Guide to Seal Oil Flushing for Generator Set

Seal oil flushing for generator sets is an essential maintenance step to ensure the safe operation and extend the service life of equipment. During the operation of generators, due to external environmental factors and system design, the seal oil system is prone to leaks or contamination, which not only affects equipment performance but can also lead to safety accidents. Regular and standardized seal oil flushing can ensure the stability of equipment operation, improve work efficiency, and effectively extend the service life of generator sets. This article will detail the importance of generator seal oil flushing, preparatory conditions before the operation, specific operational points, and precautions to ensure that the flushing work is carried out safely and orderly.

The Importance of Seal Oil Flushing

The primary role of the generator's seal oil system is to isolate the internal and external environments of the generator, preventing gas leakage or the intrusion of external substances, and maintaining the cleanliness and stability inside the equipment. However, during long-term operation, seal oil may encounter problems due to improper system design, oil aging, or pipeline contamination:

Oil contamination: Affects lubrication effectiveness and increases operational resistance.
Oil leakage issues: Leads to mixed oil inside the equipment, poor lubrication, and even causes shutdown accidents.
System failures: Such as pump blockages or pipeline accumulation, which can endanger the safe operation of the generator.

Flushing operations can remove oil stains and impurities from the system, restore the performance of the seal oil, and ensure the stable operation of the generator under various conditions.

Pre-flushing Preparation Conditions

Before carrying out flushing operations, the following conditions must be met to ensure standardized, safe, and efficient operations.

1. Familiarity with system equipment characteristics

Before flushing, it is essential to fully understand the characteristics and functions of each component in the generator's seal oil system, and to clarify which equipment can be directly flushed and which should be avoided.
For example, generator bearing housings are vulnerable parts and cannot be directly flushed. In this case, before operation, the lubricating pressure oil and lubricating oil on the empty side of the bearing housing should be short-circuited back to the oil, and relevant equipment should be used to guide it into the main oil tank to prevent damage to the bearing housing.

2. Preparation for hydrogen-side oil route short-circuiting

For hydrogen-cooled generator sets, the hydrogen-side oil inlet and return oil in the seal oil system must be short-circuited before flushing the hydrogen-side oil pipelines. The return oil must be directed into the hydrogen-side seal oil tank.
During the flushing process, to facilitate the adjustment and emptying of temporary pipelines, an oil discharge valve should be installed at the lowest point of the oil pipe to ensure that residual oil can be quickly removed after the operation is completed.

3. Check the operation of auxiliary equipment

Ensure the normal operation of the following key auxiliary equipment:
Fume and hydrogen exhaust fans: Test the operation of the equipment to ensure it can effectively expel gases during the flushing process to prevent safety hazards.
Hydrogen isolation equipment: Check the sealing and operation to avoid the impact of hydrogen leaks on the operating environment.

4. Remove parts that do not need flushing

Parts such as filter screens and filter elements in the sealed oil assembly equipment do not participate in the flushing operation and should be removed in advance. This can both avoid equipment wear and improve flushing efficiency.

5. Ensure lubricating oil quality

Use lubricating oil that meets the standards as the flushing medium. The oil must have good cleaning ability and lubrication effect to ensure ideal flushing results.

6. Strictly follow design specifications

The installation of flushing equipment and pipeline connections must be carried out strictly according to the design drawings to ensure that the connections between each component are correct and to avoid installation deviations that affect system performance.

Seal Oil Flushing Operation Steps

To ensure the safety and effectiveness of the generator seal oil flushing process, the following steps should be strictly followed.

1. Preparation and cleaning

Check and confirm that the equipment, pipelines, and auxiliary equipment are in good condition.
Ensure that the oil on the empty side of the seal oil system is connected to the lubricating oil return, preventing seal oil from entering the interior of the generator during the flushing process and affecting operational performance.

2. Start flushing

Start the flushing pump, introduce qualified lubricating oil into the pipeline system, and observe the return oil situation.
Adjust the amount of oil in the tank to ensure even distribution of the flushing medium, gradually removing impurities and accumulated oil from the pipelines.

3. Pay attention to pipeline safety

During the connection and discharge of temporary pipelines, ensure smooth oil discharge and prevent residual oil from contaminating the system.
Monitor pressure changes to avoid high or low pressure impacts on the system.

4. Post-flushing treatment

After the flushing is completed, promptly empty the residual oil in the temporary pipelines and thoroughly clean the system.
Reinstall removed filter screens, filter elements, and other components to ensure the equipment returns to normal operating conditions.

Precautions During Flushing Operations

During the generator seal oil flushing process, to ensure the safety and effectiveness of the operation, the following matters should be given special attention.

Operational safety: Seal oil flushing operations must be carried out strictly according to safety procedures to prevent oil splashes or high-temperature oil products from causing accidents.
Equipment protection: Avoid accidental damage to parts that do not participate in flushing, especially critical parts such as bearing housings.
Regular inspection: After the flushing is completed, regularly check the working condition of the seal oil system to ensure it is always in good operating condition.

Conclusion

Generator seal oil flushing is a technically demanding maintenance task that runs through the daily maintenance and fault handling of generators. By following standardized operational steps, combined with comprehensive preparation and subsequent treatment measures, flushing work can not only restore the cleanliness and performance of the seal oil system but also effectively enhance the operational reliability and service life of the generator. Regular flushing and standardized operations are crucial safeguards for ensuring the safe and stable operation of generators.