Video: Cooling Tower: Components, Working Principle, Types, Applications, and Precautions
Figure 1: Industrial cooling towers.
A cooling tower is a device that uses the contact between water and air through the process of evaporation to
dissipate waste heat generated in industrial or air conditioning systems.
In industrial production or cooling processes, waste heat generated needs to be transferred using cooling water.
Water is extracted from natural water bodies such as rivers, lakes, or seas and used as cooling water, which absorbs
the waste heat, causing the water temperature to rise, and then discharges back into the environment. This cooling
method is known as once-through cooling (OTC) .
When once-through cooling conditions are not available, a cooling tower is required for the cooling process. The
function of a cooling tower is to exchange heat between the waste heat-carrying cooling water and the air inside the
tower, transferring the waste heat to the air and dissipating it into the atmosphere.
1. Basic Components of Cooling Towers
A cooling tower typically consists of a tower body, fill material, fan, and water pump
Figure 2: Cooling tower structural diagram.
1. Tower Body: It is a vertical cylindrical structure with fills installed inside.
2. Cooling Tower Fill: It provides the largest possible heat exchange surface area for water and air.
3. Cooling Tower Fan: Used to pass air through the fills for heat transfer.
Axial Flow Fan: Used for induced draft cooling towers.
Axial/Centrifugal Fan: Used for forced draft cooling towers.
4. Water Pump: Used to circulate the cooling medium into the cooling tower.
5. Cold Water Basin: Located at the bottom of the cooling tower, it receives the cooling water.
6. Drift Eliminator: Collects water droplets carried by the airflow.
7. Air Inlet: Air inlet of the cooling tower.
8. Spray Nozzles: Spray the cooling water.
9. Cooling Tower Louvers: Ensure even airflow and retain moisture inside the cooling tower.
1.1 Which Direction Should the Cooling Tower Fan Blow? Upwards or Downwards?
The cooling tower fan usually blows upwards. Here are the reasons:
1. Assisting in the Upward Movement of Hot Air
The cooling tower fan blowing upwards helps the hot air to rise and be expelled from the tower, improving air
circulation and heat dissipation efficiency.
If the cooling tower fan blowing downwards would disrupt the air circulation, reducing cooling efficiency and
potentially causing equipment malfunctions.
2. Avoiding Water Droplet Splashing
When the cooling tower fan blows upwards, water droplets can be prevented from splashing onto the ground or
underground pipes, avoiding unnecessary inconvenience.
Figure 3: Cooling tower fans.
2. Working Principle of Cooling Towers
A cooling tower is a device that uses the contact (direct or indirect) between air and water to cool water.
Inside the cooling tower (wet type cooling tower), a water pump introduces the cooling medium (usually water) from
the bottom and evenly distributes it over the fills using spray nozzles. When the cooling medium comes into contact
with the air, the presence of fills increases the water's surface area, accelerating evaporation. The evaporation
process consumes heat, resulting in a decrease in the temperature of the cooling medium.
Simultaneously, the fan inside the cooling tower forces air through the fills, accelerating the evaporation process
of water. The airflow generated by the fan carries away the evaporated water vapor, reducing the humidity inside the
cooling tower. This evaporative cooling effect reduces the temperature of the cooling medium.
Figure 4: Wet cooling tower structure diagram.
3. Types of Cooling Towers
With the rapid development of industry, cooling towers have diversified into various types, including:
Table 1: Different types of cooling tower.
4. Application Range of Cooling Towers
Cooling towers are widely used in various industrial fields, mainly in the following aspects:
1. Electric power industry: Cooling towers are used to cool generator sets in power plants to maintain the normal
operating temperature of the generator sets.
2. Chemical industry: Cooling towers are used for cooling in the chemical production process, such as cooling
reactors, condensers, etc.
3. Manufacturing industry: Cooling towers are used to cool machine tools, coolant, etc. to maintain the normal
operating temperature of the equipment.
4. Air conditioning system: Cooling towers are used in the air conditioning systems of large commercial buildings
and industrial plants to provide cooling medium.
5. Advantages and Precautions of Cooling Towers
Cooling towers offer the following advantages:
1. Energy-Saving and Environmentally Friendly: Cooling towers utilize the evaporative cooling
effect of water,
requiring no additional energy consumption, thus saving energy. Additionally, the transfer of heat to the
surrounding environment through cooling towers does not cause environmental pollution.
2. High Efficiency: The fill structure and fan system of cooling towers ensure high heat transfer
efficiency,
enabling rapid reduction of the temperature of the cooling medium.
3. High Reliability: The cooling tower has a simple structure, stable and reliable operation, and
low maintenance
costs.
Precautions when using cooling towers include:
1. Water Quality Control: The cooling medium used in cooling towers needs to be tested and treated
regularly to
prevent problems such as scale and corrosion.
2. Regular Maintenance: Cooling towers require regular cleaning and maintenance to maintain their
normal operation
and efficient performance.
3. Safe Operation: When using the cooling tower, relevant safety operating procedures need to be
followed to ensure
the safety of personnel and equipment.
Figure 5: Cooling towers.
6. Conclusion
The cooling tower is an important heat exchange device that transfers heat to the surrounding environment through
the evaporative cooling effect of water. It plays an important role in cooling and heat recovery in industrial
production processes. Understanding the working principle and application fields of cooling towers can better
understand their importance and role in the industrial field.
At the same time, when using cooling towers, please pay attention to water quality control, regular maintenance and
safe operation to ensure its normal operation and efficient performance.
