Experimental study of the effect of using hybrid graphene and titanium oxide nanofluids in corrugated plate heat exchanger

Abstract

Heat exchangers play a critical role in various thermal systems, and enhancing their efficiency remains a major engineering challenge. Nanofluids have emerged as promising working fluids due to their superior thermal properties. This study experimentally investigates the thermal and hydraulic performance of a corrugated plate heat exchanger using hybrid nanofluids composed of graphene and titanium oxide nanoparticles dispersed in water. The motivation lies in combining the high thermal conductivity of graphene with the stability of titanium oxide to enhance heat transfer without significantly compromising flow characteristics. Nanofluids were prepared at four volume concentrations: 0.05 %, 0.1 %, 0.25 %, and 0.5 %, and tested at flow rates ranging from 2 to 5 L per minute. Key parameters including heat transfer rate, Nusselt number, friction factor, pressure drop, and exergy loss were analyzed. The results confirmed that hybrid nanofluids notably enhanced heat transfer performance, especially at lower flow rates. At 2 L/min, the heat transfer rate increased by 18.4 % with 0.05 % nanoparticle concentration, whereas at 5 L/min, the improvement was around 5 %. The friction factor increased substantially with higher nanoparticle loading rising from 0.956 for water to 9.07 for 0.5 % nanofluid at a Peclet number of 4000—yet this effect diminished at higher flow rates. Furthermore, exergy loss was consistently reduced by using nanofluids, though the benefit decreased with increasing flow rate. Overall, the findings suggest that hybrid nanofluids can significantly improve the thermal performance of corrugated plate heat exchangers.