Cooling Tower

The hot water in the main machine room passes through the pipes, transverse pipes, curved pipes and central pipes with a certain pressure through the water pump, and circulates the water pressure into the water distribution system of the Cooling Tower, and evenly spreads the water on the filler through the small holes on the water distribution pipe; The dry air with low Han value enters the tower from the bottom into the air net under the action of the fan. When the hot water flows through the packing surface, it forms a water film and exchanges heat with the air. The hot air with high humidity and high Han value is extracted from the top, and the cooling water drops into the bottom basin, and flows into the main machine through the outlet pipe.



Generally, the air entering the tower is dry and low wet-bulb temperature air. There is obviously a concentration difference and kinetic energy pressure difference of water molecules between water and air. When the fan is running, under the effect of static pressure in the tower, water molecules continue to evaporate into the air and become water vapor molecules. The average kinetic energy of the remaining water molecules will be reduced, thus reducing the temperature of circulating water.



From the above analysis, it can be seen that the evaporative cooling has nothing to do with the air temperature (usually dry bulb temperature) being lower or higher than the water temperature. As long as the water molecules can continuously evaporate into the air, the water temperature will decrease. However, the evaporation of water into the air will not continue indefinitely.



When the air in contact with water is not saturated, the water molecules continuously evaporate into the air, but when the air on the water-air contact surface reaches saturation, the water molecules cannot evaporate, but are in a dynamic equilibrium state. The number of water molecules evaporated is equal to the number of water molecules returned from the air to the water, and the water temperature remains unchanged. It can be seen from this that the drier the air in contact with water, the easier it is to evaporate, and the easier it is to reduce the water temperature.