What is the average energy loss caused by scaling of cooling tower fill? ——Principles, Effects, and Engineering Data Analysis

In the cooling tower system, the filling material is an important component for increasing the contact area between water and air and achieving efficient heat dissipation. However, in actual operation, the fill is very susceptible to fouling, sludge, algae, and suspended particles pollution, causing fouling. Once the fill is clogged, the efficiency of the cooling tower significantly decreases, leading to an increase in energy consumption of the entire air conditioning or process cooling system.

Why does fill blockage increase energy consumption?

Scaling and fouling mainly bring three major problems:

1. Decreased heat transfer efficiency

The surface of the fill is covered with dirt → the contact area between water and air decreases

The heat and moisture exchange capacity decreases → the outlet temperature of the cooling tower increases

2. Increased wind resistance

Blockage leads to obstruction of air circulation

The increase in fan load leads to an increase in power consumption

3. The increase in system temperature difference causes a decrease in the efficiency of the refrigeration unit

For every 1 ° C increase in condensate temperature, the energy consumption of the chiller increases by approximately 2-3%

Therefore, slight fouling of the cooling tower packing will significantly increase the overall system energy consumption through a chain effect.

Typical data on scaling degree and energy loss (industry experience)

1. Mild scaling (approximately 0.3-0.5mm thick)

1）Cooling tower efficiency decrease: 5-10%

2）Temperature rise of condensate: 1-2 ° C

3）System energy consumption increase: 3-6%

2. Moderate scaling (approximately 0.5-1 mm thick)

1）Decreased heat dissipation efficiency: 10-25%

2）Temperature rise of condensate water: 2-4 ° C

3）Energy consumption increase: 6-12%

4）Fan energy consumption increase: 5-10%

3. Severe scaling (>1 mm or obvious blockage)

1）Decreased heat dissipation efficiency: 30-50% or even higher

2）Condensed water temperature rise: above 5 ° C

3）System energy consumption increase: 15-25%

4）Fan energy consumption may increase by 10-20%

Why can even minor dirt cause significant energy loss?

1. Sensitivity of condensate temperature

The chiller unit is very sensitive to the temperature of condensed water:

For every 1 ° C increase in condensation temperature, the COP decreases by approximately 2-3%.

2. Changes in air resistance affect fan power

The power of a fan is roughly exponentially related to air resistance, therefore:

Resistance+10%

The energy consumption of the fan may increase by 15-20%

3. Uneven water distribution leads to ineffective filling of some materials

Actual effective heat dissipation area reduced

Localized formation of 'dry areas'

How to reduce energy loss caused by packing scaling?

1. Regularly clean 1-2 times a year

Including:

1）High frequency flushing

2）Chemical descaling

3）Disassemble and wash (in severe cases)

2. Strengthen water quality management

1）Medication (scale inhibitor, bactericide)

2）Filtering system (side filter)

3. Improve water distribution and sprinkler system

Reduce local dry areas to prevent further pollution and blockage.

4. Use anti fouling filling materials (such as PP with thicker ripples and larger gaps)