An experimental investigation of cylindrical shaped thermal storage unit consisting of phase change material based helical coil heat exchanger

Phase change materials (PCMs) have an enormous potential to store energy in the form of latent heat. The organic phase materials show more efficiency and stability in charging and discharging activities. The present work details an experimental investigation of a thermal storage unit consisting of a PCM-based helical coil heat exchanger with winded copper wires. The experimental investigation of PCM-based helical heat exchanger shows that the PCM maximum charging time in PCM-based helical coil heat exchanger for the flow rate of 15.83 ml/s, 20.00 ml/s, and 33.33 ml/s are recorded as 1370, 1290, and 1090 s, respectively. The discharging time of PCM in PCM based helical coil at top helix from 39.90 degrees C to 35.90 degrees C is 11090s while the discharging time for PCM at bottom helix from 38.93 degrees C to 35.92 degrees C is also 11,010 s. The discharging time of tap water with a PCM-based helical coil heat exchanger is found to be 12,480 s while discharging time of tap water for a simple helical coil heat exchanger is found to be 7210 s. Also, the instantaneous effectiveness of the thermal storage unit for the flow rate of 33.33 ml/s changes between 0.6023 to 0.4012. This study shows that the instantaneous effectiveness of thermal storage units is maximum for low flow rate while the minimum for higher flow rate.