Rapid thermal cycling of three phase change materials (PCMs) for cooking applications

Abstract

The suitability of the use of acetanilide, meso-erythritol and In-48Sn as phase change materials (PCMs) in latent heat thermal storage systems (LHTES) for cooking applications has been investigated under high charging and heat retrieval conditions. In-48Sn showed the greatest thermal stability up to 289.68 °C with meso-erythritol showing stability up to 177.03 °C, while acetanilide is thermally stable up to 133.33 °C. Thermal properties of acetanilide remained within stable limits with rapid thermal cycles, but rapid mass degradation was observed. Two forms of meso-erythritol were manifested with different melting points with the solidification temperature that showed considerable variations while the enthalpy of solidification remained reasonably stable. Acetanilide and meso-erythritol exhibited large degrees of supercooling below 100 °C making them undesirable to be used in a LHTES unit for cooking applications under rapid heating and cooling cycles. With the solidification temperature of In-48Sn above 100 °C throughout the thermal cycles, it proved to be a promising PCM for cooking applications under rapid heating and cooling cycles. The residues of the PCMs after thermal cycling showed no structural changes as compared with the fresh samples while the health hazards related to the PCMs were all within acceptable limits. Though the cost implication of utilizing In-48Sn is much higher as compared with the other two PCMs, its good cycling stability and its average solidification temperature being within desired cooking temperature makes it a preferred PCM candidate under fast heat retrieval condition than acetanilide and meso-erythritol.