Exploration of the entropy due to the nano–encapsulated phase change materials (NEPCMs) within oblique prismatic containers

Abstract

The finite element treatments (FEM) together with the characteristic-based split (CBS) scheme are applied to examine the entropy generation and convective flow due to the presence of the nanoencapsulated phase change materials (NEPCMs) confined an inclined prismatic containers. The enclosure is filled with elements of a porous medium (glass balls) and a sine formula is considered for the latent heat of the phase change. A combination of the shell and core heat capacity is assumed to formulate the overall heat capacity of the mixture and the computations are carried out for two different designs termed as D1 and D2. Features of the flow, solidification/melting zones, entropy generation, local and average Bejan numbers are illustrated. The main outcomes uncovered that using the second design D2 gives a reduction in the maximum values of the stream functions up to 36%. Also, the ribbon solidification/melting zones are occurred near the cold wall at the low values of t f while they are extending and moving away from the right inclined wall towards the heated area as t f is altered. Nomenclature-Nm 2 P Dimensionless pressure Pr Prandtl number Ra Rayleigh number Ste Stefan number RECEIVED

Melting Enhancement in a Triple-Tube Latent Heat Storage System with Sloped Fins

“…One major inconsistency that most PCMs are affected by is their intrinsic poor heat conductivities, which poses a detrimental effect on the TES system's response rates to the periodic energy storage/retrieval activities. Previous research identifies two major steps for overcoming this problem: (i) employing an adequate heat-transfer enhancer such as metal/graphite matrix, honeycomb, fin, nano-encapsulated phase-change materials (NEPCMs) [5][6][7], and heat pipe structures and (ii) using an efficient casing design to house the PCM so that a superior heat communication between the HTF and the PCM can be achieved [8,9]. Modifying the casing design by attaching fins to the thermally active walls is regarded as one of the most efficient approaches for intensifying the thermal responsiveness of energy storage systems [10][11][12][13][14].…”