The role of transformer oil purification device

Function of the transformer oil purification device

Transformer oil (insulating oil) purification devices are mainly used to remove impurities, moisture, gas, and other pollutants from the oil, ensure the insulation performance, cooling performance, and anti-oxidation stability of the transformer oil, and thus ensure the safety, stability, and long-term operation of the transformer.

Main functions

1. Remove moisture (dehydration)

- The moisture in the transformer oil will reduce the insulation strength of the oil, causing partial discharge or even breakdown.

- The purification device removes free water and dissolved water through vacuum dehydration or molecular sieve adsorption technology to make the moisture content in the oil meet the standard (such as ≤10ppm).

2. Remove gas (degassing)

- The air dissolved in the oil (O₂, N₂) or the combustible gas (H₂, CH₄, C₂H₂, etc.) generated by the fault will affect the insulation performance of the oil and accelerate the aging of the oil.

- Through vacuum degassing technology, the gas content in the oil is reduced to prevent bubble discharge and insulation degradation.

3. Filter solid particles (removal of impurities)

- Metal particles, fibers, dust and other impurities will reduce the insulation performance of the oil and aggravate the wear of the equipment.

- Use precision filtration (1~5μm) or centrifugal separation technology to remove tiny particles and improve the purity of the oil.

4. Restore oil quality (regeneration)

- Transformer oil that has been running for a long time will produce acidic substances, colloids and sludge due to oxidation, which will affect the heat dissipation and insulation performance.

- Through adsorption treatment (such as clay, silica gel) or chemical regeneration methods, reduce the acid value (TAN) and improve the antioxidant capacity of the oil.

5. Improve the electrical properties of the oil

- The purified oil has a higher breakdown voltage (BDV) (generally required to be ≥50kV), ensuring the insulation safety of the transformer.

- Reduce the dielectric loss factor (tanδ) and reduce energy loss.

Typical application scenarios

- New oil treatment: New transformer oil may contain trace moisture and impurities, and must be purified before it can be injected into the equipment.

- Oil maintenance during operation: filter transformer oil regularly to extend service life.

- Oil treatment after failure: if the transformer is damp, has internal discharge or overheating, causing oil quality deterioration, it needs to be purified and regenerated.

- Transformer maintenance: When the transformer is overhauled or the oil is changed, the old oil is recycled.