Start-Up Gas Turbine Frame 6B on Destilate Mode


Thread Starter


Dear Team,

We have an issue on gas turbine Frame 6B. When we tried to start on distillate mode, we got failure to ignite alarm.

FYI, our Frame 6B is dual fuel and we don't have a problem with gas.
I tried to start with gas till FSNL than changed it to distillate (and everything looks fine).

I checked FQL and Atomizing air pressure everything is okay (atomizing air pressure 6 bars on FSNL).

I checked AA booster compressor (GARDNER DENVER CYCLOBLOWER) driven with diesel starter engine when we started with distillate (we got 1 bar).

I checked the two spark plugs and its looks okay, same with flame detectors, we changed it to new ones.

Many thanks, and i look forward to hearing from you.

Did you get any other Alarm. When were the Fuel Nozzles last maintained? Did the machine ever start on Diesel? If Yes, when was that and has any other work been done since then?

When you try to ignite, does the Exhaust Temp. rise at all before you get loss of flame?
Thank you for your response.

So, we have got failure to ignite alarm only, and the machine was started and working on distillate before. We didn't work on the machine (No MI or HGPI or....).

When we tried to ignite, we didn't get any change of exhaust temperature. And, we can start on gas then change to Diesel ON fsnl WITHOUT any issue.

Thank you.
Hi again.

Check your A.A. P&ID. Please check the two non-return valves in the AA line, one just after the main A.A. compressor and one in the Booster compressor discharge line (I don't have a drawing at the moment so I can't give you Tag numbers.)

This system works automatically to change over from booster to main during start-up, as CPD increases then AA increases until AA pressure is greater than booster and the non-return valve after the main compressor opens. If this non-return valve is stuck partly open, you will have low AA pressure at the point of ignition.

Have someone on stand-by at the liquid Fuel Flow Divider and get them to check nozzle pressures when trying to ignite.

I have checked the non return valve of AA booster compressor, and I found it damaged.

We trying to get a new one for now.

For the pressure nozzle in the flow divider, I have checked it before, when we tried to start on diesel, all the nozzles are okay.

Thank you very much,

I will give a feedback soon as possible.