Exploring the effects of nanofluids on nucleate boiling: a theoretical and experimental investigation

This study evaluates the performance of silver nanofluid as a coolant in a helical shell and tube heat exchanger using water as the hot fluid. The investigation characterizes silver nanoparticles and finds they are predominantly spherical and negatively charged, resulting in stable nanofluid. The study conducts multilevel factorial analysis using different volumetric fractions of nanoparticles. It identifies fluid flow rate as having the most significant influence on effectiveness, followed by the inlet temperature of the hot fluid and the volumetric fraction of nanoparticles. The study derives a linear regression equation from calculating the effectiveness of the heat exchanger. The smallest error between calculated and experimental effectiveness was 3.8%, observed at a volumetric flow of 40 L h(-1), with an average Reynolds number of 4018, and a hot fluid inlet temperature of 60 degrees C. Although the cost of producing and characterizing silver nanoparticles was not justified, the study expands knowledge about using a scarcely explored nanofluid as a coolant in heat exchangers. The analysis shows that although the silver nanofluid used in the present study showed an increase in effectiveness compared to its base fluid (water), the cost of production and characterization of the silver nanoparticles were not justified.