In some regions, there is a significant difference in temperature between winter and summer, with some areas reaching as high as 60-70 ℃. In addition, the uneven distribution of heat load and non-condensation phenomenon between the various pipe rows of the air cooler can lead to problems that do not easily occur under normal temperature conditions, such as solidification, blockage, and freezing of the flow inside the pipes, which are prone to occur in low-temperature environments.

To prevent fluid from solidifying and freezing inside the air cooler tubes, the following measures can be taken:

(1) Uniformly distribute the fluid inside the pipe to avoid the occurrence of flow deviation. For example, using II or double II connection methods in pipeline systems, increasing the number of pipes in the bundle, and arranging the pipes reasonably.

(2) Adjust the air supply volume by using automatic angle adjustment fans and blinds. Adjust the ventilation volume when the temperature changes, and reduce the air supply volume when the temperature is low.

(3) To avoid excessive cooling of certain flows, finned tubes with large diameters and low finning ratios can be used.

(4) Install steam coils under the bundle, which are only used during equipment startup, shutdown, and intermittent operation.

(5) In winter, downstream heat transfer is used, while in summer, countercurrent heat transfer is used. In winter, high-temperature process fluids first come into contact with cold fluids. Due to the high temperature and low viscosity of the fluid, it is not easy to solidify. When the fluid temperature drops, as the air has been heated, there is no danger of solidification when in contact again. However, this will reduce the temperature difference in heat transfer and require an increase in heat transfer area. To avoid this issue, the flow direction can be switched to countercurrent heat transfer in summer.

(6) For air-cooled steam condensers, segmented condensation can be used, such as using a series system of main condensers and auxiliary condensers. In addition, it is necessary to choose the steam flow rate and length inside the pipe reasonably. If the condensation length is too long, it can easily cause supercooling and freezing of the condensate water.

(7) Calculate the wall temperature to be higher than the freezing point of the liquid.

(8) Adopting a hot air circulation air cooler, in addition to preventing liquid freezing, it can also strictly control the outlet temperature of the process fluid.