Experimental investigation in a forced draft wet cooling tower using aluminum oxide nano particles

Cooling towers are used in industries to remove the excess heat produced by industrial processes and machineries. This cooling phenomenon and its rate can be improved by mixing it with the nanoparticles. The present work focuses on the design and construction of a counter flow forced draft cooling tower with the addition of aluminum oxide (Al2O3) nanoparticles with water to enhance heat & mass transfer. Experiments are performed with the variation of the flow rate of water, water temperature, and the volume fraction of nanoparticles from 0 % to 2 % by volume fraction. The output parameters like coefficient of performance (COP), cooling characteristics coefficient (CCC), Rate of evaporation (ER), cooling tower efficiency & range have been analyzed. Nanofluid properties like viscosity, density & thermal conductivity for different volume fractions have been examined. It is observed that viscosity and thermal conductivity increased with an increase in volume fractions. Viscosity decreased whereas conductivity increased with temperature rise. Results obtained from cooling tower experiments indicated a maximum COP, CCC, ER, efficiency, and range equal to 7.12, 3.54, 3.95 g/s, 75.55 %, and 29.8ᵒC, respectively. For the various volume fractions studied, nanofluid with 2 % outperformed others with higher heat transfer rates and range values. For the 2 % volume fraction of the nanoparticles, make-up water requirements reduced by 76.19 % when it is compared to the normal water without the nanoparticles. Also, it is found that the cooling tower range, heat transfer rate, and efficiency increased by 10 %, 10.2 %, and 4.16 % when nanofluid concentration is varied from 0 % to 2 % by volume for the air velocity and water flow rate of 13 m/s and 3.5 Liters per minute (LPM) respectively.