Application of anti-icing technology in the renovation of cooling towers in cold regions

Main reasons for icing in counterflow towers: 2.1 The overhang under the tower’s air inlet is the primary cause of ice columns forming at the air inlet. 2.2 Uneven water distribution in the packing wetting area or low water temperature are the main reasons for icing at the bottom of the packing. 2.3 The de-icing pipes not only fail to prevent icing; on the contrary, they become sources of ice, providing ice for the air inlet and thus causing the entire air inlet to freeze over. 2.4 The drift of mist inside the tower pool outside the tower is the main reason for the formation of ice-covered forests on the ground on both sides of the tower’s air inlet, as shown in Figure 6. The above 4 points are the main reasons for icing in counterflow towers in cold regions. Freezing causes the following harmful effects: The structure of counterflow towers is usually made of concrete, and the most severe form of damage to such concrete structures occurs due to freeze-thaw cycles. Once freeze-thaw occurs, the surface layer of the concrete structure begins to peel off and weather, and over time this peeling becomes more severe, thereby reducing the service life of the tower’s structure. Ice forming at the lower end of the packing area can usually cause the packing to fall and break, thereby reducing the cooling efficiency and service life of the cooling tower.

The evenness of water distribution is directly related to the nozzles and the water distribution system; in addition, too low a water volume and a too small spraying radius of the nozzles severely affect the even dispersion of water. The water streams do not overlap with each other, which also leads to uneven water distribution. The water-repellent areas, where the water spray density is low, have such low enthalpy that they freeze; in fact, there is no inevitable connection between freezing and the filler. Solutions: 1. During winter when the ambient temperature is low, it is possible to reduce the number of cooling towers in operation or shut down some of the fans; for example, two fans can be turned off while one remains running, or three fans can be turned off while one stays operational, as long as the process requirements of the installation are met. This approach helps to prevent freezing while also saving energy consumption. 2. During winter operation of the cooling tower, as long as it does not affect the process requirements of the installation, the cooling water does not need to be sent to the tower; it can even be directly added to the water to prevent freezing. 3. If freezing occurs due to problems with the use and maintenance of the cooling tower. Measures such as operating the cooling tower at full capacity can be taken to increase the water spray density and melt the ice accumulated inside the tower. 4. In winter, when multiple cooling towers serve the same installation, it is possible to shut down two towers and keep one operational, or shut down three towers and keep one operational, without affecting the process requirements and ensuring the proper operation of the production facility; by increasing the water volume, the spraying density can be raised to enable full-load operation. If there is anything incorrect, please let me know.