Sofiane Amara - Academia.edu (original) (raw)
Papers by Sofiane Amara
Energy Procedia, 2011
This paper reports on an experimental realization and field testing of a recently proposed solar ... more This paper reports on an experimental realization and field testing of a recently proposed solar fiber optic mini dish light concentrator connected to a hot water accumulator. The prototype dish is 150 cm in diameter. In repeated test the collected and concentrated sunlight was transported in a one millimeter diameter optical fiber to a selective surface in the storage tank. This surface absorbs the radiation which remains trapped inside as it heat exchanges with tank fluid which temperature can reach 70°C.
Journal of Thermal Analysis …
... MA Boukli Hacene (&) Į S. Amara Į NE Chabane Sari Unité de Recherche Matériaux et Energie... more ... MA Boukli Hacene (&) Į S. Amara Į NE Chabane Sari Unité de Recherche Matériaux et Energies Renouvelables (URMER), Université Abou bekr Belkaid, 13000 Tlemcen, Algeria e ... 18. Javed S, Fahlén P, Claesson J. Vertical ground heat exchangers: a review of heat flow models ...
Etude d’un systeme de production et stockage d’eau chaude sanitaire pour le site de Tlemcen
Une maison ecologique, designe plus un concept qu'un type defini d'habitation. L'idee... more Une maison ecologique, designe plus un concept qu'un type defini d'habitation. L'idee est de combiner les differents modes de chauffage, de ventilation, d'alimentation des appareils pour reduire massivement la consommation d'energie, donc une decroissance exponentielle du rejet de CO 2 . Le travail presente est l'etude de l'impact d'une maison ecologique sur l'environnement. Afin d'aboutir a ce bilan, il faudrait d'abord faire une etude globale sur le bilan energetique, a partir duquel nous pourrons connaitre d'un cote le temps d'utilisation de chaque equipement de la maison, donc un bilan sur le rejet de CO 2 et de l'autre cote, la comptabilisation du carbone dans l'energie primaire, ainsi que le cvcle de vie des materiaux d'isolation. Les resultats obtenus ont ete confrontes aux resultats de la meme maison construite avec des materiaux non isolants, tels que la brique, le beton... La confrontation montre une differert...
The building thermal function is more important to provide improved comfort in the buildings and ... more The building thermal function is more important to provide improved comfort in the buildings and also economic development in this area. To supply domestic hot water and space heating, water must be simultaneously available at two different temperature levels. Cold water temperature, close to that of the atmosphere, and hot water between 50 and 60°C. An interesting feature of the preparation of hot water is the small variation of requirements during the year, unlike that to heating. The preparation of hot water is one of the preferred applications of solar energy in the building for several reasons. This study included concentrating solar collector in which optical fibers were used to transport the energy to the storage tank. Another technology was introduced and developed for heating and cooling buildings in the desert involving an existing ancient irrigation system called Fouggara.
-Une maison écologique, désigne plus un concept qu'un type défini d'habitation. L'idée est de com... more -Une maison écologique, désigne plus un concept qu'un type défini d'habitation. L'idée est de combiner les différents modes de chauffage, de ventilation, d'alimentation des appareils pour réduire massivement la consommation d'énergie, donc une décroissance exponentielle du rejet de CO 2. Le travail présenté est l'étude de l'impact d'une maison écologique sur l'environnement. Afin d'aboutir à ce bilan, il faudrait d'abord faire une étude globale sur le bilan énergétique, à partir duquel nous pourrons connaître d'un coté le temps d'utilisation de chaque équipement de la maison, donc un bilan sur le rejet de CO 2 et de l'autre coté, la comptabilisation du carbone dans l'énergie primaire, ainsi que le cycle de vie des matériaux d'isolation. Les résultats obtenus ont été confrontés aux résultats de la même maison construite avec des matériaux non isolants, tels que la brique, le béton… La confrontation montre une différence significative sur les plans énergétique, économiques, ainsi qu'environnementaux, ce qui nous laisse très optimistes sur le rendement des habitats écologiques. Abstract-A green home means more a concept than a defined type of housing. The idea is to combine different modes of heating, ventilation, power supply devices to massively reduce energy consumption, thus an exponential decrease in CO 2 emissions. The present work is to study the impact of a green home on the environment. To achieve this balance, we would first do a comprehensive study on energy balance, from which we can know at one hand the usage time of each household equipment, therefore a balance on the release of CO 2 and in the other side, carbon accounting in the primary energy and the life cycle of insulation materials. The results were compared with the results in the same house built with no insulation materials such as brick, concrete ... The comparison shows a significant difference in terms of energy, economically and environmentally, which leaves us very optimistic about the performance of ecological habitats.
The building thermal function is one of the significant functions of this one: it is necessary th... more The building thermal function is one of the significant functions of this one: it is necessary that within the building an environment should be maintained in order to satisfy in habitant from the thermal comfort point of view. This is to provide airconditioning in hot countries or hot seasons or heating in cold countries or cold seasons. The aim of this work is the study and modelling of a new design of thermal photo sensor with reduced losses and high efficiency aimed for the site of Tlemcen. Résumé-La fonction thermique du bâtiment est l'une des principales fonctions de celui-ci: il est nécessaire que l'environnement de la construction devrait être maintenu pour satisfaire un confort thermique de l'habitant. Cette mesure vise à assurer la climatisation dans les pays chauds ou dans les saisons chaudes et le chauffage dans les pays froids ou dans les saisons froides. Le but de ce travail est l'étude et la modélisation d'une nouvelle conception du capteur photo thermique avec des réductions des pertes thermiques et qui vise un rendement élevé pour le site de Tlemcen.
Current Alternative Energy
Aims: This paper reviews extensively the thermochemical processing of biomass to fuels and high-v... more Aims: This paper reviews extensively the thermochemical processing of biomass to fuels and high-value chemicals, with more emphasis on the process performance, conditions, and weaknesses. The important chemical compositions of biomass feedstock, their conversion technologies and most importantly, the role of catalysis in their conversion to fuels, fuel additives, based chemicals, and added-value chemicals are also discussed. Background: Fossil fuels have fueled the world economy for decades. However, given their unlimited nature, fluctuating prices and the escalating environmental concerns, there is the urgent need to develop and valorize cheaper, cleaner and sustainable alternative energy sources to curb these challenges. Biomass represents a valid alternative to fossil fuels, especially for fuel and chemical production as it represents the only natural organic renewable resource with vast abundance. A vast array of conversion technologies is used to process biomass from one form t...
Renewable and Sustainable Energy Reviews
Current Alternative Energy
Energy Procedia, 2011
In order to utilise naturally stored heat or cold from the ground, seasonal temperature variation... more In order to utilise naturally stored heat or cold from the ground, seasonal temperature variations are required. The reason is that the ground temperature is then warmer than the air temperature during winter and colder during summer. The heating and cooling demand in North Africa varies considerably with the greatest cooling demand in the East and the greatest heating demand in the West. In parts of Algeria the mean temperature difference between the coldest and warmest month is greater than 20°C, which is favourable. In current work it was shown that the ancient Fouggara system, even today would be interesting for heating and cooling of buildings in the Sahara desert.
Résumé -L'optimisation du rendement de conversion des cellules photovoltaïques est basée sur ... more Résumé -L'optimisation du rendement de conversion des cellules photovoltaïques est basée sur la compréhension et le développement du concept du dispositif. Toutefois, il existe des outils de caractérisation permettant de comprendre non seulement le fonctionnement des cellules mais aussi et surtout maîtriser les paramètres limitatifs des performances de celles-ci. Notre travail présenté porte sur l'étude des performances des cellules solaires et sur l'analyse d'une méthode numérique permettant l'extraction des paramètres des modèles de la caractéristique courant-tension d'une cellule solaire. Pour un fonctionnement donné, l'étude du rendement de conversion d'énergie maximale M η une cellule solaire nécessite un modèle analytique complet de son fonctionnement. Le modèle à une exponentielle prévoit une augmentation de V co , dès que le facteur de qualité augmente ou le courant de saturation diminue. Ceci mène à des grandes valeurs de V co incompatibles a...
Résumé -Ce travail présente les résultats d'une étude théorique de la cinétique du séchage de... more Résumé -Ce travail présente les résultats d'une étude théorique de la cinétique du séchage de la pomme de terre dans un séchoir solaire indirect. Un modèle mathématique simulant le fonctionnement du système de séchage a été élaboré. Ce modèle est validé par plusieurs études sur la pomme de terre qui, après être séchée et broyée, présente un grand intérêt pour l'industrie alimentaire notamment pour la fabrication de farine. On a utilisé la méthode des différences finies pour la résolution numérique [1]. Les résultats obtenus nous ont permis d'évaluer l'influence de la masse, du diamètre du produit et la température de l'air, agent séchant, sur le temps de séchage. Mots clés: Séchage solaire -Cinétique de séchage -Différences finis -Produit alimentaire -Temps de séchage -Teneur en eau.
Résumé -La serre tunnel agricole classique est largement répandue dans les pays du bassin méditer... more Résumé -La serre tunnel agricole classique est largement répandue dans les pays du bassin méditerranéen malgré les insuffisances qu'elle présente, notamment la surchauffe pendant le jour et le refroidissement nocturne intense, qui parfois se traduit par l'inversion de la température interne. La serre agricole a pour objectifs de créer un microclimat favorable aux exigences et à la croissance des plantes à partir des conditions climatologiques environnantes, de produire en fonction des calendriers culturaux des fruits et des légumes hors saison à bon marché et largement disponibles le long de l'année. Elle est définie par son architecture structurelle et fonctionnelle, par la qualité optique, thermique et mécanique de sa couverture et par les moyens techniques d'accompagnement. La serre est considérée comme un milieu très confiné où plusieurs composants s'échangent entre elles et dont les principaux facteurs intervenant dans ce milieu sont: la lumière, la températ...
Journal of Renewable and Sustainable Energy, 2011
Our country must face a foreseeable shortage of fossil energies and the consequences of their car... more Our country must face a foreseeable shortage of fossil energies and the consequences of their carefree use. Since the consumption of energy is increasing from every year, we are obliged to develop innovating techniques to bring at least partial solutions to the double problems of the use of the resources and fight against pollution. The sector of housing carries a considerable share of the responsibilities in this matter. The objective of a passive house is to privilege thermal comfort while contributing to energy saving. Our vision of "ecological construction" is centred on the concept of "durability of the environment," i.e., the adoption of a lifestyle which makes it possible to preserve, to maintain, and to improve quality of the resources and natural balances, and thus to spare the future. The goal of our project is to carry out the following concept that allows to: minimize the energy needs calorific of the building while providing a good quality air inside; utilize renewable energy for the energy needs of the house; control the impacts of a building on the external environment; create an healthy and comfortable environment for its users; preserve the natural resources by optimizing their use, and; promote with sustainable development.
Energy Procedia, 2011
The treatment of air in the buildings often poses the problem of the homogeneity of the temperatu... more The treatment of air in the buildings often poses the problem of the homogeneity of the temperature in any point of the room. The treatment of the room in heating mode is constraining. The difference in temperature between the puffed up air and the ambient air can generate stratification. The hot air being lighter than the cold air, one tends to find layers of hot air in height and layers of cold air partly low of the room.
pure.ltu.se
under the direction of M. Boumediene Benyoucef, Professor Emeritus, for the financial support giv... more under the direction of M. Boumediene Benyoucef, Professor Emeritus, for the financial support given to me. I am most gratitude for the highly educational and scientific advice he has not hesitated to provide during the process of this work. The basic issue of this thesis concerns one of the fundamental problems of the future of our society: How to meet the energy requirements for a large and growing world population while preserving our environment? This question is important for the world and the answers are complex and interwoven. Conventional energy sources, fossil and fissile, are polluting in the present and in the future: they erode the environment and their resources are limited. Renewable energy (hydro, wind, solar, geothermal) constitutes a minimum of pollution in the different energy systems. The technologies for using renewable energy are well known though further development and progress are made. This development also requires behavioural change, adaptation, and above all political will. The transition from an economy based on fossil energy to an economy based on renewable energy appears necessary for the protection of the environment. The cost of renewable energy is often represented as an obstacle but remains competitive in the long run. The development and availability of renewable energy, which varies because of its spatial and temporal distribution, require an adaptation of lifestyle, habits, habitat design (passive bioclimatic houses), urban planning and transportation. The focus of this thesis was to apply renewable energy in an area with hot summers and cold winter, a climate like that in the northwest of Algeria. In order to provide improved comfort in the buildings and also economic development in this area, the energy demand for heating and cooling was analyzed in the ancient city of Tlemcen. To supply domestic hot water and space heating, water must be simultaneously available at two different temperature levels. Cold water temperature, close to that of the atmosphere, and hot water between 50 and 60°C. An interesting feature of the preparation of hot water is the small variation of requirements during the year, unlike that to heating. The preparation of hot water is one of the preferred applications of solar energy in the building for several reasons. For this reason an experimental study of the thermal behaviour of a domestic hot water storage tank was undertaken. The phenomena that affect the thermal behaviour of tank especially the coupling between the solar collector and storage tank was studied. This study included concentrating solar collector in which optical fibers were used to transport the energy to the storage tank. Another technology was introduced and developed for the heating and cooling of buildings in the desert involving an existing ancient irrigation system called Fouggara. The novel idea is to use the Fouggara as an air conditioner by pumping ambient air through this underground system. Then air at a temperature of about 21°C would be supplied to the building for heating in the winter and cooling in the summer. This study shows the feasibility of using this ancient irrigation system of Fouggara and contributes to reducing and eliminating the energy demand for heating and cooling buildings in the Sahara desert.
Much work has been carried out on hot water storage during the last 20-30 years, particularly on ... more Much work has been carried out on hot water storage during the last 20-30 years, particularly on solar heat applications. Theoretical and experimental studies on the internal heat transfer have been made at laboratory scale and at larger scales. Current study, which was conducted in order to understand the stratification phenomena, involved an experimental study on the thermal behaviour in a hot water tank during charging and discharging for domestic hot water storage. Results showed no effect of stratification due to the injection fluid from the bottom of the tank and the effect of mixed convection induced by the temperature difference which created a mixture inside the tank, where the temperature was uniform across the height, and the apparition of stratification due to the fact of discharge from the bottom of the tank.
Energy Procedia, 2011
This paper reports on an experimental realization and field testing of a recently proposed solar ... more This paper reports on an experimental realization and field testing of a recently proposed solar fiber optic mini dish light concentrator connected to a hot water accumulator. The prototype dish is 150 cm in diameter. In repeated test the collected and concentrated sunlight was transported in a one millimeter diameter optical fiber to a selective surface in the storage tank. This surface absorbs the radiation which remains trapped inside as it heat exchanges with tank fluid which temperature can reach 70°C.
Journal of Thermal Analysis …
... MA Boukli Hacene (&) Į S. Amara Į NE Chabane Sari Unité de Recherche Matériaux et Energie... more ... MA Boukli Hacene (&) Į S. Amara Į NE Chabane Sari Unité de Recherche Matériaux et Energies Renouvelables (URMER), Université Abou bekr Belkaid, 13000 Tlemcen, Algeria e ... 18. Javed S, Fahlén P, Claesson J. Vertical ground heat exchangers: a review of heat flow models ...
Etude d’un systeme de production et stockage d’eau chaude sanitaire pour le site de Tlemcen
Une maison ecologique, designe plus un concept qu'un type defini d'habitation. L'idee... more Une maison ecologique, designe plus un concept qu'un type defini d'habitation. L'idee est de combiner les differents modes de chauffage, de ventilation, d'alimentation des appareils pour reduire massivement la consommation d'energie, donc une decroissance exponentielle du rejet de CO 2 . Le travail presente est l'etude de l'impact d'une maison ecologique sur l'environnement. Afin d'aboutir a ce bilan, il faudrait d'abord faire une etude globale sur le bilan energetique, a partir duquel nous pourrons connaitre d'un cote le temps d'utilisation de chaque equipement de la maison, donc un bilan sur le rejet de CO 2 et de l'autre cote, la comptabilisation du carbone dans l'energie primaire, ainsi que le cvcle de vie des materiaux d'isolation. Les resultats obtenus ont ete confrontes aux resultats de la meme maison construite avec des materiaux non isolants, tels que la brique, le beton... La confrontation montre une differert...
The building thermal function is more important to provide improved comfort in the buildings and ... more The building thermal function is more important to provide improved comfort in the buildings and also economic development in this area. To supply domestic hot water and space heating, water must be simultaneously available at two different temperature levels. Cold water temperature, close to that of the atmosphere, and hot water between 50 and 60°C. An interesting feature of the preparation of hot water is the small variation of requirements during the year, unlike that to heating. The preparation of hot water is one of the preferred applications of solar energy in the building for several reasons. This study included concentrating solar collector in which optical fibers were used to transport the energy to the storage tank. Another technology was introduced and developed for heating and cooling buildings in the desert involving an existing ancient irrigation system called Fouggara.
-Une maison écologique, désigne plus un concept qu'un type défini d'habitation. L'idée est de com... more -Une maison écologique, désigne plus un concept qu'un type défini d'habitation. L'idée est de combiner les différents modes de chauffage, de ventilation, d'alimentation des appareils pour réduire massivement la consommation d'énergie, donc une décroissance exponentielle du rejet de CO 2. Le travail présenté est l'étude de l'impact d'une maison écologique sur l'environnement. Afin d'aboutir à ce bilan, il faudrait d'abord faire une étude globale sur le bilan énergétique, à partir duquel nous pourrons connaître d'un coté le temps d'utilisation de chaque équipement de la maison, donc un bilan sur le rejet de CO 2 et de l'autre coté, la comptabilisation du carbone dans l'énergie primaire, ainsi que le cycle de vie des matériaux d'isolation. Les résultats obtenus ont été confrontés aux résultats de la même maison construite avec des matériaux non isolants, tels que la brique, le béton… La confrontation montre une différence significative sur les plans énergétique, économiques, ainsi qu'environnementaux, ce qui nous laisse très optimistes sur le rendement des habitats écologiques. Abstract-A green home means more a concept than a defined type of housing. The idea is to combine different modes of heating, ventilation, power supply devices to massively reduce energy consumption, thus an exponential decrease in CO 2 emissions. The present work is to study the impact of a green home on the environment. To achieve this balance, we would first do a comprehensive study on energy balance, from which we can know at one hand the usage time of each household equipment, therefore a balance on the release of CO 2 and in the other side, carbon accounting in the primary energy and the life cycle of insulation materials. The results were compared with the results in the same house built with no insulation materials such as brick, concrete ... The comparison shows a significant difference in terms of energy, economically and environmentally, which leaves us very optimistic about the performance of ecological habitats.
The building thermal function is one of the significant functions of this one: it is necessary th... more The building thermal function is one of the significant functions of this one: it is necessary that within the building an environment should be maintained in order to satisfy in habitant from the thermal comfort point of view. This is to provide airconditioning in hot countries or hot seasons or heating in cold countries or cold seasons. The aim of this work is the study and modelling of a new design of thermal photo sensor with reduced losses and high efficiency aimed for the site of Tlemcen. Résumé-La fonction thermique du bâtiment est l'une des principales fonctions de celui-ci: il est nécessaire que l'environnement de la construction devrait être maintenu pour satisfaire un confort thermique de l'habitant. Cette mesure vise à assurer la climatisation dans les pays chauds ou dans les saisons chaudes et le chauffage dans les pays froids ou dans les saisons froides. Le but de ce travail est l'étude et la modélisation d'une nouvelle conception du capteur photo thermique avec des réductions des pertes thermiques et qui vise un rendement élevé pour le site de Tlemcen.
Current Alternative Energy
Aims: This paper reviews extensively the thermochemical processing of biomass to fuels and high-v... more Aims: This paper reviews extensively the thermochemical processing of biomass to fuels and high-value chemicals, with more emphasis on the process performance, conditions, and weaknesses. The important chemical compositions of biomass feedstock, their conversion technologies and most importantly, the role of catalysis in their conversion to fuels, fuel additives, based chemicals, and added-value chemicals are also discussed. Background: Fossil fuels have fueled the world economy for decades. However, given their unlimited nature, fluctuating prices and the escalating environmental concerns, there is the urgent need to develop and valorize cheaper, cleaner and sustainable alternative energy sources to curb these challenges. Biomass represents a valid alternative to fossil fuels, especially for fuel and chemical production as it represents the only natural organic renewable resource with vast abundance. A vast array of conversion technologies is used to process biomass from one form t...
Renewable and Sustainable Energy Reviews
Current Alternative Energy
Energy Procedia, 2011
In order to utilise naturally stored heat or cold from the ground, seasonal temperature variation... more In order to utilise naturally stored heat or cold from the ground, seasonal temperature variations are required. The reason is that the ground temperature is then warmer than the air temperature during winter and colder during summer. The heating and cooling demand in North Africa varies considerably with the greatest cooling demand in the East and the greatest heating demand in the West. In parts of Algeria the mean temperature difference between the coldest and warmest month is greater than 20°C, which is favourable. In current work it was shown that the ancient Fouggara system, even today would be interesting for heating and cooling of buildings in the Sahara desert.
Résumé -L'optimisation du rendement de conversion des cellules photovoltaïques est basée sur ... more Résumé -L'optimisation du rendement de conversion des cellules photovoltaïques est basée sur la compréhension et le développement du concept du dispositif. Toutefois, il existe des outils de caractérisation permettant de comprendre non seulement le fonctionnement des cellules mais aussi et surtout maîtriser les paramètres limitatifs des performances de celles-ci. Notre travail présenté porte sur l'étude des performances des cellules solaires et sur l'analyse d'une méthode numérique permettant l'extraction des paramètres des modèles de la caractéristique courant-tension d'une cellule solaire. Pour un fonctionnement donné, l'étude du rendement de conversion d'énergie maximale M η une cellule solaire nécessite un modèle analytique complet de son fonctionnement. Le modèle à une exponentielle prévoit une augmentation de V co , dès que le facteur de qualité augmente ou le courant de saturation diminue. Ceci mène à des grandes valeurs de V co incompatibles a...
Résumé -Ce travail présente les résultats d'une étude théorique de la cinétique du séchage de... more Résumé -Ce travail présente les résultats d'une étude théorique de la cinétique du séchage de la pomme de terre dans un séchoir solaire indirect. Un modèle mathématique simulant le fonctionnement du système de séchage a été élaboré. Ce modèle est validé par plusieurs études sur la pomme de terre qui, après être séchée et broyée, présente un grand intérêt pour l'industrie alimentaire notamment pour la fabrication de farine. On a utilisé la méthode des différences finies pour la résolution numérique [1]. Les résultats obtenus nous ont permis d'évaluer l'influence de la masse, du diamètre du produit et la température de l'air, agent séchant, sur le temps de séchage. Mots clés: Séchage solaire -Cinétique de séchage -Différences finis -Produit alimentaire -Temps de séchage -Teneur en eau.
Résumé -La serre tunnel agricole classique est largement répandue dans les pays du bassin méditer... more Résumé -La serre tunnel agricole classique est largement répandue dans les pays du bassin méditerranéen malgré les insuffisances qu'elle présente, notamment la surchauffe pendant le jour et le refroidissement nocturne intense, qui parfois se traduit par l'inversion de la température interne. La serre agricole a pour objectifs de créer un microclimat favorable aux exigences et à la croissance des plantes à partir des conditions climatologiques environnantes, de produire en fonction des calendriers culturaux des fruits et des légumes hors saison à bon marché et largement disponibles le long de l'année. Elle est définie par son architecture structurelle et fonctionnelle, par la qualité optique, thermique et mécanique de sa couverture et par les moyens techniques d'accompagnement. La serre est considérée comme un milieu très confiné où plusieurs composants s'échangent entre elles et dont les principaux facteurs intervenant dans ce milieu sont: la lumière, la températ...
Journal of Renewable and Sustainable Energy, 2011
Our country must face a foreseeable shortage of fossil energies and the consequences of their car... more Our country must face a foreseeable shortage of fossil energies and the consequences of their carefree use. Since the consumption of energy is increasing from every year, we are obliged to develop innovating techniques to bring at least partial solutions to the double problems of the use of the resources and fight against pollution. The sector of housing carries a considerable share of the responsibilities in this matter. The objective of a passive house is to privilege thermal comfort while contributing to energy saving. Our vision of "ecological construction" is centred on the concept of "durability of the environment," i.e., the adoption of a lifestyle which makes it possible to preserve, to maintain, and to improve quality of the resources and natural balances, and thus to spare the future. The goal of our project is to carry out the following concept that allows to: minimize the energy needs calorific of the building while providing a good quality air inside; utilize renewable energy for the energy needs of the house; control the impacts of a building on the external environment; create an healthy and comfortable environment for its users; preserve the natural resources by optimizing their use, and; promote with sustainable development.
Energy Procedia, 2011
The treatment of air in the buildings often poses the problem of the homogeneity of the temperatu... more The treatment of air in the buildings often poses the problem of the homogeneity of the temperature in any point of the room. The treatment of the room in heating mode is constraining. The difference in temperature between the puffed up air and the ambient air can generate stratification. The hot air being lighter than the cold air, one tends to find layers of hot air in height and layers of cold air partly low of the room.
pure.ltu.se
under the direction of M. Boumediene Benyoucef, Professor Emeritus, for the financial support giv... more under the direction of M. Boumediene Benyoucef, Professor Emeritus, for the financial support given to me. I am most gratitude for the highly educational and scientific advice he has not hesitated to provide during the process of this work. The basic issue of this thesis concerns one of the fundamental problems of the future of our society: How to meet the energy requirements for a large and growing world population while preserving our environment? This question is important for the world and the answers are complex and interwoven. Conventional energy sources, fossil and fissile, are polluting in the present and in the future: they erode the environment and their resources are limited. Renewable energy (hydro, wind, solar, geothermal) constitutes a minimum of pollution in the different energy systems. The technologies for using renewable energy are well known though further development and progress are made. This development also requires behavioural change, adaptation, and above all political will. The transition from an economy based on fossil energy to an economy based on renewable energy appears necessary for the protection of the environment. The cost of renewable energy is often represented as an obstacle but remains competitive in the long run. The development and availability of renewable energy, which varies because of its spatial and temporal distribution, require an adaptation of lifestyle, habits, habitat design (passive bioclimatic houses), urban planning and transportation. The focus of this thesis was to apply renewable energy in an area with hot summers and cold winter, a climate like that in the northwest of Algeria. In order to provide improved comfort in the buildings and also economic development in this area, the energy demand for heating and cooling was analyzed in the ancient city of Tlemcen. To supply domestic hot water and space heating, water must be simultaneously available at two different temperature levels. Cold water temperature, close to that of the atmosphere, and hot water between 50 and 60°C. An interesting feature of the preparation of hot water is the small variation of requirements during the year, unlike that to heating. The preparation of hot water is one of the preferred applications of solar energy in the building for several reasons. For this reason an experimental study of the thermal behaviour of a domestic hot water storage tank was undertaken. The phenomena that affect the thermal behaviour of tank especially the coupling between the solar collector and storage tank was studied. This study included concentrating solar collector in which optical fibers were used to transport the energy to the storage tank. Another technology was introduced and developed for the heating and cooling of buildings in the desert involving an existing ancient irrigation system called Fouggara. The novel idea is to use the Fouggara as an air conditioner by pumping ambient air through this underground system. Then air at a temperature of about 21°C would be supplied to the building for heating in the winter and cooling in the summer. This study shows the feasibility of using this ancient irrigation system of Fouggara and contributes to reducing and eliminating the energy demand for heating and cooling buildings in the Sahara desert.
Much work has been carried out on hot water storage during the last 20-30 years, particularly on ... more Much work has been carried out on hot water storage during the last 20-30 years, particularly on solar heat applications. Theoretical and experimental studies on the internal heat transfer have been made at laboratory scale and at larger scales. Current study, which was conducted in order to understand the stratification phenomena, involved an experimental study on the thermal behaviour in a hot water tank during charging and discharging for domestic hot water storage. Results showed no effect of stratification due to the injection fluid from the bottom of the tank and the effect of mixed convection induced by the temperature difference which created a mixture inside the tank, where the temperature was uniform across the height, and the apparition of stratification due to the fact of discharge from the bottom of the tank.