Experimental correlations for the solidification and fusion times of PCM encapsulated in spherical shells

ABSTRACT

This paper reports the results of a study to investigate and develop correlations for the parameters affecting the time for complete solidification and fusion in spherical shells. For this study, four spherical shells of 35, 76, 106 and 131 mm diameter were used, the charging temperature was varied from −20°C to −5°C while the melting temperature varied from 10°C to 25°C. Water and mixtures of water and polyethylene glycol in percentages ranging from 7.5% to 50% were tested. The developed correlation for the time for complete solidification showed an agreement with experiments with maximum difference of about 5.91%. Validation of the correlation of the time for complete fusion showed maximum difference of 7.2% and minimum difference of 0.88% when compared with experimental results.

KEYWORDS:

• Solidification
• fusion in spherical shells
• PCM
• storage system
• correlations
• time for complete phase change

Nomenclature

Table

Acknowledgments

The first author wishes to thank the CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) for the doctorate scholarship and the second author wishes to thank the CNPq for the PQ research grant 304372/2016-1.