Transformerinsulating oil undergoes a series of changes while being used repeatedlyfor many operations. Constant use adds many impurities and arcing forms carbonand other gases few of which get dissolves in the oil leading to oildeterioration. Repeated use of the transformerinsulating oil in combination with moisture accumulation challenges itsfitness and draws attention on the need for a regenerationsystem.
Sedimentation, centrifugation and filtration are few methodswith which impurities are removed in oilregeneration system. Contaminated particles that settle down are removedthrough sedimentation. Oil and water are separated through layers incentrifugation and filtration separates particles based on their size. Besides these methods, water soluble acids are removed by drywashing.
Oildeterioration occurs when air gradually leaks inside the transformer andthe transformerinsulating oil comes in contact with water and oxygen. Besides, hightemperature and presence of other materials enhance oxidation in the oil andfacilitate cracking of the oil’s hydrocarbons.
Subsequently acid and sludge are formed and accelerate oildeterioration besides attacking the oil’s insulating properties. Theelectrical and chemical attributes decay as time progresses. Timely maintenanceof transformerinsulating oil through regenerationsystem can avert oildeterioration and let the apparatus function effectually.
When the oil gets polluted, the viscosity of the transformerinsulating oil is affected which in turn hits the cooling attributes of theoil. Such reduction in cooling affects the winding temperature and trips WTIand OTI relays which operate alarm and cooler control of the equipment. It should be noted that transformer operates on thermal imaging.
Besides, breakdown voltage or BDV has an important say inthe quality of the oil. Oildeterioration is highlighted in reduced BDV value and low insulation isevident.
Oilregeneration system is important because oildeterioration is inevitable in constant and repeated use. Such oildeterioration occurs due to constant change in breakdown voltage, moisture,acidity, sludge, flash point, pour point, sediments, sludge, dielectricdissipation factor, density and viscosity.
Oilregeneration system employed onsite when the oil is loaded in thetransformer. The tangent of the insulating oil, reduction in acidity, properinterfacial tension and dielectric strength, mitigated moisture and removal of particles are done so that the oil is restored to its original status.
Regenerationsystem is also done offsite where oil in the barrels are treated forremoval of pollutants.
The regenerationsystem comprises of the flow of transformerinsulating oil in columns which contain adsorbents. The contaminatedelements which cause ageing are absorbed by these adsorbents, which includeFullers Earth and bleaching clay to name a few.
These adsorbents can be reactivated even after they reachsaturation point and they remove the ageing particles in an environmentfriendly way.
On a concluding note, regenerationsystem can be chosen based on the nature of oil deterioration. Besidesremoval of contaminants, transformeroil regeneration system has evolved as effectual waste management andsustainability of the equipment as well as environmental factors. Used oils areregenerated to the standards of unused and new oils with focus on oxidation stability to guarantee hassle free operations of the transformer
http://www.hering-vpt.com/products/transformer-oil-regeneration/
