Cooling towers, also known as "cooling towers," are a type of mixed heat exchanger that uses the partial evaporation of water in the air to cool equipment. They are categorized by ventilation methods into natural ventilation, mechanical ventilation, natural cross-ventilation, and mechanical cross-ventilation types. Based on the flow of water and air, they can be classified as cross flow, counter flow, and down flow. Depending on the heat dissipation method, they are wet, evaporative cooling, dry, and dry-wet mixed types. According to the form of cooling water, they are film, droplet, and spray types. And based on their shape, they are circular towers and long towers.

The cooling tower is primarily composed of the tower body, packing, inlet window, distributor, and air guidance equipment. The lower part of the tower houses a water tank to collect the cooled water falling from the packing, which is used for water storage and regulation; below the water tank are pipes and drain pipes; above the water tank are make-up pipes and overflow pipes. The cooling tower is an essential part of the circulating cooling water system.