Characterization of Physical, Thermal and Hydrodynamic Properties of Microencapsulated Phase Change Material Slurry as a Heat Transfer Fluid

There

has been a growing interest in developing new fluids aiming to increase the

efficiency of heat transfer systems. However, specifically-designed fluids were

often too expensive. A good approach was incorporation of phase change

materials (PCM) into the fluids. Yet, it brought about particular problems

often associated with the miscibility of PCM with carrier fluids and with

meeting the increased pumping power needs. With rapidly developing

nanotechnology and introduction of new methods, micro-/nano-encapsulated PCM

(ePCM) now seems to offer a solution. Thanks to encapsulation, the phases are

always separated from each other during the heat transfer process, by which the

advantages associated with two-phase flow at the micro level can be achieved

and the advantages of single phase fluid at the macro level can be exploited.

Volumetric slurry concentrations below 25% can be assumed to be Newtonian and

under ideal conditions, the Nusselt number of the ePCM slurry is 1.5 to 4 times

higher than that of the single phase flow. In this study, the use of ePCM

slurries as heat transfer fluids and characterization of ePCM slurry as a

working fluid in a heat transfer system is addressed.