Experimental investigation on an open sorption thermal storage system for space heating

A 1 kWh lab-scale open sorption prototype was experimentally investigated to store low-temperature heat for space heating. The modular concept was adopted to develop the reactor. Activated alumina/LiCl composite sorbent with significant advantages of high mechanical strength and large bulk density was employed to obtain high volumetric storage density. The performances of different serial reactor modules are tested and compared, and results indicate that the module closer to the entrance is able to attain better sorption performance. Furthermore, the influence of vital parameters including relative humidity and flow rate of the inlet air on the system performance was investigated. Related results reveal that: (1) relative humidity is a critical factor determining the output temperature, output power and energy storage density; (2) air flow rate has inverse influence on the output power and discharging time without changing the energy storage density. In all, the investigated prototype can fulfill the space heating requirement with a system efficiency of 84.5-96.9%. Air higher than 30 degrees C can, be provided over 7.1 h corresponding to total volumetric storage density of 191 kWh/m(3) under the condition of T-i = 20 degrees C, RHi = 80% and q(m) = 17 m(3)/h, and the output power ranges from 56.7 W to 136.0 W. (C) 2017 Elsevier Ltd. All rights reserved.