Thermal behavior of melting paraffin wax process in cylindrical capsule by experimental study

This paper presents an experimental study on thermal behaviors of phase change material (PCM) during melting process in annulus cylinder. The inner cylinder was functioned as PCM storage, the outer cylinder was designed as shell, and both were made of acrylic. The PCM Storage was heated on its surface by circulating hot water as heat transfer fluid (HTF) in the shell. The variations of HTF temperature are 60, 65, 70°C and its mass flow rate is maintained at 4 liter per minutes. Thermal analysis of the melting process over time is given to provide more specific information of temperature contour change during the process. Solid–liquid melting process is shown by sequential photographs taken by the digital camera during the process in axial and radial direction. The results indicate that at the beginning of melting process, the heat transfer is dominated by conduction between inner wall of PCM storage and solid PCM. When the PCM has melt, convection holds important role in the heat transfer due to density gradient of the liquid PCM. Increasing of 5°C temperature is able to reduce about 34% of the total melting time.