I. Reduces Heat Dissipation Efficiency, Leading to Equipment Overheating
· Blockage of heat dissipation channels:
Transformers generate significant heat during operation, which is dissipated through cooling fins or air-cooling systems. Dust accumulation in the gaps of cooling fins, fan blades, or 散热通道 (heat dissipation channels) forms an insulating layer, hindering air circulation and preventing heat from escaping.
· Hazards of continuous temperature rise:
· Insulation materials inside transformers (such as winding insulation paper and oil-immersed insulation oil) are highly sensitive to temperature. When the temperature exceeds the designed allowable range (e.g., consistently above 80–95°C), the insulation materials age rapidly, with their lifespan significantly shortened (typically, every 8–10°C increase halves the insulation life).
· High temperatures can also cause transformer oil to decompose, producing flammable gases (e.g., methane, ethane), increasing internal pressure and potentially leading to safety accidents like oil spraying or explosions.
· Hygroscopicity and conductivity of dust:
· Dust in the air often contains impurities like metal particles, salt, and oil. Some dust is hygroscopic (e.g., dust in humid environments). When dust absorbs moisture, it forms a conductive dirt layer covering insulating components of transformers, such as high-voltage windings, insulators, and bushings.
· This increases the surface leakage current of insulating components, causing partial discharges (e.g., corona discharge). Long-term accumulation may lead to insulation breakdown, resulting in phase-to-phase or ground short circuits.
· Typical case:
If outdoor transformers are not cleaned for a long time, the dust on the insulator surface combines with moisture to form a "contamination layer," which is prone to "pollution flashover" (surface flashover) during rainy or foggy days, where high voltage breaks down the air through the contamination layer, causing power outages.
· Fan and bearing failures:
· For transformers with air-cooling systems, dust accumulation on fan blades causes dynamic balance imbalance, leading to vibration during fan operation. This can damage bearings or motor windings over time.
· Dust entering the bearing lubricating grease exacerbates friction and wear, shortening bearing life and even causing fan stoppage, further deteriorating heat dissipation.
· Impact on other mechanical components:
Mechanical components inside transformers, such as tap changers and oil pumps, may experience sticking operations or poor contact if contaminated by dust, affecting the tap changer's voltage regulation accuracy or the oil pump's circulation efficiency.
· Hazards of dust mixing into transformer oil:
· Transformer oil not only insulates but also carries away heat through circulation. When dust (especially metal particles and fiber impurities) enters the oil, it reacts chemically or rubs mechanically with the oil, accelerating oil oxidation and deterioration.
· Deteriorated transformer oil shows increased viscosity, decreased flash point, and reduced insulation strength, further weakening the transformer's insulation and heat dissipation capabilities, creating a vicious cycle.
· Blockage of oil filtration systems:
Dust accumulation in oil filters or pipelines hinders normal oil circulation, reducing heat dissipation efficiency and even triggering false operations of protection devices due to poor oil flow.
· Higher maintenance frequency and costs:
Dust accumulation requires regular cleaning (e.g., power outages for wiping cooling fins), increasing maintenance workload and costs. Frequent shutdowns also reduce power supply reliability.
· Elevated safety risks:
Neglected dust accumulation may lead to sudden failures (e.g., insulation breakdown or overheating fires), posing threats to personnel safety and surrounding equipment.
· Regular cleaning of cooling fins, fans, and insulators (e.g., using compressed air or specialized cleaning agents).
· Installing dust filters on air inlets of transformers to reduce dust ingress.
· Monitoring transformer temperature and oil quality regularly to detect early signs of dust-induced issues.