Experimental study of fusion and solidification of phase change material (pcm) in spherical geometry

Abstract

The objective of this work is to investigate the parameters affecting the time for complete solidification and fusion in spherical capsules and develop correlations between this time and the investigated parameters. These correlations will be used in the numerical simulations of latent heat storage systems of the fixed bed type having the phase change material, PCM encapsulated in spherical containers. Four spherical shells of 35, 76, 106 and 131 mm diameter were used at temperatures ranging from -20°C to -5°C for solidification process and temperature of 10°C, 18°C, 25°C for the melting process. Water and mixtures of water and polyethylene glycol in percentages ranging from 7.5% to 50% were used as PCM. Based on the experimental results correlations of the time for complete solidification and complete fusion were developed and compared with the experimental measurements showing good agreement and confirming the suitability of using these correlations to predict the complete phase change times. These correlations are applicable in the ranges: 0.076 m Diameter of spherical capsule 0.131m, 0.1% concentration of polyethylene glycol 0.5%, -20°C Initial temperature of PCM -5°C, 10°C Thermal bath temperature 25°C. The differences between the values predicted by the correlation and the experimental measurements are below 10%.