References of "Thomas, Sébastien"
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See detailAnalysis of solar air-conditioning systems and their integration in buildings
Thomas, Sébastien ULg

Doctoral thesis (2013)

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 ... [more ▼]

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. [less ▲]

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See detailDynamic simulations of solar combisystems integrating a seasonal sorption storage: Influence of the combisystem configuration
Hennaut, Samuel ULg; Thomas, Sébastien ULg; Davin, Elisabeth ULg et al

in Strojarstvo: Journal for Theory and Application in Mechanical Engineering (2012, December), 54(6), 433-440

This paper focuses on the sizing of solar combisystems with adsorption seasonal storage to target autonomous solar space heating. Two main configurations of the combisystem are simulated, including one or ... [more ▼]

This paper focuses on the sizing of solar combisystems with adsorption seasonal storage to target autonomous solar space heating. Two main configurations of the combisystem are simulated, including one or two tanks. The influence of the seasonal storage on the sizing of the tanks is also discussed. Results show that performances of the system with two tanks are better (2 to 4 % with seasonal storage) but some improvements should be possible for the single tank configuration. The sizing of the sensible storage is nearly independent of the solar collectors area if there is a seasonal storage. The sensible storage size increase with the collectors area without adsorption storage. The analysis is conducted in simulation using the TRNSYS program. [less ▲]

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See detailNumerical simulation and performance assessment of an absorption solar air-conditioning system coupled with an office building
Thomas, Sébastien ULg; Andre, Philippe ULg

in Building Simulation: An International Journal (2012), 5(3), 243-255

To minimize environmental impact and CO2 production associated with air-conditioning, it is reasonable to evaluate the prospects of a clean energy source. Solar energy, via thermal collectors can provide ... [more ▼]

To minimize environmental impact and CO2 production associated with air-conditioning, it is reasonable to evaluate the prospects of a clean energy source. Solar energy, via thermal collectors can provide a part of the heating needs. Moreover, it can drive absorption chiller in order to satisfy the cooling needs of buildings. The objective of the work is to evaluate accurately the energy consumption of an air-conditioning system including a solar driven absorption chiller. The complete simulation environment includes the absorption chiller itself, the cooling tower, the solar collectors field, heater, storage devices, pumps, heating-cooling distribution, emission system and building. A decrease of primary energy consumption of 22% for heating and cooling is reached when using a solar air-conditioning system instead of classical heating and cooling devices. The modelling of each subsystem is detailed. TRNSYS software modular approach provides the possibility to model and simulate this complete system. [less ▲]

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See detailExperimentation and Simulation of a Small-Scale Adsorption Cooling System in Temperate Climate
Thomas, Sébastien ULg; Hennaut, Samuel ULg; Maas, Stefan et al

in Energy Procedia (2012), 30

This paper focuses on the analysis of the operation of a solar cooling system based upon an adsorption chiller. The air-conditioned building studied is a laboratory located in a temperate climate region ... [more ▼]

This paper focuses on the analysis of the operation of a solar cooling system based upon an adsorption chiller. The air-conditioned building studied is a laboratory located in a temperate climate region (Belgium). The monitoring reveals thermal and electrical coefficient of performance (COP) of the cooling system for different time scale (10s to 1 month). The whole system including solar collectors, adsorption machine, recooling unit and hot storage is simulated. The models are then confronted to the measurements. Measurement period is shared between 2011 and 2012. Enhancements have been achieved during winter 2011 to have a more efficient system operation. The aim of this experimental work is to describe, for both measurement periods, the influence of operating conditions on the energy efficiency (thermal behavior and electrical consumption). On the simulation point of view, the main objective is to find accurate models for all the components. The adsorption chiller model is not yet precise enough to evaluate the performance of solar cooling in other conditions. [less ▲]

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See detailPerformance assessment of a small-scale adsorption chiller integrated to an already existing solar heating system
Thomas, Sébastien ULg; Andre, Philippe ULg; Maas, Stefan

in Proceedings of 4th International Conference Solar Air-Conditioning (2011, October 12)

In the context of the solar air-conditioning systems analysis, it is crucial to assess system performance by experimentations in real-time conditions. In this way, it is possible to calculate the energy ... [more ▼]

In the context of the solar air-conditioning systems analysis, it is crucial to assess system performance by experimentations in real-time conditions. In this way, it is possible to calculate the energy savings to minimize environmental impact and CO2 production induced by the operation of such a system in buildings operation. It is proposed to measure the thermal behaviour and the energy performance of a smallscale solar air-conditioning system used to cool a laboratory building in the South of Belgium. The experimental system is recently installed and fully instrumented for both thermal and electrical COP computation. Results of two months operation and data analysis are presented in this work. [less ▲]

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See detailDynamic simulation of residential buildings with seasonal sorption storage of solar energy - parametric analysis
Hennaut, Samuel ULg; Thomas, Sébastien ULg; Davin, Elisabeth ULg et al

in ISES solar world congress 2011 - Proceedings (2011, August 28)

This work focuses on the evaluation of the performances of a solar combisystem coupled to seasonal thermochemical storage using SrBr2/H20 as adsorbent/adsorbate couple. The objective is to determine the ... [more ▼]

This work focuses on the evaluation of the performances of a solar combisystem coupled to seasonal thermochemical storage using SrBr2/H20 as adsorbent/adsorbate couple. The objective is to determine the characteristics required for solar system and storage reactor to reach a 100 % solar fraction for a building with a low heating load. The complete system, including the storage reactor, is simulated, using the dynamic simulation software TRNSYS. The influence of some components and parameters of the system is estimated: weather, collectors and storage reactor parameters. [less ▲]

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See detailPré-dimensionnement par simulations dynamiques d’un réacteur de stockage thermochimique assurant l’autonomie d’un système solaire combiné.
Hennaut, Samuel ULg; Thomas, Sébastien ULg; Andre, Philippe ULg et al

in Congrès Français de Thermique 2011 - Energie Solaire et Thermique - Perpignan - 24-27 Mai 2011 (2011, May 24)

Etude du stockage de l’énergie solaire thermique sous forme thermochimique comme moyen d’assurer l’autonomie thermique d’une habitation basse énergie. La surface de capteurs nécessaire et les ... [more ▼]

Etude du stockage de l’énergie solaire thermique sous forme thermochimique comme moyen d’assurer l’autonomie thermique d’une habitation basse énergie. La surface de capteurs nécessaire et les caractéristiques du stockage sont étudiées par simulation dynamique (TRNSYS), de manière générale et pour des couples adsorbant/adsorbat particuliers (CaCl2/H2O et Charbon actif/Méthanol). Un système solaire combiné avec 14,4 m² de capteurs plans et un stockage thermochimique de 12,35 m³ de CaCl2 permet d’assurer l’autonomie thermique d’une habitation « basse énergie » située en Belgique et une grande part de la production d’eau chaude sanitaire (ECS). [less ▲]

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See detailModel validation of a dynamic embedded water base surface heat emitting system for buildings.
Thomas, Sébastien ULg; Andre, Philippe ULg; Franck, Pierre-Yves

in Building Simulation: An International Journal (2011), 4

A numerical model is developed to assess the static and dynamic operations of a new kind of floor heat emitter. Surface floor heating systems are widely used to achieve better comfort conditions in ... [more ▼]

A numerical model is developed to assess the static and dynamic operations of a new kind of floor heat emitter. Surface floor heating systems are widely used to achieve better comfort conditions in residential and tertiary building sector. Classical floor heating systems have a low thermal response while the emitting device studied in this paper is highly reactive. It allows comfort enhancement and energy savings. A finite element method based software COMSOL Multiphysics is applied to solve the heat equation. This work focuses on the thermal behaviour of the emitter itself, but does not include a building model. A test bench has been built for this application to verify the numerical model. Both computational and experimental results demonstrate the benefits of this new heating and cooling device. [less ▲]

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See detailNumerical simulation and performance assessment of an absorption solar air-conditioning system coupled with an office building
Thomas, Sébastien ULg; Andre, Philippe ULg

Conference (2010, December)

To minimize environmental impact and CO2 production associated with air-conditioning, it is reasonable to evaluate the prospects of a clean energy source. Solar energy, via thermal collectors can provide ... [more ▼]

To minimize environmental impact and CO2 production associated with air-conditioning, it is reasonable to evaluate the prospects of a clean energy source. Solar energy, via thermal collectors can provide a part of the heating needs. Moreover, it can drive absorption chiller in order to satisfy the cooling needs of buildings. The objective of the work is to evaluate accurately the energy consumption of an air conditioning system including a solar driven absorption chiller. The complete simulation environment includes the absorption chiller itself, the cooling tower, the solar collectors field, heater, storage devices, pumps, heating-cooling distribution, emission system and building. The modelling of each subsystem is detailed. TRNSYS software modular approach provides the possibility to model and simulate this complete system. [less ▲]

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See detailCombination of experimental and simulated small scale solar air-conditioning system
Thomas, Sébastien ULg; Hennaut, Samuel ULg; Andre, Philippe ULg

in EUROSUN 2010, International conference on solar heating, cooling and buildings, 28 September - 1 October 2010, Graz, Austria (2010, October 01)

It is now clearly assumed that solar assisted air conditioning is able to decrease CO2 production of building operation. One way to evaluate the energy savings potential is the simulation of ... [more ▼]

It is now clearly assumed that solar assisted air conditioning is able to decrease CO2 production of building operation. One way to evaluate the energy savings potential is the simulation of airconditioning systems. On the other hand, it is also crucial to assess system performance by experimentations. The operation of a solar cooling system in its real environment is considered here. The objective is to evaluate if sun radiation in our region (Western Europe – Belgium) in summer 2009 is enough for feeding an adsorption chiller, in other words to find experimentally the solar fraction of a solar air-conditioning system in our region. Residential application suits with equipment available in our laboratory. A combination of experimentation and simulation is used because of the lack of sorption chiller in our laboratory facilities. Hot loops are measured while cold and rejection loops are simulated. Thirty-one days were measured; energy flows analysis on the whole period reveals a theoretical solar fraction of nearly 100% but a real solar fraction of 31%. Issues related to the test implementation are emphasized and explained in this paper. [less ▲]

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See detailOptimization of dynamic embedded, Water based surface heat (and cold) emitting system for buildings.
Thomas, Sébastien ULg; Franck, Pierre-Yves ULg; Andre, Philippe ULg

Conference (2009, October)

This paper presents the heat flow model and the experimental test bench developed to optimize a new kind of heating floor. In the first part of the text is described the new kind of high reactivity ... [more ▼]

This paper presents the heat flow model and the experimental test bench developed to optimize a new kind of heating floor. In the first part of the text is described the new kind of high reactivity emitting device for building heating and cooling. A second part illustrates the numerical model developed to evaluate the device efficiency. Finally experimental test bench implementation and results are presented. Both computational and experimental results support the use of colder water in comparison to other heating devices. This implies energy savings for building heating. [less ▲]

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See detailControl strategies study of a complete solar assisted air conditioning system in an office building using TRNSYS
Thomas, Sébastien ULg; Andre, Philippe ULg

(2009, September)

It is now clearly assumed that solar assisted air conditioning is able to minimize environmental impact and CO2 production of buildings operation. How to reach highest energy savings is still a work in ... [more ▼]

It is now clearly assumed that solar assisted air conditioning is able to minimize environmental impact and CO2 production of buildings operation. How to reach highest energy savings is still a work in progress. In former literature, equipment control has been point out as a critical feature of energy consumption. Control becomes more and more important as system is complex. The complete simulation environment was developed in previous work, it includes the absorption chiller itself, the rejection circuit (cooling tower), solar panels field, heater, storage device, pumps, heating-cooling networks, emission system and building. TRNSYS software modular approach provides the possibility to model and simulate this complete system. In this article, different strategies are proposed to minimize consumption for air-conditioning. [less ▲]

Detailed reference viewed: 83 (19 ULg)
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See detailSimulation based energy consumption calculation of an office building using solar-assisted air conditioning
Thomas, Sébastien ULg; Andre, Philippe ULg

Poster (2008, October)

To minimize environmental impact and CO2 production associated with air-conditioning system operation, it is reasonable to evaluate the prospects of a clean energy source. The targets of the study are to ... [more ▼]

To minimize environmental impact and CO2 production associated with air-conditioning system operation, it is reasonable to evaluate the prospects of a clean energy source. The targets of the study are to evaluate cooling energy consumption to maintain thermal comfort in an office building and to point out solar energy to satisfy these cooling needs. Simulations were carried out with three different cooling systems in the same operating conditions to determine as accurately as possible the potential use of solar energy. For comparison purpose, the base case is a classical air-conditioning system (heat pump for cooling, gas boiler for heating). Two other configurations were simulated: a classical vapour compression system fed by photovoltaic panels and electricity grid as back-up and, absorption chiller fed by solar thermal panel field and by gas boiler. In the three chosen locations (Paris, Lisbon and Stockholm), results shown that installing photovoltaic panels on the roof is really interesting from the primary energy consumption point of view. [less ▲]

Detailed reference viewed: 163 (33 ULg)
See detailModélisation de la pyrolyse dans un gazogène à lit fixe
Thomas, Sébastien ULg

Master's dissertation (2005)

Choix d'un modèle de pyrolyse pour un gazogène à lit fixe. Dans un premier temps une résolution analytique a été effectuée. Des corrélations de dégagement de gaz ont été élaborées et implémentées dans une ... [more ▼]

Choix d'un modèle de pyrolyse pour un gazogène à lit fixe. Dans un premier temps une résolution analytique a été effectuée. Des corrélations de dégagement de gaz ont été élaborées et implémentées dans une modélisation du gazogène par éléments finis (CFD via Fluent). [less ▲]

Detailed reference viewed: 45 (1 ULg)