Transformer Oil Purifier

For transformers of different voltage ratings, a vacuum oil purifier of the corresponding specification must be selected to ensure that the purification performance meets the equipment’s insulation and operational requirements:

1. Voltage rating ≤ 35 kV: A single-stage vacuum oil purifier is recommended, with a vacuum level requirement of -0.06 to -0.08 MPa. The treated oil should have a breakdown voltage of ≥50 kV and a water content of ≤15 ppm. This is primarily suitable for routine inspections and daily maintenance of distribution transformers and plant service transformers.

2. Voltage levels of 110 kV/220 kV: A two-stage high-vacuum oil purifier is recommended, with a vacuum level requirement of ≤-0.095 MPa. The treated oil should have a breakdown voltage of ≥60–70 kV and a gas content of ≤0.3%. This is suitable for major overhauls, vacuum oil filling, and routine in-depth maintenance of main transformers.

3. 330kV–750kV Ultra-High Voltage (UHV): We recommend using a high-efficiency two-stage + regeneration module oil purifier. The required vacuum level is ≤-0.098 MPa. After treatment, the oil’s breakdown voltage should be ≥75 kV, and the dissipation loss tangent (tgδ) should be extremely low. This system is specifically designed for the deep purification of ultra-high voltage and ultra-high voltage transformers to ensure long-term stable operation of the equipment.

4. For Severely Deteriorated Oil: The Vacuum + Adsorption Regeneration Type oil purifier is recommended. The vacuum level requirement is consistent with that of the double-stage vacuum oil purifier. Its core functions include oil deacidification, decolorization, and restoration of dielectric loss, enabling the regeneration of aged oil and effectively reducing oil replacement costs.

The processing capacity (flow rate) of the oil purifier must match the capacity of the transformer equipment to ensure purification efficiency. Common selection guidelines are as follows:

1. Small transformers (≤5000 kVA): Models with a flow rate of 30 L/min or 50 L/min are recommended. Common specifications include ZJB-30 and ZJB-50, which are suitable for rapid purification and routine maintenance of small equipment.

2. Medium-sized transformers (5,000–31,500 kVA): Models with flow rates of 100 L/min or 150 L/min are recommended. Common specifications include ZJB-100 and ZJB-150, which meet the bulk oil purification needs of medium-sized equipment.

3. Large Main Transformers (≥31,500 kVA): Models with flow rates of 200 L/min or 300 L/min are recommended. Common specifications include the ZJB-200 and ZJB-300, which are suitable for major overhauls and deep purification of large main transformers, thereby improving work efficiency.

Note: In international trade contexts, oil purifier flow rates are commonly specified as 30 L/min, 50 L/min, 100 L/min, 150 L/min, 200 L/min, and 300 L/min. When selecting a model, you can directly reference these specifications to match them with the equipment capacity.

Select an oil purifier with targeted functions based on the specific contamination issues present in the oil to ensure precise and effective purification. The specific guidelines are as follows:

1. Water ingress, moisture absorption, or low dielectric strength: Prioritize single-stage or two-stage vacuum oil purifiers. These primarily utilize vacuum dehydration and degassing functions to remove free water, emulsified water, and dissolved water from the oil, thereby improving its dielectric strength.

2. High levels of impurities and cloudy oil: Prioritize a combination of a plate-and-frame oil purifier and a vacuum oil purifier. First, use the plate-and-frame unit for coarse filtration to remove large particles, then use the vacuum unit for fine filtration to thoroughly eliminate microscopic impurities and restore the oil’s clarity.

3. High gas content and bubbles in the oil: Prioritize the use of a two-stage high-vacuum oil purifier. Leveraging its powerful degassing capabilities, it removes harmful gases such as air, hydrogen, and methane from the oil, preventing bubbles from affecting the transformer’s insulation performance.

4. High acidity, discoloration, and high dielectric loss: Prioritize regenerative oil purifiers with adsorption capabilities. These units use adsorbents to decolorize and deacidify the oil, reduce dielectric loss, restore all oil parameters, and regenerate degraded oil.

5. On-site, online, and non-shutdown treatment requirements: Prioritize the use of online transformer oil purifiers (On-line Transformer Oil Purifier). These enable continuous circulation purification without affecting the transformer’s normal operation, making them suitable for on-site operation and maintenance scenarios.