Abstract
An experimental study is conducted to cool ambient air using a new humidification technique. A wind tunnel is built with a test section comprising a matrix of ceramic tubes. These ceramic tubes are of porous design to achieve air cooling by humidification. Ambient air passes over the ceramic tubes matrix (cross flow) whereas water passes through the ceramic tubes. Air temperature and relative humidity data are measured upstream and downstream of the ceramic tube bundle used to humidify the ambient air for several air and water flow velocities. Air velocity is measured at different locations along the centerline of the rectangular wind tunnel's cross section before the test section. Results show that the ambient temperature drops by about 10 degrees C when the relative humidity increases from 2% to 5.4%. Heat and mass transfer analyses are made and show good agreement with correlations available in the literature. It is noticed that the evaporation process does not follow the isenthalpic lines. Therefore, heat is transferred from the air as latent and sensible heats. A 25% decrease in the duct air outlet temperature is obtained as the water velocity increased to 0.0347 m/s (9.81 x 10(-7) m(3)/s). The results also show that the maximum estimated evaporative cooling system efficiency of the test section is about 45%. (C) 2014 Elsevier Masson SAS. All rights reserved.