Flow Maps in the Boiling Process in Domestic Refrigerators

Forced flow convection boiling and flow patterns are analytically investigated in this study to determine the behaviour of R600a within domestic refrigeration systems when copper oxide nanoparticles are added or not to this refrigerant. The flow maps are analysed, for this, the mass flows and the heat flows are of great importance since according to the numerical value of each of these the region where the flow will be found during the boiling process is established. Flow maps are presented using established correlations for halogenated refrigerants or zeotropic mixtures in the forced convection boiling process. The results showed that the heat transfer coefficient increased in mass flow while it decreased with increasing quality. On the other hand, when metallic nanoparticles are used, the heat transfer increases while maintaining the mass flow. In the same way, R600a has greater heat transfer when adding nanoparticles and decreases when oil is added, this is noticeable in the interface between intermittent and annular flow. Therefore, adding nanoparticles makes nanorefrigerants more convective compared to base fluids. All this generates an improvement in domestic refrigeration, despite having a flammable refrigerant (R600a).