What is the difference in working principle between open cooling tower and closed cooling tower?
Author：Trlon Views: Time:2020-09-22
Cooling towers are divided into closed cooling towers and open cooling towers according to whether water and air are in direct contact. The working heat exchange methods of open cooling towers and closed cooling towers are the same, and both use water for heat exchange. First explain , The cooling effect of the two cooling towers is the same, but the design structure of the open cooling tower and the closed cooling tower is completely different, what is the difference between the two?
1. The cooling principle of open cooling tower
The cooling principle of an open cooling tower is that by spraying circulating water on the glass fiber filler, and then through the contact of water and air to achieve heat exchange, and then a fan drives the airflow in the tower to circulate, and the water After the heat exchange, the hot air flow is taken out to achieve the cooling effect.
From the actual situation, we can find that this cooling method of open cooling towers, even if the initial investment is relatively small, but the water and electricity consumption is relatively large, that is to say, the operating cost is very high.
2. The cooling principle of closed cooling tower
The closed cooling tower does not need fillers during the cooling process, and its main core part is the copper tube surface cooler. To put it simply, there are two cyclic processes, namely inner and outer cycles.
For the two cyclic processes of the closed cooling tower, we can briefly introduce the following:
Internal circulation: Docking with the target equipment to form a closed circulation system (the circulation medium is soft water). Cool the target equipment and take the heat from the target equipment to the cooling unit.
External circulation: In the cooling tower, the cooling tower itself is cooled. It is not in contact with the internal circulating water, but heat exchange and heat dissipation are carried out through the copper tube surface cooler in the cooling tower. In this cooling mode, through automatic control, the operation of the motor is set according to the water temperature.
Because the environmental temperature is relatively high in spring and summer, in this case, two cycles of the closed cooling tower are required to cool down at the same time. On the contrary, the temperature in autumn and winter is not too high. Normally, we only need one internal circulation to complete the cooling process.