can every body help me?

our GE frame 9 gas turbine can not start with liquid fuel (distillate fuel). in fact we have L30FD_alm (our flame detector can not detect flame).

what problems can be happened?

 

First you need to determine whether or not you are getting failure to fire or failure to detect flame. Have you looked in the inspection ports to see if any flame is present; or have you seen an increase in exhaust temperature?

Is the atomizing air system OK (including booster compressor)?

After purge, does the speed drop back to the correct firing speed?

I am guessing you also have gas fuel and can start on that, which would indicate that the flame detectors work properly. If so, can you transfer to liquid fuel after starting on gas?

Condition of the ignition system? (Gas is usually easier to fire, so a marginal ignition system will usually impact distillate before gas.)

 

dear otised, thanks alot for your answer.

I have to say that: we are getting failure to fire. our flame detector, spark plug, booster compressor are ok. we can start with gas fuel and transfer to liquid fuel after starting on gas.

I think maybe problem is in SpeedTronic Mark 5, in some constant for example (K2FLIQ: liquid fire timer constant)....don't you think?
or some signal in firing time, for example speed,...

what parameters have to we cheek?
you think how much the Species of oil (specification) is important?

 

Sam,

I am a controls engineer, not a combustion engineer, so while I know the fuel specification is important, I can't tell you exactly which are the most important parameters. If it has changed from what was originally given to GE, then you should probably go back to GE and have them look at it. GE custom designs the fuel nozzles for the specific fuel.

Firing timer constant is unlikely to be the cause of the problem - ignition should happen within the normal 30 to 60 seconds setting for this timer. (These are numbers I remember from a long time ago.)

 

Hi..

The same problem was experienced my side. The unit failed to fire on distillate. The reason what was happening my side was atomizing air system was failed to build up sufficient pressure to spray the fuel resulting in uneven combustion. The changing of automising air booster solved the problem.

Another reason which i think is not mentioned by my friend above is the servo controlled fuel bypass valve which limits the fuel supply accordingly. A sticky valve may result in less or more fuel in the start which may result in failure to ignite. Also check the hydraulic supply system.

 

WE Have had the same situation over time with the frame 9E. it came down to 1 of the spark plugs had totally failed, and the other had the electrode burnt back up inside the outer tube/casing. starting on natural gas was fine, but it would not start on fuel oil /distillate. We use ultrasound detector/gun to check for serviceability of spark plugs, and this spark plug that was firing passed the ultra sound test, so we learned a lesson with this checking device.

 

hi ,

thanks a lot for your response.

our control bypass valve (liquid fuel control valve or VC3) doesn't have LVDT. can it be result of the problem?