Modeling of an optimized, PCM-based, thermal energy storage heat exchanger: Preliminary results

This paper investigates the thermal behavior of a PCM-based thermal storage heat exchanger, consisting of a series of vertical cavities filled with PCM and heated/cooled on their vertical sides. A simple theoretical model, based on a lumped parameter analysis, was developed and validated through experiments conducted on a test section that reproduces a scaled cavity forming the heat exchanger. The modeling aimed to identify an optimization strategy for the device; it was found that a more efficient natural circulation of the molten PCM, achieved by introducing horizontal partitions inside the cavity, resulted in a significant reduction in charging time, i.e., the time required for the complete melting of the solid phase.