Experimental study of the thermal-hydraulic performance of a brazed aluminum heat exchanger under wet-surface conditions

Using an open-loop wind tunnel and a full-cone water spray nuzzle, the air-side performance of a liquid-to-air heat exchanger is studied experimentally for wet-surface conditions. The test specimen is a brazed-aluminum, louvered-fin heat exchanger. The total capacity, pressure drop and water drainage behavior under various water usage rates and air face velocities are explored and compared to data from dry-surface conditions. The impact of spray orientation is also studied. The results are presented as plots against water usage rate or water spray rate per unit heat transfer area. The experimental data are used to validate a model developed for simultaneous heat and mass transfer of a wetted heat exchanger. Fouling on the fin surface is observed in the experiment, and fouling characteristics are discussed in this thesis