Better performance criteria for plate heat exchanger with hybrid nanofluid: flow rate or concentration

The energetic and exergetic enactments of the plate heat exchanger (corrugated) were studied theoretically using a hybrid nanofluid. Alumina–silver (Al–Ag) and magnesia–silver (Mg–Ag) nanoparticles were mixed in the propylene glycol–water brine and ethylene glycol–water brine solutions. Here, two cases were dealt with, one with a given flow rate and the other with a given area and concentration. The effect of nanoparticle concentration and hybrid nanofluid flow rate was studied on different parameters. It was observed that the overall heat transfer coefficient, pressure drop, pumping power, non-dimensional exergy destruction, entropy generation rate, and irreversibility rise with the flow rate. In contrast, the irreversibility distribution ratio reduces with the flow rate. Moreover, the trend reversed with the nanofluid volume concentration up to 0.5% concentration was observed, which can be treated as a critical parameter. In studied ranges, propylene glycol brine performs better than ethylene glycol brines. The alumina–silver combination is found to be better than the magnesia–silver combination. Increasing the flow rate is suggested as a better option than increasing the nanoparticle concentration for a given area.