COMPARATIVE ANALYSIS OF MgO-ZnO AND MgO-Al2O3 HYBRID NANOFLUIDS TO ENHANCE THERMAL PERFORMANCE OF PCM-METAL FOAM BASED HEAT EXCHANGER

Abstract

Conventional heat exchangers that utilize traditional fluids often experience delayed thermal response and inefficient heat transfer. The integrated setup of hybrid nanofluids, alongside PCM and metal foam, offers a synergistic potential to improve the thermal performance of heat exchangers. The current study aims to investigate and compare the thermal performance of MgO-ZnO/water and MgO-Al2O3/water hybrid nanofluids in a PCM-Metal Foam based heat exchanger by reducing the time taken to achieve the steady state (maximum energy storage) in the PCM-Metal Foam based heat exchanger. Each nanofluid sample contains 0.5 wt% of the total system capacity (4 liters), prepared in distilled water as two equal portions of 0.25 wt% each. The starting conditions to perform experiments, the hybrid nanofluid is circulated at 55. in the test section (PCM-Metal Foam heat exchanger) and this temperature is maintained throughout the experiment. The reference temperature of the PCM-Metal Foam heat exchanger is set at 28. at the start of the experiments. J-type thermocouples are used to collect the temperature data, which are installed on the upper and lower walls of the PCM-Metal Foam heat exchanger. The experiments were conducted at three different flow rates 0.55 l/min, 0.87 l/min, and 1.1 l/min. The results showed that the hybrid nanofluid MgO-Al2O3/water outperformed the MgO-ZnO/water hybrid nanofluid. The steady state by utilizing 0.5 wt% MgO-Al2O3/water hybrid nanofluid is achieved in 80 min, 57 min and 42 min at flow rates of 0.55 l/min, 0.87 l/ min and 1.1 l/min respectively as compared MgO-ZnO/water hybrid nanofluid where the steady state was achieved in 98 min, 66 min and 48 min at flow rates 0.55 l/min, 0.87 l/min and 1.1 l/min respectively. These results show that better convective heat transfer performance was achieved with MgO-Al2O3/water hybrid nanofluid.