Experimental testing of AQSOA FAM Z02/water adsorption system for heat and cold storage

Highlights: • The experimental testing of a FAM Z02/water thermochemical storage is presented. • Daily heat storage, seasonal heat storage and cold storage modes are evaluated. • Discharge power up to 650 W and storage capacity up to 280 Wh/kg have been measured. • Practical recommendations for improving the design are given. - Abstract: Thermal energy storage devices are crucial elements, especially in systems employing renewable energy sources. Adsorption-type storages show promising features: high energy density and possibility to be operated for heat and cold release to the user. However, only a few experimental activities on prototypes can be found in literature, especially for low temperature heat storage (<100 °C). In the present work, the design, realization and experimental characterization of a prototype using AQSOA FAM Z02/water as working pair are presented. A specific test set-up, characterised by the possibility of testing different adsorbers configuration, has been developed and an adsorber with 4.3 kg of adsorbent material has been tested under cold storage, daily heat storage and seasonal heat storage operating modes. The prototype is able to store from 620 Wh up to 1100 Wh, with a maximum energy storage density of 280 Wh/kg. The average power during the discharging phase ranges from 200 W to 650 W. Energy efficiencies obtained vary from 1.5 for daily heat storage to 0.3 for cold storage operation.