Energetic and Exergetic Performances of Plate Heat Exchanger Using Brine-Based Hybrid Nanofluid for Milk Chilling Application

Abstract

Theoretical study on the energetic and exergetic performances of a counter-flow corrugated plate heat exchanger using hybrid nanofluids for the milk chilling application has been done in the present investigation. Magnesia-silver and Alumina-silver nanoparticles have been dispersed in the ethylene glycol–water mixture and propylene glycol–water mixture (20:80 brine solutions) with different particle volume concentration separately. Effect of particle volume concentration and flow rate of the hybrid nanofluid on the heat transfer rate, convective, and overall heat transfer coefficients, mass flow rate of milk, pressure drop, pumping power, entropy generation rate, second law efficiency, irreversibility, irreversibility distribution ratio, non-dimensional exergy (NDE) destruction, and performance index have been studied. It has been observed that heat transfer rate, convective and overall heat transfer coefficients, pressure drop, pumping power, irreversibility, entropy generation rate, second law efficiency, and milk flow rate increase; while NDE destruction, performance index, and irreversibility distribution ratio decrease with the hybrid nanofluid flow rate and the volume concentration of the nanofluid. Within studied ranges, the hybrid nanofluid yields the maximum improvement of heat transfer rate and convective heat transfer coefficient of about 1.6% and 9.4%, respectively, compared to base fluid. It has also been found that silver + alumina shows slightly better performance improvement and hence hybrid nanofluid is recommended as a suitable alternative for the milk chilling units.