http://hdl.handle.net/2268/87 Chercher dans ce canal chercher http://orbi.ulg.ac.be/simple-search http://hdl.handle.net/2268/150238 Titre: Les microalgues: un défi énergétique <br/> <br/>Auteur, co-auteur: Franck, Fabrice <br/> <br/>Résumé: Les microalgues sont des micro-organismes photosynthétiques dont la culture commerciale en masse est pratiquée depuis les années '60. Les rendements en biomasse de la culture de microalgues sont supérieurs à ceux de cultures traditionnelles, et elle peut s'effectuer sur des terrains impropres à l'agriculture traditionnelle. Les perspectives d'utilisation de la biomasse microalgale pour la production de biocarburants ont suscité d'importants efforts de recherche au cours des années récentes. Les recherches en cours visent à améliorer les souches d'algues utilisables ainsi que différents aspects des procédés de production, de traitement et d'extraction de la biomasse algale afin d'aboutir à moyen terme à un procédé durable et économiquement viable. http://hdl.handle.net/2268/150237 Titre: Analysis of solar air-conditioning systems and their integration in buildings <br/> <br/>Auteur, co-auteur: Thomas, Sébastien <br/> <br/>Résumé: Due to economical and environmental concerns, the energy e fficiency of buildings nowadays has proven to play an increasingly important role. To satisfy the occupants comfort, the cooling of buildings generally involves a considerable consumption of electricity. Solar radiation, which is a free and renewable resource, is linked to the cooling needs of buildings. This work consists in the evaluation, from an energy-saving and economical point of view, of a potential use of solar energy for air-conditioning in residential and o ffice buildings. It includes an integral approach of solar air-conditioning, involving the analysis of the buildings cooling needs, the cold production devices, the solar collector fields and climates. This analysis is supported by simulations and experimental setups. The study of solar air-conditioning systems already available on the market or in laboratories reveals their operational principles as well as their main performance indicators. Two main solar cooling paths are investigated: a thermal and a photovoltaic conversion of solar energy. Besides this, the performance of the entire air-conditioning system broadens the question of the energy performance to the interactions between the diff erent parts of the system. The building thermal loads (heating, cooling, domestic hot water) of some theoretical residential and o ffice buildings are computed in a part of this work dealing with the influence of the comfort model, the building energy performance level and the climate. What comes across through this analysis is that, the location of the buildings put aside, the cooling load is greatly influenced by the envelope thermal performance and the internal gains. The cooling systems involving absorption or adsorption or vapour compression chiller cooling machines are simulated for the previously defi ned building cases. The use of solar energy through thermal collectors for heating meets higher primary energy savings than for cooling. In all cases, the thermally driven system achieves a lower energy and economical performance than a vapour compression chiller partially supplied with a photovoltaic field. Some real scale testing of solar air-conditioning systems was carried out in Arlon (Belgium). A thermally driven adsorption chiller and a vapour compression chiller with a photovoltaic grid-connected fi eld were operated during the cooling season. The measurements made during this experiment and their analysis manage to discover every thermal and electrical energy flows of the systems leading to a new adsorption chiller model. Concerning the comparison with the simulations, the main point of interest is the consumption of electricity dedicated to thermally driven systems, which is two times higher in real scale conditions. The results obtained from the monitoring campaigns corroborate the simulation results about system comparison. http://hdl.handle.net/2268/150191 Titre: Power System Simulation Challenges <br/> <br/>Auteur, co-auteur: Aristidou, Petros; Plumier, Frédéric; Van Cutsem, Thierry; Geuzaine, Christophe http://hdl.handle.net/2268/150176 Titre: Experimental study on an open-drive scroll expander integrated into an ORC (Organic Rankine Cycle) system with R245fa as working fluid <br/> <br/>Auteur, co-auteur: Declaye, Sébastien; Quoilin, Sylvain; Guillaume, Ludovic; Lemort, Vincent <br/> <br/>Résumé: The present paper focuses on the experimental characterization of an open-drive scroll expander integrated into an Organic Rankine cycle using R245fa as working fluid. The expander is a commercially available air compressor that was modified to operate in expander mode. The ORC (Organic Rankine Cycle) system is designed for a nominal heat input of 20 kW and a nominal net power output of 1.8 kW. A total of 74 steady-state operating points are measured to evaluate the expander performance over a wide range of conditions. The operating parameters that are varied include the inlet pressure (from 9 to 12 bar), outlet pressure (from 1.5 to 4 bar) and rotational speed (from 2000 to 3500 rpm). The maximum isentropic efficiency and shaft power are, respectively, 75.7% and 2.1 kW. A maximum cycle efficiency of 8.5% is reached for evaporating and condensing temperatures of 97.5 °C and 26.6 °C respectively. For most of the tests, hot water is produced in the condenser and the system therefore behaves as a CHP (combined heat and power). Depending on the water temperature requirement, a power to heat ratio varying between 1.9% and 11.8% is obtained. Water over 50 °C can be produced with a power to heat ratio higher than 8%. The experimental data points are then used to generate a performance map of the expander. This performance map allows for simulation of the use of such an expander in other ORC system http://hdl.handle.net/2268/150155 Titre: La maison zéro énergie, et après ? <br/> <br/>Auteur, co-auteur: Monfils, Stéphane <br/> <br/>Résumé: Introduction à la future réglementation, à la problématique des bâtiments existants et à la performance environnementale http://hdl.handle.net/2268/150076 Titre: Énergie nécessaire au broyage de la biomasse et des produits densifiés <br/> <br/>Auteur, co-auteur: Temmerman, Michaël <br/> <br/>Résumé: La littérature concernant la consommation énergétique du broyage dans les industries minières montre que cette problématique a été, et est encore, étudiée par de nombreux auteurs. Différents modèles de broyage sont donc disponibles pour ces industries, en particulier pour le broyage des minerais. Les principaux modèles et certaines de leurs évolutions sont repris dans la présente revue. Le broyage de la biomasse quant à lui a été bien moins étudié. Quelques études ont néanmoins porté sur la mesure des consommations énergétiques engendrées par le broyage de biomasses particulières, dans des systèmes particuliers. Rares sont celles qui prennent en compte suffisamment de paramètres relatifs à la matière entrante et sortante (granulométrie, humidité, origine, etc.) ou les caractéristiques du système de broyage. Pratiquement, aucun modèle de broyage de la biomasse n’a donc été proposé. Concernant le broyage des produits densifiés, aucune donnée ne semble disponible. À la lueur des théories de broyage de l’industrie minière, cette étude propose donc les paramètres à prendre en compte pour une éventuelle modélisation du broyage de la biomasse et des produits densifiés. Mots-clés. Broyage, biomasse, pellets, briquettes, théories http://hdl.handle.net/2268/150004 Titre: Comparing technologies for municipal solid waste management using life cycle assessment methodology: a Belgian case study <br/> <br/>Auteur, co-auteur: Belboom, Sandra; Digneffe, Jean-Marc; Renzoni, Roberto; Germain, Albert; Léonard, Angélique http://hdl.handle.net/2268/149850 Titre: Valorisation de l'énergie à l'échappement pour un moteur thermique <br/> <br/>Auteur, co-auteur: Legros, Arnaud http://hdl.handle.net/2268/149841 Titre: Boucle de Rankine pour la valorisation de l'énergie des gaz à l'échappement <br/> <br/>Auteur, co-auteur: Legros, Arnaud http://hdl.handle.net/2268/149608 Titre: Simulation and optimization of a CHP biomass plant and district heating network <br/> <br/>Auteur, co-auteur: Sartor, Kevin; Quoilin, Sylvain; Dewallef, Pierre <br/> <br/>Résumé: Biomass Combined Heat and Power (CHP) plants connected to district heating (DH) networks are recognized nowadays as a very good opportunity to increase the share of renewable sources into energy systems. However, as CHP plants are not optimized for electricity production, their operation is profitable only if a sufficient heat demand is available throughout the year. Most of the time, pre-feasibility studies are based on peak power demand and business plans only assume monthly or yearly consumption data. This approach usually turns out to overestimate the number of operating hours or oversize the plant capacity. This contribution presents a methodology intended to be simple and effective that provides accurate estimations of economical, environmental and energetic performances of CHP plants connected to district heating networks. A quasi-steady state simulation model of a CHP plant combined with a simulation model of the district heating network installed on the Campus of the University in Liège (Belgium) is used as an application framework to demonstrate the effectiveness of the selected approach. Based on the developed model and actual consumption data, several scenarios for energy savings are considered and ranked. The potential energy savings and resulting energy costs are estimated enabling more general conclusions to be drawn on the opportunity of using district heating networks in urban districts for Western Europe countries. http://hdl.handle.net/2268/149519 Titre: Design of a small-scale organic Rankine cycle engine used in a solar power plant <br/> <br/>Auteur, co-auteur: Georges, Emeline; Declaye, Sébastien; Dumont, Olivier; Quoilin, Sylvain; Lemort, Vincent <br/> <br/>Résumé: Under the economic and political pressure due to the depletion of fossil fuels and global warming concerns, it is necessary to develop more sustainable techniques to provide electrical power. In this context, the present study aims at designing, building and testing a small-scale organic Rankine cycle (ORC) solar power plant ( 3 kWe) in order to define and optimize control strategies that could be applied to larger systems. This paper presents a first step of the design of the solar power plant and focuses more specifically on the ORC engine. This design is defined on the basis of simulation models of the ORC engine and takes into account some technical limitations such as the allowed operating ranges and the technical maturity of the components. The final configuration includes a diaphragm pump, two plate heat exchangers for the regenerator and the evaporator, an air-cooled condenser, two hermetic scroll expanders in series and R245fa as the working fluid. Simulations indicate that an efficiency close to 12% for the ORC engine can be reached for evaporating and condensing temperatures of 140 and 358C, respectively. http://hdl.handle.net/2268/149494 Titre: Optimization of the operating conditions of an existing biomass CHP plant with respect to pollutants levels <br/> <br/>Auteur, co-auteur: Sartor, Kevin; Restivo, Yannick; Ngendakumana, Philippe; Dewallef, Pierre <br/> <br/>Résumé: While small and medium size biomass combined heat and power plants (i.e., up to 5 MW of electrical rated power) represent an attractive option to exploit locally available biomass resources at low cost, the corresponding investment per unit of rated power significantly rises when the installed power decreases. In these cases, secondary pollutant emissions control measures are most of the time not economically viable and primary emissions control must be used alone to avoid the formation of undesired compounds such as $NO_x$ and $SO_x$. Primary control measures require the careful optimization of fuel quality and combustion process. For plant operators, being able to accommodate biomass quality changes in order to minimize the fuel cost can be of great importance in order to guarantee the profitability of the plant. This contribution is dedicated to the development of zero-dimensional (input-output) combustion simulation model able to predict the pollutants emissions resulting from complete and incomplete combustion with respect to varying combustion operation (ambient temperature, humidity, fumes recirculation,..). This tool is intended to be integrated in global simulation model of the CHP plant and the attached district heating network installed on the University campus in Liège. Doing so, the plant operation can be optimized with respect to economic as well as environmental and energetic aspects (3E approach) thus ensuring the sustainability of the approach. http://hdl.handle.net/2268/148642 Titre: What is the right pathway to be sustainable? Case of biofuels and bioproducts in Europe <br/> <br/>Auteur, co-auteur: Belboom, Sandra; Léonard, Angélique http://hdl.handle.net/2268/147985 Titre: Importance of LUC and ILUC on the carbon footprint of bioproduct:case of bio-HDPE <br/> <br/>Auteur, co-auteur: Belboom, Sandra; Léonard, Angélique <br/> <br/>Résumé: Due to the depletion of fossil fuels and the increase of greenhouse gas emissions, solutions are needed to replace petrol based products. As a consequence, the number of biobased products developed using agricultural feedstock is continuously increasing. This study focuses on the carbon footprint of bio-HDPE produced either from Brazilian sugar cane or Belgian sugar beet. The goal of this study is to compare the carbon footprint of bio-HDPE with the fossil one, taking into account the effect of land use change. Common boundaries of the agricultural systems comprise the cultivation step for both crops, i.e. sugar cane and sugar beet, with all associated energy and fertilizer consumptions, the transportation step from field to the industrial plant, the sugar crops transformation into hydrate bioethanol, the by-products valorisation, the dehydration and polymerization steps and the HDPE incineration as end of life issue. Fossil scenario includes the production of ethylene, its polymerization and its incineration. When comparing the entire life cycle of bio and fossil HDPE, the GHG emissions are lower for the biobased product which is the willing effect. This result is only valid if no Land Use Change (LUC) or Indirect Land Use Change (ILUC) effect appears. To assess the environmental impact of the deforestation or of the transformation of a pasture into a field, the EC-Guidelines from the European Union were used in order to calculate the CO2 emissions depending on several parameters. For sugar cane, LUC consists in the transformation of pastures into fields in the region of Sao Paulo in Brazil. Three scenarios can be developed based on different agricultural practices for pasture and field (tillage and fertilizers inputs): the best, the worst and the average. The best case leads to a supplementary environmental gain. The worst and average achieve additional emissions. A payback time, considering the time needed to find again an environmental gain compared to the fossil counterpart, was calculated for the average scenario which is equal to 12 years. The ILUC effect for sugar cane is assumed to be deforestation due to the transformation of forest into pasture induced by the previous LUC effect. The rate of deforestation can vary between 16% or 100% depending on used statistics and leads to a payback time of respectively 26 and 101 years. For sugar beet, no LUC is considered. Indeed, no land expansion is available in Belgium due to small available areas. In the case of an increase of bioplastics production, Belgium should import sugar beet from neighboring countries which can induce ILUC. In this study, sugar beet is assumed to be provided by the Netherlands on pastures previously transformed into fields. The average scenario implies a payback time of 8 years. This study permits to highlight the importance of LUC and ILUC especially for energetic crops dedicated to replace fossil products. This effect can reverse expected results and induce long payback times. http://hdl.handle.net/2268/147390 Titre: Modeling and simulation of the domestic energy use in Belgium following a bottom-up approach <br/> <br/>Auteur, co-auteur: Georges, Emeline; Gendebien, Samuel; Bertagnolio, Stéphane; Lemort, Vincent <br/> <br/>Résumé: The present paper presents a “bottom-up” approach dedicated to the modeling and simulation of the domestic energy use. This methodology focuses first on a microanalysis (i.e. modeling and simulation of a set of representative households). Results from this micro-analysis are then used and extended to allow drawing conclusions at a macro-scale. The methodology can be validated by comparing simulation results to annual national energy consumption indexes or synthetic load profiles (energy consumption profiles generated from values of predefined past periods). Once the method is validated, it can be used to study the impact of different retrofit scenarios on the annual energy use and on the energy demand profiles. This paper describes the methodology developed for Belgium. http://hdl.handle.net/2268/147369 Titre: A comparison of piston, screw and scroll expanders for small scale Rankine cycle systems <br/> <br/>Auteur, co-auteur: Lemort, Vincent; Guillaume, Ludovic; Legros, Arnaud; Declaye, Sébastien; Quoilin, Sylvain <br/> <br/>Résumé: This paper aims at helping the designer of micro-scale Rankine Cycle heat engines to best select the expander among piston, screw and scroll machines. The first part of the paper presents a state of the art of these three technologies of positive displacement machines. The technical constraints inherent to each machine (rotational speed, pressure ratios, maximum temperatures, volumetric expansion ratios, etc.) are listed and the performance mentioned in the open technical and scientific literature is presented. The second part of the paper deals with the modeling of such expanders. Different simulation models are proposed: black-box, grey-box and white-box models. These three categories of modeling are specifically adapted to different purposes: design of the expander, design of the micro-CHP system, and dynamic simulation/control of the CHP unit. The last part of the paper presents a graphical methodology of selection of expansion machines and working fluids based on operating maps. It is stressed that the selections of both the expansion machine and working fluid should be conducted simultaneously. http://hdl.handle.net/2268/147365 Titre: Investigation of advanced materials for fusion alpha particle diagnostics <br/> <br/>Auteur, co-auteur: Bonheure, G.; Van Wassenhove, G.; Hult, M.; González de Orduña, R.; Strivay, David; Vermaercke, P.; Delvigne, T.; Chene, Grégoire; Delhalle, René; Huber, A.; Schweer, B.; Esser, G.; Biel, W.; Neubauer, O. <br/> <br/>Résumé: Fusion alpha particle diagnostics for ITER remain a challenging task. Standard escaping alpha particle detectors in present tokamaks are not applicable to ITER and techniques suitable for fusion reactor conditions need further research and development [1,2]. The activation technique is widely used for the characterization of high fluence rates inside neutron reactors. Tokamak applications of the neutron activation technique are already well developed [3] whereas measuring escaping ions using this technique is a novel fusion plasma diagnostic development. Despite low alpha particle fluence levels in present tokamaks, promising results using activation technique combined with ultra-low level gamma-ray spectrometry [4] were achieved before in JET [5,6]. In this research work, we use new advanced detector materials. The material properties beneficial for alpha induced activation are (i) moderate neutron cross-sections (ii) ultra-high purity which reduces neutron-induced background activation and (iii) isotopic tailoring which increases the activation yield of the measured activation product. Two samples were obtained from GERDA[7], an experiment aimed at measuring the neutrinoless double beta decay in 76Ge. These samples, made of highly pure (9 N) germanium highly enriched to 87% in isotope Ge-76, were irradiated in real D-D fusion plasma conditions inside the TEXTOR tokamak. Comparison of the calculated and the experimentally measured activity shows good agreement. Compared to previously investigated high temperature ceramic material [8], this candidate detector offers better prospects for signal to background S/B ratio, energy resolution and particle selectivity due to a unique alpha particle signature. Applicability to ITER is discussed. Finally, research needs for further development of this diagnostic technique are outlined. © 2013. http://hdl.handle.net/2268/147286 Titre: Analyse par simulation 3D de l'efficacité énergétique et du confort dans les bâtiments. Evaluation de différentes technologies sur des cas de validation académiques <br/> <br/>Auteur, co-auteur: Goffaux, Cécile; Van Moeseke, Geoffrey; Barbason, Mathieu; Reiter, Sigrid http://hdl.handle.net/2268/147284 Titre: Evaluation du besoin de cogénération en Belgique dans la perspective des plans 2020-2030. Rapport final. <br/> <br/>Auteur, co-auteur: Pacot, Pierre-Emmanuel; Reiter, Sigrid http://hdl.handle.net/2268/147283 Titre: Cartographie des Emissions annuelles de CO2 dues aux consommations énergétiques des bâtiments tertiaires en Région wallonne. Rapport de synthèse. <br/> <br/>Auteur, co-auteur: Barbason, Mathieu; Reiter, Sigrid