Common Faults and Troubleshooting Solutions for Closed Cooling Towers

Henry Zhao

Henry is a technical trainer at Oasis Bingfeng Fluid Equipment Co., Ltd. He provides training for new employees and customers, helping them to better understand and operate the company's products.

Common Faults and Troubleshooting Solutions for Closed Cooling Towers

As the core heat exchange equipment of industrial closed-loop temperature control systems, closed cooling towers are prone to various operational faults during long-term continuous operation, affected by multiple factors such as water quality, ambient temperature and humidity, and natural wear of components. Most faults are not sudden hardware damage, but gradually deteriorate due to insufficient daily inspection and delayed handling of hidden dangers. Mastering the troubleshooting logic of common faults can quickly locate the root cause, reduce unplanned downtime, and ensure stable temperature control of production lines.

Decreased Cooling Efficiency (Insufficient Heat Transfer Capacity)

This is the most frequent fault in operation and maintenance, with the core symptom of excessively high outlet temperature of internal circulation, failing to reach the designed temperature drop.

Four core causes:

 

 

 

Continuous scaling on the outer wall of heat exchange coils. Scale has extremely poor thermal conductivity, which greatly reduces the heat exchange efficiency of tube walls.

 

Clogged spray nozzles and uneven water distribution, which prevent a complete water film from forming on the coil surface and result in insufficient evaporative heat exchange.

 

Insufficient fan air volume, which leads to poor discharge of hot and humid air and deteriorates the heat exchange environment inside the tower.

 

Internal circulation flow deviating from the designed value, and abnormal medium velocity affecting the heat exchange effect.

Troubleshooting steps: Follow the principle of from easy to difficult. First check the spray water distribution status and fan operating conditions, then inspect nozzle clogging and measure the scaling thickness on coil outer walls. Finally verify the circulation pump flow and medium parameters, eliminating faults item by item.

Abnormal Noise and Vibration in Fan Operation

This is a high-frequency mechanical fault. As the power core of air circulation in the tower, the operating stability of fans directly affects the heat exchange effect.

Core causes: Dust accumulation on blade surfaces destroys the original dynamic balance, causing vibration and abnormal noise; bearing wear, loose bracket bolts and motor faults after long-term operation will also aggravate vibration problems.

Troubleshooting steps: After shutdown, first clean dust on fan blades and tighten connecting bolts between the tower body and fan bracket. During operation, detect bearing temperature rise and vibration amplitude. If abnormal noise persists, further check bearing wear and motor operating current. Perform dynamic balance correction on the fan if necessary, to avoid serious accidents such as motor burnout and blade falling off caused by aggravated vibration.

Freezing Crack and Leakage of Heat Exchange Coils

This is a high-risk fault in northern winters, and freezing damage is usually not covered by equipment warranty.

Core causes: Residual water inside coils freezes and expands in low-temperature environments, which can easily crack thin-walled red copper tubes. Common inducements include incomplete drainage after shutdown, unqualified antifreeze concentration, and water retention dead corners in pipeline layout.

Troubleshooting steps: First locate leakage points through hydraulic pressure tests, then confirm whether the antifreeze freezing point meets the local minimum temperature requirement, and check whether drain valves at the lowest point of pipelines and purge interfaces can achieve complete drainage. Meanwhile, optimize the shutdown drainage process to avoid freezing crack risks from the operation level.

Spray System Clogging and Abnormal Drift Loss

 1.Spray System Clogging

It is caused by debris accumulation in the water sump and scaling from high water hardness, which eventually leads to uneven water distribution and decreased heat exchange efficiency. Regularly clean sediment in the water sump and replace filter screens. For working conditions with poor water quality, softened water treatment devices can be equipped to reduce clogging risks from the source.

2.Abnormal Increase of Drift Loss

It is mostly caused by damaged drift eliminators, deformed air intake grilles and excessive spray pressure, which will increase makeup water volume and corrode surrounding equipment. Check the integrity of drift eliminators and air intake grilles, and adjust the operating pressure of the spray pump.

Maintenance Summary

Most faults of closed cooling towers can be warned in advance through regular inspection. Establishing an operation and maintenance system with regular cleaning, water quality control and seasonal special protection can greatly reduce the fault rate. In case of equipment abnormalities, follow the troubleshooting principle of "outside first, then inside; easy first, then difficult". Inspect item by item from the spray system, fan conditions to pipeline status, quickly locate the root cause, and prevent minor hidden dangers from evolving into major equipment losses such as coil freezing cracks and motor damage.