Numerical technique for simulation of melting within air ventilation system

The present offered system for producing cold air within the building has various tubes filled with paraffin. Existence of paraffin makes it possible to save the energy to use at night. To assimilate more heat during the day, nanoparticles of graphene have been mixed with CaCl₂·6H₂O. Different geometries for system generated with changing pitch ratio (PR^* = 4, 8) and volume of paraffin are the same for all geometries. In each geometry, influences of air Re (4500, 7500) and T_in (310.15 K and 315.15 K) as well as fraction of graphene (ϕ = 0, 0.03) have been analyzed via finite volume approach. Validation procedure indicated the right selection of numerical model and various values of Δt and size of mesh have been tested. With augment of PR^*, the number of tube reduces with greater size; thus, the period augments around 6.59% and 9.29% when Re = 4500 and 7500. As graphene nanoparticles increases, the melting time decreases around 3.01%. Augmenting Re leads to higher speed of phase changing around 32.78%. The most effective factor on melting process is T_in which provides 36.56%.