Performance evaluation of an open thermochemical energy storage system integrated with flat plate solar collector

In this study, the performance of an open thermochemical energy storage (TCES) system integrated with a flat plate solar collector is evaluated using a simplified dynamic model for space heating applications, considering a charging phase during the summer daytime and a discharging phase during the winter night. For charging and discharging operations, the time-varying solar flux (DNI) and ambient conditions in Pune, India is used. Simplified energy balance equations for the reactive packed bed and the flat plate solar collector are developed and validated against the previous reported works. The effects of the energy density and the aspect ratio of the reactive packed bed on the performance of the TCES system are evaluated using a non-dimensional parameter sigma, which is the ratio of thermal power extracted/stored to the power required to blow air through the reactive packed bed. An increase in reactive packed bed energy density by 16.66% is found to decrease the time-averaged value of sigma by 63.97% and 48.06%, respectively, for charging and discharging phases. A four-fold increase of aspect ratio of the reactive packed bed is found to increase the time-averaged value of sigma by 6.20 times and 6.35 times during the charging and discharging phases, respectively.