Heat transfer during solidification of PCM layers with inclusion of nano-powders

Abstract

For heating a room, air flow heat exchanger with involving wavy PCM layers were employed in current study. FVM was incorporated to model current unsteady process and RT30 was utilized as base PCM which is mixed with alumina nano-powders. Cold turbulent air flow enters the channel with temperature of 12 oC. Liquid paraffin converts to solid phase and heat release from the layers. So, warm air exits the domain. Amplitude of paraffin layers and fraction of alumina have been scrutinized in results. Validation with experimental paper illustrates nice agreement of current modeling. Air reaches the heat from paraffin layers and its temperature increases. Rise of time decline the outlet temperature. Augment of amplitude has various influences on outlet temperature at various time stages. The longest process belong to case with pure paraffin and a=5mm which it takes 5.33hr to finish the process. When a=20mm, φ=0.04, the best discharging rate can be obtained and process takes 3.19hr to reach full solidification. Dispersing nano-powders makes freezing time to decrease about 5.49% when a=20mm. Employing greatest amplitude cause required time to reduce about 35.82% when φ=0.04.