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• Investigation of ZnO/water nanofluid effect on the performance of a wet cooling tower. • Improving the thermal performance of the wet cooling tower using ZnO/water nanofluid. • Increasing the thermal performance of the wet cooling tower by enhancing nanofluid concentration. • Employing three PVC packing with different densities. • Enhancing the thermal performance of the wet cooling tower using denser packing. This article deals with an experimental investigation on the thermal performance of a mechanical draft wet cooling tower when using Zinc Oxide (ZnO) nanoparticles and three packing types with different densities. Stable nanofluids with different weight concentrations of ZnO/water were prepared through a two-step procedure using distilled water. First of all, the influence of three packing types including 7,9 and 18 layers are investigated on the thermal performance of the wet cooling tower using ZnO/water nanofluid with a weight concentration of 0.1%. Secondly, five ZnO/water nanofluids with weight concentrations of 0.02, 0.04, 0.06, 0.08, and 0.1% are utilized to examine the effects of nanoparticle concentration on the performance. The results indicate that water temperature difference, cooling efficiency, and tower characteristic could enhance by increasing layers of packing and weight concentrations of nanofluid. Moreover, the nanofluid effects are more notable when the denser packing is used. [ABSTRACT FROM AUTHOR]

This article deals with an experimental investigation of thermal performance of mechanical draft wet cooling towers by changing various parameters such as hot water temperature, water flow rate, air mass flow rate and stage numbers of packing. In fact, this research attempts to focus on packing density influences with an emphasis on the role of stage numbers of packing. The results imply that coefficient of efficiency is in direct relation with air mass flow rate, hot water temperature and stage numbers of packing, while it diminishes by increasing the water flow rate. On the other hand, thermal images are provided for visualizing temperature distribution within the studied cooling tower. Afterward, these images are utilized so as to obtain pertinent temperature histograms and also temperature distribution along the vertical and horizontal directions for three packings. Finally, regression analysis is employed in order to derive design equations from the measured data. [ABSTRACT FROM AUTHOR]

Wet cooling towers play a prominent role in the transfer of waste heat from industrial thermodynamic cycles. However it is a complicated task to dictate and optimize their operational conditions on account of different mass and heat transfer mechanisms between water and air flows. In this research, air mass flow rate, hot water temperature, water flow rate and stage numbers of packing are changed experimentally in order to investigate their influences on the cooling tower performance. As a matter of fact, this research attempts to focus on packing density effects with an emphasis on the role of stage numbers of packing. Consequently, the obtained results indicate that coefficient of efficiency is in direct relation with the hot water temperature, stage numbers of packing and air mass flow rate, while it diminishes by increasing the water flow rate. On the other hand, the captured thermal images and pertinent temperature histograms are investigated so as to visualize and calculate the temperature distribution within the studied cooling tower. Eventually, mathematical equations are derived from regression analysis of the measured data to recommend some practical procedures for the sake of reaching optimum operating conditions of forced draft wet cooling towers. [ABSTRACT FROM AUTHOR]

There are different mass and heat transfer mechanisms between water and air flows inside wet cooling towers (WCTs) so that it is a very difficult task to manage or optimize their operations. In this experimental work, the WCT performance is parametrically investigated in order to understand effects of water flow rate, inlet water temperature, type and arrangement of packing, and mass flow rate of air. Three different types of PVC packings (7, 9 and 18 ribs) are studied in this article separately to investigate influences of rib numbers. Furthermore, operation of the WCT is investigated by changing the inlet water temperature, rib numbers of packing, and flow rate of air and water. Ultimately, a guideline is proposed to reach optimum operating conditions of WCTs by virtue of mathematical equations derived from regression analysis of the measured data. [ABSTRACT FROM AUTHOR]