Thermodynamic analysis of shell and tube heat exchanger by using AgNO3-Graphene/H2O hybrid nanofluid

Hybrid nanofluids are proven as the emerging next generation heat transfer fluids due to their superior thermophysical properties. Current study focuses on dispersion of silver-carbon based nanoparticles (AgNO3 and graphene) in base fluid (water) to develop hybrid nanofluid (HNF) at varying concentrations (0.01 vol% to 0.03 vol%) using a two-step technique and their thermodynamic performance investigations on shell and tube heat exchanger (STHX). Prepared HNFs are found stable by conducting Zeta potential stability measurement. Experimental investigations are performed to examine the effects of flow rate (115 lph to 155 lph) on heat transfer rates, energy (eta en) and exergy (eta ex) efficiencies for both shell and tube sides of the heat exchanger. Additionally, significant dimensionless quantities like the Reynolds number (Re), Prandtl number (Pr), Nusselt number (Nu), friction factor (Ff), pressure drop, and thermal performance factor (TPF) are examined. Results reveal that, the actual, average, overall heat transfer rate, eta en and eta ex are found higher as 39.21%, 39.55%, 50.87%, 39.52%, and 70.01% respectively on the shell side and as 47.02%, 37.36%, 22.96%, 47.05%, and 32.72% respectively on the tube side than that of base fluid at mean flow rate for 0.03 vol%. The shell side exhibits a 12.76% increase in convective heat transfer compared to the tube side. A reduction in friction factor leads to an increase in pressure drop at particular flow rate for all prepared HNFs and water. Finally, TPF of prepared HNFs are evaluated and found more than one, which recommends their long-term utilization in different heat transfer applications.