Flame detectors trouble


This could well be a case for a certified engineer to have a look at.
As safety comes into play, contact the suppler for a certified engineer.


It would be great to know the plant configuration..

Did you at least checked /troubleshoot by reviewing the Application programm/software...

If not you can post here a draft /skecth of the program so we can review it and give you better advise...

Since on Gas turbine some unit do not trip on one single flame detector failure...

But the thing is you did not mention if it is related to Boiler or GT ....

NOWHERE does the original poster--or oliverm--mention what the equipment they are having the issue with is. A boiler? An HRSG (Heat Recovery Steam Generator) with auxiliary firing? A gas turbine? If a gas turbine, what manufacturer and what size/type?

I can guess, but I don't like guessing. It's not good for anyone.

Help us help you! Because the public profiles here on Control.com don't support "avatars" (where one could post about the equipment at the site they work with, and possibly their job title or position and maybe even a little about how much experience (how many years one has worked at this site or on similar units), we just don't have anywhere to go and look for the type of the unit. EXCEPT searching through past posts (if there are any) to see if there are any clues there.... And we shouldn't have to do that.

This is a world wide web forum. We are NOT sitting there beside you. We can't see what you see. We don't know what you've experienced. We don't know when the problem started (after a trip from load; after a maintenance outage; etc.). A little information can make our answers much more meaningful and concise.

Help us help you. You'll more than likely be please with the results (especially if you are working on GE-design heavy duty gas turbines!).

Awaiting replies from hsingkui and oliverm....
Hello everyone,
I am very sorry for not clarifying the question!
as follows:
GE 7F.04 DLN 2.6+ Mark VIe
The combustion system has four flame detectors, (28FD-
The (28FD-14) flame intensity will shake during operation, but the combustion seems to be normal, and the flame detector is faulty!
So my question is that if several flame detectors are abnormal at the same time (only the detector fails), it will cause the generator to trip!
We are worried that if there is a second or third one, we are worried that if there is a second or third flame detector that fails at the same time.
Thank you very much for your attention.

[Questions usually end with a question mark... " So my question is that if several flame detectors are abnormal at the same time (only the detector fails), it will cause the generator to trip! ..." (Emphasis is mine.)]

I know people intensely dislike this response, but we can't know exactly for certain what will happen with your unit without being able to see the sequencing or application code running in the Mark* we can't say for certain what will happen.

Typically, though, the Mark* will tolerate two of four flame detectors on a F-class machine with 2.6 combustors without tripping, but a third will result in a trip. That's my recollection.

The good news is: It's pretty unlikely under normal circumstances that multiple flame detectors will fail at the same time. The caveat here is that if something abnormal is happening (abnormally high turbine compartment temperatures; low cooling water flows to the flame detector cooling water coils; turbine cooling air fan(s) not working properly; gravity-operated turbine compartment cooling air louvers not working properly; CO2 dampers not properly latched; etc.) then this isn't true; one can expect multiple failures. One of the things I don't really like about putting all of the flame detectors so high in the turbine compartment is that heat rises.... So, when cooling air flows in the compartment are correct for some reason they can be adversely affected.

The other question here is: When did this flame detector start flickering? After a maintenance outage? After a trip from load?

Or, could it be a loose connector, or a loose wire or crimp-on terminal lug?

Are there any related Diagnostic Alarms (such as the analog input card the suspect flame detector is connected to)?

Please write back to let us know what you find as you troubleshoot and resolve this problem.