To cite this version:T Desrues, J Ruer, P Marty, Jf Fourmigué.A thermal energy storage process for large scale electric applications.Applied Thermal Engineering, Elsevier, 2009, 30 (5) This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Abstract: A new type of thermal energy storage process for large scale electric applications is presented, based on a high temperature heat pump cycle which transforms electrical energy into thermal energy and stores it inside two large regenerators, followed by a thermal engine cycle which transforms the stored thermal energy back into electrical energy. The storage principle is described, and its thermodynamic cycle is analyzed, leading to the theoretical efficiency of the storage system. A numerical model is developed, and the results show the feasibility of the process, even with sub-optimal parameters. Finally, key factors for improving the process performances are identified. ACCEPTED MANUSCRIPT

No abstract

Solar thermal energy is a clean, climate-friendly and inexhaustible energy resource. It is therefore promising to cope with fossil fuel depletion and climate change. Thermal storage enables to make this intermittent energy resource dispatchable, reliable on demand and more competitive. Nowadays, most of the concentrated solar power plants equipped with integrated thermal storage systems use the two-tank molten salt technology. Despite its relative simplicity and efficiency, this technology is expensive and requires huge amounts of nitrate salts. In the short to medium term, packed-bed thermal energy storage with either liquid or gaseous heat transfer fluid is a promising alternative to reduce storage costs and hence improve the development of solar energy. To design reliable, efficient and cost-effective packed-bed storage systems, this technology, which involves many physical phenomena, has to be better understood. This paper aims to sum up some key aspects about design, operation, and performances of packed-bed storage systems. In the first part, most representative setups and their experience feedback are presented. The controllability of packed-bed storage systems and the special influence of thermal stratification are pointed out. In the second part, the various numerical models used to predict packed-bed storage performances are reviewed. In the last part, some useful correlations enabling to quantify the main physical phenomena involved in packed-bed operation and modeling are presented and compared. The correlations investigated enable to calculate fluid/solid and fluid/wall heat transfer coefficients, effective thermal conductivity and pressure drop in packed beds.

No abstract

No abstract

No abstract

No abstract

No abstract