The cooling capacity's key determinants of closed cooling tower

Closed cooling tower's (Or as known as closed circuit cooling tower/closed type cooling tower/closed loop cooling tower) operation principles won't let the circulating cooling coolant direct contact with open air and other fluids, which we use water or glycol/water as circulating coolant. As the differences between closed cooling tower and open cooling tower, closed cooling tower has two separated fluid loops. The outer loop is between the spraied water, and the inner loop is in the coil pipes. The outer loop did heat exchange by spraied the water on the fills and pre-cooled before contact the coil pipes.  And the inner loops did heat exchange process by pre-cooling spraied water contacted the coil pipes. During the process, the rejected heat radiate to the spray water, and then get into the air by spray water contacted with the open air, which is similar to the open cooling tower with one exception. The process is controlled by coolant in a "closed" loop that is not directly exposed to the atmosphere or external circulating water.

The cooling tower is used to achieve a certain cooling effect, which is depending on the fills and fan air volume. Closed cooling tower's water consumption, ventilation conditions, installation location will also have a certain impact on its effect. Next, let's take a look at the impact of cooling tower fills and fan air volume on the cooling system:

1. Fills: which is the key component of closed cooling tower. The small tower generally adopts hot pressed PVC sheet or endothermic type PVC materials. The big tower will adopts wood material. The main target is to make the contact area between air and water as large as possible without affecting the wind resistance. At the same time, the heat exchange rate will also reach the maximum. The two main factors that affect the heat transfer efficiency of the fills are the shape and fills's height . Try not to damage the fills so it won't effect the water flow.

2. Air volume of fan: Large air volumen will accelerate the air flow in the tower, accelerate the heat exchange between air and water, take away heat. The main factors affecting the air volume of the fan are the shape of the fan blades, the width and length of the blades, the deflection Angle of the blade itself, the speed of the blades, the installation Angle, the speed, the motor and the transmission ratio, etc. In addition, in the case of constant air volume, the cooling effect of small water flow rate closed cooling tower is better than that of the large water flow closed cooling tower.