Effect of flow rate of heat transfer fluid on the charging behaviour of phase change material in a hot water tank

This paper presents an experimental investigation of the melting behavior of phase change material (PCM) to use in a solar domestic hot water tank. Commercial grade stearic acid is used as PCM packed in cylindrical copper tube and the hot water surrounding is used as heat transfer fluid (HTF) and sensible heat storage material. A detailed parametric investigation is performed for melting PCM in cylindrical shell of 33 mm in diameter by dividing three different layers along its axial direction. The melting behavior of the PCM in a vertical cylindrical tube with the change of flow rate of HTF is studied. The experimental results show that the melting duration in each layer of PCM is not the same. The melting duration of PCM in top layer is shorter than the bottom layer. It is also observed that the time required for complete melting is longer in lower flow rate of inlet HTF.