Experimental study of paraffin melting in cylindrical cavity with central electric heating rod

The experimental study for the melting processes of phase change material (paraffin) inside a cylindrical container under different boundary conditions of the cylindrical outside surface was carried out. In the experiments paraffin was heated by the heating rod installed in the center of the cylindrical container. The interpolation method was employed to calculate phase front and liquid fraction during the melting process by the reading of the thermocouples in an array arrangement. Paraffin near the heating rod firstly melted due to heat conduction in the initial melting stage, and then the generation and intensification of natural convection led to the acceleration of phase changes, resulting in obvious temperature stratifications in the upper region of the cylinder container. Moreover, flat temperature phenomena are described and discussed in detail. The effect of different heating powers, boundary conditions and the temperatures of water bath on melting rates is evaluated as well.