Abstract
The melting heat transfer of CuO—coconut oil embedded in a non-uniform copper metal foam—was addressed. Copper foam is placed in a channel-shaped Thermal Energy Storage (TES) unit heated from one side. The foam is non-uniform with a linear porosity gradient in a direction perpendicular to the heated surface. The finite element method was applied to simulate natural convection flow and phase change heat transfer in the TES unit. The results showed that the porosity gradient could significantly boost the melting rate and stored energy rate in the TES unit. The best non-uniform porosity corresponds to a case in which the maximum porosity is next to a heated surface. The variation of the unit placement’s inclination angle is only important in the final stage of charging, where there is a dominant natural convection flow. The variation of porous pore size induces minimal impact on the phase change rate, except in the case of a large pore size of 30 pore density (PPI). The presence of nanoparticles could increase or decrease the charging time. However, using a 4% volume fraction of nanoparticles could mainly reduce the charging time.
Highlights
The rise in the participation of renewable energy in the prevailing cooling, heating, and power infrastructures demands new encounters to be overcome
Flow and heat transfer behavior in the enclosure are influenced by the following parameters: average porosity (0.8 ≤ ε avg ≤ 0.9), the volume fraction of nanoadditives (0 ≤ VFna ≤ 0.04), the gradient of porosity, (−4 ≤ a ≤ 4), the inclination angle of the enclosed medium (0 ≤ γ ≤ π) and the pore per inch of the metal matrix
The volume of the solid matrix is increased relative to that of the fluid. Since this solid matrix is thermally conductive, heat transfer is enhanced in this case, which results in higher temperature and faster Phase Change Materials (PCMs) melting
Summary
The rise in the participation of renewable energy in the prevailing cooling, heating, and power infrastructures demands new encounters to be overcome. Experimented with the phase change heat transfer of a PCM in a copper-foam-filled shelland-tube heat exchanger These researchers found that the charging and discharging times were reduced remarkably. Regarding the phase change of nonuniform metal foams, Yang et al [28] proposed a model of the vertical porosity gradient of the metal foam, in which the porosity increases linearly from bottom to top Such non-uniform porosity could shorten the full melting time (charging time) by enhancing natural convection and improving heat transfer performance, compared with a case of uniform porosity. Girish et al [30] investigated the phase change heat transfer in a cylindrical heatsink filled with composite PCM-open metal foam They used a vertical porosity gradient from the bottom to the top of the cylinder with uniform PPI density. They showed an increase in performance by using non-uniform porosity metal foam
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
