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Time：2025-04-08 15:07:00 Reading volume：
The recycling of power grid transformer oil is an important measure to improve resource utilization, reduce operation and maintenance costs and reduce environmental pollution. The following is a complete recycling program, covering technical processes, equipment selection and management points:
1. Restoration performance: remove moisture, gas, particulate matter and aging products (acid value, furfural, etc.).
2. Extend life: restore oil dielectric strength (≥60kV) and chemical stability through regeneration.
3. Environmental compliance: avoid direct discharge of waste oil and comply with the requirements of the "National List of Hazardous Wastes" (HW08 category).
1. Pretreatment stage (preliminary purification)
- Mechanical filtration:
- Use plate and frame oil filter or centrifuge to remove ≥5μm particles (target cleanliness NAS level 6 or below).
- Equipment cost: 20,000~100,000 yuan (processing capacity 100-500L/min).
- Dehydration and degassing:
- Vacuum oil filter (vacuum degree ≤ 50Pa) removes free water (water content ≤ 10ppm) and dissolved gas (gas content ≤ 0.1%).
- Key parameters: heating temperature ≤ 65℃ (avoid oxidation).
2. Deep regeneration stage (for aged oil)
- Adsorption treatment:
- White clay adsorption: remove acidic substances (acid value ≤ 0.01mg KOH/g), but waste residue will be produced and needs to be treated.
- Molecular sieve/silica gel: selective adsorption of polar compounds (suitable for slightly aged oil).
- Electrostatic oil purification technology:
- High voltage electric field separates colloidal carbon and micron-sized particles (accuracy can reach 0.1μm), suitable for oil with severe carbonization.
- Chemical regeneration:
- Add deacidifier (such as alkaline alumina) or antioxidant (T501), and laboratory tests are required to verify compatibility.
3. Performance recovery verification
- Test indicators:
| Project | Standard requirements |
|----------------|-----------------------|
| Breakdown voltage | ≥60kV (IEC 60156) |
| Dielectric loss factor | ≤0.005 (90℃) |
| Acid value | ≤0.03mg KOH/g |
| Interfacial tension | ≥40mN/m |
- Laboratory analysis: furfural content (to determine insulation paper aging), DGA (dissolved gas analysis).
1. Integrated oil filter unit (taking a processing capacity of 300L/min as an example):
- Domestic equipment (such as Chongqing Tongrui ZYD series): 150,000~300,000 yuan, including vacuum, heating, and precision filtration modules.
- Imported equipment (such as Germany Hoffmann): 500,000~1 million yuan, long life but high maintenance cost.
2. Mobile treatment vehicle:
- Suitable for on-site operations at substations, the price is about 500,000 to 1.5 million yuan (including oil tanks and regeneration systems).
1. Grading treatment strategy:
- Mild pollution (water content <50ppm): only vacuum oil filtration is required.
- Moderate aging (acid value 0.1~0.5mg KOH/g): adsorption + filtration.
- Severe aging (acid value>0.5mg KOH/g): Consider regeneration or waste oil recovery.
2. Economic analysis:
- The regeneration cost is about 2,000~5,000 yuan/ton, and the purchase price of new oil is about 10,000~15,000 yuan/ton.
3. Environmental compliance:
- Waste clay and waste filter elements are treated as HW08 hazardous wastes, and an agreement must be signed with a qualified unit.
- Online Monitoring + Intelligent Oil Filtering:
Install sensors to monitor oil quality in real time and trigger automatic filtration (such as a case of a substation in Shaanxi, which reduced maintenance costs by 30%).
- Low-temperature regeneration technology:
Nanomaterial adsorption (such as graphene) reduces the risk of high-temperature oxidation.
1. Oil quality detection → 2. Process selection → 3. Equipment debugging → 4. Effect verification → 5. Establish a circulation file.
Through systematic processing, transformer oil can be recycled 3 to 5 times, significantly reducing the cost of power grid operation and maintenance. The plan needs to be adjusted dynamically according to the actual oil condition. It is recommended to cooperate with professional oil filtration service providers (such as Sinopec Safety Engineering Institute) to carry out pilot projects.
