Infrared Scan - Transformer Radiator Fins

[iwire]

Excellent question!
But we can speculate on and on with 1 IR pic forever so the OP needs to provide more pics of the xfmr in question.

I think it is very clear the OP is concerned about the cold fins on the left side.

Hey guys

So we had an infrared scan done on our radiator fins. It would appear that one side does not have any flow. The transformer doesn't seem to have any overheating issues but the transformer is also lightly loaded. There is no valve or plug to argue that maybe it is preventing the flow. I am assuming there is a circulation problem but other than low oil level or some other obstruction, what else can cause that? Any other suggestions?

Regards
Shells

 

[Ingenieur]

Sometimes they have pumps and/or valves
hard to believe all fins are plugged

if oil was low they would still be warm up to the level

as some one mentioned it looks like it might be behind it
it's shorter and narrower
could be perspective though

 

[FionaZuppa]

i would also think that even if the tubes on left side were clogged (if they are even on this xfrmer), we would see them as warm in IR at top and bottom from simple heat conduction. hard to believe the whole stack is ambient in the pic when we know the oil is fairly warm as seen from IR on right side. an IR pic was taken, did anyone feel the fins by hand? a pic as such would have certainly prompted a call to the manufacturer by this time.

 

[GoldDigger]

If you look at the position of the top of the tank relative to the front cover you will see that the camera is well to the right of the centerline. All differences can be attributed to perspective.

 

[kwired]

There is no flow in the left side, it is about same temp as the tank because there is no flow, JMO.

Yes you would still get some conduction of heat, but having the contained media in a closed loop condition will bring even more heat into the heat exchanger, I think. Could be plugged, but what are chances of all them being plugged and only on one side? I still believe slightly low oil level coupled with the fact the unit may not be level is the most likely answer.

 

[MD84]

Typically there is one main pipe connection at the bottom and one main pipe connection at the top of the radiator. All fins share this common route. It is common to have a shut off valve at the top and bottom. It may be possible that these valves are discrete and somewhat unnoticeable. They could be closed. It could also be possible they are blanked off in between the flanges. Many times there is also a fill and drain valve for each radiator. This would allow service of the radiator without evacuating the entire tank. All the extras are more common on larger mva transformers. Smaller distribution transformers are commonly welded with no means of servicing.

The OP did give information that the oil pressure appears to be at 0. This could indicate a gas leak in the headspace. Many times a sweating of oil is noticeable around the leaking point. This could introduce moisture to the oil which can cause sludging. The sludging could be clogging the left radiator. If the bottom pipe is clogged we could see zero flow in the left radiator.

It could be very telling to take an oil sample. Just opening the sample valve may prove the flow is inhibited.

It looks to me that the transformer is ONAN. That is no forced oil flow and no forced air flow. You can see straight through the radiator fins on the right. If there were fans they would be visible through the fins. Typically I see fans as the first stage of additional cooling. Since there are no fans I do not think there are pumps. My exposure may be limited here and there could be a pump forcing oil through the radiator which is not working and therefore blocking the oil path.

A picture of the nameplate and some additional digital and IR images would be very telling.

 

[FionaZuppa]

ok, pic perspective aside, if the unit shows the oil "hot" then i would expect to see some slight heat conduction showing up on the left lower side regardless if there is no flow. but, perhaps we just cant see it due to camera position, meaning the main bottom tube on left stack is not in view.

some of the docs for a china brand say that they either use corrugated tank walls or radiators for cooling, and all radiator units have valves. i believe most that have radiator have valves for serviceable factor. but OP said there were no valves on this unit. seems odd.

 

[MD84]

Some are low profile. It may not be apparent it is there.

 

[Shells]

my educated guess, which can be way off here, likely some flow restrictions in the tubes that are in green box. the red line is an odd heat profile, and the blue line seems to show about where its about the same temp.

why was the flir taken from just one side, what does the other side look like ??

thanks for this... will check for the other side as well...

 

[Shells]

Guys

Thank so much for all the excellent thoughts/feedback. I did engage the manufacturer and his concern was obviously around the 0 pressure. We need to restore the nitrogen blanket and check for leaks. In their current condition, there is no way to tell, and additionally, could be “free breathing”, and exposed to atmospheric contamination (moisture and particulates). Additionally, we have to obtain an oil sample to confirm which we can only do once we restore positive pressure.

I did ask the manufacturer about the valve. He didn't respond on that but will follow up on this cause the manual says a valve does exist.

I'll keep you all in the loop but my bet is it is the contamination as a result of negative pressure...

 

[MD84]

Thanks for the update. Good luck!

 

[iwire]

Thanks for the update. Good luck!

:thumbsup:

Yes, thank you Shells it is always great to hear more info.

I hope you can let us know what the outcome is.

 

[Shells]

i would also think that even if the tubes on left side were clogged (if they are even on this xfrmer), we would see them as warm in IR at top and bottom from simple heat conduction. hard to believe the whole stack is ambient in the pic when we know the oil is fairly warm as seen from IR on right side. an IR pic was taken, did anyone feel the fins by hand? a pic as such would have certainly prompted a call to the manufacturer by this time.

The fins were cold to the touch. The transformer is very lightly loaded. I did contact the manufacturer who requested the oil sample results only to find out they haven't been taken cause of negative pressure!:happysad:

 

[Shells]

Thanks for the update. Good luck!

:thumbsup:

 

[FionaZuppa]

atmospheric moisture getting in will cause condensation to form, and then may form sludge as it mixes with the oil. but, let us know what the final remedy is.

 

[zog]

The fins were cold to the touch. The transformer is very lightly loaded. I did contact the manufacturer who requested the oil sample results only to find out they haven't been taken cause of negative pressure!:happysad:

What part of the country are you located in?