Experimental proof of a thermal system for cooling and storage applications employing cacl2/silica gel composite adsorbent

Sorption systems have been widely studied for cooling applications and as thermochemical energy storage devices for provision of heating and cooling, according to seasonal requirements. In the latest years, several researchers worked on the development of composite adsorbent materials for such kind of applications, but the vast majority of work is limited to material scale or small-scale devices. In the present paper, the experimental results on a lab-scale prototype of a sorption system are presented. Its main innovative features are the use of a composite made with silica gel and calcium chloride (CaCl2) (25 % wt. of salt inside the silica matrix) along with a patented method for evaporation/condensation, which makes usage of a porous structure directly inserted in the vacuum chamber with the heat exchanger and the storage material. Experimental tests were carried out considering both the possibility of using the system as a chiller and as a thermochemical storage. In chiller operation, average powers up to 6 kW were measured, and thermal energy storage capacity of 14 MJ (cooling storage operation) and 19 MJ (heat storage operation) were measured, thus indicating that the application of composite materials in large scale systems for real-world application is feasible and efficient.