Heat Transfer Analysis Using Synthesized Silver Nanoparticles

Silver nanoparticles were synthesized via the sol-gel method from different concentrations of silver nitrate and the reducing agent hydrazine hydrate in the presence of citric acid and silver nitrate. The synthesized silver nanoparticles are then separated by evaporation through the addition of heat at 100°C. Three samples of nanoparticles were prepared and tested through XRD to ensure that the particle size reached the nanoscale (1 nm-100 nm). The sizes of the synthesized nanoparticles in the 1st, 2nd, and 3rd samples were 15 nm, 20 nm and 21 nm, respectively, and the average size was 19 nm. Nanofluids are prepared by mixing nanoparticles through ultrasonication with a base fluid (water), and the heat transfer coefficient of the nanofluids is measured in a shell and tube heat exchanger. The heat transfer coefficient of the base fluid (water) was 2926.85 W/(m2K), and the heat transfer coefficients with nanoparticles were 4928.22 W/(m2K), 5125.26 W/(m2K) and 4629.254 W/(m2K). The increases in the heat transfer coefficient for the 1st, 2nd and 3rd samples are 68%, 75% and 58%, respectively, greater than that of the base fluid.