Transformer cooling for Hermetically-sealed units

[Junior01]

Hello,
I have question about transformer.
How is Hermetically-sealed transformer cooled? I know that in air-breathing type we have conservator, breather, etc…for cooling. But, where the expansion oil goes in hermetically sealed? How it works?

 

[berkeman]

Hello,
I have question about transformer.
How is Hermetically-sealed transformer cooled? I know that in air-breathing type we have conservator, breather, etc…for cooling. But, where the expansion oil goes in hermetically sealed? How it works?

That should be pretty easy to answer with a simple Google search.

And what does the term "hermetically sealed" mean? It certainly does not mean thermally isolated...

 

[Junior01]

That should be pretty easy to answer with a simple Google search.

And what does the term "hermetically sealed" mean? It certainly does not mean thermally isolated...

Can you please give me a link where on google is that exactly explained? :)

 

[berkeman]

Can you please give me a link where on google is that exactly explained? :)

You could just start by doing a Google search on your thread title. That will get you pretty close. Then you can add or subtract search terms to refine your search. Let us know what you find...

 

[Junior01]

You could just start by doing a Google search on your thread title. That will get you pretty close. Then you can add or subtract search terms to refine your search. Let us know what you find...

The hermetically sealed oil transformers are normally manufactured with a sealed tank equipped with fins that allow the expansion at the temperature variations. But, I doesn't see this tank. Where is he placed?

 

[Windadct]

I think this is where you are off base..."I know that in air-breathing type we have conservator, breather, etc…for cooling." - these elements are to deal with thermal expansion / contraction of the oil, not for cooling.

 

[Asymptotic]

The hermetically sealed oil transformers are normally manufactured with a sealed tank equipped with fins that allow the expansion at the temperature variations. But, I doesn't see this tank. Where is he placed?

I've never worked with hermetically sealed transformers, but from what I've read their reason for being is eliminate the need for an expansion tank and desiccant breather by completely filling the tank with oil, sealing it from outside air, and designing the radiator fins to serve as hydraulic accumulators.

 

[Averagesupernova]

I don't see a problem if a reservoir is sealed up with ample volume left to make room for expansion and contraction of the fluid during heating and cooling. Just the surface area of the container may provide adequate cooling in some cases.
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Slightly off topic but relevant is the fact that automobile cooling systems at one time were sealed with no overflow jug to expell and retract coolant as the engine warmed and cooled. The radiator was not meant to be completely full. There was enough room left in the top of the radiator to allow for expansion.