Characterisation of a Rotating Adsorber Designed for Thermochemical Heat Storage Processes

The presented experimental study shows the applicability of an open adsorption process with a moving material bed of zeolite grains for aims of room heating and hot water supply of domestic buildings. Based on the idea of continuous-flow adsorption a cylindrical reactor was designed. A prototype was built and integrated in a test rig to study the operation concept for domestic heating and hot water generation. Dehydrated zeolite of the types 4A and 13X were used in form of spherical grains and humidified room air was blown through the rotating bed. Zeolite batches of about 50 kg were able to generate an adsorption heat of up to 43 MJ and temperature shifts of the process air up to 36 K depending on the inlet air water content and the initial state of hydration of the storage materials. A first test series of promising composite materials for the storage process, based on natural zeolite and salt hydrates has been conducted. For the investigated material-reactor combination design-criteria for optimized reaction technology under realistic boundary conditions were found. The collected results of batch runs allow clear statements for further system development and simulation of seasonal heat storage applications.