Experimental study on adsorption characteristics of a water and silica-gel based thermal energy storage (TES) system

Abstract

This study is focused on characterizing the adsorption process of a sorption based thermal energy storage (TES) systems. A lab scale closed loop physi-sorption based TES system was constructed and silica-gel (SiO2) is used as the adsorbent and water as the adsorbate. Experiments are conducted to investigate the impact of the temperature change of the evaporator (Teva) and the mass variation of the water (adsorbate) in the evaporator. Through the test results, three key findings can be identified that mainly affect the adsorption performance. First, a higher evaporator temperature leads to a greater uptake amount (X) because of the larger pressure difference and vapor mass flow rate. Second, the measured adsorption isotherm value in a real system is approximately 29.8-56.7% of the theoretical estimation (D-A isotherm). Third, the geometry of the vapor transmission system determines the ability to transport vapor to the reactor sufficiently and stably.