Experimental study on the air-side flow resistance of different water collecting devices for wet cooling tower applications

This paper experimentally studies the air-side flow resistance of three different water collecting devices (WCDs) being U-type, V-type and rectangle-type. A wind tunnel was designed to simulate the airflow across the WCDs within air speeds of 0.5–3.0 m/s. The effect of dry/wet conditions on the air-side flow resistance was also investigated. The results show that the air-side flow resistance of the rectangle-type WCD is the highest among all while those of U-type and V-type are more or less identical. Therefore, the U-type WCD is recommended for industrial application as it can collect more water with low air-side flow resistance. Meanwhile, wet condition produces higher air-side flow resistance when compared with dry condition for all of the studied WCDs. Finally, a correlation is developed to express air-side pressure drop as a function of air speed, air density, water-to-air volumetric flow rate ratio and non-dimensional shape parameter which has been introduced for predicting the air-side flow resistance across WCDs.