IndexMain components used with specificationsExperimental procedureExperimental resultsIn this paper an experimental study for inlet air cooling of dry cooling tower natural draft using water nebulization was carried out to obtain the optimal solution for the development of the air cooling system. The experiments are performed in an open-circuit wind tunnel with a cross section of 1x1 m2. The length of the wind tunnel is kept at 10 m (with test section of 5.2 m). The authors used 9 high-pressure hollow cone nozzles that are commercially available in the market and can serve the purpose in cooling towers. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get original essay Main components used with specifications The test section was maintained with a cross section of 1x1 m2 and a length of 5.2 m. Air was drawn into the section with a variable speed centrifugal fan driven by a 75 kW motor. The air passed through 4 diffuser plates, a honeycomb and 4 woven nylon screens to achieve uniform flow without vortices in the test section. The nozzle was kept in the center of the section with a height of 0.6 m. The PDPA system and high-speed photography system were used to take the readings. The water system consisted of three main tanks, a high-pressure water pump, a nozzle, and the flow rates were controlled by a bypass valve. Nozzles with the largest cone angle and smallest droplet size were used. Various temperature sensors, humidity sensors, speed sensors and high-precision pressure gauges were used to read the inlet and outlet conditions. Experimental procedure In all 29 experiments were conducted with different combinations of nozzles, flow parameters and physical conditions. The water and air flow rates were adjusted so as to theoretically achieve complete air saturation. The experimental procedures were as follows: (1) Adjust the air velocity to the required speed; (2) use the heater to set the required inlet air temperature; (3) Adjust the nozzle pressure to set the required water flow using the pressure water flow calibration table; (4) Wait 10 minutes for stabilization; (5) Take measurements of air temperature and humidity; (6) Simultaneously characterize the spray using the PDPA system. Experimental Results The experiments were conducted with 3 different air speeds of 1 m/s, 2 m/s and 3 m/s. 3 water pressures of 0.6, 1.4, 4.6 MPa were used at the same time. The droplet size distribution and droplet velocity at the breakup length were obtained using high-speed photography and PDPA. The analysis of the same is shown in Figure 3. The cooling efficiency of a spray is defined by ASHRAE as the ratio of the actual air temperature drop to the maximum possible temperature drop. Consequently, it can be expressed as:[image: ]Where Tdb,i, Tdb,o, and Twb are the inlet and outlet dry bulb temperatures and the air wet bulb temperature, respectively. Previously, to consider the effect of overlay, the area readings were plotted for the entire cross section of the tunnel and the graph for the same is mentioned in figure 4. It was observed that half of the area remains unchanged by the spray, then to measure.