Energy storage using phase change material in an annuli of a vertical tube-in-shell unit: Fin effect

In this study, the melting (charge) and solidification (discharge) behaviors of a phase change material (PCM) in an annuli of a vertical tube-in shell unit are investigated experimentaly. The annular space is composed of a finned heat transfer tube with different fin side length ratios and a coaxial outer shell. For each fin configuration, experiments are carried out for a constant volumetric flow rate at three different values of inlet temperature of heat transfer fluid for charging and a single value of inlet temperature of HTF for discharging. Paraffin used as phase change material (Merck/107337) while pure water as heat transfer fluid. It is disclosed that an decrease in the fin length ratio shortens the melting time for the charging process while extends the solidification time for the discharging process.