Hello
Publication GEK103623K - 2024

From the MKVI logic
On-Line Water Wash Permissives:

-Water wash skid available
-Premix Steady State / Extended Lean-Lean
-Min. IGV angle is 81 Deg
-OWW did not performed within 24Hrs
-Compressor Inlet Temp greater than 53.6 DegF
-OWW Temperature okay

IGV angle 80 deg is around 34MW, some conflicting statements floating around

Thanks for your comments

 

In my personal opinion the most important consideration is having the IGVs at or near open to maximum operating angle AND having a stable fuel flow for a stable DLN "flame" (there is no DIFFUSION flame in the primary combustion zone when operating in Premix Steady State, BUT there is combustion occurring in the primary combustion zone it's just the flame detectors can't detect it (it has a different wavelength than diffusion flame does). And, that occurs when the IGVs are at or near fully open (maximum operating angle) AND at higher fuel flows (loads). Personally, I've never done on On-Line Water Wash when a DLN-I unit wasn't operating in Premix Steady State. I have observed attempts at On-Line Water Washing at lower loads in Premix Steady State (when the IGVs were slightly closed), but in the three attempts I witnessed the machine lost flame in the secondary combustion zone and tripped shortly after the On-line Water Washing procedure (with detergent) was started.

BUT, again, the GE field service person you spoke with might have newer, better information than is even in the GEK you cited. Personally, if I had a good contact at GE I would ask him/her to open a PAC Case (or whatever they call it these days) for a second opinion (from GE) but if I needed to water wash on-line before I received the response I would still follow what is stated in the most recent publication I have been able to obtain and review. (You might also consider asking if there are any other GE publications (list the one you have been consulting) and ask for a copy (or copies) of them.) If they cite any GE publication in the response request (in the original opening PAC Case) that they provide a copy of the GE publication they are citing (even if it's the same GE publication) AND list the page number/section where they took their response from. GE publications are, unfortunately, are mostly a "one-size-fits-all" bunch of documents and I have found several instances where there were contradictions in the same document (usually because someone made a change to one section and didn't properly check to see if there were any other sections that were pertinent or related to the change being made and make the change(s) there, as well). They are NOT easy documents to read and understand. Usually, I print (or photocopy) one of these documents that are intended for multiple Frame size machines with different combustion systems and red-line through any section which doesn't specifically apply to the machine I'm working on. Yes; there is likely some sentences/paragraphs that are generic and applicable and I don't red-line those until the second or third reading (if I ultimately determine it is NOT applicable to the machine I'm working on). I'm often surprised how a 30- or 40-page document suddenly has only 6 or eight pages that are specifically applicable to the machine I'm working on--and I (and my colleagues) can ignore the rest and concentrate only on the machine-specific information and not get all that other information clouding up my (or their) understanding!

Anyway, unfortunately that's all I can add at this point. I am a rather conservative person about processes and procedures like this and tend to want to stick to the printed information I have and can cite if something should go wrong. Others are not so conservative and will try anything once, twice if doesn't result in machine damage, death or injury. I tend to think I have better-than-average critical thinking skills probably due to lots of factors, but mostly because of my four decades of experience working on GE machines. I was also fortunate that I had contacts in the company I could ask for help or information if I was really stuck or just didn't feel I had enough information to deviate from standard practice or written information (presuming there WAS written information...).

Best of luck!