Optimal designed porous media for renewable energy storage

International audienceDue to their high energy density and low heat losses during storage, thermochemical processes are promising candidates for thermal energy seasonal storage. Such process allows, coupled to solar panels, to save the summer heat overproduction and use it during the heating period of the year. The thermochemical process studied is based on the hydration and dehydration of a reactive salt by a flow of moist air, to store and release the heat. To validate the concept and its applications for household and buildings heating, some studies resulted on the development and the testing of reactor prototypes. The current step consists in designing the storage system (a designed porous material), and improving the performancesamount of energy stored and thermal powerof the reactor in working on three main aspects: the reactive salt characteristics, the porous media characteristics and the porous media design. In this work we demonstrate how the design of the porous material can be achieved for maximum heat storage, in the presence of three phenomena in the reactor: mass transfer, heat transfer and heat storage/release via a chemical reaction. We study the influence of the geometry on the overall performance of the system, and design the configuration of the storage systems using the Constructal approach