Beschreibung:
<jats:p>Thermal energy storage is of critical importance for the highly-efficient utilization of renewable energy sources. Over the past decades, the single-tank thermocline technology has attracted much attention owing to its high cost-effectiveness. In the present work, we investigate the influence of the filler porosity’s non-uniform distribution on the thermal performance of the packed-bed sensible heat thermocline storage tanks, using the analytical model obtained by the Laplace transform. Our analyses prove that the different porosity distributions can result in the significantly different behaviors of outlet temperature and thus the varied charging and discharging efficiencies, when the total amount of filler materials (i.e., the integration of porosity) is fixed. The results indicate that a non-uniform distribution of the fillers with the proper design can improve the heat storage performance without changing the total amount of the filling materials, which may provide a new way to optimize the thermocline storage tanks.</jats:p>