Modelling and simulation of a compressed air storage system coupled to a building and to a photovoltaic generator.

By now, the increasing in energy demand, the decrease of fossil resources and the environmental and climate problems caused by these fossil resources are the mains challenges of the researchers. To overcome this issues it is necessary to develop optimized and sustainable energy systems.The Compressed Air Energy Storage (CAES) and the development of Net Zero Building (Net ZEB) appear as an appropriate solution for island area with a tropical climate and no connected electric grid as Reunion island.The modelisation of a compressed Air Energy Storage system connected photovoltaic generator (PV), a building and the grid will be the main subject of this study

Sensitivity analysis and optimization of a compressed air energy storage (CAES) system powered by a photovoltaic plant to supply a building

International audienceOne of the handicaps of the large-scale integration of solar energy is due to its variability and its intermittency. The main way to overcome this issue is the energy storage technology. Knowing the high cost of batteries and their impact on the environment, we simulate a storage system based on compressed air and acting as a battery system. The CAES consists in storing the air at a high pressure in a tank during the period when the energy source is abundant, i.e., cheap, or when the energy demand is low. The compressed air is later expanded through an air turbine which generates electricity during the high demand periods, i.e. when the energy source becomes very expensive for instance. This system could be used for decentralized electricity supply or in an area with no electric grid. In order to evaluate the feasibility of a Compressed Air Energy Storage system coupled to a photovoltaic plant and a building that represents a reduced power demand, a numerical model that reflects the instant behaviour has been built. The system is composed of a photovoltaic power plant, an air compression system, a storage vessel, an expansion module, a power grid and a building. The inputs used are, on the one hand, the climate data such as ambient temperature and the global solar irradiation and, on the other hand, the load curve of a building or of the group of buildings, which has to be supplied by electricity. The overall system optimization has then been performed after having done a sensitivity analysis of the key parameters. This optimization allows us to find the most suitable size for each component of the system: compressor, tank size and photovoltaic area. Abstract One of the handicaps of the large-scale integration of solar energy is due to its variability and its intermittency. The main way to overcome this issue is the energy storage technology. Knowing the high cost of batteries and their impact on the environment, we simulate a storage system based on compressed air and acting as a battery system. The CAES consists in storing the air at a high pressure in a tank during the period when the energy source is abundant, i.e., cheap, or when the energy demand is low. The compressed air is later expanded through an air turbine which generates electricity during the high demand periods, i.e. when the energy source becomes very expensive for instance. This system could be used for decentralized electricity supply or in an area with no electric grid. In order to evaluate the feasibility of a Compressed Air Energy Storage system coupled to a photovoltaic plant and a building that represents a reduced power demand, a numerical model that reflects the instant behaviour has been built. The system is composed of a photovoltaic power plant, an air compression system, a storage vessel, an expansion module, a power grid and a building. The inputs used are, on the one hand, the climate data such as ambient temperature and the global solar irradiation and, on the other hand, the load curve of a building or of the group of buildings, which has to be supplied by electricity. The overall system optimization has then been performed after having done a sensitivity analysis of the key parameters. This optimization allows us to find the most suitable size for each component of the system: compressor, tank size and photovoltaic area

Dynamic simulation of reciprocating refrigeration compressors and experimental validation

International audienc

Modelling and dynamic simulation of solar heat integration into a manufacturing process in Réunion Island

International audienceAccording to the International Energy Agency, solar thermal energy is rarely used in industrial sector, despite its capacity to generate heat with the existing technologies. Moreover, a large part of the firms of Réunion Island are in the food-processing industry, which is the most heat consuming sector according to these studies. Among them, the Sorélait-Danone company (yoghurt production) has decided to collaborate so as to analyze the potential impact of solar heat integration into its actual heat generation system. The company has a fuel boiler which generates 7 bar saturated vapor (corresponding to a temperature of 165°C) at a nominal flow rate of 2,5 tons per hour. This boiler is supplied by a tank filled with water. In the latter, condensate coming from the process unit is mixed with the district's cold water, in order to compensate the vapor lost in the process. In this work, possibilities in terms of solar heat integration into the system have been investigated. 4 different cases have been simulated (direct or indirect integration, into the mixing tank or the boiler tank) and the corresponding saved fuel quantities have been estimated. The results of simulation show that in the best case, a fuel saving of 25 % can be expected with a total collector area of 600 m² for this company

Ice slurry production using supercooling phenomenon

International audienc

Sensitivity analysis of an outdoor swimming pool under dynamic conditions

International audiencePublic swimming pools have an important energy consumption and are rarely optimized. One way to do so is to develop a model able to represent the swimming pool behaviour (water temperature and energy consumption) whatever the climatic conditions. The evaluation of thermal losses is done in this work thanks to the presented model and to measurements (ambient air and pool's temperature, relative humidity, direction and velocity of wind, global solar irradiation) performed on a public outdoor swimming pool situated in La Reunion, a French overseas department located in the Indian Ocean close to Mauritius). Each contribution to the decrease of water's temperature is clearly identified and represented, leading to quite accurate comparisons between simulated results and tests for 4 different nights

Cartographie des modèles de confort : application aux bâtiments en rafraîchissement mixte en climat tropical

International audienceThe ADEME French Energy Agency 2050 foresights for air conditioning (AC) practices in buildings show an increased necessity to reduce the cooling demand by both passive solutions and new usages of AC systems. Mixed-mode cooling is an alternative solution for achieving summer comfort in a tropical climate. This article reviews the comfort tools available to researchers and designers for sizing and controlling these new cascade cooling systems. A case study illustrates the applicability of current standards to the tropical climate context. It points some limits and opens up for future investigation, focussing on recent research on the subject of comfort models and indices in buildings.Les prospectives ADEME 2050 pour la climatisation font état d'un besoin à réduire la demande en rafraîchissement en privilégiant les solutions passives et en développant de nouveaux usages de la climatisation. Le rafraîchissement mixte est une solution alternative pour atteindre le confort d'été en climat tropical. Cet article fait un état des outils du confort à disposition de la recherche et des concepteurs pour le dimensionnement et le pilotage de ces nouveaux modes de rafraîchissement en cascade. Un cas d'étude illustre l'applicabilité des standards actuels au contexte climatique tropical, identifie certaines limites et ouvre des perspectives d'investigation des récentes recherches sur le sujet des modèles et indices de confort dans le bâtiment

Cartographie des modèles de confort : application aux bâtiments en rafraîchissement mixte en climat tropical

International audienceThe ADEME French Energy Agency 2050 foresights for air conditioning (AC) practices in buildings show an increased necessity to reduce the cooling demand by both passive solutions and new usages of AC systems. Mixed-mode cooling is an alternative solution for achieving summer comfort in a tropical climate. This article reviews the comfort tools available to researchers and designers for sizing and controlling these new cascade cooling systems. A case study illustrates the applicability of current standards to the tropical climate context. It points some limits and opens up for future investigation, focussing on recent research on the subject of comfort models and indices in buildings.Les prospectives ADEME 2050 pour la climatisation font état d'un besoin à réduire la demande en rafraîchissement en privilégiant les solutions passives et en développant de nouveaux usages de la climatisation. Le rafraîchissement mixte est une solution alternative pour atteindre le confort d'été en climat tropical. Cet article fait un état des outils du confort à disposition de la recherche et des concepteurs pour le dimensionnement et le pilotage de ces nouveaux modes de rafraîchissement en cascade. Un cas d'étude illustre l'applicabilité des standards actuels au contexte climatique tropical, identifie certaines limites et ouvre des perspectives d'investigation des récentes recherches sur le sujet des modèles et indices de confort dans le bâtiment