ISSN Online: 2377-424X
ISBN Print: 1-56032-797-9
International Heat Transfer Conference 11
THERMAL CHARACTERISTICS OF MICROENCAPSULATED PHASE-CHANGE MATERIALS
Abstrakt
As a method to make use of a high latent heat of
a liquid-solid phase change material in a confined
convective heat transfer, a phase change material,
lauric acid, was encapsulated in tiny hollow spheres, and
mixed with water, forming a slurry of microencapsulated
phase-change material (MCPCM slurry). Four different
sizes (200, 100, 50, and 25 μm OD) of MCPCMs were
tested in this study.
Thermal characteristics of the pure lauric acid and lauric acid MCPCMs were tested by a differential scanning calorimeter, A zero-heating-rate method was used to obtain phase-change temperatures and phase-change energies of lauric acid and its capsules. The lauric acid itself had almost no super-cooling, while its capsules had consistent value of supercooling, which did not vary for various sizes of capsules. The lauric acid itself had single freezing, while the microencapsulated lauric acid had double freezings. As the size of the capsule became small, the second freezing seemed to be disappeared, which was explained by both the freezing temperature and the freezing energy.
Thermal characteristics of the pure lauric acid and lauric acid MCPCMs were tested by a differential scanning calorimeter, A zero-heating-rate method was used to obtain phase-change temperatures and phase-change energies of lauric acid and its capsules. The lauric acid itself had almost no super-cooling, while its capsules had consistent value of supercooling, which did not vary for various sizes of capsules. The lauric acid itself had single freezing, while the microencapsulated lauric acid had double freezings. As the size of the capsule became small, the second freezing seemed to be disappeared, which was explained by both the freezing temperature and the freezing energy.