Development of salt hydrate based thermochemical energy storage systems for use in building applications
The design of a thermochemical energy storage systems is a multi-level process that needs to be addressed. At a material level, salt hydrates are the most suitable materials for building heating applications. Whilst salt hydrates appear promising during micro-scale analysis, at a macro-scale several challenges arise. Salt hydrates have low deliquescence relative humidity and agglomerate, forming an impermeable block which hinders mass and heat transfer. This has led to the development of composite materials where a salt is impregnated or mixed into a host matrix. A porous host matrix increases surface area and prevents salt agglomeration, improving water vapour diffusion. From a system design outlook, different bed types, reactors and configurations are currently being designed and tested in which salt hydrates are implemented. However, there needs to be a merging at both material and system levels to develop an efficient thermochemical storage system. This research addresses this through the study of the salt hydrate SrCl2.6H2O in various host matrices, at both micro- and lab-scale levels for an open reactor system. Furthermore, it covers a criteria to effectively design a thermochemical energy storage system and critically analyses current system configurations.