E-mail sinonshseo@gmail.com
Time：2025-04-18 11:47:25 Reading volume：
The vacuum dehydration oil purification system is mainly used for the regeneration and purification of transformer oil (insulating oil). Its core function is to remove pollutants such as moisture, gas, and solid particles in the oil, restore the oil's insulation strength, chemical stability and antioxidant properties, thereby ensuring the safe and stable operation of power equipment (such as transformers, reactors, mutual inductors, etc.).
(1) Deep dehydration (moisture removal)
- Remove free water (suspended water visible to the naked eye).
- Remove dissolved water (molecular-level bound water in the oil, usually < 50 ppm).
- Goal: Reduce the moisture content in the oil to ≤ 10 ppm (UHV transformers have stricter requirements, such as ≤ 5 ppm).
- Significance: Moisture will significantly reduce the insulation strength (breakdown voltage) of the oil and accelerate the aging of oil-paper insulation.
(2) Efficient degassing (removal of dissolved gases)
- Remove oxygen (O₂): prevent oil oxidation and delay the increase of acid value.
- Removal of nitrogen (N₂) and carbon dioxide (CO₂): Reduce the risk of bubble discharge.
- Removal of fault gases (H₂, CH₄, C₂H₂, etc.): Reduce the risk of flammability during post-fault processing.
- Target: Gas content ≤ 0.1% (volume fraction).
(3) Precision filtration (removal of solid impurities)
- Filter metal particles, fibers, carbides, etc. (filtration accuracy 1~5μm).
- Target: Oil cleanliness reaches NAS 1638 level 6 or ISO 4406 15/12/10.
- Significance: Particles may cause partial discharge or mechanical wear.
(4) Restore oil quality performance
- Increase breakdown voltage (≥50kV/2.5mm, new oil standard ≥60kV).
- Reduce dielectric loss factor (tanδ) and reduce energy loss.
- Delay oil aging and reduce acid value and sludge generation.
(1) New oil treatment
- New oil may absorb moisture and gas during transportation and storage, and needs to be purified before injection into the equipment.
(2) Maintenance during operation
- Regularly purify the operating oil to prevent the accumulation of moisture and impurities (especially in high humidity environments).
(3) Oil regeneration after fault
- After the transformer is damp, overheated, or discharged, the moisture, gas and particulate matter in the oil exceed the standard and need to be treated urgently.
(4) Oil treatment during maintenance
- When the transformer is overhauled, the oil is extracted and purified before being reinjected to avoid the introduction of new pollutants.
| Advantages | Description |
|-------------------------|-------------------------------------------------------------------------|
| Efficient dehydration | Vacuum spray/thin film evaporation technology, moisture removal rate >95%. |
| Synchronous degassing | Remove gases such as O₂ and N₂ while dehydrating to prevent oil oxidation. |
| Integrated purification | Water, gas and particulate matter can be removed in a single treatment without multiple sets of equipment. |
| Automation control | PLC automatically adjusts temperature, vacuum and flow to avoid human operation errors. |
| Extend equipment life | Keep oil clean, reduce transformer insulation aging and reduce failure rate. |
| Parameters | Before treatment (typical value) | After treatment (standard value) | Standard basis |
|-------------------|--------------------------|--------------------------|-------------------|
| Water content | ≤50ppm (wet oil may be higher) | ≤10ppm | GB/T 7600 |
| Gas content | ≤3% (volume fraction) | ≤0.1% | DL/T 703 |
| Breakdown voltage | ≤30kV/2.5mm | ≥50kV/2.5mm | IEC 60156 |
| Particle contamination | NAS 1638 Level 10 | NAS 1638 Level 6 | ISO 4406 |
- Temperature control: The oil temperature must not exceed 65℃, otherwise it will accelerate oxidation.
- Vacuum maintenance: The vacuum tank pressure needs to be stable at 0.5~1kPa, otherwise, the dehydration efficiency will be affected.
- Anti-moisture: The transformer needs to be sealed after treatment (such as replacing the respirator silicone) to prevent air moisture from entering again.
- Regular equipment maintenance:
- Check whether the vacuum pump oil is emulsified.
- ｒｅｐｌａｃｅ the clogged filter element.
- Calibrate the sensor (temperature, pressure).
The vacuum dehydration oil purification system uses heating + high vacuum + precision filtration to comprehensively solve the water, gas and particle pollution problems of transformer oil, ensuring that the insulation performance of the oil meets the standards, thereby improving the reliability of the transformer, extending its service life and reducing power outages. It is one of the core equipment for oil management in the power system and is widely used in power plants, substations, high-voltage laboratories and other scenarios.
