibility to be adapted to any heat source and the option to add a cooling system. The model has been developed entirely on the software Matlab. Then, a genetic algorithm is used to perform an optimisation in order to find the design with the maximal power output and minimal number of thermoelectric modules. With the cooling system included, the total surface of exchange and pumping power is also considered. A preliminary analysis is conducted to analyse the impact of the heat flux and surface temperature constraint on such system. Thereafter, a multi-objective optimisation is performed to find the optimal design considering multiple optimisation objectives. Finally, different heuristic algorithms are compared for solving the thermoelectric model proposed. The performance is discussed using different performance criteria to show the pros and cons of each heuristic algorithm when solving a complex optimisation design problem.
Filliard, Bruno. "Étude de la possibilité de récupération de chaleur par voie thermodynamique pour la réhabilitation des maisons individuelles." Phd thesis, École Nationale Supérieure des Mines de Paris, 2009. http://pastel.archives-ouvertes.fr/pastel-00005944.
Saix, Christian. "Contribution à l'étude des sols non saturés en température : application à l'exploitation thermique du sous-sol." Montpellier 2, 1987. http://www.theses.fr/1987MON20187.
Guillet, Rémi. "La Combustion par voie humide et ses performances." Nancy 1, 2002. http://docnum.univ-lorraine.fr/public/SCD_T_2002_0149_GUILLET.pdf.
In the past, water has been used as additive component to improve combustion efficiency, to boost power, even as an anti-knock agent, as technique to reduce NOx formation. Today, using a wet combustion technique, gas turbines, generators concerned by the water vapor latent heat recovery, can benefit with a significant efficiency increasing from the energy saving and environment protection point of view. In wet combustion techniques, three fluids are supplied to the process: the fuel, the oxidizing or combustion agent and the additive waterTo analyse the wet combustion processes, the Combustion Hygrometric Diagram method is presented. Using wet bulb temperature as major parameter, this method is recommended for efficiency analysis, two-phases exchangers sizing. Many information of the water influence on the combustion processes behaviour are also given in this thesis
Chagnon-Lessard, Noémie. "Maximizing power output of heat engines through design optimization : Geothermal power plants and novel exhaust heat recovery systems." Doctoral thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/38297.
Heat engines design leading to maximum power output often depends on the hot source temperature and the cold source temperature. This is why drawing guidelines from optimal designs of these machines according to diverse operating temperatures may facilitate their conception. Such a study is proposed by this thesis for two types of heat engines. In the first instance, the Organic Rankine Cycle (ORC) is a power thermodynamic cycle used among others in geothermal power plants exploiting low-temperature reservoirs. This type of power plants raises keen interest around the world for being one the most environmentally friendly power production modes. In these power plants, a geofluid is pumped from the ground to transfer its heat to a working fluid operating in a closed cycle. The geofluid is then reinjected in the geological basin. Researchers are currently attempting to characterize in a better way the geothermal potential of diverse geological environments. Considering the province of Québec’s relatively cold underground, studies try to determinate whether it is possible to profitably operate geothermal power plants. Another important research question is to determine, for a given context, the optimal geothermal power plant design, and the amount of power that could be generated. To answer this question, Organic Rankine Cycles (subcritical and transcritical) are first simulated and optimized for geofluid temperatures from 80 to 180°C and for condensing temperatures of the working fluid from 0.1 to 50°C. Thirty-six (36) pure fluids are investigated for each temperature combination. Next, cycles models are improved by adding a cooling tower, a recuperative system and a constraint on the minimum reinjection temperature. ORCs with dual-pressure heater are simulated and optimized as well. Optimization runs are performed considering 20 working fluids for the same range of geofluid temperature and for ambient air wet bulb temperature from 10 to 32°C. In the second instance, the Inverted Brayton Cycle (IBC) is a thermodynamic cycle that could be used as a waste heat recovery system for engines exhaust gases. This is an open cycle which includes a gas turbine, a heat exchanger and a compressor as a basic layout. There is a configuration where the water condensed during the cooling of the gases is evacuated upstream of the compressor in order to reduce the mass flow rate and improve the system global efficiency. The Powertrain and Vehicle Research Centre (PVRC) of the University of Bath is interested in finding out whether particular IBC variants arising from this configuration could be viable options. These variants led to the creation of three novel thermodynamic cycles that couple the IBC with (i) a steam turbine, (ii) a refrigeration cycle, and (iii) both additions. Including both already existing cycles described in the preceding paragraph, five IBC layouts are simulated and optimized for exhaust gases temperatures from 600 to 1200 K and for heat sink temperatures from 280 to 340 K. The purpose of this thesis is to offer a tool that help engineers designing the systems previously introduced (ORC and IBC), so that they produced a maximized specific work output. As a set of charts, this tool can be used for a large range of hot source temperature (geofluid or exhaust gases) and of heat sink temperature.
Le, Lostec Brice. "Récupération des rejets thermiques pour la production de chaleur et de froid avec une machine à absorption." Thèse, Université de Sherbrooke, 2010. http://savoirs.usherbrooke.ca/handle/11143/1920.
Jordana, François. "Étude techno-économique de la récupération de chaleur dans les effluents gazeux des cuves d'électrolyse d'une aluminerie." Master's thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/25811.
The objective of this study is to propose heat recovery strategies in a primary aluminum smelter by considering technical and economic aspects. After analyzing the various heat sources and sinks, it was decided to focus the study on the flue gases exiting the electrolysis cells. Two applications are envisioned and presented in two scientific articles: heating buildings within the aluminum smelter, and heating a greenhouse. In both cases, a dynamic model of heating requirement is proposed, associated to the detailed design of heat exchangers and equipment. Then, an optimization is performed to minimize the implementation capital and operation costs. Last, several case studies are presented in order to analyze the variability of the retained solutions.
Peralez, Johan. "Récupération d'énergie par cycle de Rankine à bord d'un véhicule : commande et gestion énergétique." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10024/document.
More than 30% of the energy produced by internal combustion engines (ICE) is dissipated as heat through the exhaust gases. The interest of manufacturers in heat recovery systems based on the thermodynamic Rankine cycle is justified by announced reductions in fuel consumption ranging from 5 and 10% depending on the system and the driving cycle. The aim of this thesis is to help remove the main barriers associated with supervising and controlling Rankine processes for ≪ mobile ≫ applications. This dissertation is based on three study cases, each corresponding to a pilot process installed in engine test benches at IFP Energies nouvelles (IFPEN). These are applications to be integrated respectively on board light-duty vehicles with spark-ignition engine, heavy-duty trucks and trains with Diesel-electric propulsion. An original nonlinear (model-based) control law for the temperature and the pressure tracking at the evaporator outlet is proposed. It is shown experimentally that the system can be maintained under conditions allowing continuous energy recovery, even during highly transient road cycles. Then the supervision of Rankine systems is addressed, resulting in the choice of optimal set-points (in term of energy management) for the low-level controller. An optimal control problem is formulated, allowing online implementation via dynamic real-time optimization.The proposed approach is validated on a realistic simulator, showing significant benefits in the amount of energy recovered when compared with the classical (static) approach found in Rankine cycle literature
Cenusa, Victor-Eduard. "Contribution à l'amélioration du couplage thermodynamique entre l'installation de la turbine à gaz et l'installation de la turbine à vapeur dans les centrales électriques à cycles combinés gaz/vapeur." Nancy 1, 2004. http://docnum.univ-lorraine.fr/public/SCD_T_2004_0228_CENUSA.pdf.
In 1st chapter is made: a) a presentation the state of the art in gas turbines (GT) and combined cycles (CC); b) an analyze of CC which use "H" technologies. The 2nd chapter shows the original mathematical model and the computing program of GT, based on sheet data (manufacturer's data). The 3rd and 4th chapters show the mathematical models and computing programs for the heat recovery steam generator (HRSG) exergetic optimization with one and two pressure level of steam production, by imposing the total heat transfer area. Into the 5th chapter is made a sensibility analysis of HRSG optimization. The 6th chapter shows the CC optimization with HRSG which have one or two pressure level of steam production without reheating. The final section contents the closing conclusions
Bezzina, Mohammed. "Approche statistique pour la génération de cascades optimales de colonnes de rectification avec récupération d'énergie." Toulouse, INPT, 1989. http://www.theses.fr/1989INPT007G.
Puscasu, Onoriu. "Dispositifs innovants pour la récupération de l'énergie thermique." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0012/document.
The present work is a contribution to the domain of energy harvesting. The developed conversion is made at centimeter scale, and the generated electrical power is sufficient for low power devices, as for example wireless sensor nodes. An innovative technology for heat energy harvesting is proposed, with the goal to fabricate thin, flexible, and low cost devices for a use without a heat sink. Their working principle relies on a two-step conversion of heat into electricity: thermo-mechanical (with thermal bimetals) and mechanoelectrical (with piezoelectrics). Several prototypes have been built, resulting in flexible matrix devices that are a few millimeters thick and work without a heat sink with natural convection. The generated signals are voltage peaks above 10 V, for an available mechanical power in the order of 200 µW around 75°C. Several studies have been done for the optimization of the devices and the characterization of their components. Scale laws have been established, and predict significant power gain with miniaturization. Analytical models have been elaborated for the behavior of the piezoelectric and for the thermal behavior of a device. The first use cases have been identified, and the first tests have been performed in environments proposed by potential end users
Zhao, Ruijie. "Analysis, simulation and optimization of ventilation of aluminum smelting cells and potrooms for waste heat recovery." Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/25771.
Due to the high energy requirement and ~50% efficiency of energy conversion in aluminum reduction technology, the waste heat is enormous but hard to be recovered. The main reason lay in its relatively low temperature. Moreover, any changes may affect other aspects of the production process, positively or negatively. A complete understanding of the heat transfer and fluid flow in aluminum smelting cells can help to achieve a good trade-off between modifications and maintenance of cell conditions. The present work aims at a systematic understanding of the heat transfer in aluminum smelting cell and to propose the most feasible way to collect the waste heat in the cell. First, a thermal circuit network is developed to study the heat loss from the top of a smelting cell. By associating the main thermal resistances with material or operating parameters, a sensitivity analysis with respect to the parameters of interest is performed to determine the variables that have the most potential to maximize the thermal quality of the waste heat in the pot exhaust gas. It is found that the reduction of pot draft condition is the most efficient solution. Then, a more detailed Computational Fluid Dynamics (CFD) model is developed. A good agreement between the two models is achieved. Second, a systematic analysis of the reduction of draft condition is performed based on CFD simulations. Three issues that may be adversely affected by the draft reduction are studied and corresponding modifications are proposed and verified in CFD simulations. The first issue, maintaining total top heat loss, is achieved by exposing more anode stubs to the air and enhancing the radiative heat transfer. The second one is to verify the influence of the draft reduction on the heat stress in potroom and limited influence is observed in the simulations. Finally, the pot tightness is enhanced by reducing pot openings in order to constrain the level of fugitive emissions under reduced pot draft condition. The results have revealed that 50% reduction in the normal draft level is technically realisable and that the temperature of pot exhaust gas can be increased by 50-60 ˚C.
Bourhaleb, Houssine. "Etude et expérimentation d'une chaîne énergétique solaire avec capteur à air, stockage thermique souterrain et récupération par pompe à chaleur." Valenciennes, 1987. https://ged.uphf.fr/nuxeo/site/esupversions/69924e8c-5370-4c55-aef3-3e377d2fa6a1.
Danel, Quentin. "Étude numérique et expérimentale d'un cycle de Rankine-Hirn de faible puissance pour la récupération d'énergie." Thesis, Paris, CNAM, 2016. http://www.theses.fr/2016CNAM1091/document.
This research was motivated by environmental constraints which impose a reduction in greenhouse gas emissions. The aim of the thesis was to explore the possibility of reducing the consumption of an internal combustion engine using a bottom waste heat recovery system. The study focused on waste heat recovery for low power installations. The Rankine cycle technology was selected to exploit the heat source. An experimental test bench was designed and set up. A hot gas generator simulates an internal combustion engine. Part of the thermal power is absorbed by the evaporator and partially converted into mechanical power. The heat exchanger and piston expander were designed and built in-house. A numerical static model with experimental validation of the evaporator was developed. The model was used to explore the performances of the Rankine cycle over a large operating range. Under restrictive hypotheses, the numerical model showed that is possible to reduce the consumption of a tractor by about 3 to 4 %. A piston expander dynamic model was developed to assist in sizing the expander. The model was used to define a piston expander concept with a simple distribution mechanism. Although a classical distribution mechanism offers better performances, this concept is promising for systems that are simple, small-scale and low-cost
Le, Van Long. "Étude de la faisabilité des cycles sous-critiques et supercritiques de Rankine pour la valorisation de rejets thermiques." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0117/document.
This thesis concerns the feasibility study of subcritical and supercritical organic Rankine cycles for industrial waste heat recovery at relatively low temperature. Initially, a state of the art of ORCs (Organic Rankine Cycles) and their working fluids has been achieved. We conducted a preliminary comparison of several configurations from the scientific literature. In a second step, methods of energy and exergy analysis were applied to evaluate and optimize the performance of the ORCs. Indeed, sole energy analysis is not enough to access the proper use of the energy potential of the available heat source that corresponds to an industrial waste heat. Exergy analysis, in a complementary way to the energy analysis, enables us to locate the energy resources losses in the various components of the system and to determine their true magnitude and their causes. A thermo-economic optimization of waste heat recovery systems using a subcritical or supercritical Rankine cycle has been performed. According to the results, the industrial waste heat recovery at low temperature (e.g. heat source 150 ° C) using a subcritical ORC is more interesting on economic point of view than the system using a supercritical Rankine cycle
Ndenge, Che Martin. "Contribution à l'étude d'un échangeur fluidisé à circulation auto-entretenue des solides." Compiègne, 1986. http://www.theses.fr/1986COMPI192.
Tajmouati, Abdelall. "Etude des transferts de chaleur et de matière dans les matrices alvéolaires. Application à la récupération des métaux précieux contenus dans les catalyseurs de postcombustion automobile usages." Perpignan, 1992. http://www.theses.fr/1992PERP0131.
Hampikian, Zélia. "De la distribution aux synergies ? : Circulations locales d’énergie et transformations des processus de mise en réseau de la ville." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1001/document.
Within the framework of the ongoing energy transition objectives, energy circulations at the infra-urban level are increasingly promoted. For instance, local, national and transnational stakeholders suggest the reuse of heat currently being wasted by diverse human activities (industries, data centres, wastewaters …). Alternatively, distributed energy sharing between different urban functions (residential, services, retail …) at the urban block or district scale is promoted. In short, several forms of connections through energy exchange between urban activities are encouraged and examples of those are multiplying.The thesis offers to capture those connections as new forms of urban networks that supersede or overlap a century-old network model based on techno-economic efficiency, socio-economic and socio-spatial solidarity and consumptions growth. It aims at understanding what these local circulations change to the co-construction of cities and energy networks.To do so, the approach combines the results of two different strands of work. On the one side, urban and sociotechnical studies of networked infrastructures allow to understand the reconfigurations of those systems. On the other side, industrial ecology works analyse the dynamics that lead to material circulations between human activities. The articulation of their results makes it possible to grasp the considered object in its social, technical and metabolic dimensions, that is, in a sociomaterial perspective.The analysis is mainly based on three French case studies of which the emergence, running and evolution are investigated: industrial waste heat reuse in the heat network of the city of Dunkirk, heat extraction from a data center to be distributes the in a district of Marne-la-Vallée and energy sharing in the La Confluence district in Lyon. More broadly, suggested or implemented reconfigurations of the organisation of energy provision are reviewed.The results of the study are threefold. First, these new forms of urban network are not solely motivated by techno-economic efficiency. The interests of the stakeholders all come into alignment with an objective of optimization of energy flows uses: from techno-economic efficiency, the goal becomes metabolic efficiency. Second, the networks formed by those circulations are unstable, in particular because of the uncertainties that regard short and long term availability of energy flows. Hence, they do not reproduce the solidarities that emerge from conventional large and stable networks. Third, to reduce those instabilities, actors suggest evolutions that aim at reducing their dependencies on uncertain flows. These evolutions all result in the growth of the network, but do not follow an objective of universalisation. On the contrary, an important spatial selection is operated, according to the perceived materiality of flows by actors. Instead of leading to new consumptions in a supply rationale, the logic becomes one of existing flows integration.To sum up, the thesis shows a “metabolic turn” in the process of networking the urban through energy circulations. While infrastructures extension has long been at the centre of networks construction, pre-existing produced and consumed flows can now become the primary motivation of building connections
Garrier, Sylvain. "Conception et simulation d'un réservoir d'hydrure de magnésium avec récupération de la chaleur de réaction à l'aide d'un matériau à changement de phase." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00940452.
Bernoux, Pierre. "Etude de la distribution d'un mélange liquide-vapeur à l'entrée des échangeurs de chaleur." Nancy 1, 2000. http://www.theses.fr/2000NAN10075.
Maldistribution of two-phase flow causes a significant decrease of thermal and hydraulic performance of heat exchangers. The objective of this work is the identification of the parameters which control the distribution of the phases. In order to do that, a specific experimental set-up has been designed to simulate a compact heat exchanger working in adiabatic conditions with refrigerant 113. The effects of the following parameters have been studied : inlet mass quality, mean mass velocity, nozzle inlet diameter and number of channels. The distribution of the phases and the pressure drops have been measured in each channel. Flow pattern at the inlet of the test-section and in the inlet manifold has been observed and has given information about the two-phase flow shucture evolution. Simultaneously, a separated phase model is proposed to describe the two-phase flow in this geometry. A first sensitivity study is presented
Seck, Gondia. "Modélisation prospective de l'industrie diffuse pour l'évaluation de l'impact de politiques de Maîtrise De l'Énergie (MDE) à partir du générateur de modèle TIMES : la récupération de chaleur par Pompes à Chaleur (PAC) dans l'industrie agroalimentaire." Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 2012. http://pastel.archives-ouvertes.fr/pastel-00662459.
Seck, Gondia Sokhna. "Modélisation prospective de l'industrie diffuse pour l'évaluation de l'impact de politiques de Maîtrise De l'Énergie (MDE) à partir du générateur de modèle TIMES : la récupération de chaleur par Pompes à Chaleur (PAC) dans l'industrie agroalimentaire." Thesis, Paris, ENMP, 2012. http://www.theses.fr/2012ENMP0001/document.
The growing energy prices due to the rarefaction of the fossil fuels and the consideration of the environmental impacts makes inevitable the involvement of industrials to promote energy efficiency policy and emissions reductions. We notice that the Non-energy intensive industry (NEI), by opposition to the energy intensive industry (EI), is expected to play an important role because of their economic and energy importance and its relatively high growth rate. It becomes then a priority target especially since it has been neglected in energy analysis despite the continuing policy interest in energy efficiency and the many reports and book written on the topic. How can NEI contribute effectively to the reduction of the energy consumptions and the CO2 emissions? Which technologies and/or policies should be implemented to reach these objectives?This PhD work is then based on a technical economic optimization of the sectoral energy system, by using a “bottom-up” model with TIMES framework, in a relevant prospective approach of the energy and environmental consequences of MDE policies in NEI. This model relies on a representation by energy end-uses contrary to the EI because of the unsuitability of the approach product/process. As part of this, we analyzed the industrial heat recovery on processes through the deployment of HP in Food & Drink industry, the most important NEI's sector.Then, this prospective modelling allows observing the shape of investments of HP in response to energy constraints or incentive policies within the mechanism of Energy Savings Certificate or valuation of CO2 emissions. It can give, on one hand, a possibility of study which giving the different adjustment of a tax on gas emissions by the authorities of regulation to reach their environmental and energy objectives in NEI over a medium or long-term horizon. On the other hand, it is very useful as a good decision-making tool by determining differentiated costs for energy savings within the investments of efficient technologies at the highest level of disaggregation for a better sectoral screening
Soupart-Caron, Adèle. "Stockage de chaleur dans les matériaux à changement de phase." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI078/document.
This PhD thesis deals with the understanding of the heat transfer mechanisms and with the development of thermal energy storage system for the industrial waste heat recovery application. The use of Phase Change Materials (PCM) is attractive for its high storage density and its possibility to deliver heat at constant temperature. However, the PCM low thermal conductivity leads to develop heat transfer improvement methods, such as heat exchangers with increased heat transfer surface. The goal is to characterize the behavior of such heat exchangers An experimental study, where four several heat exchangers have been tested with different orientations (horizontal/vertical) and injection types (upward/downward), highlighted the impact of natural convection during the melting process and the volume contraction one during the solidification. These results have been validated through a 3D numerical model. A performance comparison method based on an energy calculation through an experimental mesh is proposed and enables to select a heat exchanger on criteria such as the storage density, the characteristic time and the cost. Three PCM, adapted to our application, have been tested at the intended temperature (100-200 °C) by integrating them into a storage system made of a stainless steel tube with aluminum circular fins. Their ability to resist to repeated cycles has been assessed and their behavior has been compared. The salts mixture, H105 (Tmelting = 122 °C), is not selected for the application because of it low storage density (≈ 56 kWh/m3) and its large melting area. The sebacic acid (Tmelting = 132 °C) has a repeatable behavior with cycles and a higher storage density (≈ 66 kWh/m3) and is appropriate as storage material. The sugar alcohol, erythritol (Tmelting = 118 °C), has good thermo-physical properties (128 kWh/m3) but the crystallization control is a key point to use it as a PCM
Sayah, Haytham. "Récupération de l'énergie des solides massifs : cas d'acier de la coulée continue." Thesis, Paris, ENMP, 2012. http://www.theses.fr/2012ENMP0111.
Steel production industry is one of the most energy consuming sectors. The state-of-the-art indicates that steel slabs leaving the continuous casting process are cooled without energy recovery by radiating to the atmosphere and convection. Not only a large amount of energy is wasted but this type of cooling is time consuming. During the cooling process of steel slabs from an initial temperature of approximately 900°C to outdoor air temperature, 580 MJ per ton of steel are wasted. This study has defined a method and an equipment capable of extracting the energy at high exergy value during cooling.The energy could be recovered using two different systems. The first is a direct thermodynamic generation cycle. The selected direct cycle is the Hirn cycle with intermediate reheating having an overall efficiency of 30 % and producing about 10 MW electric power. The second is an indirect system using SYLTHERM 800 as an intermediate heat transfer fluid between the metal slabs and an organic Rankine cycle using R-245fa as a working fluid with 17.6 % efficiency and producing about 6 MW. In both systems the dominant heat transfers to recover heat are conduction for the floor heat exchanger and radiation for the ceiling heat exchanger.A test bench was mounted, using a similitude technique, to study heat transfers. The variation of the thermal contact resistance as a function of the contact temperature is studied as well as the thermal behaviour of the conduction heat exchanger. The thermodynamic and the thermal studies led to a preliminary design of the recovery equipment.A numerical model is developed using the component interaction network. This model can reproduce the same physical phenomena taking place in the recovery equipment
Di, Cairano Luca. "Etude d'un système réversible climatisation/cycle Rankine organique : application au cas du véhicule terrestre." Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEM066.
In a light duty vehicle, waste heat recovery is a promising solution for reducing engine fuel consumption and emissions. The strong compactness, weight and cost requirements of the automotive sector are preventing the integration of waste heat recovery systems in vehicles. This work is proposing as a possible solution a multi-generation system called hereafter ReverCycle. ReverCycle is a system with three operating modes: vapor compression air conditioning, Organic Rankine Cycle (ORC) and ejector refrigeration cycle. The system can provide one function at a time. ReverCycle advantages are its compactness and cost since it is possible to exploit the vehicle air conditioning components. This means that the air conditioning scroll compressor is converted into a reversible compressor/expander machine and the condenser is mutualized for the three operating modes. The calculation of the fuel economy and the technical feasibility of the system are investigated combining a modeling approach with experimental activity. A global vehicle model reproduces the vehicle dynamic working conditions and the interaction between the different vehicle sub-systems. The model estimates the annual average fuel economy for different climatic regions. Two different vehicle architectures are investigated: a conventional vehicle and a series hybrid vehicle. For a conventional vehicle the maximum fuel economy is obtained in an oceanic climate ( e.g. Paris) with a 2.1% improvement at a hot start initial condition for the engine and 1.3% improvement at a cold start initial condition. The reference driving cycle for the fuel economy evaluation is the WLTC (Worldwide harmonized Light vehicles Test Cycles). For a series hybrid vehicle the maximum fuel economy is obtained in a continental climate ( e.g. Moscow) with a 2.2% improvement at a hot start initial condition for the engine and 1.2% improvement at a cold start initial condition. The realization of ReverCycle proof of concept has allowed validating its technical feasibility. Experimental tests have mainly focused on the ORC operating mode. The experimental results show that the maximum cycle efficiency is 3.9% for a steady-state point. The average maximum cycle efficiency over a dynamic cycle, equivalent to a typical conventional vehicle operating mode, is 3.3%
Ayachi, Mohamed Fadhel. "Intégration des cycles de Rankine organiques dans la valorisation de la chaleur fatale industrielle à basses et moyennes températures." Perpignan, 2013. http://www.theses.fr/2013PERP0002.
Nowadays, the gradual depletion of fossil fuels combined with constraints on emissions of greenhouse gases have radically modified the research paradigms and led to increasingly restrictive standards for heavy industry in terms of energy consumption and environmental impact. In that context, this PhD has been performed in the framework of the ANR - EESI - ENERCO_LT project. It is structured around two main axes. The first axis consists of the exergy analysis and the optimization of Organic Rankine Cycles for waste heat recovery from dry and wet flue gases available at low and medium temperatures. By thermodynamic optimization, the recovery potential of a wide range of pure fluids and blends are assessed for various designs and have allowed to indicate how we can meet high efficiency, acceptable operating conditions and environmental friendly objectives. Subsequently, a technical and economic optimization method is developed. This later is based on the equivalent system concept. The second axis regards the retrofitting at the pilot scale (5 kW), the experimental study and the modeling of two expander types: a positive displacement scroll machine and a dynamic radial-inflow turbine
Besbes, Karim. "Pompes à chaleur à haute température récupérant la chaleur sur des buées ou de la vapeur d'eau à moyenne température." Thesis, Paris, ENMP, 2015. http://www.theses.fr/2015ENMP0091/document.
The mechanical vapour compression high temperature heat pump for industry using electricity is one of the most effective innovative technologies to recover the industrial waste heat at low and medium temperature (<90°C). However, given the current industrial heat needs, the heat pump target temperature levels remain too low and slow strongly its implantation. Overwhelmingly, the drying processes reject saturated moist air at middle temperature (50°C-90°C) and have heat needs at very high temperature (110°C-150°C). The large temperature difference between the source and the heat need and the level off temperature that is needed, today, makes the heat pump integration in such processes an interesting energy and technological challenge, whose economic stake is considerable. The present works tackle, with a generic methodology of thermodynamic optimisation cycles based on the entropy minimization in the heat exchangers, to identify the most efficiency heat pump architectures from an energy point of view. The theoretical analysis allowed to detect the transcritical heat pump architecture, in conditions of high temperature glides between the inlet and the outlet of the heat need. The development of a transcritical high temperature heat pump demonstrator using the R32 as working fluid allowed to demonstrate the technical feasibility of a heat pump that can reach the target temperature of 120°C from 60°C with an available heat source at 50°C, and to demonstrate its high energy efficiency (COP = 4)
Cremieux, Marie-Adélaïde. "Etude de l’impact de la rugosité et de différentes structurations de surface sur le transfert de chaleur dans les passages condensation des vaporiseurs-condenseurs cryogéniques." Thesis, Paris, HESAM, 2021. http://www.theses.fr/2021HESAC032.
The aim of this research project is to deepen current knowledge of the mechanisms involved in the condensation of nitrogen (pure or in the presence of non condensable gases) with a view to developing correlations and / or a theoretical approach allowing to better model these phenomena. This knowledge will lead to propose ways of optimizing the design of the equipments in industrial condition. In order to do this, an experimental device allowing the study of the local heat transfer coefficient, during condensation, under controlled (and relevant) conditions will be mounted
Nowicki, Cassandre. "Inventaire thermo-énergétique d'une aluminerie et évaluation du potentiel de récupération et d'intégration des rejets thermiques." Thesis, Université Laval, 2012. http://www.theses.ulaval.ca/2012/29385/29385.pdf.
Giraud, Loïc. "Modélisation dynamique et gestion avancée de réseaux de chaleur." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAT111.
District Heating (DH) are currently fast-growing in France. This situation is explained by their ability to exploit and disseminate massively, at a reasonable price, energy sources with low CO2 contents in the sectors of space heating and domestic hot water production, nowadays strongly emitters of greenhouse gases. Improving the control of these complex energy systems is a key issue for increasing their competitiveness and promote their development.This thesis focuses on the optimal control of DH systems. For this application, we have developed and tested an algorithm that optimizes, given a load prediction, the use of the production means, the supply temperature and the differential pressure. Compared to existing methods, the original features of the developed solution are to fully exploit the thermal storage capacity of the network and to determine the best compromise between costs for pumping and heat losses.This thesis begins with a work on dynamic modeling carried out at the component scale. Based on an experimental validation approach, we systematically sought the best compromise between accuracy and computational efficiency (Chapter 1). The case study, described in Chapter 2, is a virtual DH at the district scale, representing the Grenoble case. For the development of the advanced control system, we then present a linearized version of the distribution network model that we integrate into an optimizer relying on Mixed Linear Programming. The proposed control algorithm is described in Chapter 3. It combines a nonlinear dynamic model and the aforementioned optimizer. The topic of the fourth chapter is the evaluation of the performance of our algorithm by simulation and comparison with existing methods of control. A final chapter examines the robustness of the algorithm in real control conditions considering various sources of uncertainty
Garnier, Cédric. "Contribution à l'optimisation de la puissance thermique disponible en régime transitoire pour le confort dans une automobile." Nantes, 2007. http://www.theses.fr/2007NANT2157.
High efficiency automotive engines have been developed to cope with the fuel price rising and air pollution standards evolution. High efficiency combustion leads to reduced engine capacity and fuel consumption for the same performance, but also contributes decreasing the available thermal power for the car cabin heating system. Car parts manufacturers so propose additional heating systems to compensate for the thermal deficit and ensure passengers’ confort during thermal transient periods (cold start, urban driving). The goal of this work is to develop a new additional heating system using heat recovery on admission and exhaust lines. A zero-dimensional combustion model is developed for engine performance and emissions prediction. A thermal simulation software using nodal method to describe heat transfer between the engine components (water loop, oil loop, engine block. . . ) is coupled with the combustion model. The global model is therefore able to predict the car cabin blown air temperature, depending on vehicle characteristics, heating strategies and driving cycles. The software is validated by comparison of numerical results with experimental measurements realised on a car placed in a climatic wind tunnel. Simulations of different new heating systems are finally used to identify the best solution, compared to existing technologies, taking into account environmental and economical objectives. This highlights the significant potential of heat recovery on the engine admission line. An increase of 28°C of the blown air temperature and a decrease of 18% of the fuel consumption are obtained compared to conventional electric heaters