The impact of TCMs in TES systems with PCMs: Modelling and dynamic simulation of a novel prototype

• A TRNSYS model of a novel TES system using TCMs and PCMs was developed. • The model allowed to simulate the system in dynamic mode at system scale. • TCM charging and discharging were defined by equations based on experimental data. • The ability of TCM to increase the efficiency of the hybrid system was investigated. • Seasonal electricity was cut by 8.8 %, while seasonal COP increased from 3.4 to 3.8. Among sensible, latent and thermochemical thermal energy storage (TES), thermochemical materials (TCMs) result to be the most promising solution to achieve EU target for 2050 of net-zero GHG emissions. A novel TES solution using TCMs and phase change materials (PCMs) for space heating and cooling is being developed within the Horizon Europe project ECHO. A TRNSYS model able to simulate the prototype in dynamic mode at system scale was created to optimise the installation and testing of the prototype. Experimental data from a small set-up of the reactor were used to define the equations describing the charging and discharging phases of TCM, which were implemented in the reactor model. The ability of TCM to increase the efficiency of the system where it is adopted was investigated for the heating period. The TCM-integrated heat pump system showed an 8.8 % reduction in seasonal electricity consumption compared to the system without TCM, and an increase in the seasonal COP from 3.4 to 3.8. Finally, the evaluation of the thermal contribution provided by TCM combined with PCM highlighted that the two TES systems were able to cover about 10 % of the heating energy demand, with PCM accounting for almost 50 % of the TCM contribution.