Numerical model to design a thermochemical storage System for solar power plant

Abstract

Storage of the heat is one of the key points in the development of concentrated solar power plants. Although at an early research stage, thermochemical storage offers several advantages, as for example high energy density, long term storage or high storage temperature. A new concept, in which the reactive material is shaped in a structured, monolithic shape, through which air can flow, was lately proposed. This new concept, exhibiting high surface area and good heat transfer properties, was successfully tested in lab-scale. The next step is the installation of a prototype reactor in an existing solar facility. The definition of the design of such a reactor, as well as the nominal operating conditions, is made through a CFD numerical model, developed and described in this study. A typical charge and discharge cycle is analyzed and used to define the operating conditions. Through simulations, the optimal design and shape of the reactor (height to length ratio, distributor shape, etc.) is defined. The optimization method, defined for this process, shows the importance of the flow uniformity on the reactor performances. The pressure drop threshold, needed to obtain a uniform flow, is found and the reactor shape is defined accordingly.