Enhanced heat transfer performance of silver Nanofluids as coolants in a helical Shell and tube heat exchanger: an experimental study

Silver nanofluids have recently emerged as a promising coolant for enhancing heat transfer performance. This study experimentally investigates the heat transfer characteristics of silver nanofluid in a helical shell and tube heat exchanger. Spherical silver nanoparticles of 143 nm mean diameter were synthesized using a chemical reduction method and characterized comprehensively. The nanofluid was utilized as the tube-side coolant at volumetric concentrations of 1.5% and 2.5%, with its effectiveness compared to water. The impacts of concentration and fluid flow rate on heat transfer coefficient and effectiveness were evaluated under varying conditions. Results showed improved heat transfer performance using silver nanofluid, with the maximum enhancement at 2.5% concentration. The heat transfer coefficient and effectiveness increased with higher flow rate, demonstrating the importance of optimizing fluid flow conditions. This study provides new insights into harnessing silver nanofluids for thermal engineering applications and quantifies the effects of concentration and flow on the viability of silver nanofluids as efficient coolants in heat exchangers.