▎ 摘　　要

The water-based hybrid nanofluid is proposed as a cooling agent in a corrugated counter-flow type plate heat exchanger aimed at sub-ambient temperature applications. For this purpose, an experimental investigation has been done with different working fluids. Fluids considered as a coolant are DI water, alumina nanofluid, and alumina-graphene hybrid nanofluid in 80:20 nanoparticle ratio by volume with a total volume concentration of 0.01% dispersed in DI water. Various exergy related performance factors like coolant outlet temperature, coolant exergy rate, irreversibility rate, non-dimensional exergy, and second law efficiency have been considered. The influence of coolant inlet temperature and flow rate on different parameters has been investigated. Coolant outlet temperature, coolant exergy rate, irreversibility rate and non-dimensional exergy augments by 2.5%, 4.8%, 7.5% and 3.5%, respectively. While the second law efficiency degrades using nanoparticles and increasing flow rate and decreases with the coolant inlet temperature.