Why is closed cooling tower superior to open cooling tower

First of all, we need to understand what is a cooling tower, understand the generation of cooling tower and cooling principle, in order to better understand the difference between open type and closed type. The cooling tower is a device that uses water as a circulating coolant to absorb heat from a system and discharge it into the atmosphere to reduce the temperature of the water. It is to use cold water after contact with the air flow on heat cooling coil pipe to produce steam, steam evaporated, and taken away the heat, to achive principle of radiation heat transfer, and it purpose is to dispersed the heat generated by industrial equipments or air conditioning devices, and reduce the water temperature, in order to ensure the normal operation of the system. Usually the devices are designed like a  barrel, so we call them the cooling tower.

Secondly, what is called open cooling tower. The circulating water is sprayed on the filler of glass fiber by means of spray, and the contact between water and air is used to achieve heat exchange. Then the air flow in the tower is driven by the fan to circulate, and the hot air flow after heat exchange with water is taken out, so as to achieve cooling.

What is a closed cooling tower? It is dry (low enthalpy value) air driven by the fan, through the air in-let and get into the cooling tower; Saturated steam flows from high temperature water molecules with high pressure to air with low pressure, and the hot and humid (high enthalpy) water is sprayed into the tower by the water self-propagating water system. When water droplets contact with air, on the one hand, due to the direct heat transfer between air and air, on the other hand, due to the pressure difference between the surface of water vapor and air, evaporation occurs under the action of pressure, which takes away the heat in water, namely evaporation heat transfer, so as to achieve the purpose of cooling.

The difference between open cooling tower and closed cooling tower is summarized as the following points to describe:

1. The cooling principle is different. As stated in the above concept, the medium in the closed cooling tower has a completely closed cycle in the cooling coil pipes and is not in direct contact with air, while the medium in the open cooling tower is directly cooled by filler.

2. Different cooling methods. Closed cooling tower realizes double cycle cooling, namely the combination of air cooling and water cooling, while open cooling tower is single cycle cooling with only air cooling.

3. The cooling medium is different. Closed cooling tower can directly cooling water, oil, alcohol, quench water, salt water and chemical liquid and other media, medium no loss, composition stability, and open cooling tower in principle only cooling water.

4. The cooling temperature is different. Closed cooling tower can cool high-temperature medium, while open cooling tower can only cool water below 65℃ in principle, which largely depends on the material of heat sink.

5. Prices are different. The purchase cost of closed cooling tower is relatively high, generally 3-5 times higher than that of open cooling tower.

6. Energy saving effect is different. The drift rate and evaporation rate of closed cooling tower are much lower than that of open cooling tower.

7. The degree of protection for the cooling equipment varies. Circulation fluid closed operation, so will not be contaminated, evaporation, concentration, no need to add water and medicine, thus ensuring the use and life of the associated equipment, daily management is also very convenient; Open cooling tower circulation fluid because of evaporation and concentration, must be perennial dosing, water, and because the fluid direct contact with the air, easy to be polluted, when encountered vulcanization day, fluid acid reaction, resulting in damage to the associated equipment.

8. Different levels of maintenance. Closed cooling tower does not need frequent shutdown for maintenance, stable and safe operation, can reduce the failure rate of associated equipment, suitable for systems requiring continuous operation; The open cooling tower must be frequently shut down for maintenance, not suitable for continuous operation of the system.

9. Use performance is different. For example, the circulation fluid in closed cooling tower will not produce algae and salt crystals due to no sunlight exposure and no contact with air, "no need to remove algae and salt", so as to guarantee the high-performance operation of the system. Open cooling tower circulation fluid open operation, exposed to the sun, easy to produce algae and salt crystallization, thus affecting the performance of the system.

10. Environmental protection. Closed cooling tower can be dry operation, not breeding all kinds of bacteria, so it is especially suitable for the occasion of air purification needs, but also often used in dry areas; Open cooling tower cannot operate dry.

11. Security. Closed cooling tower when the fluid is volatile or toxic, irritant solution, the use of closed circulation system, will not pollute the environment, so widely applicable to the fluid has strict requirements of the system; However, when the fluid in open cooling tower is volatile toxic and irritating solution, there are safety risks in using open cooling tower operation mode.

To sum up, there is a big difference between open and closed cooling towers, but there is no good or bad cooling tower, only suitable for the needs of cooling system, different cooling systems provide different cooling methods and cooling tower type.

Hutal is a professional cooling tower manufacturer, please contact for further information.