The reasons why the water temperature of a closed cooling tower cannot be lowered may involve multiple aspects. The following is a detailed analysis of these reasons:

1. Insufficient air volume

Fan problem: The fan is a key component that accelerates the air flow in the tower and increases the heat exchange between air and water. If the fan size is not appropriate or the installation position is improper (such as the cooling tower is placed indoors or there are obstructions at the air inlet), the air volume will be insufficient, thereby affecting the heat exchange efficiency and preventing the water temperature from being lowered.

Fan failure: Fan blade deformation, breakage, bearing damage or transmission device failure (such as belt loosening, breakage), etc., may all lead to reduced air volume, thereby affecting the heat exchange effect.

2. Uneven spraying
Spray head blockage: Spray head blockage will cause uneven spraying, resulting in insufficient water in some areas and reducing the cooling effect. The spray head should be checked, cleaned or replaced regularly.
Water distribution trough problem: If the water distribution trough is not designed properly or fails, it may also cause uneven spraying.

3. Improper selection
The manufacturer did not fully consider the specific working conditions of the customer when selecting the model. For example, the model of the cooling tower will be different if the electric furnace is placed in a different position.
Therefore, when choosing a model, you must fully understand the specific cooling parameters and select the model in combination with the characteristics of the industry. This requires the selection of experienced large manufacturers and professional engineering teams to design a suitable tower type, which can not only ensure the heat dissipation effect, but also reduce the investment cost.

4. Aging or damage of equipment. Aging, deformation or blockage of fillers: fillers are important components to increase the contact area between water film and air and improve heat exchange efficiency. If the filler is aged, deformed or blocked, the contact area between air and water will be reduced, thereby affecting the heat exchange effect.
Coil corrosion or damage: Coil corrosion or damage will cause circulating water leakage, affecting the cooling effect. At the same time, scaling or blockage of the coil will also affect the heat exchange efficiency.
Aging and damage of seals: Aging and damage of seals will cause water leakage at the connection, thereby affecting the normal operation and cooling effect of the cooling tower.

5. Water quality problems
Deterioration of circulating water quality: Deterioration of circulating water quality will cause scaling or blockage of the coil, affecting the heat exchange efficiency. The circulating water should be treated regularly, such as adding descaling agents, bactericides, etc.

6. Improper operation and maintenance
Improper operation: If the operation is not carried out in accordance with the operating procedures, the cooling tower may not operate normally, thus affecting the cooling effect.
Insufficient maintenance: Regular maintenance and upkeep of the cooling tower is an important measure to ensure its normal operation. If the maintenance is insufficient, it may cause equipment aging, damage or frequent failures, thus affecting the cooling effect.

In summary, the reasons why the water temperature of the closed cooling tower cannot be lowered may involve insufficient air volume, uneven spraying, improper selection, equipment aging or damage, water quality problems, and improper operation and maintenance. In order to solve this problem, it is necessary to investigate and repair from multiple angles to ensure the normal operation and cooling effect of the closed cooling tower.