Oil in Gas turbine filter house

Hello dear
I am working in a combined cycle power plant. There are two Gas Turbine units having capacity of 110MW each. The GT's are GE frame 9E.03 DLN-1 machines. Recently during filter changing work we noticed some oil in the filter house. Now it is winter here the humidity is not very high in Bangladesh. We could not found the source of the oil. Is it the oil from mist eliminator? We dont know but we need to find out the source and prevent it coming inside the filter house.
 
Hello dear
I am working in a combined cycle power plant. There are two Gas Turbine units having capacity of 110MW each. The GT's are GE frame 9E.03 DLN-1 machines. Recently during filter changing work we noticed some oil in the filter house. Now it is winter here the humidity is not very high in Bangladesh. We could not found the source of the oil. Is it the oil from mist eliminator? We dont know but we need to find out the source and prevent it coming inside the filter house.
Look like a good situation to check your system P&ID's and see where oil is used in your filter house as we don't know. Why don't you have a check and come back to us.
 
kaag27,

The P&IDs are always the best first place to start looking--always.

What's missing most from the original post is: Where was the oil found in the air inlet filter structure??? This would be a HUGE clue to where it might be coming from, eh? And, the next important detail would be the amount of oil found in the air inlet filter structure....

I would suggest that if the oil were coming from the L.O. Mist Eliminator that it would be entering either through the filters (in which case that would be obvious when the old filters were being removed), OR from a leak somewhere in the air filter house enclosure very near to the discharge line of the L.O. Mist Eliminator (which was likely placed very close to the air inlet filter structure--which is never a good idea).

The other, not-so-obvious, possible source of lube oil in the inlet filter house structure might be the air used for the self-cleaning inlet air filters. Now, that would most likely be found inside the filter elements when they are removed during replacement, and may also be found just outside the center openings of the air filter elements. It could also be a leak in the piping/manifold which supplies air to the solenoids used for pulsing the self-cleaning inlet air filters.

The usual source of compressed air for the self-cleaning inlet air filters was axial compressor discharge extraction--a line was connected to the combustion wrapper and then was routed to a stationary filter/dryer assembly (sometimes referred to as the Air Processing Skid/Dryer) which had a pressure regulator, a strainer, a couple of dryer elements and a large finned heat exchanger. This served to remove moisture (usually only water (condensate)) and to cool the compressor discharge extraction (which would usually be sever hundred degrees (C or F) as well as to regulate the pressure of the compressed air fed to the self-cleaning inlet air filter system. If this system is showing signs of oil coming from the drains, or contaminating the dryer elements, then it's likely the oil is coming from a leak somewhere inside the combustion wrapper (usually the #2 bearing area) which is being drawn into the extraction line which is supplying the self-cleaning inlet air filters.

Some turbines were supplied, and possibly retrofitted, with separate compressor(s) which supplied the air so the self-cleaning air filters could be pulsed when the turbine was not running (this wasn't always very effective, except in very dry environments with very fine dust--and not all turbines are installed at such locations, but that never stopped anyone from ordering or specifying something which was unnecessary.) If the air compressor(s) were leaking oil, that could be a source.:cool:
Again, this possibility would probably be found either in the lower filter elements or at a leak in the compressed air piping, probably at the lower levels of the air inlet filter structure. It could be at higher elevations, but, well, it's kind of hard to envision that. We also don't know what the configuration of the air inlet filter structure is--it could be a tall vertical structure, or a short horizontal structure, or something in between. (It's common of many people that they think that ALL GE-design Frame 9E heavy duty gas turbines are alike, when in fact, there is a lot of customization of accessories, such as the inlet filter structures.)

Anyway, it's always best to understand the systems, AND to review the P&IDs when looking for answers to problems like this. And, when posting for help to forums like this, the more information you can provide the better the responses will usually be. With this new website it is ALSO possible to attache photographs and drawings.... A VERY handy feature, indeed! As is commonly said, "A picture is worth a thousand words!" and can be very helpful. A photograph of the outside of the air inlet filter structure showing the proximity of the L.O. Mist Eliminator discharge, and a photograph of the area and amount of oil found in the air inlet filter structure could be very helpful. Very helpful, indeed!

Please write back to let us know: 1) where the oil was found, and,

2) what the source is determined to be.

(If you wanted to add a couple of photographs, that would be excellent. A LOT of people read these threads, now and in the future, and when they see photographs they will be encouraged to add photo's when they post for help or information!)

Best of luck!
 
kaag27,

The P&IDs are always the best first place to start looking--always.

What's missing most from the original post is: Where was the oil found in the air inlet filter structure??? This would be a HUGE clue to where it might be coming from, eh? And, the next important detail would be the amount of oil found in the air inlet filter structure....

I would suggest that if the oil were coming from the L.O. Mist Eliminator that it would be entering either through the filters (in which case that would be obvious when the old filters were being removed), OR from a leak somewhere in the air filter house enclosure very near to the discharge line of the L.O. Mist Eliminator (which was likely placed very close to the air inlet filter structure--which is never a good idea).

The other, not-so-obvious, possible source of lube oil in the inlet filter house structure might be the air used for the self-cleaning inlet air filters. Now, that would most likely be found inside the filter elements when they are removed during replacement, and may also be found just outside the center openings of the air filter elements. It could also be a leak in the piping/manifold which supplies air to the solenoids used for pulsing the self-cleaning inlet air filters.

The usual source of compressed air for the self-cleaning inlet air filters was axial compressor discharge extraction--a line was connected to the combustion wrapper and then was routed to a stationary filter/dryer assembly (sometimes referred to as the Air Processing Skid/Dryer) which had a pressure regulator, a strainer, a couple of dryer elements and a large finned heat exchanger. This served to remove moisture (usually only water (condensate)) and to cool the compressor discharge extraction (which would usually be sever hundred degrees (C or F) as well as to regulate the pressure of the compressed air fed to the self-cleaning inlet air filter system. If this system is showing signs of oil coming from the drains, or contaminating the dryer elements, then it's likely the oil is coming from a leak somewhere inside the combustion wrapper (usually the #2 bearing area) which is being drawn into the extraction line which is supplying the self-cleaning inlet air filters.

Some turbines were supplied, and possibly retrofitted, with separate compressor(s) which supplied the air so the self-cleaning air filters could be pulsed when the turbine was not running (this wasn't always very effective, except in very dry environments with very fine dust--and not all turbines are installed at such locations, but that never stopped anyone from ordering or specifying something which was unnecessary.) If the air compressor(s) were leaking oil, that could be a source.:cool:
Again, this possibility would probably be found either in the lower filter elements or at a leak in the compressed air piping, probably at the lower levels of the air inlet filter structure. It could be at higher elevations, but, well, it's kind of hard to envision that. We also don't know what the configuration of the air inlet filter structure is--it could be a tall vertical structure, or a short horizontal structure, or something in between. (It's common of many people that they think that ALL GE-design Frame 9E heavy duty gas turbines are alike, when in fact, there is a lot of customization of accessories, such as the inlet filter structures.)

Anyway, it's always best to understand the systems, AND to review the P&IDs when looking for answers to problems like this. And, when posting for help to forums like this, the more information you can provide the better the responses will usually be. With this new website it is ALSO possible to attache photographs and drawings.... A VERY handy feature, indeed! As is commonly said, "A picture is worth a thousand words!" and can be very helpful. A photograph of the outside of the air inlet filter structure showing the proximity of the L.O. Mist Eliminator discharge, and a photograph of the area and amount of oil found in the air inlet filter structure could be very helpful. Very helpful, indeed!

Please write back to let us know: 1) where the oil was found, and,

2) what the source is determined to be.

(If you wanted to add a couple of photographs, that would be excellent. A LOT of people read these threads, now and in the future, and when they see photographs they will be encouraged to add photo's when they post for help or information!)

Best of luck!
Thanks a lot. I will upload photos of our filter house
 
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