Power Transformer Oil Purification, Filtration and Hot Oil Circulation

[kskarpas]

Hi, I am looking for a paper or article to describe in details the Power Transformer Oil Purification, Filtration and Hot Oil Circulation.
It would be helpful to explain the reason for vacuuming the transformer tank, how we are degassing the oil and why we are doing hot oil circulation. Thank you in advance.

 

[ScottyUK]

Have you checked with the service providers? They will likely have references for what is a well-known technology.

 

[melspuds]

kskarpas,
If you have a transformer that has gas in the oil, that means that you have arcing or a fault in your windings. If that is the case, I would take it out of service as soon as possible. Since you don't have the basic understanding of insulating- cooling transformer oil fundamentals, you should hire a experienced contractor.
Good luck;
Dave

 

[prc]

There are plenty of literature on the subject.A free one EPRI report no.1002913 Transformer Maintenance and application guide (Chaper 8.Go to epri.com and put the report no in search field) IEEE Standard C57.93-2013 on Transformer installlation and maintenance is another guide.J&P Transformer book is also a good source.

 

[kskarpas]

Thank you all for your feedback, I am just trying to find the theoretical background of this subject, I am not trying to do the job by myself. Thank you all.

 

[RBlais13]

Pulling vaccum on the transformer pulls moisture from the insulation layers around the core.

The filtration unit on the oil processing equipment removes particulate contamination (carbon, dirt.....etc)

The heaters on the oil processing equipment heat the oil up so that moisture can be removed

As stated before, combustable gasses that are found are a direct result of arcing occurring in the transformer. If this transformer has a Load Tap Changer, than some arching can be expected during operation.

 

[crshears]

Further to what RBlais13 wrote:

Heating of the oil reduces its viscosity, facilitating both flow and filtration.

The combination of heating the oil and drawing a vacuum on it / above it facilitates the removal of moisture due to the increase of vapour pressure differential between the oil and the water.

Underload tap changers ar commonly contained within tanks that are physically separate from the main transformer tank, which keeps the oil in the main tank far cleaner thus reducing or eliminating the deposition of nasty carbon-type residuals atop the transformer internals, whatever they be. The separate ULTC tanks can readily be equipped with filtration units that can be made to run [automatically cycle] for any given count of tapchanger operations.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[ScottyUK]

Gas in oil is not necessarily indicative of arcing, it is indicative of abnormal heating. Damaged laminations or a bad joint can result is gassing. The ratios of specific gases can indicate the nature of the fault and the temperature range involved. Arcing has a characteristic signature.