Progetto SWS Heating - D6.2 Lab-scale test results of the prototype SWS-STES configuration - RE-73/24

The present deliverable 6.2 refers to the activities performed in the framework of Task 6.2 which was dedicated to the testing of the lab-scale sorption thermal energy storage (STES) for the performance analysis under controlled conditions. Due to the availability of a dedicated testing rig, able to emulate real operating conditions of a STES, it was agreed to perform experimental tests at the CNR ITAE lab in Messina (Italy). The first version of the lab-scale STES was delivered by FAHR to ITAE on Month 42 (November 2021), and the first tests started after the installation in the lab. Unfortunately, the experimental outcomes highlighted some issues related to the system design, which were preventing the proper operation of the module, especially due to the low permeability of the sorbent material inside the adsorber. After internal discussion among the coordinator, ITAE, OTH, FAHR and UDL, a new design was issued by OTH, basically by modifying the orientation of the adsorber from horizontal to vertical and by filling it with a mixture of SWS and microporous silica gel, to optimize the mass transfer efficiency inside the adsorber. A first attempt to reconstruct the prototype according to the new design was carried out directly by ITAE at their premise, nevertheless, due to the occurred damaging of a vacuum valve the system was not vacuum tight anymore. It was then agreed to let FAHR manufacturing the new design of the STES. The final version of the lab-scale STES was delivered to ITAE by FAHR on Month 57 (February 2023). The installation and testing were started after the acquisition of the heating wires needed for the proper operation of the STES, that could not be provided by FAHR. The testing campaign aimed at investigating the operating conditions and the achievable performance of the STES. For this reason, several different testing conditions were carried out, and repeated to verify the reliability of the measurement.