Wet cooling towers (or open cooling towers) operate on the principle of evaporative cooling. Evaporative cooling involves adding water vapor to the air, thereby lowering the temperature of the air and water. The energy required to evaporate the water is taken from the remaining volume of water, thus lowering its temperature. Cooling water from the plant is pumped to a height of about 10 m and distributed over the cooling tower packing, from which it pours into a well at the bottom. Inside the wet cooling tower, fill is added to increase the contact surfaces and the contact time between air and water to provide better heat transfer.
Wet cooling tower refers to a cooling tower with external spray and relying on water evaporation for cooling. The heat is carried out by the cooling liquid and dissipated in the air through conduction and evaporation, which is called wet cooling.
Wet cooling tower includes round cooling tower, square cross flow cooling tower and square counter flow cooling tower.
Power generation industry, e.g:
Biomass power plants
Gas-fired power plants
Waste incineration plants
Petroleum power plants
Cooling towers are divided as counter flow and cross flow towers according to operating principles. In counter flow cooling towers, the water flows top-down while the air moves from down-top. In cross flow cooling towers, while the water fall top-down, air current is horizontal. In recent years, forced draft counter flow towers has being preferred.
In counter flow induced draft type cooling towers, heated water, coming from facility, is homogenously sprayed to all section of tower in top-down with the help of specially manufactured waterworks system and fountains. Sprayed water mass falls into pieces by floating in tower fills. Air, having the humidity of exterior environment, is absorbed from down to top on fills with the help of motor fan group. Water, meeting the air on the inlay cooling surface, heats input to the air and a part of it cools by vapouring. Cool water is sent to facility by gathering in tower cold water basin. Air, whose humidity rises (close to saturation point) as result of vapouring, is thrown to atmosphere from the fan deck at the top of tower.
The wet cooling tower can make use of water to cool machineries that heat up and use the natural evaporation process to cool machinery. These towers rely on the heat exchange between the machinery, the water in the tower, and the air passing through the tower.
a. The structure of the whole wet cooling tower is light and exquisite, easy to assemble, strong and durable, with a good cooling effect.
b. The natural draft wet cooling tower is beautiful and durable, convenient for logistics transportation, assembly and maintenance.
c. The cooling tower has high heat exchange efficiency, the limit temperature of water cooling is the wet bulb temperature of the air.
The wet cooling tower includes a circular cooling tower, a square cross flow cooling tower, and a square counter flow cooling tower. Compared with dry cooling tower, the wet cooling tower has smaller volume and higher heat dissipation efficiency, which can effectively control water pollution. The wet cooling tower is widely used in every department of the national economy, especially in cooling water circulation systems.