ISSN Online: 2688-7231
ISBN Flash Drive: 978-1-56700-497-7
ISBN Online: 978-1-56700-496-0
Modified Numerical Model for Solidification Shrinkage of Phase Change Materials with Large Difference in Phase Specific Heat and Density
要約
Phase change material (PCM) can be used as the storage material because of its high energy density. Most of the PCMs used in the fields of thermal engineering have large phase difference in thermophysical properties, i.e. density, specific heat, and thermal conductivity. During the melting and solidification cycles of PCMs, the phase density difference often causes undesirable shrinkage void formation and residual stresses. These shrinkage voids affect the heat transfer performance of PCM based thermal energy storage systems. Some metallic PCMs have large phase differences in density and specific heats. In the present work, an energy equation is developed by incorporating different specific heats and densities for different phases. Continuity equation and energy equation are derived from the first principle to obtain the source terms. Numerical simulation is carried out using octadecane as the PCM. Two case studies are considered. In the first case, the densities are kept the same, while specific heats of two phases are taken differently. In the second study, both specific heats and densities are taken differently for different phases. The numerical results are validated with experimental results reported in the literature.