Abstract
•Freezing process of paraffin within a system with fins was simulated.•The kind of PCM is RT28 and CuO nano-powders are added.•With changing style of fins from A to C, liquid fraction declines about 37.93%.•The minimum required time occurs for case C.
Freezing process of paraffin within a system with fins was simulated in this paper. The kind of PCM is RT28 and CuO nano-powders are added to enhance the conductivity. Three configurations for fins were assumed in this research and all of them have equal volume of paraffin. These two techniques have positive effect on reducing required time of process. Although buoyancy has no sensible impact on freezing phenomena, its related term was considered in equations. Structure grid has been created in ANSYS FLUENT to augment the accuracy. Homogeneous formulation for nanoparticle was applied and implicit approach for modeling of transient term was incorporated. Cold flow within the pipe makes RT28 to lose heat and freezing begins from the region next to the inner wall. Existence of fins makes conduction stronger and freezing time decreases. With changing style of fins from A to C, liquid fraction declines about 37.93% while temperature augments about 0.45% when t = 50 min. The minimum required time occurs for case C in which whole paraffin converts to solid after 65 min.