Experimental study on the evaporative cooling of an air-cooled condenser with humidifying air

Using six different materials to construct a water curtain, this study aims to determine the most effective spray cooling of an air cooled heat exchanger under wet conditions. The experiments were carried out at a mass flow rate of 0.005–0.01 kg/s (spraying water), an airspeed of 0.6–2.4 m/s and a run time of 0–72 h for the material degradation tests. The experimental results indicate that the cooling efficiency, the heat rejection, and the sprinkling density increase as the amount of spraying water increases, but, the air-flow of the condenser is reduced at the same time. In addition, the cooling efficiency of the pads decreases with an increase of the inlet air velocity. In terms of experimental range, the natural wood pulp fiberscan can reach 42.7–66 % for cooling efficiency and 17.17–24.48 % for increases of heat rejection. This means that the natural wood pulp fiberscan pad most effectively enhances cooling performance, followed in terms of cooling effectiveness by the special non-woven rayon pad, the woollen blanket, biochemistry cotton and kapok, non-woven cloth of rayon cotton and kapok, and white cotton pad, respectively. However, the natural wood pulp fiberscan and special non-woven rayon display a relatively greater degradation of the cooling efficiency than the other test pads used in the material degradation tests.