Numerical investigation of a plate heat exchanger thermal energy storage system with phase change material
Mehrdad Taghavi, Minna Poikelispää, Vaibhav Agrawal, Seppo Syrjälä, Tero Joronen
Abstract
Plate-type thermal energy storage systems (PTESs) have been proposed to mitigate the effect of the low thermal conductivity of phase change materials on the performance and efficiency of thermal energy storage systems. Nevertheless, a prompt reduction in the thermal power of PTESs due to the drop/rise in the outlet temperature at the early stage of the charging/discharging process has not been well resolved. To remedy this, the current study proposes a modified PTES and presents a computational fluid dynamics model of this PTES for performance and efficiency analysis. The results show that the outlet temperature of the modified PTES is constant for 100 min in the melting and 33 min in the solidification processes, while this temperature drops/raises almost immediately in the similar PTESs after starting these processes. In addition, the presented PTES shows an improvement of 75 % and 28.6 %, respectively, in the energy storage capacity per unit volume and effectiveness than a roll-bonded PTES.