Experimental study on hydrothermal characteristics of shell and tube heat exchanger using phase change material-based hybrid nanofluid

The shell-and-tube heat exchanger (STHX) is probably the most ubiquitous form of heat exchanger in many industrial settings. In the current investigation, various nanofluids (Al₂O_3, PCM, CNT, Al₂O₃+PCM, and Al₂O₃+CNT) at volume concentrations of 0.01% and 0.1% were used to test the hydrothermal performance in a STHX. This study aimed to investigate the influence of the Nusselt number and friction factor on the Reynolds number and the hydrothermal performance of STHX at various volume fractions. The execution of an experimental investigation accomplished this. The findings demonstrated that the pressure drop and heat transfer coefficient depend on the nanofluid's flow rate, that it is superior to DI water and improves with volume. The h_i/∆p value rises for Al₂O₃ due to pressure drop impacting heat transmission, but it falls for phase change material (PCM) and Al₂O₃+PCM nanofluids. The hybrid nanofluid Al₂O₃+CNT flowing at 10lpm in the tube has a 15.60% greater friction factor and an average Nusselt number of 38.08% compared to the base fluid. The heat transfer coefficient, Nusselt number, pressure drop, and friction factor for Al₂O₃+PCM at 8.33lpm increase by 9.18%, 8.91%, 36.84%, and 5.98%, respectively, with an increase in volume concentration from 0.01 to 0.1%. Nanofluids that are either mono- or hybrid and contain PCM dispersion have a better heat transfer coefficient at low flow rates. The pressure loss increases with increasing flow rate because PCM particles raise dynamic viscosity.