A Study of the degradation of a silica gel based thermal energy storage system

Emmanuel Nyarko Ayisi

Master's thesis

Abstract:

An energy storage system was designed to test the adsorption capacity and cycle repeatability of silica gel using a low-grade heat for the desorption phase. The design specification requirement was to maximize adsorption of the silica gel and test the number of cycles that can be achieved and the total energy obtained whiles a low-grade heat energy is used for the desorption phase. The D - A model was chosen for the determination of the maximum adsorption capacity and activation energy of the silica gel due to better performance in fitting. A mean specific power of 29.5 W/kg was obtained for cycle 1, with a 22.7 % loss in the specific power at the end of the 5 cycles. The mean specific energy density of (292 - 225) kJ/kg after 165 mins was obtained. It was also observed that, higher flowrate aid in higher adsorption and desorption rates while lower flowrates aid in lower desorption and adsorption rate.

Abstract:

An energy storage system was designed to test the adsorption capacity and cycle repeatability of silica gel using a low-grade heat for the desorption phase. The design specification requirement was to maximize adsorption of the silica gel and test the number of cycles that can be achieved and the total energy obtained whiles a low-grade heat energy is used for the desorption phase. The D - A model was chosen for the determination of the maximum adsorption capacity and activation energy of the silica gel due to better performance in fitting. A mean specific power of 29.5 W/kg was obtained for cycle 1, with a 22.7 % loss in the specific power at the end of the 5 cycles. The mean specific energy density of (292 - 225) kJ/kg after 165 mins was obtained. It was also observed that, higher flowrate aid in higher adsorption and desorption rates while lower flowrates aid in lower desorption and adsorption rate.

Keywords

Silica Gel, Adsorption, Energy Storage, Material Degradation, Experimental Device.

Language used: English

Date on which the thesis was submitted / produced: 12. 6. 2020

Thesis defence

• Supervisor: prof. Ing. Karel Fraňa, Ph.D.

Technical University of Liberec

Faculty of Mechanical Engineering

Master programme / field:
Mechanical Engineering / Machines and Equipment Design