Studies on a potassium carbonate salt hydrate based thermochemical energy storage system

A potassium carbonate salt hydrate based Thermochemical Energy Storage System (TESS) suitable for various heating applications encountered in cold ambient conditions is proposed. The hydration-dehydration reaction rate expressions of potassium carbonate salt hydrate are utilized to estimate the reaction times. A thermodynamic analysis is carried out for the operating cycle of a single charge-single discharge TESS to understand the effects of various operating parameters on its performance. The ambient temperature plays an important role in influencing the performance of the TESS, as it determines the supply/outlet pressure of water vapour for the respective chemical reaction. For ambient temperature of 10 ?, the system with optimized parameters yields a cycle efficiency of 57.7%, specific heating power of 127.3 W kg(-1) and volumetric energy storage density of 158.6 kWh m(-3).