New retrofit method to cooling capacity improvement of mechanical draft wet cooling tower group

Abstract

The airflow distribution of the mechanical draft wet cooling tower group will become very uneven under crosswind conditions, and the cooling capacity of leeward towers can be seriously reduced. To strengthen the heat and mass transfer of the leeward tower and improve the cooling capacity of the tower group, a new retrofit method is proposed that removes the tower wall between the rain zone of the tower group. The airflow can enter the leeward tower from the windward tower, even flow out from the air inlet of the leeward tower under crosswind conditions, and the airflow distribution becomes more uniform in the tower group. A 3D numerical model of the mechanical cooling tower group is established and validated. The cooling capacity of the tower group is studied under variation crosswind velocities (0 m/s–12 m/s) and crosswind angles (0°–90°) by numerical calculation. The results show that the distribution of outlet water temperature in the retrofit tower group is more uniform. The retrofit tower group can increase the circulating water temperature drop of the leeward tower under the crosswind angle of 0° and 45°. Under the crosswind angle of 0°, the temperature drop of the circulating water increases 0.52 ℃ maximum and 0.31 ℃ on average. Under the crosswind angle of 45°, it increases 0.92 ℃ maximum and 0.59 ℃ on average. Under the crosswind angle of 90°, it increases 0.19 ℃ maximum and 0.09 ℃ on average.